Disallow user-defined function calls in global variable init

src/compiler/translator/ValidateGlobalInitializer.cpp

@@ -17,6 +17,7 @@ class ValidateGlobalInitializerTraverser : public TIntermTraverser
     ValidateGlobalInitializerTraverser(const TParseContext *context);
 
     void visitSymbol(TIntermSymbol *node) override;
+    bool visitAggregate(Visit visit, TIntermAggregate *node) override;
 
     bool isValid() const { return mIsValid; }
     bool issueWarning() const { return mIssueWarning; }
@@ -59,6 +60,16 @@ void ValidateGlobalInitializerTraverser::visitSymbol(TIntermSymbol *node)
     }
 }
 
+bool ValidateGlobalInitializerTraverser::visitAggregate(Visit visit, TIntermAggregate *node)
+{
+    // Disallow calls to user-defined functions in global variable initializers.
+    if (node->getOp() == EOpFunctionCall && node->isUserDefined())
+    {
+        mIsValid = false;
+    }
+    return true;
+}
+
 ValidateGlobalInitializerTraverser::ValidateGlobalInitializerTraverser(const TParseContext *context)
     : TIntermTraverser(true, false, false),
       mContext(context),

src/tests/compiler_tests/ExpressionLimit_test.cpp

@@ -405,12 +405,9 @@ TEST_F(ExpressionLimitTest, Recursion)
             return vec3(float(r) / 255.0, float(g) / 255.0, float(b) / 255.0);
         }
 
-        // these external calls used to incorrectly trigger
-        // recursion detection.
-        vec3 hairColor0 = rgb(151, 200, 234);
-        vec3 faceColor2 = rgb(183, 148, 133);
-
         void main() {
+            vec3 hairColor0 = rgb(151, 200, 234);
+            vec3 faceColor2 = rgb(183, 148, 133);
             gl_FragColor = u_color + vec4(hairColor0 + faceColor2, 0);
         }
     );

src/tests/compiler_tests/MalformedShader_test.cpp

@@ -508,6 +508,23 @@ TEST_F(MalformedShaderTest, AssignUniformToGlobalESSL1)
     }
 }
 
+// Global variable initializers need to be constant expressions (ESSL 1.00 section 4.3)
+// Initializing with an user-defined function call should be an error.
+TEST_F(MalformedShaderTest, AssignFunctionCallToGlobal)
+{
+    const std::string &shaderString =
+        "precision mediump float;\n"
+        "float foo() { return 1.0; }\n"
+        "float b = foo();\n"
+        "void main() {\n"
+        "   gl_FragColor = vec4(b);\n"
+        "}\n";
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}
+
 // Global variable initializers need to be constant expressions (ESSL 3.00 section 4.3)
 // Initializing with a non-constant global should be an error.
 TEST_F(MalformedShaderTest, AssignNonConstGlobalToGlobal)