Implement notion of a "container format" (#213)

The big addition here is that the Slang "bytecode" is no longer treated as just a "code generation target" (`CodeGenTarget`) akin to DX bytecode (DXBC) or SPIR-V, but instead is a `ContainerFormat` that can be used to emit all the results of a compile request (well, currently just the IR-as-BC, but the intention is there).

Getting to this goal involved some prior checkins that eliminated bogus "targets" that weren't really akin to SPIR-V or DXBC: `-target slang-ir-asm` and `-target reflection-json`. Those targets were really in place to support testing, and so they've been made more explicit testing/debug options.

This change eliminates `-target slang-ir` and instead tries to allow the user to specify `-o foo.slang-module` as an output file name, that indicates the intention to output a "container" file that will wrap up all the generated code.

I've also gone ahead and generalized the existing `-target` option so that we are actually building up a *list* of code generation targets. This is largely just a cleanup, since it forces code to be more aware of when it is doing something target-specific vs. target independent. For example, reflection layout information lives on a requested target, and not on the compile request as a whole, and similarly output code is per-target, per-entry-point.

As a cleanup, I eliminated support for per-translation-unit output. This was vestigial code from back when I used to try and do HLSL generation for a whole translation unit instead of per-entry-point (which turned out to be a lot of complexity for little gain), and it was only being used in the `hello` example and the `render-test` test fixture - in both cases fixing it up was easy enough. I've stubbed out the old `spGetTranslationUnitSource` API, but haven't removed it yet.

1 files changed, 38 insertions, 1 deletions

diff --git a/slang.h b/slang.h
index 231ef7472..ff79d698b 100644
--- a/slang.h
+++ b/slang.h
@@ -89,7 +89,20 @@ extern "C"
         SLANG_SPIRV_ASM,
         SLANG_DXBC,
         SLANG_DXBC_ASM,
-        SLANG_IR,
+    };
+
+    /* A "container format" describes the way that the outputs
+    for multiple files, entry points, targets, etc. should be
+    combined into a single artifact for output. */
+    typedef int SlangContainerFormat;
+    enum
+    {
+        /* Don't generate a container. */
+        SLANG_CONTAINER_FORMAT_NONE,
+
+        /* Generate a container in the `.slang-module` format,
+        which includes reflection information, compiled kernels, etc. */
+        SLANG_CONTAINER_FORMAT_SLANG_MODULE,
     };
 
     typedef int SlangPassThrough;
@@ -231,6 +244,20 @@ extern "C"
         SlangCompileRequest*    request,
         int target);
 
+    /*!
+    @brief Add a code-generation target to be used.
+    */
+    SLANG_API void spAddCodeGenTarget(
+        SlangCompileRequest*    request,
+        SlangCompileTarget      target);
+
+    /*!
+    @brief Set the container format to be used for binary output.
+    */
+    SLANG_API void spSetOutputContainerFormat(
+        SlangCompileRequest*    request,
+        SlangContainerFormat    format);
+
     SLANG_API void spSetPassThrough(
         SlangCompileRequest*    request,
         SlangPassThrough        passThrough);
@@ -389,6 +416,16 @@ extern "C"
         int                     entryPointIndex,
         size_t*                 outSize);
 
+    /** Get the output bytecode associated with an entire compile request.
+
+    The lifetime of the output pointer is the same as `request`.
+    */
+    SLANG_API void const* spGetCompileRequestCode(
+        SlangCompileRequest*    request,
+        size_t*                 outSize);
+
+
+
     typedef struct SlangVM          SlangVM;
     typedef struct SlangVMModule    SlangVMModule;
     typedef struct SlangVMFunc      SlangVMFunc;