slang.git/source/slang/slang-serialize-ast.h, branch master

Add support for on-demand AST deserialization (#7482)

2025-06-19T00:11:16+00:00

Note that this change does not actually *enable* on-demand deserialization of ASTs, because doing so is incompatible with the current compiler architecture where we have both an `ASTBuilder` and a `SharedASTBuilder`, and there are important invariants about how all AST nodes related to the core module must be created before those of any module using the core module. Instead, this change simply adds the *infrastructure* for on-demand deserialization, and ensures that those code paths get used at runtime, but actually "demands" all of the nodes in a given serialized AST immediately as part of the deserialization process. Important notes about the implementation approach: * PR #7242 ensured that all of the code accessing the direct member declarations of a `ContainerDecl` went through a small(-ish) set of accessor methods. This change takes advantage of that work by further abstracting the storage of the direct member declarations out in a type, `ContainerDeclDirectMemberDecls`, which makes it easy to add custom serialization logic for just that type. * The `ContainerDeclDirectMemberDecls` type also stores two pointers (one a `RefPtr` and the other a plain pointer) that are only used in the case where the members of a given `ContainerDecl` are being accessed through on-demand deserialization. This can be queried using the `isUsingOnDemandDeserialization()` method but any code accessing a `ContainerDecl` through the intended public API should never need to care about that detail. * Many of the accessor methods that were added in PR #7242 now branch on whether `isUsingOnDemandDeserialization()` is set. The normal code path is unchanged, and the implementation logic for the on-demand-deserialization case is largely held in `slang-serialize-ast.cpp`, to keep it close to the definitions of the serialized data structures themselves. * A few types in the `slang-ast-*.h` headers have had `FIDDLE()` annotations added to them, so that they can be used to synthesize some of the serialization logic that was previously hand-written. * The `_registerBuiltinDeclsRec()` function (which is used to scan the built-in module ASTs for the various "magic" declarations that the `SharedASTBuilder` needs to know about) was factored a bit to support the way that registration needs to behave differently in the case of loading a serialized module (if we kept using the existing recursive search, then it would force every declaration in the core module to be loaded right away). The new `_collectBuiltinDeclsThatNeedRegistrationRec()` function mirrors the overall traversal pattern to produce a flat list that gets included in the serialized AST module. Note in particular that we no longer call `registerBuiltinDecls()` from within `_readBuiltinModule()`. * The interface of the `Module` type was slightly expanded so that there is a more complete API for accessing the declarations exported from the module. Previously they could only be queried by their mangled name, but the new API also allows the entire list to be iterated over. The `ensureLookupAcceleratorBuilt()` method factors out the logic for building those data structures for a module. Note that in the case where on-demand deserialization is being used for a module, the `findExportedDeclByMandledName()` query will use serialized data directly, rather than build the lookup accelerators as C++ data structures (this is required if we are to avoid immediately deserializing all of the (exported) declarations in the core module as soon as it is loaded). * A few methods related to loading serialized modules (e.g., `loadSerializedModule()`) have been updated so that along with a pointer to the serialized `ModuleChunk` (which, for those who aren't aware, is a pointer directly into the serialized bytes of the module file), they receive an `ISlangBlob` that refers to the entire blob holding the serialized data (which the `ModuleChunk` is part of). Passing this pointer down allows code running under these methods to retain a reference-counted pointer to the blob to stop the memory of the serialized module from being released until deserialization has been completed. * The data types defined in `slang-fossil.h` have been overhauled significantly: * The most important change that is relevant to this work is the introduction of the `Fossilized` template, which is used to statically map a "live" C++ type `T` to its binary fossilized representation. The `slang-fossil.h` file provides infrastructure allowing `Fossilized` to be specialized for user-defined types, and also provides the necessary mappings for the core types like strings, arrays, and dictionaries. * A key point is that in C++ code, one can take a value of some type `Foo`, serialize it using a `Fossil::SerialWriter`, get a pointer to that serialized data, and then directly cast it to a `Fossilized*` and navigate the serialized data directly (without deserializing it back into a `Foo`). For that process to work, any specialization of `Fossilized` must be sure to match the layout that will be produced by the `serialize()` implementation for `T`, when writing to a `Fossil::SerialWriter`. * Another key change in the public interface of `slang-fossil.h` is that dynamically-typed traversal of the data used to be handled just with `FossilizedValRef`, but now uses a few different types. The `Fossil::ValRef` and `Fossil::AnyValRef` types are used to capture the use cases that want reference-like behavior (basically a `Fossil::ValRef` can be thought of as sort of like a `T&`), while `Fossil::ValPtr` and `Fossil::AnyValPtr` are used for cases that want pointer like behavior (akin to `T*`). * Then there are related changes in `slang-serialize-fossil.*`: * The implementation of `Fossil::SerialReader` has been changed to use `Fossil::AnyValPtr` in most places where it formerly used `FossilizedValRef`. Using pointers (that can be null) instead of a weird kind of pseudo-reference (that could still be null) to traverse things was making the code harder to follow than it ought to be, in terms of understanding the levels of indirection in various places. * Some of the state that was previously in `Fossil::SerialReader` has been split into `Fossil::ReadContext`. This type allows multiple `Fossil::SerialReader`s to be created to read from the same serialized blob(s), while maintaining a persistent mapping from fossilized data pointers to live object pointers. The `ReadContext` also maintains the work list of deferred deserialization actions waiting to be performed, and only flushes that list when the last currently-open `SerialReader` is about to go out of scope. * In order to support the split of `Fossil::SerialReader` described above (and also to clean up something that didn't quite feel right in the original serialization design) the base serialization framework in `slang-serialize.h` has been tweaked so that a `Serializer` now wraps *two* pointers instead of just one. The first pointer continues to be an implementation of `ISerializerImpl`, which handles the actual reading/writing of data, while the other pointer is an explicit "context" pointer for operations that need additional user-defined context. * Similar to the changes made to the accessors for direct member declarations in a `ContainerDecl`, the `Module::findExportedDeclByMangledName()` method was updated to conditionally execute a different code path in the case of a module that has been loaded from serialized data. * Some improvements have been made to the fiddle tool: * Most importantly, the error-handling logic around Lua script execution has been cleaned up to better match correct Lua idiom. Native functions exposed to the Lua scripts have been changed to just use `lua_call` instead of `lua_pcall`, so rather than attempt to intercept Lua errors they will just automatically propagate them. * All Lua-related errors are caught at the top level, and reported in a way that uses the source location of the fiddle template that was being evaluated when the error was raised. In most cases, a Lua error should be accompanied by a stack trace of the Lua evluation state. The file paths and line numbers given should be accurate, but aren't directly double-clickable in the Visual Studio output panel, because they use a different format (a good future change might be to process the Lua stack trace and rewrite it into a format that is better for our needs). * Fixed a subtle bug where having "raw" content (parts of the template that should neither be evaluated nor emitted into the output) that consisted of only whitespace could result in a template being translated to invalid Lua code. * The bulk of the change is, unsurprisingly, in `slang-serialize-ast.cpp`. * This file has been refactored enough to look like a complete rewrite. A lot of work has been put into comments that describe the overall approach being taken, so hopefully it can be understood even by somebody who wasn't familiar with the previous code. Some of these are just plain cleanups, rather than being directly related to on-demand serialization. * Where possible, the code for reading and writing types that needed custom serialization has been moved so that the read/write functions are next to one another, making it easier to visually confirm that the serialized representations match on the read and write sides. * Where possible, the serialization logic for all types (not just the AST nodes, as was the case before) is being generated via fiddle. * Rather than just defining `serialize()` overloads for each of the relevant types, the code now defines `Fossilized<...>` specializations for these types as well, to enable statically-typed in-memory traversal of the serialized data. Note, however, that for the most part the `Fossilized<...>` representation types are *not* being used by the code (really only the `ASTModuleInfo` and `ContainerDeclDirectMemberDeclsInfo` types are traversed directly). This can be considered more as work to prove out the design of the `Fossil<...>` template approach, and it may or may not end up being relevant in the future. * The trivial bit of work to enable on-demand deserialization is in `ASTSerialReadContext::handleContainerDeclDirectMemberDecls()` where, rather than recursively reading the contained declarations, the method effectively just grabs the current cursor of the `Fossil::SerialReader` (which is pointed into the fossilized data) and stashes it into the `ContainerDeclDirectMemberDecls`, along with a `RefPtr` to the `ASTSerialReadContext` itself. Those stashed pointers are what enables the accessors on `ContaienrDeclDirectMemberDecls` to look up information on-demand. * The more interesting bits of the approach mostly come at the end of the file, where the accessor operations for on-demand deserialization are implemented. Once all the relevant work has been done to write the data structures, and produce `Fossilized<...>` types with the right layout, the work itself may seem almost trivial: a little bit of array iteration, and a little bit of binary-search lookup. * As a reminder, all of this infrastructure for on-demand deserialization is now in place and able to be invoked by the rest of the compiler, but declarations are currently all being loaded eagerly. The `SLANG_DISABLE_ON_DEMAND_AST_DESERIALIZATION` macro is being used to enable a small bit of extra logic in `ASTSerialReadContext::_cleanUpASTNode` so that the "cleanup" on a just-deserialized `ContainerDecl` includes eagerly querying its list of direct member declarations, which will cause them to be recursively deserialized.

Generalize serialization system used for AST (#7126)

2025-05-21T04:55:39+00:00

This change takes the new approach to serialization that was used for the AST and generalizes it in a few ways: * The new approach is no longer tangled up with the RIFF format. The serialization system supports multiple different implementations of the underlying format. The existing RIFF format is now supported as one back-end, but support for others will follow in subsequent changes. * The new approach is no longer deeply specialized to AST serialization. The old code had things like serialization for `List`s and `Dictionary`s, but it was embedded inside the `AST{Encoding|Decoding}Context`, and thus couldn't be leveraged for other serialization tasks. This change factors out a completely AST-independent `Serializer` implementation, with an `ASTSerializer` layered on top of it to provide the additional context needed. * There is less duplication of code between reading and writing of serialized data. The old code had both the `ASTEncodingContext` and `ASTDecodingContext`, with serialization logic for most types being implemented in both, but with the constraint that those implementations needed to be kept in sync to avoid serialization-related runtime failures. A key property of the revamped approach is that a single `serialize()` method for a type implements both the reading and writing directions of serialization.

Cleanups related to RIFF support (#7041)

2025-05-12T17:28:05+00:00

A new approach to AST serialization (#6854)

2025-04-22T20:26:57+00:00

* A new approach to AST serialization This change completely overhauls the way that AST nodes are being serialized, and the offline source-code generation steps that enable that serialization. In practice, this ends up being a complete overhaul of the way that *modules* are being serialized (not just the AST part), although things like the serialization format for the Slang IR and for source locations are not affected. The rest of this commit message is broken down in to sections, in an attempt to help guide anybody looking at the code in how to make sense of all the changes. The Old C++ Extractor --------------------- AST serialization used to be driven by information scraped using the `slang-cpp-extractor` tool, which did an ad hoc parse of the C++ declarations of the AST node types and then generated a set of "X macros" that could be for macro-based code generation within the rest of the compiler. While the existing approach was functional, it wasn't easy to understand or maintain, and it has been getting in the way of forward progress on other features we'd like to work on in the language and compiler. This change removes the `slang-cpp-extractor` tool entirely. Marking Up the AST Declarations ------------------------------- The most notable change that contributors to the compiler may notice is the large number of invocations of a macro `FIDDLE()` on the declarations of the AST node types. The basic idea is that only declarations (namespaces, types, fields) that are preceded by `FIDDLE()` are visible to the code generator tool. So if somebody is working with the AST and wondering why a new node type isn't working, or why a field they added isn't being serialized correctly, it is probably because they need to add `FIDDLE()` in front of it. Generating the Boilerplate Code ------------------------------- The file `slang-ast-boilerplate.cpp` provides a good example of how the information extracted from the marked-up AST declarations gets used. In that file, the `FIDDLE TEMPLATE` construct is used to generate type information for each of the AST node types. Similar logic is used in `slang-ast-forward-declarations.h` to generate the declaration of the `ASTNodeType` enumeration, and forward-declare all the AST node classes. For many parts of the code, simply including that file replaces the need for the old `slang-generated-*.h` files. Replacing Visitors and Related Logic ------------------------------------ The old visitor types for the AST used the macros that were generated by `slang-cpp-extractor`, so something new was needed to replace them. The same goes for the `SLANG_AST_NODE_VIRTUAL_CALL` macros. The core of the solution implemented here is in `slang-ast-dispatch.h`. Given a "dispatchable" AST node type (say, `Expr`), a call like: ``` ASTNodeDispatcher(expr, [&](auto e) { return doSomething(e); }) ``` is an expression of type `R`, which does the equivalent of something like: ``` switch(expr->getTag()) { case ASTNodeType::VarExpr: return doSomething(static_cast(expr)); // ... } ``` The `SLANG_AST_NODE_VIRTUAL_CALL` macro is now implemented in terms of `ASTNodeDispatcher`. The implementation of the visitor types is more involved. The code in this change retains some of the macro names from the original version, just to try and make the parallels more clear. The visitor types are all implemented on top of the `ASTNodeDispatcher` approach, and use `FIDDLE TEMPLATE` to generate all the boilerplate `visit*()` method declarations. Refactoring of `Linkage` Module Loading --------------------------------------- Needing to revisit all the places where modules get deserialized made it clear that there is a lot of complexity and apparent duplication in the core routines on the `Linkage` that get used for loading modules. This change tries to clean up some of that logic, but it is worth noting that there are two legacy features that get in the way of making things as clean as they should be: * The `LoadedModuleDictionary` type that gets passed around a lot exists entirely to handle the corner case where somebody uses the Slang API to perform a compilation with multiple `TranslationUnitRequest`s in the same `FrontEndCompileRequest`, and one of the translation units `import`s the module defined by another of the translation units. * There are a lot of special-case behaviors and routines entirely there to support the `ModuleLibrary` feature, although that feature should be considered deprecated (or at least subject to getting entirely re-designed down the line). The basic idea of the cleanup is that all of the (non-deprecated) ways load a module from a serialized binary, or compile one from source should now bottleneck through `loadModuleImpl`, which then bifurcates into `loadSourceModuleImpl` for the compilation case and `loadBinaryModuleImpl` for the deserialization case. High-Level Serialization Approach --------------------------------- The old serialization logic used the [RIFF](https://en.wikipedia.org/wiki/Resource_Interchange_File_Format) format to encode the high-level structure of things, and this change retains that usage (and actually doubles down on the RIFF usage). The old serialization system relied on the idea that for any given type `Foo` that wants to support serialization, there should be something like a `SerialFooData` type in C++, that can represent the state of a `Foo`, and then the actual serialization applied to that `SerialFooData`. This means that in most cases there are four pieces of code written: * During serialization: * Copying the data of a `Foo` in memory over to a `SerialFooData` in memory * Writing the state of a `SerialFooData` into the serialized data stream * During deserialization: * Reading the state of a `SerialFooData` from a serialized data stream * Copying the data of the `SerialFooData` in memory over to a `Foo` The new logic gets rid of the intermediate `SerialFooData`. In the serialization direction, we take a `Foo` and write it to the `RIFFContainer` directly, or using some other utilities layered on top of it. In the deserialization direction, we have additional flexibility. Given a `RIFFContainer::Chunk*` that represents a serialized `Foo`, we often navigate through the in-memory representation of the RIFF data to get to the parts of the serialized value that we actually want/need, without needing to deserialize the entire `Foo`. To support this kind of operation, this change introduces a few helper types like `ContainerChunkRef` an `ModuleChunkRef`, that are little more than typed wrappers around a `RIFFContainer::Chunk*`. The Module "Container" Part --------------------------- A serialized `Module` is encoded as a RIFF chunk, using logic in `slang-serialize-container.cpp` - both before and after this change. This change reorganizes a lot of the code in that file, to account for the way that eliminating the intermediate `SerialContainerData` type streamlines the overall task of writing out the parts of the module. In the deserialization logic... there isn't really much to do in `slang-serialize-container.cpp`. Most of the logic in `slang.cpp` and `slang-module-library.cpp` that pertains to deserializing modules uses the `ModuleChunkRef`-based approach, and simply extracts the pieces of the serialized module that it needs. The Actual Serialization of the AST ----------------------------------- The actual AST serialization logic is in `slang-serialize-ast.cpp`. The basic approach in both the writing and reading directions is: * Use the `FIDDLE TEMPLATE` system to generate a set of functions, one for each AST node type, that recursively invoke the read/write logic on each field of that node (after recursively invoking the case for its direct superclass) * Use the `ASTNodeDispatcher` system to dispatch out to those functions whene reading or writing anything derived from `NodeBase` * For now, handle all types *not* derived from `NodeBase` by hand. There's a lot of room for improvement around that last item: it should be just as easy to generate the serialization and deserialization logic for other types that don't inherit from `NodeBase`, but the current change tries to err on the side of making the logic as explicit and simplistic as possible, rather than trying to get too clever too soon. The actual serialization *format* used for the AST is almost comically simplistic: the code uses hierarchical RIFF chunks to emulate a JSON-like structure. This is a very wasteful representation (e.g., a `bool` or a null pointer each take up *8 bytes*), but the goal for now is to start with the simplest thing that could possibly work, and only add more cleverness once we are sure it won't get in the way of important future improvements (like lazy/on-demand deserialization or IR and AST, to improve compiler startup times). The files `slang-serialize.{h,cpp}` have been co-opted to define a new pair of types `Encoder` and `Decoder` that are used for a more-or-less stream-oriented way or reading or writing RIFF chunks for the JSON-like structure. Almost everything related to the actual AST serialization could do with a cleanup pass, and some time spent on picking good/better names for everything. Smaller Stuff ------------- * Cleaned up a lot of code that was using bare `ASTNodeType` or the extractor's `ReflectClassInfo` type to consistently use `SyntaxClass`. * Fixed an apparent bug in how the destination-driven code genarator was handling `TryExpr`s * Fixed an apparent bug in how the GLSL legalization pass was handling translation of certain `SV_*` semantics. * format code * fixup: template errors caught by non-VS compilers * format code * fixup: more template errors * fixup: more stuff VS didn't catch * fixup: it's amazing VS doesn't catch these... * fixup: yet more template stuff VS ignores * fixup: more VS template nonsense * fixup: unreachable return macro usage * fixup: more unreacable returns * fixup: unused parameter * fixup: strict aliasing * fixup: allow missing entry point list chunk * fixup: wasm build script * fixup: AST changes since this PR was created --------- Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> Co-authored-by: Yong He

format

2024-10-29T06:49:26+00:00

* format * Minor test fixes * enable checking cpp format in ci

Shader caching (#2432)

2022-10-12T16:55:09+00:00

* Changed all getEntryPointCode calls to use RendererBase::getEntryPointCodeFromShaderCache * Hashing hooked up, tests pass but need to add more to fully test functionality * checkpoint * Checkpoint: File system creation seems functional, saving is broken * checkpoint: Fixed filename generation from MD5 hash, shader blob might be going missing ahead of pipeline state creation * Fixed a lot of bugs related to hash code generation, shader cache is likely working but needs further testing * Added workaround for module loading by re-creating the test device, shader cache test functional * Vulkan shader caching bug fixed, checkpoint commit before more refinement * pre-ToT merge checkpoint * checkpoint commit, improving cache keys * Significantly expanded items included in the dependency hash for Module; Added dependency hash functions to SpecializedComponentType and RenamedEntryPointComponentType * Temporarily disable shader cache test * Mid cleanup changes, solution successfully builds * Added several helper update functions to slang-md5 to help simplify usage; Added a function under ISession to compute a hash for all linkage-related items; Function renames and cleaned up some comments * Ran premake.bat; Renamed getASTBasedHashCode to computeASTBasedHash * Added slang unit tests for Checksum and MD5; Extended gfx shader cache test to test with multiple shader files and one shader file with multiple entry points * Solution builds and shader cache tests pass, but at least a couple other tests now failing * ran premake.bat * More cleanup changes * Added shaderCachePath field to IDevice desc in gfx.slang, gfx-smoke.slang should be functional * ran premake * cleanup changes; Adding test printf to getEntryPointCodeFromShaderCache to see if output can be seen in CI * Removed debugging printfs; Added handling for getEntryPointCode() failing * Cleanup changes; Jonathan's fixes to SerialWriter to zero initialize otherwise uninitialized memory; Change to SwizzleExpr creation to zero initialize elementCount * Changed enable_if_t to enable_if * Fixed enable_if * Added test for import vs include and changes to included and imported files; Fixed build errors in CUDA; Renamed shader cache statistics fields * cleanup changes * Readd removed file * Restructured computeDependencyBasedHash calls, added computeDependencyBasedHashImpl to all classes dervied from ComponentType * Applied same restructuring to the AST hash functions * Cleanup changes; Moved HashBuilder out to slang-digest.h and added some helper functions to streamline the process of adding items to a hash * Cleanup; Fixed incorrect expected results for shader import and include test

Use Reflection for (Serial)RefObject Serialization (#1567)

2020-10-06T21:07:22+00:00

* First pass at generalizing serializer. * Split out ReflectClassInfo * Use the general ReflectClassInfo * Fix some typos in debug generalized serialization. * Add calculation of classIds. Make distinct addCopy/add on SerialClasses. * Write up of more generalized serialization * WIP to transition from ASTSerialReader/Writer etc to generalized SerialReader/Writer and associated types. * Improvements to SerialExtraObjects. Keep RefObjects in scope in factory * Compiles with Serial refactor - doesn't quite work yet. * First pass serialization appears to work with refector. * Split out type info for general slang types. * Split out slang-serialize-misc-type-info.h * DebugSerialData -> SerialSourecLocData DebugSerialReader -> SerialSourceLocReader DebugSerialWriter -> SerialSourceLocWriter * Remove unused template that only compiles on VS. * Fix warning around unused function on non-VS. * Improve output of type names that are in scopes in C++ extractor. Update premake5.lua to run generation for RefObject derived types. * C++ extractor working on RefObject type. * Split out serialization functionality that spans different types into slang-serialization-factory.cpp/.h Put AST type info into header. Removed RefObjectSerialSubType - use RefObjectType Add filtering for RefObject derived types Remove construction and filteringhacks. * Set up field serialization for SerialRefObject derived types. * Fix template problem compiling on Clang/Gcc * Work in progress to make Value types work. * Added slang-value-reflect.cpp

Generalizing Serialization (#1563)

2020-09-30T17:28:56+00:00

Share debug information between AST and IR (#1547)

2020-09-17T20:47:57+00:00

* Test if blob is returned. * Rename serialize files so can be grouped. * StringRepresentationCache -> SerialStringTable * Split out SerialStringTable from slang-serialize-ir * First pass at reorganizing serialization/containers. Remain some issues about debug info. * Fix bug in calculating sourceloc. * Improve calcFixSourceLoc * Make allocations for payload RiffContainer align to at least 8 bytes. This is important for read, if the payload can contain 8 byte aligned data. Note this has no effect on Riff file format alignment rules. * Improve comments around RiffContainer and alignment. * Remove SerialStringTable, can just use StringSlicePool instead. * Typo fix for Clang/Linux. Co-authored-by: Tim Foley