Mark private types as invalid in the public symbol table.

Previously, in public code, private types didn't exist anywhere in the
symbol table chain, and those names were free for the taking. Now, we
register them as invalid types in the public symbol table. This prevents
them from being used as variable names, and gives a more explicit error
if you try to use them as a type.

Change-Id: I9a943bf923639b72cbf36b1acf4b4fbe70982786
Bug: skia:12538
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/459119
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

gn/sksl_tests.gni

@@ -637,6 +637,16 @@ sksl_rte_error_tests = [
   "/sksl/runtime_errors/ProgramTooLarge_NestedLoops.rts",
   "/sksl/runtime_errors/ProgramTooLarge_SplitLoops.rts",
   "/sksl/runtime_errors/ProgramTooLarge_StackDepth.rts",
+  "/sksl/runtime_errors/ReservedNameISampler2D.rts",
+  "/sksl/runtime_errors/ReservedNameSampler.rts",
+  "/sksl/runtime_errors/ReservedNameSampler1D.rts",
+  "/sksl/runtime_errors/ReservedNameSampler2D.rts",
+  "/sksl/runtime_errors/ReservedNameSampler2DRect.rts",
+  "/sksl/runtime_errors/ReservedNameSampler3D.rts",
+  "/sksl/runtime_errors/ReservedNameSamplerExternalOES.rts",
+  "/sksl/runtime_errors/ReservedNameSubpassInput.rts",
+  "/sksl/runtime_errors/ReservedNameSubpassInputMS.rts",
+  "/sksl/runtime_errors/ReservedNameTexture2D.rts",
   "/sksl/runtime_errors/UnsupportedTypeFragmentProcessor.rts",
   "/sksl/runtime_errors/UnsupportedTypeSampler.rts",
   "/sksl/runtime_errors/UnsupportedTypeTexture.rts",

resources/sksl/runtime_errors/ReservedNameISampler2D.rts

@@ -0,0 +1 @@
+int isampler2D;

resources/sksl/runtime_errors/ReservedNameSampler.rts

@@ -0,0 +1 @@
+int sampler;

resources/sksl/runtime_errors/ReservedNameSampler1D.rts

@@ -0,0 +1 @@
+int sampler1D;

resources/sksl/runtime_errors/ReservedNameSampler2D.rts

@@ -0,0 +1 @@
+int sampler2D;

resources/sksl/runtime_errors/ReservedNameSampler2DRect.rts

@@ -0,0 +1 @@
+int sampler2DRect;

resources/sksl/runtime_errors/ReservedNameSampler3D.rts

@@ -0,0 +1 @@
+int sampler3D;

resources/sksl/runtime_errors/ReservedNameSamplerExternalOES.rts

@@ -0,0 +1 @@
+int samplerExternalOES;

resources/sksl/runtime_errors/ReservedNameSubpassInput.rts

@@ -0,0 +1 @@
+int subpassInput;

resources/sksl/runtime_errors/ReservedNameSubpassInputMS.rts

@@ -0,0 +1 @@
+int subpassInputMS;

resources/sksl/runtime_errors/ReservedNameTexture2D.rts

@@ -0,0 +1 @@
+int texture2D;

src/sksl/SkSLCompiler.cpp

@@ -243,7 +243,7 @@ const ParsedModule& Compiler::loadVertexModule() {
 }
 
 static void add_glsl_type_aliases(SkSL::SymbolTable* symbols, const SkSL::BuiltinTypes& types) {
-    // Add some aliases to the runtime effect modules so that it's friendlier, and more like GLSL
+    // Add some aliases to the runtime effect modules so that it's friendlier, and more like GLSL.
     symbols->addAlias("vec2", types.fFloat2.get());
     symbols->addAlias("vec3", types.fFloat3.get());
     symbols->addAlias("vec4", types.fFloat4.get());
@@ -259,6 +259,12 @@ static void add_glsl_type_aliases(SkSL::SymbolTable* symbols, const SkSL::Builti
     symbols->addAlias("mat2", types.fFloat2x2.get());
     symbols->addAlias("mat3", types.fFloat3x3.get());
     symbols->addAlias("mat4", types.fFloat4x4.get());
+
+    // Alias every private type to "invalid". This will prevent code from using built-in names like
+    // `sampler2D` as variable names.
+    for (BuiltinTypePtr privateType : kPrivateTypes) {
+        symbols->addAlias((types.*privateType)->name(), types.fInvalid.get());
+    }
 }
 
 const ParsedModule& Compiler::loadPublicModule() {

src/sksl/ir/SkSLVarDeclarations.cpp

@@ -39,6 +39,10 @@ String VarDeclaration::description() const {
 
 void VarDeclaration::ErrorCheck(const Context& context, int line, const Modifiers& modifiers,
         const Type* baseType, Variable::Storage storage) {
+    if (*baseType == *context.fTypes.fInvalid) {
+        context.fErrors->error(line, "invalid type");
+        return;
+    }
     if (context.fConfig->strictES2Mode() && baseType->isArray()) {
         context.fErrors->error(line, "array size must appear after variable name");
     }

tests/sksl/runtime_errors/ReservedNameISampler2D.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'isampler2D'
+1 error

tests/sksl/runtime_errors/ReservedNameSampler.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler'
+1 error

tests/sksl/runtime_errors/ReservedNameSampler1D.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler1D'
+1 error

tests/sksl/runtime_errors/ReservedNameSampler2D.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler2D'
+1 error

tests/sksl/runtime_errors/ReservedNameSampler2DRect.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler2DRect'
+1 error

tests/sksl/runtime_errors/ReservedNameSampler3D.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler3D'
+1 error

tests/sksl/runtime_errors/ReservedNameSamplerExternalOES.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'samplerExternalOES'
+1 error

tests/sksl/runtime_errors/ReservedNameSubpassInput.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'subpassInput'
+1 error

tests/sksl/runtime_errors/ReservedNameSubpassInputMS.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'subpassInputMS'
+1 error

tests/sksl/runtime_errors/ReservedNameTexture2D.skvm

@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'texture2D'
+1 error

tests/sksl/runtime_errors/UnsupportedTypeSampler.skvm

@@ -1,6 +1,4 @@
 ### Compilation failed:
 
-error: 1: no type named 'sampler2D'
-error: 1: no type named 's'
-error: 1: expected a declaration, but found ';'
-3 errors
+error: 1: invalid type
+1 error

tests/sksl/runtime_errors/UnsupportedTypeTexture.skvm

@@ -1,6 +1,4 @@
 ### Compilation failed:
 
-error: 1: no type named 'texture2D'
-error: 1: no type named 's'
-error: 1: expected a declaration, but found ';'
-3 errors
+error: 1: invalid type
+1 error