Front-end: Implement GL_EXT_shader_non_constant_global_initializers.

This lets ES shaders use non-constant initializers for non-constant globals.

Test/100.frag

@@ -213,6 +213,12 @@ float fooinit()
 
 int init1 = gl_FrontFacing ? 1 : 2; // ERROR, non-const initializer
 
+#ifdef GL_EXT_shader_non_constant_global_initializers
+#extension GL_EXT_shader_non_constant_global_initializers : enable
+#endif
+
+int init2 = gl_FrontFacing ? 1 : 2;
+
 #pragma STDGL invariant(all)
 
 #line 3000

Test/baseResults/100.frag.out

@@ -82,7 +82,7 @@ ERROR: 0:192: '.' : cannot apply to an array: nothing
 ERROR: 0:193: '.length' : not supported for this version or the enabled extensions 
 ERROR: 0:194: '.' : cannot apply to an array: method
 ERROR: 0:194: 'a' : can't use function syntax on variable 
-ERROR: 0:214: 'non-constant global initializer' : not supported with this profile: es
+ERROR: 0:214: 'non-constant global initializer (needs GL_EXT_shader_non_constant_global_initializers)' : not supported for this version or the enabled extensions 
 ERROR: 0:3000: '#error' : line of this error should be 3000  
 ERROR: 0:3002: '' :  syntax error
 ERROR: 77 compilation errors.  No code generated.
@@ -90,6 +90,7 @@ ERROR: 77 compilation errors.  No code generated.
 
 Shader version: 100
 Requested GL_EXT_frag_depth
+Requested GL_EXT_shader_non_constant_global_initializers
 Requested GL_EXT_shader_texture_lod
 Requested GL_OES_EGL_image_external
 Requested GL_OES_standard_derivatives
@@ -376,6 +377,18 @@ ERROR: node is still EOpNull!
 0:214        false case
 0:214        Constant:
 0:214          2 (const int)
+0:220  Sequence
+0:220    move second child to first child (temp mediump int)
+0:220      'init2' (global mediump int)
+0:220      Test condition and select (temp mediump int)
+0:220        Condition
+0:220        'gl_FrontFacing' (gl_FrontFacing bool Face)
+0:220        true case
+0:220        Constant:
+0:220          1 (const int)
+0:220        false case
+0:220        Constant:
+0:220          2 (const int)
 0:?   Linker Objects
 0:?     'a' (global 3-element array of mediump int)
 0:?     'uint' (global mediump int)
@@ -407,6 +420,7 @@ ERROR: node is still EOpNull!
 0:?     'fi3' (const mediump float)
 0:?       5.000000
 0:?     'init1' (global mediump int)
+0:?     'init2' (global mediump int)
 
 
 Linked fragment stage:
@@ -414,6 +428,7 @@ Linked fragment stage:
 
 Shader version: 100
 Requested GL_EXT_frag_depth
+Requested GL_EXT_shader_non_constant_global_initializers
 Requested GL_EXT_shader_texture_lod
 Requested GL_OES_EGL_image_external
 Requested GL_OES_standard_derivatives
@@ -700,6 +715,18 @@ ERROR: node is still EOpNull!
 0:214        false case
 0:214        Constant:
 0:214          2 (const int)
+0:220  Sequence
+0:220    move second child to first child (temp mediump int)
+0:220      'init2' (global mediump int)
+0:220      Test condition and select (temp mediump int)
+0:220        Condition
+0:220        'gl_FrontFacing' (gl_FrontFacing bool Face)
+0:220        true case
+0:220        Constant:
+0:220          1 (const int)
+0:220        false case
+0:220        Constant:
+0:220          2 (const int)
 0:?   Linker Objects
 0:?     'a' (global 3-element array of mediump int)
 0:?     'uint' (global mediump int)
@@ -731,4 +758,5 @@ ERROR: node is still EOpNull!
 0:?     'fi3' (const mediump float)
 0:?       5.000000
 0:?     'init1' (global mediump int)
+0:?     'init2' (global mediump int)
 

glslang/MachineIndependent/ParseHelper.cpp

@@ -5083,11 +5083,13 @@ TIntermNode* TParseContext::executeInitializer(const TSourceLoc& loc, TIntermTyp
         // "In declarations of global variables with no storage qualifier or with a const
         // qualifier any initializer must be a constant expression."
         if (symbolTable.atGlobalLevel() && ! initializer->getType().getQualifier().isConstant()) {
-            const char* initFeature = "non-constant global initializer";
+            const char* initFeature = "non-constant global initializer (needs GL_EXT_shader_non_constant_global_initializers)";
-            if (relaxedErrors())
+            if (profile == EEsProfile) {
-                warn(loc, "not allowed in this version", initFeature, "");
+                if (relaxedErrors() && ! extensionTurnedOn(E_GL_EXT_shader_non_constant_global_initializers))
-            else
+                    warn(loc, "not allowed in this version", initFeature, "");
-                requireProfile(loc, ~EEsProfile, initFeature);
+                else
+                    profileRequires(loc, EEsProfile, 0, E_GL_EXT_shader_non_constant_global_initializers, initFeature);
+            }
         }
     }
 

glslang/MachineIndependent/Versions.cpp

@@ -182,6 +182,8 @@ void TParseVersions::initializeExtensionBehavior()
     extensionBehavior[E_GL_ARB_sparse_texture_clamp]         = EBhDisable;
 //    extensionBehavior[E_GL_ARB_cull_distance]                = EBhDisable;    // present for 4.5, but need extension control over block members
 
+    extensionBehavior[E_GL_EXT_shader_non_constant_global_initializers] = EBhDisable;
+
     // #line and #include
     extensionBehavior[E_GL_GOOGLE_cpp_style_line_directive]          = EBhDisable;
     extensionBehavior[E_GL_GOOGLE_include_directive]                 = EBhDisable;
@@ -256,6 +258,7 @@ void TParseVersions::getPreamble(std::string& preamble)
             "#define GL_OES_tessellation_point_size 1\n"
             "#define GL_OES_texture_buffer 1\n"
             "#define GL_OES_texture_cube_map_array 1\n"
+            "#define GL_EXT_shader_non_constant_global_initializers 1\n"
             ;
     } else {
         preamble = 
@@ -284,6 +287,7 @@ void TParseVersions::getPreamble(std::string& preamble)
             "#define GL_ARB_sparse_texture2 1\n"
             "#define GL_ARB_sparse_texture_clamp 1\n"
 //            "#define GL_ARB_cull_distance 1\n"    // present for 4.5, but need extension control over block members
+            "#define GL_EXT_shader_non_constant_global_initializers 1\n"
             ;
     }
 

glslang/MachineIndependent/Versions.h

@@ -130,6 +130,8 @@ const char* const E_GL_ARB_sparse_texture2              = "GL_ARB_sparse_texture
 const char* const E_GL_ARB_sparse_texture_clamp         = "GL_ARB_sparse_texture_clamp";
 //const char* const E_GL_ARB_cull_distance            = "GL_ARB_cull_distance";  // present for 4.5, but need extension control over block members
 
+const char* const E_GL_EXT_shader_non_constant_global_initializers = "GL_EXT_shader_non_constant_global_initializers";
+
 // #line and #include
 const char* const E_GL_GOOGLE_cpp_style_line_directive          = "GL_GOOGLE_cpp_style_line_directive";
 const char* const E_GL_GOOGLE_include_directive                 = "GL_GOOGLE_include_directive";