Vulkan: Add the #define VULKAN 100 when compiled for Vulkan.

Note this requires test-based piecing together of the preamble string,
so it changed to being a std::string to make it easier to do.

This closes issue #254.

Test/nonVulkan.frag

@@ -2,4 +2,8 @@
 
 layout(constant_id = 17) const int arraySize = 12;            // ERROR
 layout(input_attachment_index = 1) int foo;                   // ERROR
-layout(push_constant) uniform ubn { int a; } ubi;             // ERROR
+layout(push_constant) uniform ubn { int a; } ubi;             // ERROR
+
+#ifdef VULKAN
+#error VULKAN should not be defined
+#endif

Test/vulkan.vert

@@ -37,3 +37,11 @@ void foo()
 }
 
 layout(set = 1, push_constant) uniform badpc { int a; } badpcI;  // ERROR, no descriptor set with push_constant
+
+#ifndef VULKAN
+#error VULKAN should be defined
+#endif
+
+#if VULKAN != 100
+#error VULKAN should be 100
+#endif

glslang/MachineIndependent/ShaderLang.cpp

@@ -629,7 +629,9 @@ bool ProcessDeferred(
     parseContext->initializeExtensionBehavior();
     
     // Fill in the strings as outlined above.
-    strings[0] = parseContext->getPreamble();
+    std::string preamble;
+    parseContext->getPreamble(preamble);
+    strings[0] = preamble.c_str();
     lengths[0] = strlen(strings[0]);
     names[0] = nullptr;
     strings[1] = customPreamble;

glslang/MachineIndependent/Versions.cpp

@@ -215,10 +215,10 @@ void TParseVersions::initializeExtensionBehavior()
 
 // Get code that is not part of a shared symbol table, is specific to this shader,
 // or needed by the preprocessor (which does not use a shared symbol table).
-const char* TParseVersions::getPreamble()
+void TParseVersions::getPreamble(std::string& preamble)
 {
     if (profile == EEsProfile) {
-        return
+        preamble = 
             "#define GL_ES 1\n"
             "#define GL_FRAGMENT_PRECISION_HIGH 1\n"
             "#define GL_OES_texture_3D 1\n"
@@ -227,10 +227,6 @@ const char* TParseVersions::getPreamble()
             "#define GL_OES_EGL_image_external 1\n"
             "#define GL_EXT_shader_texture_lod 1\n"
 
-            // #line and #include
-            "#define GL_GOOGLE_cpp_style_line_directive 1\n"
-            "#define GL_GOOGLE_include_directive 1\n"
-
             // AEP
             "#define GL_ANDROID_extension_pack_es31a 1\n"
             "#define GL_KHR_blend_equation_advanced 1\n"
@@ -260,7 +256,7 @@ const char* TParseVersions::getPreamble()
             "#define GL_OES_texture_cube_map_array 1\n"
             ;
     } else {
-        return
+        preamble = 
             "#define GL_FRAGMENT_PRECISION_HIGH 1\n"
             "#define GL_ARB_texture_rectangle 1\n"
             "#define GL_ARB_shading_language_420pack 1\n"
@@ -283,12 +279,18 @@ const char* TParseVersions::getPreamble()
             "#define GL_ARB_gl_spirv 1\n"
             "#define GL_ARB_sparse_texture2 1\n"
             "#define GL_ARB_sparse_texture_clamp 1\n"
-
-            "#define GL_GOOGLE_cpp_style_line_directive 1\n"
-            "#define GL_GOOGLE_include_directive 1\n"
 //            "#define GL_ARB_cull_distance 1\n"    // present for 4.5, but need extension control over block members
             ;
     }
+
+    // #line and #include
+    preamble += 
+            "#define GL_GOOGLE_cpp_style_line_directive 1\n"
+            "#define GL_GOOGLE_include_directive 1\n"
+            ;
+
+    if (vulkan > 0)
+        preamble += "#define VULKAN 100\n";
 }
 
 //

glslang/MachineIndependent/parseVersions.h

@@ -104,7 +104,7 @@ public:
     void setCurrentSourceName(const char* name) { currentScanner->setFile(name); }
     void setCurrentString(int string) { currentScanner->setString(string); }
 
-    const char* getPreamble();
+    void getPreamble(std::string&);
     bool relaxedErrors()    const { return (messages & EShMsgRelaxedErrors) != 0; }
     bool suppressWarnings() const { return (messages & EShMsgSuppressWarnings) != 0; }
 

hlsl/hlslParseHelper.h

@@ -48,7 +48,7 @@ public:
     virtual ~HlslParseContext();
     void setLimits(const TBuiltInResource&);
     bool parseShaderStrings(TPpContext&, TInputScanner& input, bool versionWillBeError = false);
-    const char* getPreamble();
+    void getPreamble(std::string&);
 
     void C_DECL error(const TSourceLoc&, const char* szReason, const char* szToken,
         const char* szExtraInfoFormat, ...);