skia2/include/sksl/DSLSymbols.h
Ethan Nicholas 549c6b8739 Added Poison values to SkSL to improve DSL error handling
This also tightens up the rules around releasing DSL objects.

Bug: skia:12133
Change-Id: I11a6d8fbcec58374f7b5ed5ced1c5c112e2b7cc7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/421323
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2021-06-28 19:15:16 +00:00

73 lines
1.7 KiB
C++

/*
* Copyright 2021 Google LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SKSL_DSL_SYMBOLS
#define SKSL_DSL_SYMBOLS
#include "include/core/SkStringView.h"
#include "include/private/SkSLString.h"
#include "include/sksl/DSLExpression.h"
#include <memory>
namespace SkSL {
class SymbolTable;
namespace dsl {
class DSLVar;
// This header provides methods for manually managing symbol tables in DSL code. They should not be
// used by normal hand-written DSL code, where we rely on C++ to manage symbols, but are instead
// needed when DSL objects are being constructed programmatically (as in DSLParser).
/**
* Pushes a new symbol table onto the symbol table stack.
*/
void PushSymbolTable();
/**
* Pops the top symbol table from the stack. As symbol tables are shared pointers, this will only
* destroy the symbol table if it was never attached to anything (e.g. passed into a Block
* constructor).
*/
void PopSymbolTable();
/**
* Returns the current symbol table. Outside of SkSL itself, this is an opaque pointer, used only
* for passing it to DSL methods that require it.
*/
std::shared_ptr<SymbolTable> CurrentSymbolTable();
/**
* Returns an expression referring to the named symbol.
*/
DSLPossibleExpression Symbol(skstd::string_view name);
/**
* Returns true if the name refers to a type.
*/
bool IsType(skstd::string_view name);
/**
* Adds a variable to the current symbol table.
*/
void AddToSymbolTable(DSLVar& var);
/**
* Attaches a String to the current symbol table. The String will persist as long as the symbol
* table remains in memory.
*/
const String* Retain(String s);
} // namespace dsl
} // namespace SkSL
#endif