added initial GLSL support to skslc

src/sksl/SkSLIRGenerator.cpp

Index: src/sksl/SkSLIRGenerator.cpp
diff --git a/src/sksl/SkSLIRGenerator.cpp b/src/sksl/SkSLIRGenerator.cpp
index f250c4bb0cc0d59c44c2a72244c78ce0203f6985..0bbd0b2b37e99a53bece98b8d1d2a33ffe47c8fa 100644
--- a/src/sksl/SkSLIRGenerator.cpp
+++ b/src/sksl/SkSLIRGenerator.cpp
@@ -182,7 +182,6 @@ std::unique_ptr<VarDeclaration> IRGenerator::convertVarDeclaration(const ASTVarD
                 currentVarSizes.push_back(nullptr);
             }
         }
-        sizes.push_back(std::move(currentVarSizes));
         auto var = std::unique_ptr<Variable>(new Variable(decl.fPosition, modifiers, decl.fNames[i], 
                                                           *type, storage));
         std::unique_ptr<Expression> value;
@@ -193,9 +192,16 @@ std::unique_ptr<VarDeclaration> IRGenerator::convertVarDeclaration(const ASTVarD
             }
             value = this->coerce(std::move(value), *type);
         }
-        variables.push_back(var.get());
-        fSymbolTable->add(decl.fNames[i], std::move(var));
-        values.push_back(std::move(value));
+        if ("gl_FragCoord" == decl.fNames[i] && (*fSymbolTable)[decl.fNames[i]]) {
+            // already defined, just update the modifiers
+            Variable* old = (Variable*) (*fSymbolTable)[decl.fNames[i]];
+            old->fModifiers = var->fModifiers;
+        } else {
+            variables.push_back(var.get());
+            fSymbolTable->add(decl.fNames[i], std::move(var));
+            values.push_back(std::move(value));
+            sizes.push_back(std::move(currentVarSizes));
+        }
     }
     return std::unique_ptr<VarDeclaration>(new VarDeclaration(decl.fPosition, std::move(variables), 
                                                               std::move(sizes), std::move(values)));
@@ -574,7 +580,8 @@ std::unique_ptr<Expression> IRGenerator::convertIdentifier(const ASTIdentifier&
             const Field* field = (const Field*) result;
             VariableReference* base = new VariableReference(identifier.fPosition, field->fOwner);
             return std::unique_ptr<Expression>(new FieldAccess(std::unique_ptr<Expression>(base),
-                                                               field->fFieldIndex));
+                                                               field->fFieldIndex,
+                                                               true));

[dogben, 2016/07/31 23:20:20]

nit: use enum, or "/*inAnonymousInterfaceBlock*/ true"

Same nit below.

[ethannicholas, 2016/08/02 16:13:18]

Done.

         }
         case Symbol::kType_Kind: {
             const Type* t = (const Type*) result;
@@ -651,18 +658,31 @@ static bool determine_binary_type(const Context& context,
                    right.canCoerceTo(*context.fBool_Type);
         case Token::STAR: // fall through
         case Token::STAREQ: 
-            // FIXME need to handle non-square matrices
             if (left.kind() == Type::kMatrix_Kind && right.kind() == Type::kVector_Kind) {
-                *outLeftType = &left;
-                *outRightType = &right;
-                *outResultType = &right;
-                return left.rows() == right.columns();
+                // determine final component type
+                if (determine_binary_type(context, Token::STAR, left.componentType(),
+                                          right.componentType(), outLeftType, outRightType,
+                                          outResultType, false)) {
+                    *outLeftType = &left;

[dogben, 2016/07/31 23:20:21]

Seems like you need *outLeftType = &(*outResultType)->toCompound(context,
left.columns(), left.rows()); and similarly for outRightType. I assume
SpvOpMatrixTimesVector doesn't work for dmat3 * vec3.

Same below.

[ethannicholas, 2016/08/02 16:13:18]

Completely reworked this.

+                    *outRightType = &right;
+                    *outResultType = &(*outResultType)->toCompound(context, left.rows(), 1);
+                    return left.rows() == right.columns();

[dogben, 2016/07/31 23:20:20]

Should be left.columns() == right.columns() because the vector is implicitly
transposed.

(Or maybe I'm confused, and it's implicitly transposed below, in which case you
would need left.columns() == right.columns() below.)

+                } else {
+                    return false;
+                }
             }  
             if (left.kind() == Type::kVector_Kind && right.kind() == Type::kMatrix_Kind) {
-                *outLeftType = &left;
-                *outRightType = &right;
-                *outResultType = &left;
-                return left.columns() == right.columns();
+                // determine final component type
+                if (determine_binary_type(context, Token::STAR, left.componentType(),
+                                          right.componentType(), outLeftType, outRightType,
+                                          outResultType, false)) {
+                    *outLeftType = &left;
+                    *outRightType = &right;
+                    *outResultType = &(*outResultType)->toCompound(context, right.columns(), 1);
+                    return left.columns() == right.rows();
+                } else {
+                    return false;
+                }
             }
             // fall through
         default:
@@ -1043,7 +1063,7 @@ std::unique_ptr<Expression> IRGenerator::convertField(std::unique_ptr<Expression
     auto fields = base->fType.fields();
     for (size_t i = 0; i < fields.size(); i++) {
         if (fields[i].fName == field) {
-            return std::unique_ptr<Expression>(new FieldAccess(std::move(base), (int) i));
+            return std::unique_ptr<Expression>(new FieldAccess(std::move(base), (int) i, false));
         }
     }
     fErrors.error(base->fPosition, "type '" + base->fType.description() + "' does not have a "