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* Initial sizeof/alignof implementation. (#2954)jsmall-nvidia2023-07-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Initial sizeof implementation. * Small macro improvement. * Fix some typos. * Refactor NaturalSize. Add more sizeof tests. * Use _makeParseExpr to add sizeof support. * Add size-of.slang diagnostic result. * Fix typo in folding with macro change. * Add a sizeof test of This. * Some more NaturalSize coverage. * Simple alignof support. * Testing for alignof. * Added 8 bit enum to check enums values are correctly sized. * Add alignof to completion. * Lower sizeof/alignof to IR. sizeof/alignof IR pass. Tests for simple generic scenarios. * Make append handle invalid properly. Improve comments. --------- Co-authored-by: Theresa Foley <10618364+tangent-vector@users.noreply.github.com>
* Warn on semicolon after `if`. (#2948)Yong He2023-06-29
| | | | | | | | | * Warn on semicolon after `if`. * add test result --------- Co-authored-by: Yong He <yhe@nvidia.com>
* Multiple cast issue fix (#2940)jsmall-nvidia2023-06-26
| | | | | | | | | | | | | * Small fixes and improvements around reflection tool. * Make PrettyWriter printing a class. * WIP parens casting issue. * Fix issue with multiple casts. * Match previous location point for casting, with 'fast' path. * Removed logic to output the found decl, as not needed to construct ExplicitCastExpr.
* Allow multiple attributes to not require separating comma (#2939)jsmall-nvidia2023-06-22
| | | | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * Small fixes and improvements around reflection tool. * Make PrettyWriter printing a class. * Allow attributes without comma separation.
* Fix for generic with scope issue (#2925)jsmall-nvidia2023-06-20
| | | | | | | | | | | | | | | | | * Small fixes and improvements around reflection tool. * Make PrettyWriter printing a class. * Sundary improvements around StringBlob. * Fix for generic scope issue. * Fix expected output. * Add scope-generic test. --------- Co-authored-by: Theresa Foley <10618364+tangent-vector@users.noreply.github.com>
* Add finalized keywords for autodiff. (#2882)Yong He2023-05-12
| | | Co-authored-by: Yong He <yhe@nvidia.com>
* MVP for higher order functions (#2849)Ellie Hermaszewska2023-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * MVP for higher order functions * Add shader subgroup partitioned glsl intrinsics * Implement parsing and checking for tuple types Currently there is no way to do anything useful with them from the source language however * neaten * Correct precedence of function type parsing * neaten * higher order function tests * function types of any arity * Inference for higher order functions * Add second test for unsynchronized params * regenerate vs projects * dx11 -> dx12 for saturated cooperations tests * Disable saturated cooperation tests on vulkan They fail on release builds in CI, not essential for the higher order function work however * remove saturated-cooperation tests * Remove unnecessary assert and clarify control flow in AddDeclRefOverloadCandidates * Add Tuple type name mangling * Use functype keyword to introduce function types * Add more inference tests for hof --------- Co-authored-by: Yong He <yonghe@outlook.com>
* Various dxc/fxc compatibility fixes. (#2863)Yong He2023-05-02
| | | | | | | | | | | | | * Various dxc/fxc compatibility fixes. * Cleanup. * Fix test cases. * Fix comments. --------- Co-authored-by: Yong He <yhe@nvidia.com>
* Fix most of the disabled warnings on gcc/clang (#2839)Ellie Hermaszewska2023-04-26
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* StringBuilder to lowerCamel (#2840)jsmall-nvidia2023-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * WIP lowerCamel Dictionary. * WIP more lowerCamel fixes for Dictionary. * Add/Remove/Clear * GetValue/Contains * Fix tabs in dictionary. Count -> getCount * Fix fields with caps. * Key -> key Value -> value Use m_ for members where appropriate. Use lowerCamel in linked list. * Some small fixes/improvements to Dictionary. * Kick CI. * Small tidy on String. * Append -> append * ToString -> toString ProduceString -> produceString * Small fixes. * StringToXXX -> stringToXXX * Fix typo introduced by Append -> append. * Made intToAscii do reversal at the end. --------- Co-authored-by: Yong He <yonghe@outlook.com>
* Dictionary using lowerCamel (#2835)jsmall-nvidia2023-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * WIP lowerCamel Dictionary. * WIP more lowerCamel fixes for Dictionary. * Add/Remove/Clear * GetValue/Contains * Fix tabs in dictionary. Count -> getCount * Fix fields with caps. * Key -> key Value -> value Use m_ for members where appropriate. Use lowerCamel in linked list. * Some small fixes/improvements to Dictionary. * Kick CI.
* Warn on float-to-double coercion for arguments. (#2802)Yong He2023-04-13
| | | | | | | | | | | | | * Warn on float-to-double coercion for arguments. * Fix test. * Rename. * Fixup. --------- Co-authored-by: Yong He <yhe@nvidia.com>
* Add PyTorch C++ binding generation. (#2734)Yong He2023-03-26
| | | | | | | | | * Add PyTorch C++ binding generation. * fix --------- Co-authored-by: Yong He <yhe@nvidia.com>
* Add support for emitting cuda kernel and host functions. (#2712)Yong He2023-03-17
| | | | | | | | | | | * Add support for emitting cuda kernel and host functions. * Update test. * Fix cuda preamble emit. --------- Co-authored-by: Yong He <yhe@nvidia.com>
* Add transposition logic for constructor opcodes. (#2618)Yong He2023-01-30
| | | | | | | | | | | * Add transposition logic for constructor opcodes. * Fix. * Add language server regression test. --------- Co-authored-by: Yong He <yhe@nvidia.com>
* Allow `no_diff` modifier on parameters (#2538)Yong He2022-11-29
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* Improve parser recovery around invalid function definitions. (#2525)Yong He2022-11-21
| | | | | | | | | | | * Improve parser recovery around invalid function definitions. * Fix. * Clean up. * Clean up. Co-authored-by: Yong He <yhe@nvidia.com>
* Data flow validation pass for diagnosing derivative loss. (#2523)Yong He2022-11-18
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* Mesh shader support (#2464)Ellie Hermaszewska2022-11-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Add gdb generated files to .gitignore * Switch to c++17 TODO: Ellie update coding style doc * WIP mesh shaders * Add MeshOutputType and mesh output decorations * Lift array type layout creation out of _createTypeLayout in preparation for sharing it elsewhere * Initial pass at GLSL legalization for mesh shaders * Create output types for builtin mesh outputs This should be rendered as an out paramter block * Handle writes to member fields in mesh shader output * Per primitive output from mesh shaders * Add mesh shader tests * Redeclare mesh output builtins * Remove unused instruction * Emit explicit mesh output max max size * Add unimplemented warning for array members in mesh output * Implement mesh output splitting for GLSL in terms of getSubscriptVal * Allow HLSL syntax for mesh output modifiers * Improve error messages for mesh output * Add test for HLSL style mesh output syntax * Emit explicit mesh output indices max size * HLSL generation support for mesh shaders * Better errors for mesh shader misuse * Neaten comments * Regenerate vs2019 project files * Fix build on vs2019 * Retreat on c++17 Will make the change in a separate PR * slang-glslang binary dep 11.10.0 -> 11.12.0-32 * Fixes for msvc compiler * Update msvc project
* Minimum binary arithmetic reverse autodiff working. (#2514)Edward Liu2022-11-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | * Initial plumbing of backward autodiff in the frontend. * More plumbing. * Initial reverse autodiff working. * Bug fixes. * Misc. * Remove redundant code. * More clean up. * Misc. * Rebase and add backward diff test. * Disable test. * Clean up. * Minor fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Higher order differentiation. (#2487)Yong He2022-11-04
| | | Co-authored-by: Yong He <yhe@nvidia.com>
* Make `DifferentialPair` able to nest. (#2477)Yong He2022-11-01
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* Rename `__jvp`-->`__fwd_diff`. (#2471)Yong He2022-10-27
| | | Co-authored-by: Yong He <yhe@nvidia.com>
* Auto synthesis of Differential type (#2466)Yong He2022-10-26
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* Add syntax for multi-level break. (#2431)Yong He2022-10-06
| | | | | | | | | * Add syntax for multi-level break. * Fix. * Fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Language feature: pointer sized int types. (#2401)Yong He2022-09-15
| | | | | | | | | | | | | | | | | | | | | * Language feature: pointer sized int types. * Fix. * small change to test. * Fix stdlib. * Fix. * Fix. * Add typedef for `size_t` in stdlib. * Fix test. * Add `intptr_t::size` constant. Co-authored-by: Yong He <yhe@nvidia.com>
* Multi parameter `__subscript` (#2392)Yong He2022-09-05
| | | | | | | | | | | * Multi parameter `__subscript` * Fix. * Fix bugs. * Fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Compiler time evaluation of all int and bool operators. (#2376)Yong He2022-08-24
| | | | | | | | | * Compiler time evaluation of all int and bool operators. * Fix linux compile error. * Fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Fix logic of `is` operator. (#2359)Yong He2022-08-12
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* Add `none` literal that is convertible to `Optional`. (#2356)Yong He2022-08-10
| | | | | | | | | | | * Add `none` literal that is convertible to `Optional`. * Fix cpu code gen. * Include vk and cpu test for is-as operator test. * Inline comparison operators. Co-authored-by: Yong He <yhe@nvidia.com>
* `is` and `as` operator and `Optional<T>`. (#2355)Yong He2022-08-10
| | | | | | | * `is` and `as` operator and `Optional<T>`. * Fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Language server pointer type support + add `DLLImport` test (#2350)Yong He2022-08-10
| | | | | | | | | | | | | | | | | | | * Language server pointer type support. + Natvis for AST. * Add completion suggestion for GUID. * Make executable test able to use slang-rt. * Fix gcc argument for rpath. * Fix DLLImport on linux. * Fix windows. * Fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Basic pointer usages. (#2342)Yong He2022-08-03
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* Support `class` types. (#2321)Yong He2022-07-12
| | | | | | | | | * Support `class` types. * Ignore class-keyword test * Fix codereview comments and warnings. Co-authored-by: Yong He <yhe@nvidia.com>
* Language server fixes and improvements (#2304)Yong He2022-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | * Language server: Inlay hints. * Signature help for base exprs that is not a declref. * Fix checking of jvp operator. * Fix. * Add clang-format based auto formatting. * Fix clang error. * Fix clang-format discovery logic. * Fine tune auto formatting and completion experience. * Update macos workflow. * Fixes to configurations. * Fix parser recovery to trigger completion for index exprs. * Typo fix. Co-authored-by: Yong He <yhe@nvidia.com>
* Added basic auto-diff capabilities for local load/store and simple ↵Sai Praveen Bangaru2022-06-25
| | | | | | | | | | | arithmetic. Also added type-checking during the semantic stage. (#2303) * Added JVPTranscriber to handle differentiation of load, store, var, param and return instructions, as well as conversion of data and function types * Changed class names to be more in line with convention. Added correct type checking for __jvp() and verified that simple calls with only loads and stores are processed correctly * Added logic to differentiate basic arithmetic and literals inside IRConstruct and fixed the way parameters are differentiated Co-authored-by: Yong He <yonghe@outlook.com>
* Added basic syntax to mark and request function derivatives, as well as the ↵Sai Praveen Bangaru2022-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | framework for passes to process them. (#2297) * Added a decorator to mark functions for forward-mode differentiation * Fill out support for calls to non-decl values The existing compiler logic has a few places (semantic checking plus AST-to-IR lowering) where it assumes that function calls (`InvokeExpr`) are only ever made to expressions that resolve to a specific `Decl` (`DeclRefExpr`). This assumption allows semantic checking and lowering code to inspect things like the parameter list of an actual declaration, rather than just the type signature of the callee, and that infrastructure is used to support various features (e.g., default argument values on parameters). The AST and IR representations themselves have no matching requirement, and the places where the more general case of call expressions would need to be supported were relatively clear in the code. This change attempts to add suitable logic into each of those places. Note that this change does *not* surface any valid way to form input code that would cause these new code paths to be executed, so it is entirely possible that there are bugs in the logic as written here. The primary goal of this change is simply to get a sketch of the correct code checked in so that we have something to build on once we have language features that will require this support. * fixup: warnings-as-errors * Added parser logic for '__jvp(<fn-name>)' operator * Fixed issue with missing overload candidate item and added basic parsing test for the __jvp syntax * Added a blank JVP Auto-diff pass and a pass that replaces 'JVPDerivativeOf' calls with the differentiated function * Added a couple comments * Added parameter handling for the JVP pass Co-authored-by: Theresa Foley <tfoley@nvidia.com>
* More Language Server Improvements. (#2289)Yong He2022-06-22
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* Language server: document symbols (#2287)Yong He2022-06-16
| | | | | | | * Language Server: Document Symbol outline. * Fix highlighting of extension decls. Co-authored-by: Yong He <yhe@nvidia.com>
* Follow up on Language Server Improvement (#2275)Yong He2022-06-13
| | | | | | | * Fix typo and improve parser recovery. * Add search path configuration. Co-authored-by: Yong He <yhe@nvidia.com>
* Language Server improvements. (#2269)Yong He2022-06-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Language Server improvements. - Improve parser robustness around `attribute_syntax`. - Exclude instance members in a static query. - Coloring accessors - Improved signature help cursor range check. * Add expected test result. * Language server: support configuring predefined macros. * Fix constructor highlighting. * Improving performance by supporting incremental text change notifications. * Fix UTF16 positions and highlighting of constructor calls. * Add completion suggestions for HLSL semantics. * Fix tests. * Fix: don't skip static variables in a static query. * Include literal init expr value in hover text. * Fix scenarios where completion failed to trigger. * Fixing language server protocol field initializations. Co-authored-by: Yong He <yhe@nvidia.com>
* Actual global support (#2262)jsmall-nvidia2022-06-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * Use TerminatedUnownedStringSlice for literals in output C++. * Remove Escape/Unescape functions used in slang-token-reader.cpp Add target type of 'host-cpp' etc to map to the target types. * Fix some corner cases around string encoding. * Added unit test for string escaping. Fixed some assorted escaping bugs. * Updated test output. * Added decode test. * Stop using hex output, to get around 'greedy' aspect. Use octal instead. * Added HostHostCallable Small changes to use ArtifactDesc/Info instead of large switches. * Fix C++ emit to handle arbitrary function export. * Add options handling for callable without an output being specified. * Can compile with COM interface. Added example using com interface. * Use the IR Ptr type instead of hack in C++ emit for interfaces. * Fix issue with outputting the COM call when ptr is used. * Fix crash issue on compilation failure. * Add support for __global. * Added `ActualGlobalRate` Added special handling around globals and COM interfaces. Tested out in cpu-com-example. * Fix typo in NodeBase. * Support for accessing globals by name working. * Check that actual global initialization is working. * Refactor the com replacement such that it doesn't need a cache or do anything special with GlobalVar. * Remove context. Only create replacement if needed. * Split out COM host-callable into a unit-test. * host-callable com testing on C++and llvm. * Comment around the COM ptr replacement. * Disable com test on vs 32 bit. Fix C++ prelude * Disable 32 bit targets testing com host-callable. * Use JSON parsing to locate VS version. * Need platform detection in C++prelude. * Fix com host callable test for LLVM. * Work around for not being able to include "targetConditionals.h"
* Major language server features. (#2264)Yong He2022-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Major language server features. * Include slangd in binary release. * Fix compiler issues. * Fix compiler error. * Completion resolve. * Various improvements. * Update diagnostic test expected output. * Bug fix for source locations. * Adjust diagnostic update frequency. * Update github actions to store artifacts. * Fix infinite parser loop. * Fix parser recovery. * Fix parser recovery. * Update test. * Fix test. * Disable IR gen for language server. * Allow commit characters in auto completion. * Fix lookup for invoke exprs. * More parser robustness fixes. * update solution file Co-authored-by: Yong He <yhe@nvidia.com>
* New language feature: basic error handling. (#2253)Yong He2022-06-01
| | | | | | | | | * New language feature: basic error handling. * Fix. * Fix `tryCall` encoding according to code review. Co-authored-by: Yong He <yhe@nvidia.com>
* Support for HLSL `export` (#2223)jsmall-nvidia2022-05-05
| | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * Add support for HLSL `export`. * Test for using `export` keyword.
* Fix errors when building with the latest Xcode (#2215)Vincent Isambart2022-04-28
| | | | | | | * Fix errors when building with the latest Xcode * Bring back unused variable to better match comments Co-authored-by: jsmall-nvidia <jsmall@nvidia.com>
* Disable `class` keyword to define a new type (#2212)jsmall-nvidia2022-04-28
| | | | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * Disable class keyword. * Add class keyword test. * Fix test diagnostic.
* Support `[DllImport]` (#2181)Yong He2022-04-12
| | | | | | | | | | | | | | | | | * Support `[DllImport]` * Fix. * Fix. * Fix array type emit in cpp. * Fix. * Fix. * Fix Co-authored-by: Yong He <yhe@nvidia.com>
* Fix issue with multiple namespace openings (#2176)jsmall-nvidia2022-04-05
| | | | | | | * #include an absolute path didn't work - because paths were taken to always be relative. * Added sample-grad-clamp-lod sample. * Fix handling multiple reopenings of namespaces.
* Add support for HLSL unorm/snorm (#2095)Theresa Foley2022-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Read/write resource types (what D3D/HLSL often refer to as UAVs) can be broadly categorized based on whether they require an underlying format (e.g., a `DXGI_FORMAT`) for reads, or not. D3D refers to the ones that require a format as "typed" UAVs (even though a `RWStructuredBuffer<MyData>` is clearly "typed" at the HLSL level). Vulkan refers to these cases as "storage images" and "storage texel buffers." Under the D3D model, an application does not have to specify the exact format for a formatted/"typed" UAV in order for loads to work, but it *does* need to specify if an HLSL resource with a declared `float` or vector-of-`float` element type will be backed by data with a `*_UNORM` or `*_SNORM` format. This is where the `unorm` and `snorm` type modifiers come in. Superficially, it might seem that adding this feature to the Slang compiler is "just" a matter of adding the two modifiers, which is easily done with a pair of one-line `syntax` declarations in `core.meta.slang` plus the corresponding AST node types. Unfortunately the superficial view misses the detail that, to date, Slang has not had any support for *type modifiers* at all, and has only supported *declaration modifiers*. The distinction has so far not mattered, even with modifiers like `const` because, e.g., the difference between a "`const` array of `float`" and an "array of `const float`" doesn't really matter. So, adding these two modifiers required introducing a lot of infrastructure along the way. Let's walk through what needed to happen: * As described above, the actual `syntax` was added easily in the Slang stdlib * I added a new subclass of `Modifier` for `TypeModifier`s in the AST, and added the AST nodes for `unorm` and `snorm` as subclasses of that. * In order to syntactically support modifiers applied to types (e.g., `unorm float`), I needed to add a `ModifiedTypeExpr` subclass of `Expr` that represents a base type expression with one or more modifiers applied * The parser needed some subtle new logic. There are two main cases where type modifiers will come up: 1. In contexts where we might be parsing a declaration (e.g., `const unorm float a`), we need to support a list of modifiers that might freely mix type modifiers and "declaration modifiers" which are not intended to apply to types. In this case we need to split the lis tof modifiers into the type-related ones and the declaration-related ones, and attach each subset to the appropriate place. This is very important for features like C-style pointers, where in `static const float* a;`, the `static` modifier applies to the entire declaration of `a`, but the `const` modifier *only* applies to the `float` type specifier, and *not* to the outer pointer type (the actual type of `a`). 2. In contexts where we are not parsing a declaration (e.g., a generic type argument), we need to support a list of modifiers and appy them *all* to the type specifier being parsed, even if some of them might not be appropriate. * While working in the parser I implemented a certain amount of unrelated cleanup for code that was using raw `Modifier*`s to represent lists of modifiers, instead of the purpose-built `Modifiers` type. * The `_parseGenericArg` case needed specific work, because it is an important case in the grammar where we need to parse *either* a type expression or a value exprssion, but cannot easily predict which we will see. The fix implemented for now is to always try to parse modifiers and, if we see any, to assume we are in the type case. Because of the rules for how modifiers in a C-like language inhere to the type specifier (and not necessarily the entire type), we need to refactor some of the type expression parsing routines to support parsing a "suffix" of a type expression. * Note: I decided to be conservative and only make these changes in `_parseGenericArg` because that is place that is *needed* in order for user code with `unorm`/`snorm` to work, but in practice a user could still confuse our parser by using type modifiers as part of a cast (e.g., `x = (unorm float)y;`). While there is currently no reason why a user should want to do this, it *does* suggest that we need to be prepared to see type modifiers in other ambiguous "expression or type?" contexts. We have so far preferred to avoid looking up built-in syntax declarations like modifiers in expression contexts, because we want to allow users to create variable names that might conflict with some of the more surprising modifier keywords in HLSL (e.g., both `triangle` and `sample` are modifier keyword). A nuanced strategy may be required when we get around to closing this gap (which will be needed around when we want full pointer support, since a cast like `(const SomeType*)somePtr` is pretty common). * In semantic checking, we now need a `visitModifiedTypeExpr`, which visits the base expression to produce a `Type` and then checks each of the `Modifier`s attached to it. During this process we need to translate the AST-level `Modifier`s into something that can exist properly in the universe of `Type`s. We introduce a `ModifiedType` subclass of `Type`, distinct from the `ModifiedTypeExpr` subclass of `Expr`. Furthermore, we introduce a `ModifierVal` subclass of `Val`, distinct from `Modifier`/`TypeModifier`. * One unfortunate thing here is that it means we have both, e.g., `UNormModifier` to represent the parsed syntax, and `UNormModifierVal` to represent the `Type`/`Val`-level representation of the same concept. It is quite likely that we are near the point where we can/should consider having two distinct AST representations: one for freshly-parsed ASTs and one for semantically-checked ASTs. The `Type`/`Val` hierarchy clearly belongs to the latter. * No actual semantic checking is currently being applied to the `unorm` and `snorm` modifiers, although we should in principle check that they are only being applied to `float` and vector-of-`float` types. * In an attempt to simplify some of the creation logic and build a tiny bit of reusable infrastructure, I went ahead and added the skeleton of a dedupe-caching system in `ASTBuilder` so that we can easily ensure only a single `UNormModifierVal` and a single `SNormModifierVal` ever get created inside the scope of a single builder. * TODO: Thinking about this, I'm now worried the deduplication does not mean I can make the simplifications I currently do in semantic checking by assuming that any two `UNormModifierVal`s will be pointer-identical. This is because we do not currently (IIRC) have the required "bottleneck" in the compiler where all ASTs get serialized after initial checking, and then deserialized when `import`ed into a downstream module, so that every AST node during a checking step comes from a single `ASTBuilder`. Hmm... * If we can rely on deduplication to do its thing, then the `Val` and `Type` implementations of modifiers can be relatively simple. * TODO: One issue here is that the equality comparison for `ModifiedType` currently checks for the same base type and the same modifiers in the same order. This works for now when we only have a small number of type modifiers and any given type will hae at most one, but in the longer run it relies on us to implement some kind of canonicalization scheme, which would both ensure that between `Modified(T, {A, B})` and `Modified(T, {B, A})` only one is allowed (that is, a canonical ordering on modifiers), and that we do not allow `Modified(Modified(T, {A}), {B})`. * TODO: One other issues is that the `ModifiedType` case does not currently interact correctly with the `as()`-based casting for types (whereas that operation *does* interact in a semantically-correct fashion with `typedef`s). Fixing this issue in a robust way really depends on us re-architecting the `Type` system so that *any* `Type` can have modifiers attached, with modifiers affecting type identity/deduplication. * The key place where `ModifiedType` creates a complication in semantic checking is type conversion/coercion. A user is likely to declare a `RWTexture2D<unorm float>`, fetch from it (producing a value of type `unorm float`) and then assign the result to a `float` variable, prompting for a conversion from `unorm float` to `float` (because they are distinct `Type`s). * We handle this case in the core `_coerce()` operation by checking if either `toType` or `fromType` is a `ModifiedType`. If *either* one is a modified type, we apply logic to check for modifiers that are present on one and not the other. Basically we check which modifiers need to be "dropped" and which need to be "added" during conversion, and validate that these modifiers *can* be dropped/added without creating a semantic error. The only type modifiers we support right now *can* be dropped/added like this, so we are fine. * TODO: When we add more complete pointer support, we could need logic here to validate when casts between, e.g., `const int*` and `int*` should/shouldn't be allowed. * Note: Even opening the door to type modifiers at all creates the same kind of challenges for user-defined generic types (and functions!) since `MyType<int>` and `MyType<const int>` are distinct instantiations in a future where we support `const` as a type modifier. We *may* need to plan to restrict where modified types can be used, so that certain built-in generic types support modified types as arguments, but user-defined types don't (or at least might need to opt-in to get support). * The result of a `_coerce()` that drops/adds modifiers is a `ModifierCastExpr`, which is a kind of no-op AST node that merely expresses that the conversion is allowed and valid. * In IR lowering we currently do the simple thing and translate a `ModifiedType` to a distinct IR node called `AttributedType`. * The change in terminology from "modifier" to "attribute" is to follow the way that these kinds of modifiers best map to the `IRAttr` case in the IR (rather than the `IRDecoration` case). We probably ought to do a careful terminology scrub here, because having this terminology mismatch between IR and AST could be a source of confusion. * TODO: In principle, using `IRAttributedType` creates the same basic problems as using `ModifiedType`: code that is usin `as()` or similar operations to check for a specific subclass of `IRType` may not see the case they were looking for due to use of `IRAttributedType`. * Initially I had hoped to avoid the problem by having the `IRAttr`s be attached directly as operands to an otherwise-ordinary `IRType`. E.g., a lowered `unorm float4` would be an `IRVectorType` with an "extra" operand that is an `IRUNormAttr`, something like: `Vector<Float, 4, UNorm>`. This sounds great (and looks great!), but runs into the problem that it is incompatible with the way we currently represent things like generic type parameters. A generic type parameter `T` is represented as an `IRParam`, and it does *not* make sense to have an additional `IRParam` to represent `const T` or `unorm T`, etc. * The Right Way to solve this stuff at both the AST and IR levels is to avoid passing around bare `Type*` or `IRType*` in general, and instead use a value type that implements the needed policy more directly: something like a `TypeHolder` or `IRTypeHolder` (placeholder name). The `*Holder` type would abstract over the various "wrapper" nodes required to store all the additional data like attributes but, importantly, would *not* allow that extra information to be dropped or lost during operations like casting (e.g., note how the current `Type` implementation of `as()` loses information on `typedef` names, making our error messages slightly worse). This is actually quite similar to how we currently use the `DeclRef<T>` system to allow working with what is *usually* a `T*` under the hood, but in a way that ensures we don't lose track of any generic substitution information. * During C-like code emit we have a process that turns an `IRType` into a chain of declarators as needed to emit a C-like declaration with pointers, arrays, etc. The `IRAttributedType` case needs to get folded into this logic. Basically, when we see an `IRAttributedType` we immediately emit any modifiers that are required to be in a prefix position, then recursively emit the underlying type with an extra layer of declarator that tracks the modifiers, so that we can emit any modifiers that should be placed in a postfix position *after* the type. As a specific example, our C/C++ back-end would want to use the postifx option to handle `const`, because then it can properly emit stuff like `int const * const *` and not the incorrect `const const int**`. * The HLSL emit logic overrides the prefix case for handling type attributes, and uses it to emit `unorm` and `snorm` where they occur. * One unfortunate detail is that (apparently) some downstream HLSL compilers do not allow the `unorm`/`snorm` modifiers to apply to `vector<float, *>` types, even though that should be semantically valid. Instead, they only support `float`, `float2`, `float3`, and `float4` explicitly. To work around this issue, we go ahead and change our HLSL emit logic so that when we encountered 1-to-4 component vectors of `float`, `int`, or `uint` we emit the type name using the typical HLSL shorthand. This is actually a signficicant change in our HLSL output, but it both seemed like a good fix to have anyway, and was also the only obvious way to address the downstream parser shortcomings without a massive kludge. * As a result of this change the `half-texture.slang` test broke, since it was using raw HLSL as the expected output. I changed the test to do a DXIL comparison instead, which is our preferred way of testing cross-compilation behavior (since it is more robust in the face of small changes to our source output).
generated by cgit v1.2.3 (git 2.39.1) at 2026-06-01 18:48:05 +0000