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/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SKSL_FUNCTIONDECLARATION
#define SKSL_FUNCTIONDECLARATION
#include "SkSLExpression.h"
#include "SkSLModifiers.h"
#include "SkSLSymbol.h"
#include "SkSLSymbolTable.h"
#include "SkSLType.h"
#include "SkSLVariable.h"
namespace SkSL {
/**
* A function declaration (not a definition -- does not contain a body).
*/
struct FunctionDeclaration : public Symbol {
FunctionDeclaration(Position position, SkString name,
std::vector<const Variable*> parameters, const Type& returnType)
: INHERITED(position, kFunctionDeclaration_Kind, std::move(name))
, fDefined(false)
, fBuiltin(false)
, fParameters(std::move(parameters))
, fReturnType(returnType) {}
SkString description() const override {
SkString result = fReturnType.description() + " " + fName + "(";
SkString separator;
for (auto p : fParameters) {
result += separator;
separator = ", ";
result += p->description();
}
result += ")";
return result;
}
bool matches(const FunctionDeclaration& f) const {
if (fName != f.fName) {
return false;
}
if (fParameters.size() != f.fParameters.size()) {
return false;
}
for (size_t i = 0; i < fParameters.size(); i++) {
if (fParameters[i]->fType != f.fParameters[i]->fType) {
return false;
}
}
return true;
}
/**
* Determine the effective types of this function's parameters and return value when called with
* the given arguments. This is relevant for functions with generic parameter types, where this
* will collapse the generic types down into specific concrete types.
*
* Returns true if it was able to select a concrete set of types for the generic function, false
* if there is no possible way this can match the argument types. Note that even a true return
* does not guarantee that the function can be successfully called with those arguments, merely
* indicates that an attempt should be made. If false is returned, the state of
* outParameterTypes and outReturnType are undefined.
*/
bool determineFinalTypes(const std::vector<std::unique_ptr<Expression>>& arguments,
std::vector<const Type*>* outParameterTypes,
const Type** outReturnType) const {
assert(arguments.size() == fParameters.size());
int genericIndex = -1;
for (size_t i = 0; i < arguments.size(); i++) {
if (fParameters[i]->fType.kind() == Type::kGeneric_Kind) {
std::vector<const Type*> types = fParameters[i]->fType.coercibleTypes();
if (genericIndex == -1) {
for (size_t j = 0; j < types.size(); j++) {
if (arguments[i]->fType.canCoerceTo(*types[j])) {
genericIndex = j;
break;
}
}
if (genericIndex == -1) {
return false;
}
}
outParameterTypes->push_back(types[genericIndex]);
} else {
outParameterTypes->push_back(&fParameters[i]->fType);
}
}
if (fReturnType.kind() == Type::kGeneric_Kind) {
assert(genericIndex != -1);
*outReturnType = fReturnType.coercibleTypes()[genericIndex];
} else {
*outReturnType = &fReturnType;
}
return true;
}
mutable bool fDefined;
bool fBuiltin;
const std::vector<const Variable*> fParameters;
const Type& fReturnType;
typedef Symbol INHERITED;
};
} // namespace
#endif