Add support for dumping intermediates for debugging.

Calling:

    spSetDumpIntermedites(compileRequest, true);

will set up a mode where Slang tries to dump every intermediate HLSL, GLSL, DXBC, SPIR-V, etc. file it generates. If SPIR-V or DXBC is requested then we also dump assembly of those.

Right now the files are all named as `slang-<counter>.<ext>`, and get dropped in whatever the working directory is, but I'm open to ideas on how to improve that.

Note: this change introduces a new binary interface to `glslang`, so pulling it requires an updated `glslang.dll`.

2 files changed, 60 insertions, 21 deletions

diff --git a/tools/glslang/glslang.cpp b/tools/glslang/glslang.cpp
index f07937b97..98bcf14d6 100644
--- a/tools/glslang/glslang.cpp
+++ b/tools/glslang/glslang.cpp
@@ -78,12 +78,8 @@ static void dumpDiagnostics(
     dump(log.c_str(), log.length(), request->diagnosticFunc, request->diagnosticUserData, stderr);
 }
 
-extern "C"
-_declspec(dllexport)
-int glslang_compile(glslang_CompileRequest* request)
+static int glslang_compileGLSLToSPIRV(glslang_CompileRequest* request)
 {
-    glslang::InitializeProcess();
-
     EShLanguage glslangStage;
     switch( request->slangStage )
     {
@@ -109,12 +105,15 @@ int glslang_compile(glslang_CompileRequest* request)
     glslang::TProgram* program = new glslang::TProgram();
     auto programPtr = std::unique_ptr<glslang::TProgram>(program);
 
-    int sourceTextLength = (int) strlen(request->sourceText);
+    char const* sourceText = (char const*)request->inputBegin;
+    char const* sourceTextEnd = (char const*)request->inputEnd;
+
+    int sourceTextLength = (int)(sourceTextEnd - sourceText);
 
     shader->setPreamble("#extension GL_GOOGLE_cpp_style_line_directive : require\n");
 
     shader->setStringsWithLengthsAndNames(
-        &request->sourceText,
+        &sourceText,
         &sourceTextLength,
         &request->sourcePath,
         1);
@@ -163,20 +162,52 @@ int glslang_compile(glslang_CompileRequest* request)
 
         dumpDiagnostics(request, logger.getAllMessages());
 
-        if (request->disassembleResult)
-        {
-            std::stringstream spirvAsmStream;
-            spv::Disassemble(spirvAsmStream, spirv);
-            std::string result = spirvAsmStream.str();
-            dump(result.c_str(), result.length(), request->outputFunc, request->outputUserData, stdout);
-        }
-        else
-        {
-            dump(spirv.data(), spirv.size() * sizeof(unsigned int), request->outputFunc, request->outputUserData, stdout);
-        }
+        dump(spirv.data(), spirv.size() * sizeof(unsigned int), request->outputFunc, request->outputUserData, stdout);
     }
 
-    glslang::FinalizeProcess();
+    return 0;
+}
+
+static int glslang_dissassembleSPIRV(glslang_CompileRequest* request)
+{
+    typedef unsigned int SPIRVWord;
+
+    SPIRVWord const* spirvBegin = (SPIRVWord const*)request->inputBegin;
+    SPIRVWord const* spirvEnd   = (SPIRVWord const*)request->inputEnd;
+
+    std::vector<SPIRVWord> spirv(spirvBegin, spirvEnd);
+
+    std::stringstream spirvAsmStream;
+    spv::Disassemble(spirvAsmStream, spirv);
+    std::string result = spirvAsmStream.str();
+    dump(result.c_str(), result.length(), request->outputFunc, request->outputUserData, stdout);
 
     return 0;
 }
+
+extern "C"
+_declspec(dllexport)
+int glslang_compile(glslang_CompileRequest* request)
+{
+    glslang::InitializeProcess();
+
+    int result = 0;
+    switch(request->action)
+    {
+    default:
+        result = 1;
+        break;
+
+    case GLSLANG_ACTION_COMPILE_GLSL_TO_SPIRV:
+        result = glslang_compileGLSLToSPIRV(request);
+        break;
+
+    case GLSLANG_ACTION_DISSASSEMBLE_SPIRV:
+        result = glslang_dissassembleSPIRV(request);
+        break;
+    }
+
+    glslang::FinalizeProcess();
+
+    return result;
+}
diff --git a/tools/glslang/glslang.h b/tools/glslang/glslang.h
index 8686f019e..f02d43882 100644
--- a/tools/glslang/glslang.h
+++ b/tools/glslang/glslang.h
@@ -4,10 +4,18 @@
 
 typedef void (*glslang_OutputFunc)(void const* data, size_t size, void* userData);
 
+enum
+{
+    GLSLANG_ACTION_COMPILE_GLSL_TO_SPIRV,
+    GLSLANG_ACTION_DISSASSEMBLE_SPIRV,
+};
+
 struct glslang_CompileRequest
 {
     char const*         sourcePath;
-    char const*         sourceText;
+
+    void const*         inputBegin;
+    void const*         inputEnd;
 
     glslang_OutputFunc  diagnosticFunc;
     void*               diagnosticUserData;
@@ -17,7 +25,7 @@ struct glslang_CompileRequest
 
     int                 slangStage;
 
-    bool                disassembleResult;
+    unsigned            action;
 };
 
 typedef int (*glslang_CompileFunc)(glslang_CompileRequest* request);