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* Use slang- prefix on slang compiler and core source (#973)jsmall-nvidia2019-05-31
| | | | | | | | | | | | * Prefixing source files in source/slang with slang- * Prefix source in source/slang with slang- prefix. * Rename core source files with slang- prefix. * Update project files. * Fix problems from automatic merge.
* String/List closer to conventions, and use Index type (#959)jsmall-nvidia2019-04-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * List made members m_ Tweaked types to closer match conventions. * Use asserts for checking conditions on List. Other small improvements. * List<T>.Count() -> getSize() * List<T> Add -> add First -> getFirst Last -> getLast RemoveLast -> removeLast ReleaseBuffer -> detachBuffer GetArrayView -> getArrayView * List<T>:: AddRange -> addRange Capacity -> getCapacity Insert -> insert InsertRange -> insertRange AddRange -> addRange RemoveRange -> removeRange RemoveAt -> removeAt Remove -> remove Reverse -> reverse FastRemove -> fastRemove FastRemoveAt -> fastRemoveAt Clear -> clear * List<T> FreeBuffer -> _deallocateBuffer Free -> clearAndDeallocate SwapWith -> swapWith * List<T> SetSize -> setSize Reserve -> reserve GrowToSize growToSize * UnsafeShrinkToSize -> unsafeShrinkToSize Compress -> compress FindLast -> findLastIndex FindLast -> findLastIndex Simplify Contains * List<T> Removed m_allocator (wasn't used) Swap -> swapElements Sort -> sort Contains -> contains ForEach -> forEach QuickSort -> quickSort InsertionSort -> insertionSort BinarySearch -> binarySearch Max -> calcMax Min -> calcMin * Initializer::Initialize -> initialize List<T>:: Allocate -> _allocate Init -> _init IndexOf -> indexOf * * Put #include <assert.h> in common.h, and remove unneeded inclusions * Small refactor of ArrayView - remove stride as not used * getSize -> getCount setSize -> setCount unsafeShrinkToSize->unsafeShrinkToCount growToSize -> growToCount m_size -> m_count * Some tidy up around Allocator. * Use Index type on List. * Refactor of IntSet. First tentative look at using Index. * Made Index an Int Did preliminary fixes. Made String use Index. * Partial refactor of String. * String::Buffer -> getBuffer ToWString -> toWString * Small improvements to String. String:: Buffer() -> getBuffer() Equals() -> equals * Try to use Index where appropriate. * Fix warnings on windows x86 builds.
* Add options to control optimization and debug information (#897)Tim Foley2019-03-12
| | | | | | | | | | | | | | | | | | | The short version for command-line users is: * Use `-g` to get debug info in the output, where supported * Use `-O0` to disable optimizations, in case that improves debugability * Use `-O2` for optimized/release builds where you can spend the extra compile time The command-line options are matched with new API functions `spSetDebugInfoLevel()` and `spSetOptimizationLevel()` that set the equivalent information. Right now these settings only affect how we invoke fxc and dxc. In the longer run I expect we will want to use them to control other things: * Once we are emitting our own SPIR-V, the `-g` option should control what source-level name information we include in it. * Whether or not `-g` is used could be used to decide whether we preserve the "name hints" in the IR, which in turn decide whether we output GLSL/HLSL source that uses names based on the original program. * We will eventually need/want to include some amount of optimization passes on the Slang IR, and the `-O` options should control which of those passes are enabled on a particular invocation. In this change I decided to expose the options at the level of the entire compile request for API users, and to store the actual information on the Linkage. We might want to revisit this decision and instead allow for the level of optimization to be chosen per-target as part of back-end state. Similarly, we might want to have more fine-grained control over the level of debug output per-target (although we'd still need a front-end setting to determine what debug info is generated into the Slang IR).
* Split front- and back-ends (#846)Tim Foley2019-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Split front- and back-ends This change is a major refactor of several of the types that provide the behind-the-scenes implementation of the public C API. The goal of this refactor is primarily to allow for future API services that let the user operate both the front- and back-ends of the compiler in a more complex fashion. For example, as user should be able to compile a bunch of source code into modules, look up types, functions, etc. in those modules, specialize generic types/functions to the types they've looked up, and then finally request target code to be gernerated for specialized entry points. The back-end code generation they trigger should re-use the front-end compilation work (parsing, semantic checking, IR generation) that was already performed. The most visible change is that `CompileRequest` has been split up into several smaller types that take responsibility for parts of what it did: * The `Linkage` type owns the storage for `import`ed modules, and well as the `TargetRequest`s that represent code-generation targets. The intention is that an application could use a single `Linkage` for the duration of its runtime (so long as it was okay with the memory usage), so that each `import`ed module only gets loaded once. For now, this type needs to manage the search paths, file system, and source manager, because of its responsibility for loading files. * A `FrontEndCompileRequest` owns the stuff related to parsing, semantic checking, and initial IR generation. This most notably includes the `TranslationUnitRequest`s and the `FrontEndEntryPointRequest`s (which used to be just `EntryPointRequest`s). It's main job is to produce AST and IR modules for each translation unit, and to find and validate the entry points. The front-end request does *not* interact with generic arguments for global or entry-point generic parameters. * The main output of both `import` operations and front-end translation units is the `Module` type, which is just a simple container for both the AST module (to service the reflection/layout APIs, and also for semantic checking of code that `import`s the module) and the IR module (for linking and code generation). This type captures the commonalities between the old `LoadedModule` (which is now just an alias for `Module`) and `TranslationUnitRequest` (which now owns a `Module`). * The secondary output of front-end compilation is a `Program`, which comprises a list of referenced `Module`s and validated `EntryPoint`s that will be used together. Layout and code generation both need a `Program` to tell them what modules and entry points will be used together (we don't want to just code-gen everythin that has ever been loaded into the linakge). The `Program`s created by the front-end do not include generic arguments, so they may provide incomplete layout information and/or be unsuitable for code generation. * A `BackEndCompileRequest` owns stuff related to turning a `Program` into output kernels for the targets of a `Linkage`. Most of the data it owns beyond the `Program` to be compiled is minor, so this is a good candidate for demotion from a heap-allocated object to just a `struct` of options that gets passed around. * The `CompileRequestBase` type is an attempt to wrap up the common functionality of both front-end and back-end compile requests. Most of it is just exposing the availability of a linkage and `DiagnosticSink`, so this type is a good candidate for subsequent removal. The main interesting thing it has is the flags related to dumping and validation of IR, so there is probably a good refactoring still to be made around deciding how options should be handled going forward. * Behind the scenes, the `Program` type is set up to handle some level of on-line compilation and layout work. The `Program` knows the `Linkage` it belongs to, and allows for a `TargetProgram` to be looked up based on a specific `TargetRequest`. A `TargetProgram` then allows layout information and compiled kernel code to be asked for on-demand, in order to support eventual "live" compilation scenarios. * The `EndToEndCompileRequest` type is a composition/coordination type that replaces the old `CompileRequest` in a way that uses the services of the various other types. It owns a few pieces of state that only make sense in the context of an end-to-end compile (e.g., there is really no way to "pass through" code when the front- and back-ends are run separately) or a command-line compile (everything to do with specifying output paths for files is really just for the benefit of `slangc`, and might even be moved there over time). * One important detail is that the `EndToEndCompilRequest` owns all of the string-based generic arguments for both global and entry-point generic parameters. The logic in `check.cpp` for dealing with those arguments has been heavily refactored to separate out the parsings steps that are specific to end-to-end compilation with string-based type arguments, and the semantic checking steps that result in a specialized `Program` (which can be exposed through new APIs that aren't tied to end-to-end compilation). It is perhaps not surprising that this change had a lot of consequences, so I'll briefly run over some of the main categories of changes required: * I changed the way that global generic arguments are passed via API (use `spSetGlobalGenericArgs` instead of the generic arguments for `spAddEntryPointEx`, which are not just for entry-point generics), which has been a change that we've needed for a long time. This is technically a breaking API change, although we should have very few client applications that care about it. * A bunch of places that used to take "big" objects like `CompileRequest` now just take the sub-pieces they care about (e.g., a function might have only needed a `Linkage` and a `DiagnosticSink`). This makes many subroutines or "context" struct types more generally useful, at the cost of taking more parameters. * In a few cases the conceptually clean separation of the layers breaks down (often for edge-case or compatibility features), and so we may pass along additional objects that are allowed to be null, but are used when present. A big example of this is how the back-end code generation routines accept an `EndToEndCompileRequest` that is optional, and only used to check whether "pass through" compilation is needed. We should probably look into cleaning this kind of logic up over time so that we don't need to violate the apparent separation of phases of compilation. * In cases where separation of layers was being broken for the sake of GLSL features, I went ahead and ripped them out, since all of that should be dead code anyway. * In many cases I increased the encapsulation of data in the core types to help track down use sites and make sure they are following invariants better. * In cases where code was doing, e.g., `context->shared->compileRequest->session->getThing()` I have tried to introduce convenience routines so that the usage site is just `context->getThing()` to improve encapsulation and allow changes to be made more easily going forward. * The `noteInternalErrorLoc` functionality was moved off of the compile request and into `DiagnosticSink`, since that is the one type you can rely on having around when you want to note an internal error. We may consider going forward if (and how) it should reset the counter used for noting locations on internal errors. * A few APIs now take `DiagnosticSink*` arguments where they didn't before, and as a result some public APIs need to create `DiagnosticSink`s to pass in, before going ahead and ignoring the messages. In the future there should be variations of these APIs that accept an `ISlangBlob**` parameter for the output. * fixup: missing include for compilers with accurate template checking (non-VS) * fixup: review feedback
* Not finding dxil no longer an error. Outputs a warning. (#781)jsmall-nvidia2019-01-16
| | | | | | | * * Allow dxc compilation to take place if dxil is not found. * Output a warning that output will not be signed. * Remove .dll from dxil in warning so more applicable cross platform.
* Feature/external compiler reporting (#776)jsmall-nvidia2019-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | * Added support for converting SlangResult to string in PlatformUtil. * * Added reportExternalCompilerError * Made external compilers use this * Made DiagnosticSink accept UnownedStringSlice * Made emitXXX compiler functions return SlangError * Use smart pointers to handle life of Com interfaces * * Make SlangResult compatible with HRESULT for some common cases. * Make PlatformUtil::appendResult return SlangResult * Compile check SLANG_RESULT. * Add tests for checking diagnostics from external compilers. * * Make external compiler tests only run on windows for now. * Added 'windows' and 'unix' categories * Added categories based on what backends are available. Will make more tests run on linux and handle case where dxcompiler is not available on appveyor. * * Added spSessionCheckPassThroughSupport * Use to determine whats available for categories for tests * Add support for outputting source filename/s when using pass through.
* * Fix bug outputing dxbc assembly (#719)jsmall-nvidia2018-11-13
| | | * Make the disassembly methods returns SlangResult and String as last output param so as to make error case clear.
* 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.
* Add support for a "strict" floating-point mode (#709)Tim Foley2018-11-01
| | | | This change adds an API function and command line options for controlling the default floating-point behavior for a target, with options for "fast" and "precise" computation. The "precise" option gets mapped to the "IEEE strictness" mode in `fxc` and `dxc` (there is currently no equivalent option for glslang that I could find).
* Disable warnings when compiling through dxc (#710)Tim Foley2018-11-01
| | | | | I had hoped to just disable certain warnings (false positives that trigger based on how Slang outputs HLSL code), but dxc doesn't support fine-grained control over warnings from the command line (we might investigate `#pragma`-based options later). There are enough user complaints about how downstream compiler errors come mixed with tons of distracting warnings that disabling them will lead to a better user experience for now. This change also fixes a long-standing bug where apparently dxc does *not* guaranteee that the diagnostic blob it returns is nul-terminated (despite this convention being established by fxc), so that we need to nul-terminate it ourselves before emitting any diagnostic messages produced by dxc.
* 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
* Work around dxc matrix layout behavior (#694)Tim Foley2018-10-26
| | | | | | | | | | | | | | The Slang compiler allows the default matrix layout convention (row-major vs. column-major) to be specified via the command line or API. When generating output HLSL, Slang emits a `#pragma pack_matrix` directive for the chosen default convention, so that a user can generate plain HLSL output and still have it encode their desired defaults. The problem that has arisen is that many released versions of dxc (including those in the most recent Windows SDK at this time) *ignore* the `#pragma pack_matrix` directive (the feature has since been added to top-of-tree dxc). The main fix here is to instead pass the `-Zpr` option in to dxc when invoking it if the row-major (non-default) convention is requested. This will solve the problem for clients that use Slang to generate DXIL, but not for clients who use Slang to generate plain HLSL that they then pass into dxc (those clients are assumed to be able to work around the problem for themselves). In order to test the change, I added a test that fills a constant buffer with sequential integers, and then reads out the rows/columns of an `int3x4` matrix with both row- and column-major layout, as well as an integer placed *after* the matrix, so we can see the offset it was given. The `render-test` application did not yet support generating code via dxc/DXIL, so I added an option for that. This ends up assuming that anybody who is running the D3D12 tests will also have a version of dxc available.
* 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 basic support for Shader Model 6.3 profiles (#594)Tim Foley2018-06-06
| | | | | | | | | | | | | | | | * Add basic support for Shader Model 6.3 profiles This adds `vs_6_3` and friends as available profiles, but doesn't add any new builtins specific to Shader Model 6.3. In order to better support the ray tracing shader stages, Slang will not automatically map any attempt to compile a DXR shader up to SM 6.3 (the shader model officially required for these stages) and to the `lib_*` profiles (because there are no stage-specific profiles for these cases). As an added detail, when invoking `dxcompiler.dll` to generate DXIL for DXR shaders, specify an empty entry-point name, since that is expected for `lib_*` profiles. * Fixup: don't drop [shader(...)] attributes The previous change makes the "effective profile" for DXR compiles no longer include a stage, but we had been using the stage stored on the effective profile in exactly one place: when determining what to output for a `[shader("...")]` attribute. This fixup makes it so that we use the stage from the profile on the entry-point layout instead, which seems like the right choice anyway, if we are ever going to emit multiple entry points at once.
* 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
* fixed all warningsYong He2017-11-04
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* Allow use of dxc compiler for DXIL generation (#241)Tim Foley2017-11-01
- Add shader model 6.0, 6.1, and 6.2 targets - Add DXIL and DXIL assembly as output formats - Add header for DXC API to `external/` - Add `dxc-support.cpp` that wraps usage of the API - Add `-pass-through dxc` option, equivalent to what we have for `fxc` Notes: * This does *not* include any logic to add `dxcompiler.dll` to our build process; that is way out of scope for the build complexity I'm ready to deal with * For right now, the use of `dxcompiler.dll` is hard-coded, and it must be discoverable in the current executable's search path; options to customize can come later * The `-pass-through` option is kind of silly because the code doesn't actually pay attention to the value (just whether it is set). If you set it to `fxc` but ask for DXIL, we pass through `dxc` anyway.