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* First step toward supporting use of interfaces as existential types (#716)Tim Foley2018-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First step toward supporting use of interfaces as existential types Traditional generics involve universal quantification. E.g., a declaration like: ``` void drive<T : IVehicle>(T vehicle); ``` indicates for *for all* types `T` that implement the `IVehicle` interface, the `drive()` function is available. In contrast, whend directly using an interface type like: ``` IVehicle v = ...; v.doSomething(); ``` we only know that there *exists* some concrete type (we could call it `E`) such that `v` refers to a value of type `E`, and `E` implements the `IVehicle` interface. In order to perform an operation like `v.doSomething()` we need to "open" the existential value so that we can look at the concrete type and how it implements the `IVehicle.doSomething` requirement. This change adds a very explicit representation of existentials to Slang's IR. An operation like `e = makeExistential(v, w)` creates a value of some existential type (interfaces being our only existential types for now), by wrapping a concrete value `v` (the type of `v` can be seen as an implicit operand) and a witness table `w` showing that the type of `v` implements the requirements of the chosen interface type. In turn, opening of an existential is handled with operations `extractExistential{Value|Type|WitnessTable}` which pull the corresponding piece of information out of a value of existential type (which somewhere in the code had to have been created with `makeExistential`). The change includes a trivial simplification pass that can detect cases where an `extractExistential*` operation is applied direclty to a `makeExistential` operation, so that there is only one possible result that could be extracted. This allows for simplification of existential types used in trivial ways for local variables (this is mostly so I can check in a functional test, rather than to actually support useful code involving interfaces right now). The logic in the semantic checking phase of the compiler is comparatively more complex. When we are about to perform member lookup given an expression like `obj.member` we will first check if `obj` has an existential type, and if it does we will construct a suitable local context in which we extract the value, type, and witness table from the existential (these all become explicit AST expression nodes), and then use the extracted value as the base of the lookup operation. The nature of existential values is that two different values with the same existential (interface) type could wrap concrete values with differnt types, so that we need to carefully refer only to the extracted type/value/witness-table of specific *values*. We handle this right now by conceptually moving the existential-type value into a local variable (by introducing a `LetExpr` that amounts to `let v = <init> in <body>`) and then require that the extract expressions must refer to the (immutable) variable declaration from which they are extracting a value. (Eventually we should expand this so that when using an immutable local variable of existential type we just use that variable as-is rather than introduce a new temporary) A simple test case is included that uses an interface type in an almost trivial way for a local variable; this test can be run and produces the expected results. A more complex test case that passes an existential into a function is included, but left disabled because a more aggressive simplification approach is required to generate working code from it. * Add missing file for expected test output * Fixups for merge from top-of-tree
* Make shader parameters not writable (#750)Tim Foley2018-12-12
| | | | | There was already logic in place to make `const` variables not be writable, and this change extends it to also consider global shader parameters (in HLSL, any global variable that is *not* marked `static` or `groupshared`) to be rvalues instead of lvalues. As noted in the comments on this change, we could lift that restriction later on, if we have good handling of global variables with resource types in the back-end, but for now it is safer to just rule this out in the front-end.
* Running tests in slang-test process (#740)jsmall-nvidia2018-12-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * First pass at having an interface to write text to that can be replaced. Simplifed and made more rigerous the interface used to write formatted strings. * Added AppContext to simplify setting up and parsing around of streams. * Added more simplified way to get the std error/out from AppContext. * Work in progress using dll for tools to speed up testing. * First pass at ISlangWriter interface. * Added support for writing VaArgs. Added NullWriter. * Use ISlangWriter for output. * Use ISlangWriter for output - replacing OutputCallback. Make IRDump go to ISlangWriter * SlangWriterTargetType -> SlangWriterChannel Improvements around AppContext * Shared library working with slang-reflection-test. * Dll testing working for render-test. * Include va_list definintion from header. * Fix errors from clang. * Fix typo for linux. * Added -usexes option * Fix typo. * Fix arguments problem on linux. * Fix typo for linux. * Add windows tool shared library projects. * Fix warning from x86 win build. Fix signed warning from slang-test/main.cpp * First attempt at getting premake to work on travis, and run tests. * Try moving build out into script. * Invoke bash scripts so they don't have to be executable. * Drive configuration/tests from env parameters set by travis * Try using source to run travis tests. * Remove the build.linux directory - but doing so will overwrite Makefile. * Made -fno-delete-null-pointer-checks gcc only. * Try to fix warning from -fno-delete-null-pointer-checks * Turn of warnings for unknown switches. * Try to make premake choose the correct tooling. * Disabled missing braces warning. * Disable -Wundefined-var-template on clang. * -Wunused-function disabled for clang. * Fix typo due to SlangBool. * Remove this nullptr tests. * "-Wno-unused-private-field" for clang. * Added "-Wno-undefined-bool-conversion" * Add DominatorList::end fix. * Split scripts into travis_build.sh travis_test.sh * Fix gcc/clang template pre-declaration issue around QualType. * Fix premake to build such that pthread correctly links with slang-glslang
* Change how buffers are emitted (#741)Tim Foley2018-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Change how buffers are emitted This is a change with a lot of pieces, which can't always be separated out cleanly. I'm going to walk through them in what I hope is a logical order. The main goal of this change was to allow arrays of structured buffers to translate to Vulkan. Consider two declarations of structured buffers in HLSL/Slang: ```hlsl StructuredBuffer<X> single; StructuredBuffer<Y> multiple[10]; ``` The current translation logic was handling `single` by translating it into an *unnamed* GLSL `buffer` block like: ```glsl layout(std430) buffer _S1 { X single[]; }; ``` That syntax allows an expression like `single[i]` in Slang to be translated simply as `single[i]` in GLSL. But that naive translating doesn't work for `multiple`, since we need to declare a array of blocks in GLSL, which requires giving the whole thing a name: ```glsl layout(std430) buffer _S2 { Y _data[]; } multiple[10]; ``` Now a reference to `multiple[i][j]` in Slang needs to become `multiple[i]._data[j]` in GLSL. To avoid having way too many special cases around single structured buffers vs. arrays, it makes sense to allows emit things in the latter form, so that we instead lower `single` as: ```glsl layout(std430) buffer _S1 { X _data[]; } single; ``` So that now a reference to `single[i]` becomes `single._data[i]` in GLSL. Most of that can be handled in the standard library translation of the structured buffer indexing operations. The only wrinkle there is that there were some *old* special-case instructions in the IR intended to handle buffer load/store operations (these were added back when I was trying to keep the "VM" path working). These aren't really needed to have structured-buffer operations work; they can be handled as ordinary functions as far as the stdlib is concerned. I removed the old instructions. Along the way, it became clear that a few other cases follow the same pattern. Byte-addressed buffers are an obvious case. We were lowering HLSL/Slang: ```hlsl ByteAddressBuffer b; ... uint x = b.Load(0); ``` to GLSL like: ```glsl layout(std430) buffer _S1 { uint b[]; }; ... uint x = b[0]; ``` That logic would fail for arrays the same way that the structured buffer case was failing. The fix is the same: use named `buffer` blocks and then introduce an explicit `_data` field: ```glsl layout(std430) buffer _S1 { uint _data[]; } b; ... uint x = b._data[0]; ``` Just like with structured buffers, all of the VK translation for operations on byte-addressed buffers can be implemented directly in teh stdlib, so once the emit logic was changed it was just a matter of adding `._data` to a bunch of VK tranlsations. It turns out that arrays of constant buffers have more or less the same problem, and furthermore we have some problems with any code that directly uses the modern HLSL `ConstantBuffer<T>` type. Note: the emit logic around constant buffers sometimes refers to "parameter groups" because that is being used in the compiler as a catch-all term for constant buffers, texture buffers, and parameter blocks. The existing code was going out of its way to reproduce the way that constant buffer declarations are implicitly referenced in HLSL: ```hlsl cbuffer C { float f; } ... float tmp = f; // No reference to `C` here ``` This can be seen in the emit logic with the `isDerefBaseImplicit` function, which is used to take the internal IR representation for a reference to `f` (which is closer to the expression `(*C).f` or `C->f`) and leave off any reference to `C` so that we emit just `f`. That kind of logic just flat out doesn't work in some important cases. Arrays of constant buffers are a clear one: ```hlsl ConstantBuffer<X> cbArray[3]; ... X x = cbArray[0]; ``` There is no way to translate that to an ordinary `cbuffer` declaration at all. The same problem can be created without arrays, though: ```hlsl ConstantBuffer<X> singleCB; ... X x = singleCB; ``` The current strategy for translating constant buffers was translating `singleCB` into a `cbuffer` declaration that reproduced the fields of `X` as its members, which just wouldn't work: ```hlsl cbuffer singleCB { float f; // field of `X` } ... X x = singleCB; // ERROR: there is nothing named `singleCB` in this HLSL ``` The new strategy is more consistent. We still generate a `cbuffer` declaration for a single constant buffer, but we always give it a single field of the chosen element type: ```hlsl cbuffer singleCB { X singleCB; } ... X x = singleCB; // this works fine! ``` And in the array case we generate code that uses the explicit `ConstantBuffer<T>` type: ```hlsl ConstantBuffer<X> cbArray[3]; ... X x = cbArray[0]; ``` The GLSL output is more complicated because unlike with HLSL there is no implicit conversion from a uniform block to its element type (there is no notion of an element type). The array case thus needs a `_data` field similar to what we do for structured buffers: ```glsl layout(std140) uniform _S3 { X _data; } cbArray[3]; ... X x = cbArray[0]._data; ``` And then the non-array case needs to have a similar `_data` field for consistency: ```glsl layout(std140) uniform _S1 { X _data; } singleCB; ... X x = singleCB._data; ``` This is handled by inserting the necessary reference to `_data` whenever we dereference a constant buffer, either as part of a load instruction (loading from the whole CB as a pointer), or an `IRFieldAddress` instruction which forms a pointer into the CB (e.g., `&(singleCB->f)` becomes `singleCB._data.f`). The current emit logic handles `ParameterBlock<X>` differently from `ConstantBuffer<X>`, but really only to allow parameter blocks to be explicitly named in the output, while constant buffers were left implicit by default. Thus the only difference was a legacy one (from back when trying to exactly reproduce the HLSL text we got as input was considered an important goal), and the new approach to emitting constant buffers would get rid of it. I removed the separate logic for emitting `ParameterBlock<X>` and just let the handling for constant buffers deal with it. Note that any resource types inside of a `ParameterBlock<X>` would have been moved out as part of legalization, so that a parameter block is 100% equivalent to a constant buffer when it comes time to emit code. Unsurprisingly, changing the way we generate HLSL and GLSL output for all these buffer types meant that any tests that were directly comparing the output of `slangc` against `fxc`, `dxc`, or `glslang` broke. The basic approach to fixing the breakage in GLSL tests was to update the GLSL baseline to reflect the new output startegy. In some cases I used macros to name the various `_S<digits>` temporaries so that future renaming will hopefully be easier (it would be great if we auto-generated temporary names with a bit more context). There was one GLSL test (`tests/bugs/vk-structured-buffer-binding`) that was using raw GLSL expected output, and this was changed to use a GLSL baseline to generate SPIR-V for comparison. For HLSL tests we were sometimes running the same input file through `slangc` and `fxc`/`dxc`, and in these cases I macro-ized the various `cbuffer` declarations to generate different declarations depending on the compiler. I completely dropped the tests coming from the D3D SDK because they aren't providing much coverage, and updating them would change them so far from the original code that the purported benefit (using a body of existing shaders) would be lost. I also dropped the explicit matrix layout qualifiers in the `matrix-layout` test because the new output strategy breaks those for GLSL (you can't put matrix layout qualifiers on `struct` fields, and now the body of every constant buffer is inside a `struct`). This isn't as big of a loss as it seems, because our handling of those qualifiers wasn't really right to begin with. Slang users should only be setting the matrix layout mode globally (and we should probably switch to error out on the explicit qualifiers for now). The other thing that got dropped is tests involving `packoffset` modifiers. Slang already warns that it doesn't support these, and the way they were used in the test cases is actually misleading. For the binding/layout-related tests, the goal was to show that Slang reproduces the same layout as fxc, in which case explicitly enforcing a layout via `packoffset` seems like cheating (are we sure we enforced the layout fxc would have produced?). The real reason was that Slang used to emit explicit `packoffset` on *every* field of a `cbuffer` it would output, because of an `fxc` bug where you couldn't use `register` on textures/samplers declared inside a `cbuffer` unless *every* field in the `cbuffer` used a `register` or `packoffset` modifier. Slang hasn't required that behavior in a while because it now splits textures and samplers, and the one test case where we needed `packoffset` to work around the `fxc` bug in the baseline HLSL has been macro-ified even more to work around the bug. The amount of churn in the test cases is unfortunate, but it continues to point at the weakness of any testing strategy that checks for exact equivalent between Slang's output and that of other compilers. We need to keep working to replace these tests with better alternatives. In `check.cpp` there is logic to perform implicit dereferencing, so that if you write `obj.f` where `obj` is a `ConstantBuffer<X>` (or some other "pointer-like" type) and `f` is a field in `X`, then this effectively translates as `(*obj).f`. That is, we dereference the value of type `ConstantBuffer<X>` to get a value of type `X`, and then refer to the field of the `X` value. There was a problem where the logic to insert that kind of implicit dereference operation was using a reference (`auto& type = ...`) for the type of the expression being dereferenced, and then clobbering it. This would mean that an expression of type `ConstantBuffer<X>` would have its type overwritten to be just `X` and then codegen would break later on. I'm not sure how we haven't run into that before. The `array-of-buffers` test case was added to confirm that we now support arrays of constant, structured, and byte-address buffers for both DXIL and SPIR-V output. Okay, so that was a lot of stuff, but hopefully it is clear how this all works to make the output of the compiler more consistent and explicit, while also supporting the required new functionality. * fixup: review feedback
* Feature/early depth stencil (#727)jsmall-nvidia2018-11-21
| | | | | | | | | | | | | | * First pass support for early depth stencil. * Add a simple test to check if output has attributes. * Use cross compilation to test [earlydepthstencil] on glsl. * If target is dxil, use dxc to test against. Add hlsl to test earlydepthstencil against. * * Added spSessionHasCompileTargetSupport * Made slang-test use spSessionHasCompileTargetSupport to ignore tests that cannot run
* Feature/shared library refactor (#712)jsmall-nvidia2018-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * * Added ISlangSharedLibraryLoader and ISlangSharedLibrary * Implemented default implementations * Added slang API function to get/set the ISlangSharedLibraryLoader on the session * Put function caching onto the Session - so that if the loader is chaged, its easy to reset the shared libraries, and functions * Run premake. * Fix problem with setting null, would cause an unnecessary function/shared lib flush. * * Unload SharedLibrary when DefaultSharedLibrary is deleted. * Make SharedLibrary handle unload safely if already unloaded. * Refactor SharedLibrary, such that it becomes a utility class - simplifying it's semantics. * Simplified ISlangSharedLibrary such that doesn't have unload and isLoaded so easier to implement. Use updated SharedLibrary impl. * Disable aarch64 on windows * Premake windows files without aarch64 build. * Moved slang-shared-library to core (so can be used in code outside of main slang) Fixed problem in premake5 where on windows projects were incorrectly constructed * Allowed RefObject to base class of com types Added ConfigurableSharedLibraryLoader Added -dxc-path -fxc-path -glslang-path Fix problem with dxc-path not honoring it's path when loading dxil * Added documentation for command line control of dll loading paths. * Remove some tabbing issues. * Change name of include guard.
* Rework command-line options handling for entry points and targets (#697)Tim Foley2018-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Rework command-line options handling for entry points and targets Overview: * The biggest functionality change is that the implicit ordering constraints when multiple `-entry` options are reversed: any `-stage` option affects the `-entry` to its *left* instead of to its *right* as it used to. This is technically a breaking change, but I expect most users aren't using this feature. * The options parsing tries to handle profile versions and stages as distinct data (rather than using the combined `Profile` type all over), and treats a `-profile` option that specifies both a profile version and a stage (e.g., `-profile ps_5_0`) as if it were sugar for both a `-profile` and a `-stage` (e.g., `-profile sm_5_0 -stage fragment`). * We now technically handle multiple `-target` options in one invocation of `-slangc`, but do not advertise that fact in the documentation because it might be confusing for users. Similar to the relationship between `-stage` and `-entry`, any `-profile` option affects the most recent `-target` option unless there is only one `-target`. * The logic for associating `-o` options with corresponding entry points and targets has been beefed up. The rule is that a `-o` option for a compiled kernel binds to the entry point to its left, unless there is only one entry point (just like for `-stage`). The associated target for a `-o` option is found via a search, however, because otherwise it would be impossible to specify `-o` options for both SPIR-V and DXIL in one pass. * The handling of output paths for entry points in the internal compiler structures was changed, because previously it could only handle one output path per entry point (even when there are multiple targets). The new logic builds up a per-target mapping from an entry point to its desired output path (if any). Details: * Support for formatting profile versions, stages, and compile targets (formats) was added to diagnostic printing, so that we can make better error messages. This is fairly ad hoc, and it would be nice to have all of the string<->enum stuff be more data-driven throughout the codebase. * Test cases were added for (almost) all of the error conditions in the current options validation. The main one that is missing is around specifying an `-entry` option before any source file when compiling multiple files. This is because the test runner is putting the source file name first on the command line automatically, so we can't reproduce that case. * Several reflection-related tests now reflect entry points where they didn't before, because the logic for detecting when to infer a default `main` entry point have been made more loose * On the dxc path, beefed up the handling of mapping from Slang `Profile`s to the coresponding string to use when invoking dxc. * A bunch of tests cases were in violation of the newly imposed rules, so those needed to be cleaned up. * There were also a bunch of test cases that had accidentally gotten "disabled" at some point because there were comparing output from `slangc` both with and without a `-pass-through` option, but that meant that any errors in command-line parsing produced the *same* error output in both the Slang and pass-through cases. This change updates `slang-test` to always expect a successful run for these tests, and then manually updates or disables the various test cases that are affected. * When merging the updated test for matrix layout mode, I found that the new command-line logic was failing to propagate a matrix layout mode passed to `render-test` into the compiler. This was because the `-matrix-layout*` options were implemented as per-target, but the target was being set by API while the option came in via command line (passed through the API). It seems like we want matrix layout mode to be a global option anyway (rather than per-target), so I made that change here. * Add missing expected output files * A 64-bit fix * Remove commented-out code noted in review
* Feature/premake linux (#689)jsmall-nvidia2018-10-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Premake work in progress for linux. * Added dump function. * Remove examples on linux Small warning fix. * * Don't build render-test on linux * Removed work around virtual destructor warning, and just used virtual dtor for simplicity * Git ignore obj directories * Fix premake working on windows. * * Fix sprintf_s functions * Make generates arg parsing more robust * Added FloatIntUnion to avoid type punning/strong aliasing issues, and repeated union definitions. * Work around problems building on linux with getClass claiming a strict aliasing issue. * Fix for targetBlock appearing potentiall used unintialized to gcc. * Linux slang link options -fPIC to make dll. * Add -fPIC to build options on linux. * Add -ldl for linux on slang. * Fixes to try and get premake working with .so on linux. * Make core compile with -fPIC * Try to fix linux linking with --no-as-needed before -ldl * Add rpath back. * Remove render-gl from linux build. * Re-add location for linux. * Don't include <malloc.h> except on windows. * Remove unused line to fix warning on osx. * Remove ambiguity on OSX for operator <<. * Fixing ambiguity with operator overloading and Int types for OSX. * Fix ambiguity around UInt and operator * Fix ambiguity of UInt conversion for OSX. * Added UnambiguousInt and UnambiguousUInt to make it easier to work around OSX integer coercion for UInt/Int types.
* Add support for static methods in interfaces (#680)Tim Foley2018-10-18
| | | | | | | This change allows an interface to include `static` methods as requirements, so that types that conform to the interface will need to satisfy the requirement with a `static` method. The essence of the check is simple: when checking that a method satisfies a requirement, we enforce that both are `static` or both are non-`static`. Making that simple change and adding a test change broke a few other places in the compiler that this change tries to fix. The main fix is to handle cases where we might look up an "effectively static" member of a type through an instance, and to make sure that we replace the instance-based lookup with type-based lookup. There was already logic along these lines in `lower-to-ir.cpp`, so this change centralizes it in `check.cpp` where it seems to logically belong.
* Add basic support for [mutating] methods (#667)Tim Foley2018-10-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By default, when writing a "method" (aka "member function") in Slang, the `this` parameter is implicitly an `in` parameter. So this: ```hlsl struct Foo { int state; int getState() { return state; } void setState(int s) { state = s; } }; ``` is desugared into something like this: ```hlsl struct Foo { int state }; int Foo_getState(Foo this) { return this.state; } // BAD: void Foo_setState(Foo this, int s) { this.state = s; } ``` That "setter" doesn't really do what was intended. It modifies a local copy of type `Foo`, because `in` parameters in HLSL represent by-value copy-in semantics, and are mutable in the body the function. Slang was updated to give a static error on the original code to catch this kind of mistake (so that `this` parameters are unlike ordinary function parameters, and no longer mutable). Of course, sometimes users *want* a mutable `this` parameter. Rather than make a mutable `this` the default (there are arguments both for and against this), this change adds a new attribute `[mutating]` that can be put on a method (member function) to indicate that its `this` parameter should be an `in out` parameter: ```hlsl [mutating] void setState(int s) { state = s; } ``` The above will translate to, more or less: ```hlsl void Foo_setState(inout Foo this, int s) { this.state = s; } ``` One added detail is that `[mutating]` can also be used on interface requirements, with the same semantics. A `[mutating]` requirement can be satisfied with a `[mutating]` or non-`[mutating]` method, while a non-`[mutating]` requirement can't be satisfied with a `[mutating]` method (the call sites would not expect mutation to happen). The design of `[mutating]` here is heavily influenced by the equivalent `mutating` keyword in Swift. Notes on the implementation: * Adding the new attribute was straightforward using the existing support, but I had to change around where attributes get checked in the overall sequencing of static checks, because attributes were being checked *after* function bodies, but with this change I need to look at semantically-checked attributes to determine the mutability of `this` * The check to restrict it so that `[mutating]` methods cannot satisfy non-`[mutating]` requirements was easy to add, but it points out the fact that there is a huge TODO comment where the actual checking of method *signatures* is supposed to happen. That is a bug waiting to bite users and needs to be fixed! * While we had special-case logic to detect attempts to modify state accessed through an immutable `this` (e.g., `this.state = s`), that logic didn't trigger when the mutation happened through a function/operator call (e.g., `this.state += s`), so this change factors out the validation logic for that case and calls through to it from both the assignment and `out` argument cases. * The error message for the special-case check was updated to note that the user could apply `[mutating]` to their function declaration to get rid of the error. * The semantic checking logic for an explicit `this` expression was already walking up through the scopes (created during parsing) and looking for a scope that represents an outer type declaration that `this` might be referring to. We simply extend it to note when it passes through the scope for a function or similar declaration (`FunctionDeclBase`) and check for the `[mutating]` attribute. If the attribute is seen, it returns a mutable `this` expression, and otherwise leaves it immutable. * The IR lowering logic then needed to be updated so that when adding an IR-level parameter to represent `this`, it gives it the appropriate "direction" based on the attributes of the function declaration being lowered. The rest of the IR logic works as-is, because it will treat `this` just like an other parameter (whether it is `in` or `inout`). * This biggest chunk of work was the "implicit `this`" case, because ordinary name lookup may resolve an expression like `state` into `this.state`, so that the `this` expression comes out of "thin air." To handle this case, I extended the structure of the "breadcrumbs" that come along with a lookup result (the breadcrumbs are used for any case where a single identifier like `state` needs to be embellished to a more complex expression as a result of lookup), so that it can identify whether a `Breadcrumb::Kind::This` node comes from a `[mutating]` context or not. Similar to the logic for an explicit `this`, we handle this by noting when we pass through a `FunctionDeclBase` when moving up through scopes, and look for the `[mutating]` attribute on it. The rest of the work was just plumbing the additional state through.
* Support cross-compilation of ray tracing shaders to Vulkan (#663)Tim Foley2018-10-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Move to newer glslang * Support cross-compilation of ray tracing shaders to Vulkan This change allows HLSL shaders authored for DirectX Raytracing (DXR) to be cross-compiled to run with the experimental `GL_NVX_raytracing` extension (aka "VKRay"). * The GLSL extension spec is marked as experimental, so that any shaders written using this support should be ready for breaking changes when the spec is finalized. * "Callable shaders" are not exposed throug the GLSL extension, so this feature of DXR will not be cross-compiled. * The experimental Vulkan raytracing extension does not have an equivalent to DXR's "local root signature" concept. This does not visibly impact shader translation (because the local/global root signature mapping is handled outside of the HLSL code), but in practice it means that applications which rely on local root signatures on their DXR path will not be able to use the translation in this change as-is; more work will be needed. The simplest part of the implementation was to go into the Slang standard library and start adding GLSL translations for the various DXR operations. In some cases, like mapping `IgnoreHit()` to `ignoreIntersectionNVX()` this is almost trivial. The various functions to query system-provided values (e.g., `RayTMin()`) were also easy, with the only gotcha being that they map to variables rather than function calls in GLSL, and our handling of `__target_intrinsic` assumes that a bare identifier represents a replacement function name, and not a full expression, so we have to wrap these definitions in parentheses. The tricky operations are then `TraceRay<P>()` and `ReportHit<A>()`, because these two are generics/templates in HLSL. GLSL doesn't support generics, even for "standard library" functions, so the raytracing extension implements a slightly complex workaround: the matching operations `traceNVX()` and `reportIntersectionNVX()` pass the payload/attributes argument data via a global variable. That is, shader code for the GLSL extensions writes to the global variable and then calls the intrinsic function. The linkage between the call site and the global is established by a modifier keyword (`rayPayloadNVX` and `hitAttributeNVX`, respectively) and in the case of ray payload also uses `location` number to identify which payload global to use (since a single shader can trace rays with multiple payload types). Our translation strategy in Slang tries to leverage standard language mechanisms instead of special-case logic. For example, to translate the `ReportHit<A>()` function, we provide both a default declaration that will work for HLSL (where the operation is built-in with the signature given), and a *definition* marked with the `__specialized_for_target(glsl)` modifier. The GLSL definition declares a function `static` variable that will fill the role of the required global, and then does what the GLSL spec requires: assigns to the global, and then calls the `reportIntersectionNVX` builtin (which we declare as a separate builtin). Our ordinary lowering process will turn that `static` variable into an ordinary global in the IR, and the `[__vulkanHitAttributes]` attribute on the variable will be emitted as `hitAttributeNVX` in the output. There is no additional cross-compilation logic in Slang specific to `ReportHit<A>()` - the target-specific definition in the standard library Just Works. The case for `TraceRay<P>()` is a bit more complicated, simply because the GLSL `traceNVX()` function needs to be passed the `location` for the payload global. We implement the payload global as a function-`static` variable, with the knowledge that every unique specialization of `TraceRay<P>()` will generate a unique global variable of type `P` to implement our function-`static` variable. We then add a slightly magical builtin function `__rayPayloadLocation()` that can map such a variable to its generated `location`; the logic for this is implemented in `emit.cpp` and described below. We also changed the `RayDesc` and `BuiltinTriangleIntersectionAttributes` types from "magic" intrinsic types over to ordinary types (because the GLSL output needs to declare them as ordinary `struct` types). This ends up removing some cases in the AST and IR type representations. By itself this change would break HLSL emit, because in that case the types really are intrinsic. We added a `__target_intrinsic` modifier to these types to make them intrinsic for HLSL, and then updated the downstream passes to handle the notion of target-intrinsic types. The logic for binding/layout of entry point inputs and outputs was updated so that raytracing stages don't follow the default logic for varying input/output parameters. This is because the input/output parameters of a raytracing entry point aren't really "varying" in the same sense as those in the rasterization pipeline. In particular, the SPIR-V model for raytracing input and output treats "ray payload" and "hit attributes" parameters as being in a distinct storage class from `in` or `out` parameters. We also detect cases where a ray tracing stage declares inputs/outputs that it shouldn't have. This logic could conceivably be extended to other stages (e.g., to give an error on a compute shader with user-defined varying input/output). The type layout logic added cases for handling raytracing payload and hit-attribute data, but this is currently just a stub implementation that follows the same logic as for varying `in` and `out` parameters (it cannot give meaningful byte sizes/offsets right now). To my knowledge the GLSL spec doesn't currently specify anything about layout, and I haven't read the DXR spec language carefully enough to know what it says about layout. A future change should update the layout logic to allow for byte-based layout of ray payloads, etc. so that we can query this information via reflection. The GLSL legalization logic in `ir.cpp` was updated to factor out the per-entry-point-parameter code into its own function, and then that function was updated to special-case the input/output of a ray-tracing shader. While for rasterization stages we typically want to take the user-declared input/output and "scalarize" it for use in GLSL (in part to deal with language limitations, and in part to tease system values apart from user-defined input/output), the GLSL spec for raytracing requires payload and hit attribute parameters to be declared as single variables. There is also the issue that even for an `in out` parameter, a ray payload parameter should only turn into a single global, whereas the handling for varying `in out` parameters generates both an `in` and an `out` global for the GLSL case. Other than the handling of entry point parameters, the GLSL legalization pass doesn't need to do anything special for ray tracing shaders. The trickiest change in the `emit.cpp` logic is that we now generate `location`s for ray payload arguments (the outgoing from a `TraceRay()` call) on demand during code generation. This is a bit hacky, and it would be nice to handle it as a separate pass on the IR rather than clutter up the emit logic, but this approach was expedient. Basically, any of the global variables that got generated from the `static` declarations in the standard library implementation of `TraceRay()` will trigger the logic to assign them a `location`. The logic for emitting intrinsic operations added a few new `$`-based escape sequences. The `$XP` case handles emitting the location of a generated ray payload variable; this is how we emit the matching location at the site where we call `traceNVX`. The `$XT` case emits the appropriate translation for `RayTCurrent()` in HLSL, because it maps to something different depending on the target stage. All of the test cases here consist of a pair of an HLSL/Slang shader written to the DXR spec, plus a matching GLSL shader for a baseline. The GLSL shaders are carefully designed so that when fed into glslang they will produce the same SPIR-V as our cross-compilation process. This kind of testing is quite fragile, but it seems to be the best we can do until our testing framework code supports *both* DXR and VKRay. A bunch of the core changes ended up being blocked on issues in the rest of the compiler, so some additional features go implemented or fixed along the way: The first big wall this work ran into was that the `__specialized_for_target` modifier hasn't actually been working correctly for a while. It turns out that for the one function that is using it, `saturate()`, we have been outputting the workaround GLSL function in *all* cases (including for HLSL output) rather than only on GLSL targets. The problem here is that for a generic function with a `__specialized_for_target` modifier or a `__target_intrinsic` modifier, the IR-level decoration will end up attached to the `IRFunc` instruction nested in the `IRGeneric`, but the logic for comparing IR declarations to see which is more specialized (via `getTargetSpecializationLevel()`) was looking only at decorations on the top-level value (the generic). The quick (hacky) fix here is to make `getTargetSpecializationLevel()` try to look at the return value of a generic rather than the generic itself, so that it can see the decorations that indicate target-specific functions. A more refined fix would be to attach target-specificity decorations to the outer-most generic (to simplify the "linking" logic). The only reason not to fold that into the current fix is that the `__target_intrinsic` modifier currently serves double-duty as a marker of target specialization *and* information to drive emit logic. The latter (the emit-related stuff) currently needs to live on the `IRFunc`, and moving it to the generic could easily break a lot of code. This needs more work in a follow-on fix, but for now target specialization should again be working. The other big gotcha that the simple "just use the standard library" strategy ran into was that function-`static` variables weren't actually implemented yet, and in particular function-`static` variables inside of generic functions required some careful coding. The logic in `lower-to-ir.cpp` has this `emitOuterGenerics()` function that is supposed to take a declaration that might be nested inside of zero or more levels of AST generics, and emit corresponding IR generics for all those levels. This is needed because two different AST functions nested inside a single generic `struct` declaration should turn into distinct `IRFunc`s nested in distinct `IRGeneric`s. The tricky bit to making that all work is that the same AST-level generic type parameter will then map to *different* IR-level instructions (the parameters of distinct `IRGeneric`s) when lowering each function. The existing logic handled this in an idiomatic way by making "sub-builders" and "sub-contexts." This change refactors some of the repeated logic into a `NestedContext` type to help simplify the pattern, and applies it consistently throughout the `lower-to-ir.cpp` file. Besides that cleanup, the major change is `lowerFunctionStaticVarDecl` which, unsurprisingly, handles lower of function-`static` variables to IR globals. The careful handling of nested contexts here is needed because if we are in the middle of lowering a generic function, then a `static` variable should turn into its *own* `IRGeneric` wrapping an `IRGlobalVar`. The body of the function should refer to the global variable by specializing the global variable's `IRGeneric` to the parameters of the *functions* `IRGeneric`. This tricky detail is handled by `defaultSpecializeOuterGenerics`. An additional subtlety not actually required for this raytracing work (and thus not properly tested right now) is handling function-`static` variables with initializers. These can't just be lowered to globals with initializers, because HLSL follows the C rule that function-`static` variables are initialized when the declaration statement is first executed (and this could be visible in the presence of side-effects). The lowering strategy here translates any `static` variable with an initializer into *two* globals: one for the actual storage, plus a second `bool` variable to track whether it has been initialized yet. There are some opportunities to optimize this case, especially for `static const` data, but that will need to wait for future changes. We've slowly been shifting away from the model where a user thinks of a "profile" as including both a stage and a feature level. Instead, the user should think about selecting a profile that only describes a feature level (e.g., `sm_6_1`, `glsl_450`, etc.), and then separately specifying a stage (`vertex`, `raygeneration, etc.) for each entry point. The challenge here is that the command-line processing still only had a single `-profile` switch, and no way to specify the stage. Adding the `-stage` option was relatively easy, but making it work with the existing validation logic for command-line arguments was tricky, because of the complex model that `slangc` supports for compiling multiple entry points in a single pass. * In `slang.h` add new reflection parameter categories for ray payloads and hit attributes, as part of entry point input/output signatures. * A previous change already updated our copy of glslang to one that supports the `GL_NVX_raytracing` extension, so in `slang-glslang.cpp` we just needed to map Slang's `enum` values for the raytracing stage names to their equivalents in the glslang code. * Moved the logic for looking up a stage by name (`findStageByName()`) out of `check.cpp` and into `compiler.cpp`, with a declaration in `profile.h` * Added a `$z` suffix to the GLSL translation of `Texture*.SampleLevel()`, to handle cases where the texture element type is not a 4-component vector. Note that this fix should actually be applied to *all* these texture-sampling operations, but I didn't want to add a bunch of changes that are (clearly) not being tested right now. * The layout logic for entry points was updated to correctly skip producing a `TypeLayout` for an entry point result of type `void`, which meant that the related emit logic now needs to guard against a null value for the result layout. * In `ir.cpp`, dump decorations on every instruction instead of just selected ones, so that our IR dump output is more complete. * Added a command-line `-line-directive-mode` option so that we can easily turn off `#line` directives in the output when debugging. Not all cases where plumbed through because the `none` case is realistically the most important. * Parser was fixed to properly initialize parent links for "scope" declarations used for statements, so that we can walk backwards from a function-scope variable (including a `static`) and see the outer function/generics/etc. * Added GLSL 460 profile, since it is required for ray tracing. Also updated the logic for computing the "effective" profile to use to recognize that GLSL raytracing stages require GLSL 460. * Added some conventional ray-tracing shader suffixes to the handling in `slang-test`. This code isn't actually used, but was relevant when I started by copy-pasting some existing VKRay shaders as the starting point for my testing. * Fixup: typos
* Improve support for non-32-bit types. (#643)Tim Foley2018-09-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main change here is to fill out the `BaseType` enumeration so that it covers the full range of 8/16/32/64-bit signed and unsigned integers, as well as 16/32/64-bit floating-point numbers, and then propagate that completion through various places in the code. More details: * The current `half`, `float`, `double`, `int`, and `uint` types are still the default names for their types, so things like `float16_t` and `int32_t` were added as `typedef`s. * We still need to generate the full gamut of vector/matrix `typedef`s for the new types, so that things like `float16_t4x3` will work (yes, I know that is ugly as sin, but that's the HLSL syntax...). * A few pieces of dead code from earlier in the compiler's life got removed, since I did a find-in-files for `BaseType::` and tried to either update or delete every site. * A few call sites that were enumerating integer base types in an ad-hoc fashion were changed to use a single `isIntegerBaseType()` function that I added in `check.cpp` * When compiling with dxc for shader model 6.2 and up, we enable the compiler's support for native 16-bit types via a flag. * The public API enumeration for reflection of scalar types added cases for 8- and 16-bit integers (it already exposed the other cases we need) * The lexer was updated to be extremely liberal in what kinds of suffixes it allows on literals. I also removed the logic that was treating, e.g., `0f` as a floating-point literal (it doesn't seem to be the right behavior). That would now be an integer literal with an invalid suffix. * The logic in the parser that applies types to literals was updated to handle a few more cases: `LL` and `ULL` for 64-bit integers, and `H` for 16-bit floats. * The mangling logic needed to be updated to handle the new cases, and I consolidated the handling of those types in their front-end and IR forms. * Removed the explicit `BasicExpressionType::ToString` logic, since all basic types are `DeclRefType`s in the front end, and we can just print them out as such. * As a bit of a gross hack, fudged the conversion costs so that `int` to `int64_t` conversion is a bit more costly. The problem there is that given an operation like `int(0) + uint(0)`, the best applicable candidates ended up being `+(uint,uint)` and `+(int64_t,int64_t)` because the cost of a single `int`-to-`uint` conversion was the same as the sum of the cost of an `int`-to-`int64_t` and a `uint`-to-`int64_t`. A better long-term fix here is to completely change our overload resolution strategy, but that is obviously way too big to squeeze into this change. * Type layout computation was updated to handle all the new types and give them their natural size/alignment. Note that this does *not* work for down-level HLSL where `half` is treated as a synonym for `float`. It also doesn't deal with the fact that many of these types aren't actually allowed in constant buffers for certain shader models. A future change should work to add error messages for unsupported stuff during type layout (or just make the types themselves require support for certain capabilities)
* Add a better error message for common global generic failure (#634)Tim Foley2018-09-13
| | | | | | | | | | | | | | | | | | | A common mistake that seems to come up when using global generic type parameters: ```hlsl interface IHero { ... } type_param H : IHero; ParameterBlock<H> gHero; ``` is to accidentally try to specialize the type parameter `H` using `H` itself as the argument (instead of some concrete type like `Batman`). The current front-end checks naively let this pass, because `H` satisfies all the requirements (it sure does declare that it implements `IHero`, which is the only requirement we have). This currently leads to downstream failure when we generate code with generic type parameters still left in the IR. This change implements a simple fix which is to: - Check when we are trying to specialize a global generic parameter using another global generic parameter, since this is currently always a mistake - Add a special-case diagnostic for the 99% case of this failure, which is specializing a type parameter to itself This fix is primarily motivated by the way generics support will initially be implemented in Falcor.
* Add basic support for #pragma once (#630)Tim Foley2018-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | * Improve diagnostic messages for function redefinition The front-end was using internal "not implemented" errors instead of friendly user-facing errors to handle: * Redefinition of a function (same signature and both have bodies) * Multiple function declarations/definitions with the same parameter signature, but differnet return types This change simply turns both of these into reasonably friendly errors that explain what went wrong and point to the previous definition/declaration as appropriate. * Add support for detecting #pragma directives and handling them The logic here mirrors what was set up for preprocessor directives, just for "sub-directives" in this case. The only case here is the default one, which now reports a warning for directives we don't understand. * Add basic support for #pragma once Fixes #494 The approach here is simplistic in the extreme. When we see a `#pragma once` directive, we put the current file path (the location of the `#pragma` directive, as reported by our source manager) into a set, and then any paths in that set are ignored by subsequent `#include` directives. This should work for simple cases of `#pragma once`, but it is likely to fail in a variety of cases because our filesystem layer currently makes no attempt to normalize/canonicalize paths. Improving the robustness of the solution is left to future work. This change includes a simple test case to confirm that a second `#include` of a file with a `#pragma once` is successfully ignored.
* Support for [[vk::push_constant]] (#629)jsmall-nvidia2018-08-22
| | | | | | | | | | * Support for attributed [[vk::push_constant]] and [[push_constant]]. Can also use layout(push_constant). * Fix test so matches the expected output. * Add expected output to binding-push-constant-gl.hlsl * Trivial change to force travis rebuild to test the gcc linux build really has a problem.
* Improve model-viewer support for lights (#626)Tim Foley2018-08-10
| | | | | | | | | | | | | | | | | | * Improve model-viewer support for lights The main visible change here is that the model-viewer example supports multiple light sources, with a basic UI for adding new light sources to the scene, and for manipulating the ones that are there. Along the way I also refactored the `IMaterial` decomposition to be a bit less naive, while still only including a completely naive Blinn-Phong implementation. I also went ahead and spruced up the `cube.obj` file so that it has multiple materials, although it is still a completely uninteresting asset. * Fixup: Windows SDK version
* Feature/attributed binding (#621)jsmall-nvidia2018-07-31
| | | | | | | | | | | | | | | * Typo fix, and added dxc to command line documentation. * Fix small typos. Added support for Scope to lexer. Fix bug in Token ctor. * Add support for attribute names that are scoped. * Added GLSLBindingAttribute. Make binding work through core.met.slang. * Allow [[gl::binding(binding, set)]] [[vk::binding(binding,set)]]
* Support for Tessellation (#607)jsmall-nvidia2018-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Fix typo OuptutTopologyAttribute -> OutputTopologyAttribute First pass support for handing tesselation shaders - domain and hull. * Added attribute PatchConstantFuncAttribute * Added visitHLSLPatchType(HLSLPatchType* type) such that the patch type template parameters are handled * Added IRNotePatchConstantFunc - such that the patch constant function is referenced within IR * Added support for outputing typical tesselation attributes (although minimal validation is performed) * Added findFunctionDeclByName * Small improvements to diagnostic. * Improved diagnostics and checking for geometry shader attributes. * Added diagnostic if patchconstantfunc is not found Handle assert failure when outputing a domain shader alone and therefore attr->patchConstantFuncDecl is not set. * Simple script tess.hlsl to test out domain/hull shaders. * Added url for where hull shader attributes are defined. * Fix unsigned/signed comparison warning. * Restore removal of fix in "Improve generic argument inference for builtins (#598)" * Update tessellation test case to compare against fxc The test was previously comparing against fixed expected DXBC output, but this caused problems when the test runner tried to execute the test on Linux (where there is no fxc to invoke...), and would also be a potential source of problems down the road if different users run using different builds of fxc. The simple solution here is to convert the test to compare against fxc output generated on the fly. That test type is already filtered out on non-Windows builds, so it eliminates the portability issue (in a crude way). I also changed the test to compile both entry points in one compiler invocation, just to streamline things into fewer distinct tests. * Eliminate unnecessary call to `lowerFuncDecl` In a very obscure case this could cause a bug, if the patch-constant function had somehow already been lowered (because it was called somewhere else in the code). The call should not be needed because `ensureDecl` will lower a declaration on-demand if required, so eliminating it causes no problems for code that wouldn't be in that extreme corner case.
* Improve generic argument inference for builtins (#598)Tim Foley2018-06-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes #487 The basic problem here is that the user writes something like: ```hlsl float invSqrt2 = 1 / sqrt(2); ``` In this case the user knows that `sqrt()` is only defined for floating-point types, so they expect this to compile something like: ```hlsl float invSqrt2 = float(1) / sqrt(float(2)); ``` The challenge this creates for the Slang compiler is that we use generics to streamline our declarations of all the builtins, so that the scalar `sqrt()` function is actually declared as: ```hlsl T sqrt<T:__BuiltinFloatingPointType>(T value); ``` The `__BuiltinFloatingPointType` is an `interface` defined as part of the standard library, such that only built-in floating-point types conform to it (that is, `half`, `float`, and `double`). When generic argument inference applies to a call like `sqrt(2)`, we see an argument of type `int`, and try to infer `T=int`, which leads to a failure because `int` does not conform to `__BuiltinFloatingPointType`. The point where this currently fails in in the logic to "join" two types for inference, which is supposed to pick the best type that can represent both of two input types. E.g., a join between `float` and `int3` would be `float3`, since both of those types can convert to it, and it is the "minimal" type with that property. So, the goal here is simple: we want a "join" between `int` and `__BuiltinFloatingPointType` to yield the `float` type. The way we handle that in this change is to special case the join of a basic scalar type and an interface, by enumerating all the basic scalar types, filtering them for ones that support the chosen interface and can be implicitly converted from the argument type, and then picking the "best" of them (the comments in the code explain what "best" means in this context). The technique used here could be generalized in the future to deal with user-defined types or more cases, but that would risk slowing down overload resolution even more, which is already the most expensive part of our semantic checking pass. A test case has been added for the specific case of `sqrt()` applied to an `int` argument.
* Initial support for enum declarations (#599)Tim Foley2018-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Slang `enum` declarations will always be scoped, e.g.: ```hlsl enum Color { Red, Green = 2, Blue, } Color c = Color.Red; // Not just `Red` ``` A user can write `enum class` as a placebo for now (to ease sharing of headers with C++). Slang does not currently support the `::` operator for static member lookup, so it must be `Color.Green` and not `Color::Green`. Support for `::` as an alternate syntax could be added later if there is strong user demand. An `enum` type can have a declared "tag type" using syntax like C++ `enum class`: ```hlsl enum MyThings : uint { First = 0, // ... } ``` The `enum` cases will store their values using that type. An `enum` that doesn't declare a tag type will use the type `int` by default. Enum cases are assigned values just like in C/C++: cases can have explicit values, but otherwise default to one more than the previous case, or zero for the first case. All `enum` types will automatically conform to a standard-library `interface` called `__EnumType`, which is used so that basic operators like equality testing can be defined generically for all `enum` types. This change only adds one operator at first (the `==` comparison), but other should be added later. An `enum` case needs to be explicitly converted to an integer where needed (e.g., `int(Color.Red)`). This is implemented by having the main integer types (`int` and `uint`) support built-in initializers that can work for *any* `enum` type (or rather, anything conforming to `__EnumType`). Eventually these will be restricted so that an `enum` type can only be converted to its associated tag type. IR code generation completely eliminates `enum` types and their cases. The `enum` type will be replaced with its tag type, and the cases will be replaced with the tag values. Currently this could leave some mess in the IR where cast operations are applied between values that actually have the same type.
* Fix global atomic functions (#582)Tim Foley2018-05-29
| | | | | | | | | Fixes #581 This change adds a new parameter passing mode `__ref` to exist alongisde `in`, `out`, and `inout`. The `__ref` modifier indicates true by-reference parameter passing (whereas `inout` is copy-in-copy-out). This is not intended to be something that users interact with directly, but rather a low-level feature that lets us provide a correct signature for the `Interlocked*()` operations in the standard library. Most of the support for passing what are logically addresses around already exists in the IR, so the majority of the work here is just in introducing the new type `Ref<T>` and then using it appropriately when lowering `__ref` parameters/arguments to the IR.
* A bunch of work to resolve #569 (#576)Tim Foley2018-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * render-test should not fail on HLSL compiler *warnings* The logic in `render-test` that invokes `D3DCompile` was causing a test to fail if it produced any warnings (not just if compilation fails). Warning output can be dealt with by the test runner, since it will compare output between runs anyway, and it is useful to be able to run something through `render-test` that compiles with warnings. * Be more careful about deleting IR instructions There was an `IRInst::deallocate()` method that had a precondition that the instruction should already be removed from its parent and clear out all its operands before calling, but it wasn't checking this and the few call sites weren't doing things right either. I consolidated things on `IRInst::removeAndDeallocate()` which does all the things: removes from the parent, clear out operands, and then deallocates. I also made sure to clear out the type operand. This clears up some crashing issues where passes were removing instructions but those instructions would still show up as users of other instructions. * Don't emit bitwise not for non-Boolean types It seems like the logic in `emit.cpp` messed things up and decided that `Not` (the IR instruction that is equivalent to `!` in the AST) should emit as `!` for Boolean types and `~` for other types, but this makes no sense (e.g., `~(a & 1)` is very different from `!(a & 1)`, even when interpreted as a condition). It seems like this logic was intended for the `BitNot` case, where `~a` and `!a` are actually equivalent for Boolean values (but a target language might not like `~a` on `bool` values). Maybe the original plan was that the `Not` instruction should only apply to Boolean values in the first place, and that other values should be converted to `bool` (or a vector of `bool`) before applying `Not`, but even in that case the emit logic makes no sense. This caused an actual problem for one of my test cases, so it was important to fix it now. * Fix issue with cached resolution for overoaded operators The basic problem was that the lookup logic was forming a key based on the *first* definition it found for the overloaded operator, but that means that when processing a prefix `++a` call we might look up the *postfix* definition of `operator++` and decide to use its opcode as the key. This "fixes" the logic by looking for the first definition with a "compatible" definition (e.g., a `__prefix` function if we are checking a `PrefixExpr`), and then uses its opcode. A better fix in the long run would be to make the cache just be keyed on the operator name and the "fixity" of the expression (prefix, postfix, or infix). * Introduce an intermediate structured control-flow representation The code previously used a single function called `emitIRStmtsForBlocks` in `emit.cpp` that would take a logical sub-graph of the CFG and emit it as high-level statements. It would do this by recognizing operations like coniditional branches that it could turn into high-level `if` statements, etc. The main problem with this function was that it mixed together the logic for how we restructure the program with the logic for how we emit high-level code from that structure. This change splits those two parts of the algorithm by introducing an intermediate data structure: a tree of `Region`s, which represent single-entry regions of the CFG. There are subclasses of `Region` corresponding to various structured control-flow constructs, and then a leaf case that wraps a single `IRBlock`. The new function `generateRegionsForIRBlocks()` (in `ir-restructure.cpp`) now handles the restructuring work, by building one or more `Region`s to represent a sub-graph, while `emitRegion()` handles emitting HLSL/GLSL source code from a region. Splitting things in this way opens up some opportunities for future changes: * We can expand the set of IR control-flow constructs allowed, so long as we can still generate structure `Region`s from them, without having to mess with the emit logic (e.g., we could start to support multi-level `break` by introducing temporaries as needed). In the limit we can generate our `Region`s using something like the "Relooper" algorithm. * We can emit to other representations while retaining the same control-flow restructuring support. E.g., if we drop the structured information from the IR, then emitting to SPIR-V for Vulkan would require us to use the strucured control-flow information from these `Region`s. * We can do analysis that needs to understand `Region` structure. This is relevant to issue #569, which was what prompted me to start on this work. Now that we have a representation of the nesting of `Region`s, we can use it to reason about visibility of values between blocks. During development of this change I ran into a gotcha, in that I had been assuming each IR block would map to a single `Region`, forgetting that our current lowering of "continue clauses" in `for` loops leads to them being duplicated. The `Region` representation handles this by having a linked-list struct mapping IR blocks to the `SimpleRegion`s that represent them. I added a test case that includes a `for` loop with a continue clause that is reached along multiple paths just to make sure that we continue to support that case. The compiler output should not change as a result of this work; this is supposed to be a pure refactoring change. * Add a pass to resolve scoping issues in generated code Fixes #569 The basic problem arises because the structured control flow that we output in high-level HLSL/GLSL doesn't match the "scoping" rules of an SSA IR. In particular, SSA says that a value can be used in any block that is dominated by the definition, but in the presence of `break` and `continue` statements it is easy to construct cases where a block dominates something that is not in its scope for structured control flow. Consider: ```hlsl for(;;) { int a = xyz; if(a) { int b = a; break; } int c = a; } int d = b; ``` This program is invalid as HLSL, because the variable `b` is referenced outside of its scope, but if we look at the CFG for this function, it is clear that the block that computes `b` dominated the block that computes `d`. IR optimizations can easily create code like this, so we need to be ready for it. The previous change added an explicit `Region` structure to represent the structured control flow that we re-form out of the IR, and this change adds a pass that exploits the structuring information to detect cases like the above and introduce temporaries to fix the scoping issue. For example, the pass would change the earlier code block into something like: ```hlsl int tmp; for(;;) { int a = xyz; if(a) { int b = a; tmp = b; break; } int c = a; } int d = tmp; ``` That is, we introduce a new `tmp` variable at a scope "above" both the definition and use of `b`, and then we copy `b` into that temporary right where it is computed, and then use the temporary instead of the original `b` at the use site. A few details that came up during the implementation: * Downstream compilers may get confused by code like the above, and complain that `tmp` may be used before it is initialized, even though the very definition of dominators in a CFG means we don't have to worry about it. Still, I introduced some one-off code to initialize the temporaries just to silence spurious warnings coming from fxc. * We need to be careful not to apply this logic to "phi nodes" (the parameters of basic blocks) since they will already be turned into temporaries by the emit logic, and trying to introduce temporaries with this pass led to broken code (I still need to investigate why). It may be that a future version of this pass should also take the code out of SSA form, so that we can introduce both kinds of temporaries in a single pass (and maybe eliminate some unnecessary variables by doing basic register allocation). There is another transformation that could fix some issues of this kind, by moving code out of a structured control-flow construct and to the "join point" after it. For example, we could turn our loop from the start of this commit message into: ```hlsl for(;;) { int a = xyz; if(a) { break; } int c = a; } int b = a; int d = b; ``` Moving the definition of `b` to after the loop is possible because there is no way to get out of the loop without executing that code anyway. Now the scoping issue for `d`'s use of `b` has gone away, but of course we've introduced a *new* scoping issue for `a`, when it gets used by `b`. Adding a pass to re-arrange control flow like this could reduce the cases where we have to apply the current pass, but it wouldn't eliminate them entirely. That means such a pass can be deferred to future work. This change includes a test case the reproduces the original issue, so that we can confirm the fix works.
* Cleanups around behavior when the compiler fails (#553)Tim Foley2018-05-11
| | | | | | | | | | | | | | * Cleanups around behavior when the compiler fails * Add another case where we try to `noteInternalErrorLoc()` if an exception in thrown. This one is the in the logic for emitting an IR instruciton. This could be improved by adding another layer at the function level (as a catch-all for instructions with no location), but something is better than nothing. * Change a bunch of `assert()`s over to `SLANG_ASSERT()`s, so that we can theoretically take more control over them (e.g., make release builds with asserts enabled) * Some other small cleanups around the assertions we perform. In the survey I made, I didn't really see many obvious "smoking gun" cases where we could produce a significantly better error message for some of the unimplemented/unexpected paths, other than to actually implement the missing functionality. * fixup
* Speedup type checking using cached overload resolution results.Yong He2018-05-02
| | | | | | | This change adds caches to built-in operator overload resolution and type coersion to avoid running these time-consuming operations every time. - Adds `TypeCheckingCache` type, which is defined in check.cpp, that contains two dictionaries for the cached results of `ResolveInvoke` and `CanCoerce` calls. - Add `destroyTypeCheckingCache` and `getTypeCheckingCache` methods to `Session` class to reuse these cached results over the entire session.
* Diagnose attempts to write to fields in methods (#530)Tim Foley2018-05-01
| | | | | | | | | | | | | | | | * Diagnose attempts to write to fields in methods Work on #529 This helps to avoid the case where a Slang user writes a struct with helpful `setter` methods, and finds that it doesn't work as expected because the `this` parameter is currently handled like an `in` parameter (passed by value, but mutable in the callee). Fixing this issue actually involved making a more broad fix to how l-value-ness is propagated. The existing checking logic was assuming that l-value-ness is just a property of a particular member declaration (e.g., a field is either mutable or not), and didn't take into account whether the "base expression" was mutable. This change fixes that oversight, which might lead to additional errors being issued if we aren't correctly making things mutable when we should. A `ThisExpr` was already immutable by default, so that part didn't actually need to change. Just propagating its immutability through was enough. As an additional assistance to users, I have added an extra diagnostic that triggers when a "destination of assignment is not an l-value" error occurs and the left-hand-side expression seems to be based on `this` (whether implicitly or explicitly). This will ideally help users to understand that the "setter" idiom is not yet supported. * Fixed setRadius typo
* Better diagnostics when compilation is aborted (#517)Tim Foley2018-04-20
| | | | | | | | | | | | | | * Improve messages when compilation is aborted. Make sure to include the information from any `Slang::Exception` that was thrown, so that the poor user can at least point us at our own message string from an assertion failure. This doesn't provide them line-number information in their code or the Slang codebase, so there is still work to be done in making the compiler more friendly about this stuff. * When aborting compilation, try to note what source location we were working on This is handled by having exception handlers on the stack at key bottleneck points in semantic checking and IR generation, which can then emit a diagnostic to note what we were working on when things failed. This is not intended to be an indiciation to the user that their code is at fault for a compiler crash (it is always our fault), but might give them a chance to work around whatever bug is blocking them.
* Diagnose use of an implicit cast as an argument for an `out` parameter (#516)Tim Foley2018-04-20
| | | | | | | | | | | | | Work on #499 Two big fixes here: * The logic for checking constraints on `out` arguments wasn't actually triggering because it relied on function parameters being given an `OutType` if they are marked `out`, but the code wasn't actually doing that. Fixing the computation of types for functions resolved that issue. * Next, I added a specific diagnostic to follow up the "expected an l-value" error to let the user know that their argument was implicitly converted, and that is why it doesn't count as an l-value in Slang's rules. I've added a test case to ensure that we retain this diagnostic until we can do a true fix for the issue. The right long-term fix is to have an AST representation of all the implicit casts involved (e.g., in both directions for an `inout` parameter), and then have the IR generate explicit code for the conversions in each direction (the `LoweredVal` representation can handle this sort of thing).
* Introduce an IR-level type system (#481)Tim Foley2018-04-11
| | | | | | | | | | | | | | | | | * Introduce an IR-level type system Up to this point, the Slang IR has used the front-end type system to represent types in the IR. As a result (but ultimately more importantly) the IR representation of generics and specialization has used AST-level concepts embedded in the IR. For example, to express the specialization of `vector<T,N>` to a concrete type `float` for `T`, we needed an IR operation that could represent the specialization, with operands that somehow represented the type argument `float`. The whole thing was very complicated. The big idea of this change is to introduce a new representation in which types in the IR are just ordinary instructions, so that using them as operands makes sense. The hierarchy of IR types closely mirrors the AST-side hierarchy for now, and that will probably be something we should maintain going forward. In order to make these changes work, though, I also had to do major overhauls of things like the way substitutions are performed, how we check interface conformances, the way lookup through interface types is done, etc. etc. This is a big change, and unfortunately any attempt to summarize it in the commit message wouldn't do it justice. * Fix 64-bit build warning * Fix up some clang warnings/errors
* Fix several issues discovered by Falcor (#467)Tim Foley2018-03-30
| | | | | | | | | | | | | Fixes #466 Most of these are Vulkan-related regressions. * Kludge the definition of `GroupMemoryBarrierWithGroupSync()` for GLSL so that it works around parentheses that the emit logic now introduces. * Don't emit `static` for global constants when targetting GLSL * Emit the `flat` modifier for varying input/output with integer type, when targetting GLSL * Avoid checking parameter default-value expressions more than once, because this can crash when the checking introduces syntax that is not expected to appear in the input AST
* Avoid crash when bad argument given to [instance(...)] attribute (#464)Tim Foley2018-03-29
| | | | | | | | | | | | | | | | Fixes #463 Some of the attributes were failing to check for a `null` result from `checkConstantIntVal`, and so they crashed when a bad expression was used in an attribute. The particular way this had been triggered was that a user put an HLSL geometry shader in the same file with other code, using an entry point like: ```hlsl [instance(COUNT)] void myGeometryShader(...) {...} ``` They then defined `COUNT` as a preprocessor macro when compiling using the GS, but left it undefined otherwise. The result was that the argument to the `instance` attribute would fail to type check, and thus wouldn't count as a constant integer value, so that `checkConstantIntVal` returns `null` and results in the crash. The workaround for the user is to always define `COUNT`, even when not compiling the GS. The fix in the compiler is to guard against `null` in these cases and bail out of attribute checking. I also implemented logic so that `CheckIntegerConstantExpression` (which is invoked by `checkConstantIntVal`) will not produce an additional error message if the underlying expression failed to type check. In this casem the user will get an `undefined identifier: COUNT` error message, and we don't need to waste their time by also telling them that this isn't a compile-time constant expression.
* Add support for default parameter values in IR codegen (#459)Tim Foley2018-03-29
| | | | | | | | | | | | | Fixes #61 When lowering from AST to IR, if a call site doesn't supply an argument expression for each of the parameters to the callee, then use the default value expressions (stored as the "initializer" of the parameter decl) for each omitted parameter. This relies on the front-end to have already checked the call site for validity. Along the way I also cleaned up some of the checking of parameter declarations so that it is more like the checking of ordinary variable declarations (although the code is not yet shared). I also cleaned out some dead cases in the lowering logic for when we don't actually have a declaration available for a callee (these would only matter if we supported functions as first-class values). I added a simple test case to confirm that call sites both with and without the optional parameter work as expected. The strategy in this change is extremely simplistic, and might only be appropriate for default parameter value expressions that are compile-time constants (which should be the 99% case). This may require a major overhaul if we decide to handle default parameter values differently (e.g., by generating extra functions to ensure that the separate compilation story is what we want). Another issue that could change a lot of this logic would be if we start to support by-name parameters at call sites, since we could no longer assume that the argument and parameter lists align one-to-one (with the argument list possibly being shorter). Any work to add more flexible argument passing conventions would need to build a suitable structure to map from arguments to parameters, or vice-versa.
* Unify all generic parameters, even if some mismatch (#454)Tim Foley2018-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | * Fix decl-ref printing to handling NULL pointers If the underlying decl, or its name is NULL, then use an empty string for the declaration name. This issue was found when debugging, but could bite non-debug cases too, if we ever try to print something like a generic type constraint, which has no name. * Unify all generic parameters, even if some mismatch Fixes #449 The front end tries to infer the right generic arguments to use at a call site using a sloppily implemented "unification" approach. The basic idea is that if you pass a `vector<float,3>` into a function that operates ona `vector<T,N>` where `T` and `N` are generic paameters, then the unification will try to unify `vector<float,3>` with `vector<T,N>` which will lead to it recursively unifying `float` with `T` and `3` with `N`, at which point we have viable values to substitute in for those parameters. Where the existing approach is maybe not quite right is in how it handles obvious unification failures. So if we ask the code to unify, say, `float` with `uint`, it will bail out immediately because those can't be unified. This sounds right superficially, but in some cases with might be calling a function that takes a `vector<float,N>` and passing a `vector<uint,3>` and we'd like to at least get far enough along with unification to see that `N` should be `3` so that the front end can maybe decide to call the function anyway, with some amount of implicit conversion. Over time I've had to modify a lot of the "unification" logic so that it doesn't treat the obvious failures as a hard stop, and instead just returns the failure as a boolean status, but keeps on trying to unify things even after such a failure. When doing unification as part of inference for generic arguments, there will usually be subsequent steps (e.g., type conversions for function aguments) that will catch the type errors that arise. This specific change is to make is so that when unifying the substitutions for a generic decl-ref, we try to unify all the pair-wise arguments, and don't bail out on the first mismatch (so that the `float`-vs-`uint` failure above doesn't lead to us skipping the `3` and `N` pairing). The one case we need to watch out for in all of this is when unification is used to check if an `extension` declaration (which might be generic) is actually application to a concrete type. In that case we obviously don't want an extension for `vector<float,N>` to apply to `vector<uint,3>`, so it is important that the extension case check the return status from the unification logic (*or* in the future, it could just confirm that the substituted type is equivalent to the original as a post-process...). I've added a test case that reproduces the original failure that surfaced the bug. * fixup: add expected test output
* Add support for DirectX Raytracing (DXR) (#451)Tim Foley2018-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | * Add support for DirectX Raytracing (DXR) This is an initial pass to add support to Slang for the shader stages introduced by DirectX Raytracing (DXR). * Add declarations for DXR intrinsic types and functions to the Slang standard library. The way our compilation works, these will then get propagated through the IR as intrinsics and get spit back out again as-is during HLSL code emission. * Declare the DXR-related stages. This is the main work that affects the compiler's C++ implementation rather than being something we can add via the standard library today. * Switch around the encoding of the `Profile` type so that the stage is in the low bits, allowing API users to pass an ordinary `SlangStage` to operations that expect a `SlangProfileID`. - This represents a direction I'd like to push in long term, where the user specifies stage and "feature level" separately rather than using composite profiles like `vs_6_0`. The introduction of these new stages seems like a good point to try and make a clean break here and not introduce, e.g., `rgs_6_1` for ray generatin shaders. * Upgrade "effective profile" computation so that it advances the required version based on the specified stage (e.g., DXR stages seem to require at least shader model 6.1). - This is a bit of a kludge overall, but ideally we don't want a typical user to have to think about "feature level" stuff much at all. The ideal workflow is that they just hand us a source file and we work out entry points and their required feature levels in the compiler (and let the user query it when we are done). Until we implement that for real, stopgaps like this are required. Overall these are relatively small changes for supporting some major new API behavior. Slang's design helps out here, by allowing a lot of things to be specified in the stdlib (including generic intrinsic functions), but some of this is also owed to the DXIL-influenced design of DXR - e.g., the use of global functions in place of `SV_*` semantics. * fixup: typos * Fixup: use `pixel` instead of `fragment` as primary stage name This is to match HLSL conventions when generating output code, even if the Slang project officially favors the more correct term "fragment shader."
* Entry point attribute (#447)Tim Foley2018-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Typo * Add [shader(...)] and clean up some literal handling * Add supporting for validating the `[shader(...)]` attribute, by checking that its argument is a string literal that names a known shader stage. * Split the `ConstantExpr` class into distinct subclasses rooted at `LiteralExpr`, so we have `BoolLiteralExpr`, `IntegerLiteralExpr`, `FloatingPointLiteralExpr`, and `StringLiteralExpr` * Add a `String` type to the stdlib, to be used as the type of a string literal. This change allows code using `[shader(...)]` to be accepted by the front-end again, but it does nothing about emitting it in final HLSL. * Allow entry points to be specified via [shader(...)] Before this change, the compiler would track a list of `EntryPointRequest` objects, based on what the suer specified via API and/or command-line options. Each entry point request would get matched up with an AST `FuncDecl` as part of semantic checking, and then the back end steps (layout, codegen, etc.) would work from that information. This change makes the compiler modal, in that it can *either* continue to use an explicit list of entry point requests (this is the mode when the list is non-empty), or it can rely on user-supplied attributes on entry point functions to drive codegen (this is the mode when the list is empty). User-specified `[shader(...)]` attributes are processed at the same place where the association from `EntryPointRequest`s to `FuncDecl`s would otherwise be made, and basically does the same thing in the opposite direction: looks for `FuncDecl`s with the appropriate attribute and synthesizes an `EntryPointRequest` for them. Subsequent processing should ideally not know where a given `EntryPointRequest` came from, and should handle both methods of specifying the entry points equivalently. One design choice that might not make immediate sense is that we do *not* process a function as an entry point (applying further validation, etc.) just because it has a `[shader(...)]` modifier, unless we are in the appropriate mode (which in this case is the mode where the user didn't specify their own entry points via API or command line). This is to handle cases where the user wants to explicitly compile only one entry point, so that they (1) don't want us to spend time validating code they don't care about, (2) don't want do get output they don't expect, and (3) might actually be presenting us with code that violates the language rules due to a combination of `#define`s in effect (e.g., they might have a `[shader("vertex")]` function that transitively executes a `discard` because of how the preprocessor was configured, but they don't care because they are compiling a fragment entry point). This decision might be something we revisit over time. As part of this work, I had to add some logic to pick a "profile version" to use for a combination of a target and stage (because when you specify `[shader("vertex")]` the compiler can't tell if you want `vs_5_0`, `vs_5_1`, etc.). This isn't really complete right now, because something like `-target dxbc` *also* doesn't determine a profile, so there is a bit of a kludge at present. We need to figure out a good long-term plan here, which might involve keeping target format, feature level/version, and pipeline stage as truly orthogonal concepts, rather than conflating them. That would involve more work in the API and command-line layers to de-compose things when the user specifies, e.g., `vs_5_1`, but might make downstream logic easier to manage. * Emit [shader(...)] attribute on entry point for SM 6.1 and later This should help ensure that the output from Slang can be compiled with dxc `lib_*` profiles. * Fix warning
* Overhaul implementation of [attributes] (#443)Tim Foley2018-03-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing code parsed all of the square-bracket `[attributes]` into `HLSLUncheckedAttribute`, and then went on to hand-convert some of them to specialized subclasses of `HLSLAttribute`. When attributes didn't check, they were left as-is, and no error message was issued, because at the time the compiler was focused on accepting arbitrary input. This change greatly overhauls the handling of `[attributes]`. Attributes are now declared in the stdlib, with declarations like: ```hlsl __attributeTarget(LoopStmt) attribute_syntax [unroll(count: int = 0)] : UnrollAttribute; ``` In this syntax, the `unroll` part is giving the attribute name (the `[]` are just for flavor, to make the declaration look like a use site; we could drop it if we don't like the clutter), the `count` is a parameter of the attribute, which we expect to be of type `int`, and which has a default value of `0` if unspecified. The `: UnrollAttribute` part specifies the meta-level C++ class that will implement this attribute (and corresponds to a class in `modifier-defs.h`). This syntax is similar to our current `syntax` declarations. I'm starting to think we should change it to something like a `__meta_class(UnrollAttribute)` modifier, and then use that uniformly across all cases (e.g., also replacing the curreent `__magic_type(Foo)` syntax). The `__attributeTarget(LoopStmt)` is a modifier that specifies the meta-level C++ class for syntax that this attribute is allowed to attach to. It is legal to have more than one of these. Attributes continue to be parsed in an unchecked form, so that we don't tie up semantic analysis and parsing more than necessary. During checking, we look up the attribute name in the current scope, and then replace the unchecked attribute with a more specific one *if* the checking passes. Checking proceeds in generic and attribute-specific phases. The generic phase includes checking the number of arguments against those specified in the attribute declaration (I don't currently check types, or handle default arguments), and then checking that at least one `__attributeTarget(...)` modifier applies to the syntax node being modified. The attribute-specific phase then applies to the specialized C++ subclass of `Attribute`, and does the actual checking right now (e.g., that step is responsible for actually type-checking things at present). This can obviously be improved over time. With this support I went ahead and added declarations for all the HLSL attributes I could find documented on MSDN. I also added a provisional declaration for the `[shader(...)]` attribute that has been added to dxc, but which is not yet documented. One important detail here is that lookup of attribute names needs to be done carefully, so that we don't let, e.g., local variables shadow an attribute declaration: ```hlsl int unroll = 5; // This attribute should *not* get confused by the local variable `unroll` [unroll] for(...) { .. } ``` The lookup logic already has a notion of a `LookupMask` that can be used to filter declarations out of the result. In this change I surfaced that mask through the main lookup API (rather than requiring a second pass to "refine" lookup results), and made is so that the default lookup mask does *not* include attributes, while an explicit mask can be used to look up *only* attributes. (An alternatie design we discussed was to follow the approach of C# and have the declaration of an attribute like `[unroll]` actually be `unrollAttribute`, with a suffix. I decided not to follow that approach for now because it seemed like printing good error messages in that case could require us to carefully trim the `Attribute` suffix off of names at times, and using the existing mask behavior seemed simpler.) To verify that the shadowing behavior is indeed correct, I modified the `loop-unroll.slang` test case. Smaller notes: * Removed the `HLSL` prefix from several of the C++ attribute classes * Made sure to actually validate the modifiers on statements * Special-cased checking for `ParamDecl` with a null type, because I'm re-using `ParamDecl` for attribute parameters, but can't give a concrete type to some of them right now * Deleting some old, dead emit-from-AST logic around attributes, rather than try to "fix" code that doesn't run (a more complete scrub of that code is still needed) * Fixed AST inheritance hierarchy so that a `Modifier` is a `SyntaxNode` rather than a `SyntaxNodeBase`. I have *no* idea why we have both of those, and we need to clean that up soon.
* Add a case to `TryUnifyVals` to cover `SubtypeWitness` vals (#435)Yong He2018-03-06
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* Falcor fixes (#402)Tim Foley2018-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Re-define deprecated compile flags By including these flags in the header file, with a value of zero, we can allow some existing code to compile even after the major changes to the implementation. * The `SLANG_COMPILE_FLAG_NO_CHECKING` option will effectively be ignored, since checking is always enabled. * The `SLANG_COMPILE_FLAG_SPLIT_MIXED_TYPES` option will now act as if it is always enabled (and indeed some of the code has been relying on this flag being set always). * Make subscript operators writable for writable textures This even had a `TODO` comment saying that we needed to fix it, and now I'm seeing semantic checking failures because we didn't define these and so we find assignment to non l-values. * Fix definitions of any() and all() intrinsics These should always return a scalar `bool` value, but they were being defined wrong in two ways: 1. They were using their generic type parameter `T` in the return type 2. They were returning a vector in the vector case, and a matrix in the matrix case. This change just alters the return type to be `bool` in all cases. * Fix bug in SSA construction When eliminating a trivial phi node, it is possible that the phi is still recorded as the "latest" value for a local variable in its block. When later code queries that value from the block (which can happen whenever another block looks up a variable in its predecessors), it would get the old phi and not the replacement value. I simply added a loop that checks if the value we look up is a phi that got replaced, and then continues with the replacement value (which might itself be a phi...). A more advanced solution might try to get clever and have the map itself hold `IRUse` values so that we can replace them seamlessly. * Simplify IR control flow representation This change gets rid of various special-case operations for conditional and unconditional branches, and instead requires emit logic to recognize when a direct branch is targetting a `break` or `continue` label. The new approach here isn't perfect, but it seems beter than what we had before, because it can actually work in the presence of control-flow optimizations (including our current critical-edge-splitting step). * Load from groupshared isn't groupshared When loading from a `groupshared` variable, the resulting temporary shouldn't have the `groupshared` qualifier on it. This might eventually need to generalize to a better understanding of storage modifiers in the IR, but I don't really want to deal with that right now. * Don't emit references to typedefs in output code Now that we are using the IR for all codegen, we shouldn't be dealing with surface-level things like `typedef` declarations in the output code; just use the type that was being referred to in the first place. * Fix floating-point literal printing for IR The IR was calling `emit()` instead of `Emit()` (we really need to normalize our convention here), and was implicitly invoking a default constructor on `String` that takes a `double` (that constructor should really be marked `explicit`), and which doesn't meet our requirements for printing floating-point values. * Fix error when importing module that doesn't parse We already added a case to bail out if semantic checking fails, but neglected to add a case if there is an error during parsing of a module to be imported. Note: this logic doesn't correctly register the module as being loaded (but still in error), so users could see multiple error messages if there are multiple `import`s for the same module. * Improve error message for overload resolution failure - Drop debugging info from the candidate printing - Add cases to print `double` and `half` types properly * Fixup: switch loopTest to ifElse in expected IR output
* Remove support for the -no-checking flag (#392)Tim Foley2018-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Remove support for the -no-checking flag Fixes #381 Fixes #383 Work on #382 - No longer expose flag through API (`SLANG_COMPILE_FLAG_NO_CHECKING`) and command-line (`-no-checking`) options - Remove all logic in `check.cpp` that was withholding diagnostics (including errors) when the no-checking mode was enabled - Remove `HiddenImplicitCastExpr`, which was only created to support no-checking mode (it represented an implicit cast that our checking through was needed, but couldn't emit because it might be wrong) - Remove logic for storing function bodies as raw token lists when checking is turned off. I'm leaving in the `UnparsedStmt` AST node in case we ever need/want to lazily parse and check function bodies down the line. - Remove a few of the code-generation paths we had to contend with, but keep the comment about them in place. - Remove GLSL-based tests that can't meaningfully work with the new approach. - Fix other tests that used a GLSL baseline so that their GLSL compiles with `-pass-through glslang` instead of invoking `slang` with the `-no-checking` flag. - Remove tests that were explicitly added to test the "rewriter + IR" path, since that is no longer supported. There is more cleanup that can be done here, now that we know that AST-based rewrite and IR will never co-exist, but it is probably easier to deal with that as part of removing the AST-based rewrite path. We've lost some test coverage here, but actually not too much if we consider that we are dropping GLSL input anyway. * Fixup: test runner was mis-counting ignored tests * Fixup: turn on dumping on test failure under Travis * Fixup: enable extensions in Linux build of glslang
* Fix some crashing bugs around local variable declarations. (#385)Tim Foley2018-01-26
| | | | | | | | | | | | | | | | | | | | | The basic problem here arises when a local variable is used either before its own declaration: ```hlsl int a = b; ... int b = 0; ``` or when a local variable is used *in* its own decalration: ```hlsl int b = b; ``` In each case, Slang considers the scope of the `{}`-enclosed function body (or nested statement) as a whole, and so the lookup can "see" the declaration even if it is later in the same function. This behavior isn't really correct for HLSL semantics, so the right long-term fix is to change our scoping rules, but for now users really just want the compiler to not crash on code like this, and give an error message that points at the issue. This change makes both of the above examples print an error message saying that variable `b` was used before its declaration, which is accurate to the way that Slang is interpreting those code examples. This is currently treated as a fatal error, so that compilation aborts right away, to avoid all of the downstream crashes that these cases were causing.
* Trying to get generic extensions to workTim Foley2018-01-21
| | | | | | - Don't drop specializations on a method when adding it to requirement dictionary - Handle extension declarations under a generic when emitting to IR
* Improvements and bug fixes for global type parametersYong He2018-01-21
| | | | | | 1. allow spReflection_FindTypeByName to accept arbitrary type expression string 2. allow const int generic value to be used as expression value, and as array size 3. various bug fixes in witness table specialization / function cloning during specializeIRForEntryPoint to avoid creating duplicate global values, not copying the right definition of a function from the other module, not cloning witness tables that are required by specializeGenerics etc.
* bug fixesYong He2018-01-20
| | | | | fixes #373 fixes bug that misses current translation unit's scope when resolving entry-point global type argument expression.
* Allow arbitrary type string as type argument in spAddEntryPointEx.Yong He2018-01-19
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* All compiler fixes to get ir branch work with falcor feature demo.Yong He2018-01-17
| | | | | | | | | - support overloaded generic function. this involves adding a new expression type, `OverloadedExpr2` to hold the candidate expressions for the generic function decl being referenced. - make BitNot a normal IROp instead of an IRPseudoOp - make sure we clone the decorations of parameters when cloning ir functions - propagate geometry shader entry point attributes (`[maxvertexcount]` and `[instance]`) through HLSL emit - IR emit: handle geometry shader entry-point parameter decorations, such as 'triangle'. - IR emit: treat geometry shader stream output typed ir value as `should fold into use`.
* bug fixes to get falcor example shader code to compile.Yong He2018-01-16
| | | | | 1. prevent cyclic lookups when an interface inherits transitively from itself. 2. in `createGlobalGenericParamSubstitution`, create a default substitution for the base type declref before using it to lookup the witness table.
* Allow extension on interface (#369)Yong He2018-01-16
| | | | | | | This completes item 5 in issue #361. The interesting change is that when checking for interface conformance, we include the requirements (include transitive interfaces) defined in extensions as well. (check.cpp line 1946) All the other changes are for one thing: reoder the semantic checkings to two explicit stages: check header and check body. In check header phase, we check everything except function bodies, register all extensions with their target decls, then check interface conformances for all concrete types. In body checking phase, we look inside the function bodies and check concrete statements/expressions. This change ensures that we take extension into consideration in all places where it should be.
* temporary workaround to fix test case failures.Yong He2018-01-14
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* allow extension of a concrete type to implement additional interfaceYong He2018-01-14
| | | | Also support the scenario that the extension declares conformance to interface I, and a method M in I is already supported by the base implementation.
* Fix creation of `ThisTypeSubstitution`.Yong He2018-01-13
| | | | `createDefaultSubstitutions` now responsible for creating a `ThisTypeSubstitution` when `decl` is an `InterfaceDecl`. This is to ensure a reference to an associated type decl from the same interface that defines the assoctype decl will get a `ThisTypeSubstitution` so that the right hand side of it can be replaced by future substitutions.
* Support nested genericsYong He2018-01-12
| | | | fixes #362