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effect_parser.cpp
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effect_parser.cpp
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/*
* Copyright (C) 2014 Patrick Mours. All rights reserved.
* License: https://github.com/crosire/reshade#license
*/
#include "effect_lexer.hpp"
#include "effect_parser.hpp"
#include "effect_codegen.hpp"
#include <cassert>
#include <algorithm>
#include <functional>
struct on_scope_exit
{
template <typename F>
on_scope_exit(F lambda) : leave(lambda) { }
~on_scope_exit() { leave(); }
std::function<void()> leave;
};
reshadefx::parser::parser()
{
}
reshadefx::parser::~parser()
{
}
bool reshadefx::parser::parse(std::string input, codegen *backend)
{
_lexer.reset(new lexer(std::move(input)));
// Set backend for subsequent code-generation
_codegen = backend;
consume();
bool parse_success = true;
while (!peek(tokenid::end_of_file))
{
if (!parse_top())
parse_success = false;
}
return parse_success;
}
// -- Error Handling -- //
void reshadefx::parser::error(const location &location, unsigned int code, const std::string &message)
{
if (_errors.size() > 1000)
return; // Stop printing any more errors after a certain amount
_errors += location.source;
_errors += '(' + std::to_string(location.line) + ", " + std::to_string(location.column) + ')' + ": error";
_errors += (code == 0) ? ": " : " X" + std::to_string(code) + ": ";
_errors += message;
_errors += '\n';
}
void reshadefx::parser::warning(const location &location, unsigned int code, const std::string &message)
{
_errors += location.source;
_errors += '(' + std::to_string(location.line) + ", " + std::to_string(location.column) + ')' + ": warning";
_errors += (code == 0) ? ": " : " X" + std::to_string(code) + ": ";
_errors += message;
_errors += '\n';
}
// -- Token Management -- //
void reshadefx::parser::backup()
{
_token_backup = _token_next;
_lexer_backup_offset = _lexer->input_offset();
}
void reshadefx::parser::restore()
{
_lexer->reset_to_offset(_lexer_backup_offset);
_token_next = _token_backup; // Copy instead of move here, since restore may be called twice (from 'accept_type_class' and then again from 'parse_expression_unary')
}
void reshadefx::parser::consume()
{
_token = std::move(_token_next);
_token_next = _lexer->lex();
}
void reshadefx::parser::consume_until(tokenid tokid)
{
while (!accept(tokid) && !peek(tokenid::end_of_file))
{
consume();
}
}
bool reshadefx::parser::accept(tokenid tokid)
{
if (peek(tokid))
{
consume();
return true;
}
return false;
}
bool reshadefx::parser::expect(tokenid tokid)
{
if (!accept(tokid))
{
error(_token_next.location, 3000, "syntax error: unexpected '" + token::id_to_name(_token_next.id) + "', expected '" + token::id_to_name(tokid) + '\'');
return false;
}
return true;
}
// -- Type Parsing -- //
bool reshadefx::parser::accept_symbol(std::string &identifier, scope &scope, symbol &symbol)
{
// Starting an identifier with '::' restricts the symbol search to the global namespace level
const bool exclusive = accept(tokenid::colon_colon);
if (exclusive ? !expect(tokenid::identifier) : !accept(tokenid::identifier))
{
// No token should come through here, since all possible prefix expressions should have been handled above, so this is an error in the syntax
if (!exclusive)
error(_token_next.location, 3000, "syntax error: unexpected '" + token::id_to_name(_token_next.id) + '\'');
return false;
}
identifier = std::move(_token.literal_as_string);
// Can concatenate multiple '::' to force symbol search for a specific namespace level
while (accept(tokenid::colon_colon))
{
if (!expect(tokenid::identifier))
return false;
identifier += "::" + std::move(_token.literal_as_string);
}
// Figure out which scope to start searching in
scope = { "::", 0, 0 };
if (!exclusive) scope = current_scope();
// Lookup name in the symbol table
symbol = find_symbol(identifier, scope, exclusive);
return true;
}
bool reshadefx::parser::accept_type_class(type &type)
{
type.rows = type.cols = 0;
if (peek(tokenid::identifier) || peek(tokenid::colon_colon))
{
type.base = type::t_struct;
backup(); // Need to restore if this identifier does not turn out to be a structure
scope scope; symbol symbol;
if (std::string identifier; accept_symbol(identifier, scope, symbol))
{
if (symbol.id && symbol.op == symbol_type::structure)
{
type.definition = symbol.id;
return true;
}
}
restore();
return false;
}
else if (accept(tokenid::vector))
{
type.base = type::t_float; // Default to float4 unless a type is specified (see below)
type.rows = 4, type.cols = 1;
if (accept('<'))
{
if (!accept_type_class(type)) // This overwrites the base type again
return error(_token_next.location, 3000, "syntax error: unexpected '" + token::id_to_name(_token_next.id) + "', expected vector element type"), false;
else if (!type.is_scalar())
return error(_token.location, 3122, "vector element type must be a scalar type"), false;
if (!expect(',') || !expect(tokenid::int_literal))
return false;
else if (_token.literal_as_int < 1 || _token.literal_as_int > 4)
return error(_token.location, 3052, "vector dimension must be between 1 and 4"), false;
type.rows = static_cast<unsigned int>(_token.literal_as_int);
if (!expect('>'))
return false;
}
return true;
}
else if (accept(tokenid::matrix))
{
type.base = type::t_float; // Default to float4x4 unless a type is specified (see below)
type.rows = 4, type.cols = 4;
if (accept('<'))
{
if (!accept_type_class(type)) // This overwrites the base type again
return error(_token_next.location, 3000, "syntax error: unexpected '" + token::id_to_name(_token_next.id) + "', expected matrix element type"), false;
else if (!type.is_scalar())
return error(_token.location, 3123, "matrix element type must be a scalar type"), false;
if (!expect(',') || !expect(tokenid::int_literal))
return false;
else if (_token.literal_as_int < 1 || _token.literal_as_int > 4)
return error(_token.location, 3053, "matrix dimensions must be between 1 and 4"), false;
type.rows = static_cast<unsigned int>(_token.literal_as_int);
if (!expect(',') || !expect(tokenid::int_literal))
return false;
else if (_token.literal_as_int < 1 || _token.literal_as_int > 4)
return error(_token.location, 3053, "matrix dimensions must be between 1 and 4"), false;
type.cols = static_cast<unsigned int>(_token.literal_as_int);
if (!expect('>'))
return false;
}
return true;
}
switch (_token_next.id)
{
case tokenid::void_:
type.base = type::t_void;
break;
case tokenid::bool_:
case tokenid::bool2:
case tokenid::bool3:
case tokenid::bool4:
type.base = type::t_bool;
type.rows = 1 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::bool_);
type.cols = 1;
break;
case tokenid::bool2x2:
case tokenid::bool3x3:
case tokenid::bool4x4:
type.base = type::t_bool;
type.rows = 2 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::bool2x2);
type.cols = type.rows;
break;
case tokenid::int_:
case tokenid::int2:
case tokenid::int3:
case tokenid::int4:
type.base = type::t_int;
type.rows = 1 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::int_);
type.cols = 1;
break;
case tokenid::int2x2:
case tokenid::int3x3:
case tokenid::int4x4:
type.base = type::t_int;
type.rows = 2 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::int2x2);
type.cols = type.rows;
break;
case tokenid::uint_:
case tokenid::uint2:
case tokenid::uint3:
case tokenid::uint4:
type.base = type::t_uint;
type.rows = 1 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::uint_);
type.cols = 1;
break;
case tokenid::uint2x2:
case tokenid::uint3x3:
case tokenid::uint4x4:
type.base = type::t_uint;
type.rows = 2 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::uint2x2);
type.cols = type.rows;
break;
case tokenid::float_:
case tokenid::float2:
case tokenid::float3:
case tokenid::float4:
type.base = type::t_float;
type.rows = 1 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::float_);
type.cols = 1;
break;
case tokenid::float2x2:
case tokenid::float3x3:
case tokenid::float4x4:
type.base = type::t_float;
type.rows = 2 + static_cast<unsigned int>(_token_next.id) - static_cast<unsigned int>(tokenid::float2x2);
type.cols = type.rows;
break;
case tokenid::string_:
type.base = type::t_string;
break;
case tokenid::texture:
type.base = type::t_texture;
break;
case tokenid::sampler:
type.base = type::t_sampler;
break;
case tokenid::storage:
type.base = type::t_storage;
break;
default:
return false;
}
consume();
return true;
}
bool reshadefx::parser::accept_type_qualifiers(type &type)
{
unsigned int qualifiers = 0;
// Storage
if (accept(tokenid::extern_))
qualifiers |= type::q_extern;
if (accept(tokenid::static_))
qualifiers |= type::q_static;
if (accept(tokenid::uniform_))
qualifiers |= type::q_uniform;
if (accept(tokenid::volatile_))
qualifiers |= type::q_volatile;
if (accept(tokenid::precise))
qualifiers |= type::q_precise;
if (accept(tokenid::groupshared))
qualifiers |= type::q_groupshared;
if (accept(tokenid::in))
qualifiers |= type::q_in;
if (accept(tokenid::out))
qualifiers |= type::q_out;
if (accept(tokenid::inout))
qualifiers |= type::q_inout;
// Modifiers
if (accept(tokenid::const_))
qualifiers |= type::q_const;
// Interpolation
if (accept(tokenid::linear))
qualifiers |= type::q_linear;
if (accept(tokenid::noperspective))
qualifiers |= type::q_noperspective;
if (accept(tokenid::centroid))
qualifiers |= type::q_centroid;
if (accept(tokenid::nointerpolation))
qualifiers |= type::q_nointerpolation;
if (qualifiers == 0)
return false;
if ((type.qualifiers & qualifiers) == qualifiers)
warning(_token.location, 3048, "duplicate usages specified");
type.qualifiers |= qualifiers;
// Continue parsing potential additional qualifiers until no more are found
accept_type_qualifiers(type);
return true;
}
bool reshadefx::parser::parse_type(type &type)
{
type.qualifiers = 0;
accept_type_qualifiers(type);
if (!accept_type_class(type))
return false;
if (type.is_integral() && (type.has(type::q_centroid) || type.has(type::q_noperspective)))
return error(_token.location, 4576, "signature specifies invalid interpolation mode for integer component type"), false;
else if (type.has(type::q_centroid) && !type.has(type::q_noperspective))
type.qualifiers |= type::q_linear;
return true;
}
bool reshadefx::parser::parse_array_size(type &type)
{
// Reset array length to zero before checking if one exists
type.array_length = 0;
if (accept('['))
{
if (accept(']'))
{
// No length expression, so this is an unsized array
type.array_length = -1;
}
else if (expression expression; parse_expression(expression) && expect(']'))
{
if (!expression.is_constant || !(expression.type.is_scalar() && expression.type.is_integral()))
return error(expression.location, 3058, "array dimensions must be literal scalar expressions"), false;
type.array_length = expression.constant.as_uint[0];
if (type.array_length < 1 || type.array_length > 65536)
return error(expression.location, 3059, "array dimension must be between 1 and 65536"), false;
}
else
{
return false;
}
}
// Multi-dimensional arrays are not supported
if (peek('['))
return error(_token_next.location, 3119, "arrays cannot be multi-dimensional"), false;
return true;
}
// -- Expression Parsing -- //
bool reshadefx::parser::accept_unary_op()
{
switch (_token_next.id)
{
case tokenid::exclaim: // !x (logical not)
case tokenid::plus: // +x
case tokenid::minus: // -x (negate)
case tokenid::tilde: // ~x (bitwise not)
case tokenid::plus_plus: // ++x
case tokenid::minus_minus: // --x
break;
default:
return false;
}
consume();
return true;
}
bool reshadefx::parser::accept_postfix_op()
{
switch (_token_next.id)
{
case tokenid::plus_plus: // ++x
case tokenid::minus_minus: // --x
break;
default:
return false;
}
consume();
return true;
}
bool reshadefx::parser::peek_multary_op(unsigned int &precedence) const
{
// Precedence values taken from https://cppreference.com/w/cpp/language/operator_precedence
switch (_token_next.id)
{
case tokenid::question: precedence = 1; break; // x ? a : b
case tokenid::pipe_pipe: precedence = 2; break; // a || b (logical or)
case tokenid::ampersand_ampersand: precedence = 3; break; // a && b (logical and)
case tokenid::pipe: precedence = 4; break; // a | b (bitwise or)
case tokenid::caret: precedence = 5; break; // a ^ b (bitwise xor)
case tokenid::ampersand: precedence = 6; break; // a & b (bitwise and)
case tokenid::equal_equal: precedence = 7; break; // a == b (equal)
case tokenid::exclaim_equal: precedence = 7; break; // a != b (not equal)
case tokenid::less: precedence = 8; break; // a < b
case tokenid::greater: precedence = 8; break; // a > b
case tokenid::less_equal: precedence = 8; break; // a <= b
case tokenid::greater_equal: precedence = 8; break; // a >= b
case tokenid::less_less: precedence = 9; break; // a << b (left shift)
case tokenid::greater_greater: precedence = 9; break; // a >> b (right shift)
case tokenid::plus: precedence = 10; break; // a + b (add)
case tokenid::minus: precedence = 10; break; // a - b (subtract)
case tokenid::star: precedence = 11; break; // a * b (multiply)
case tokenid::slash: precedence = 11; break; // a / b (divide)
case tokenid::percent: precedence = 11; break; // a % b (modulo)
default:
return false;
}
// Do not consume token yet since the expression may be skipped due to precedence
return true;
}
bool reshadefx::parser::accept_assignment_op()
{
switch (_token_next.id)
{
case tokenid::equal: // a = b
case tokenid::percent_equal: // a %= b
case tokenid::ampersand_equal: // a &= b
case tokenid::star_equal: // a *= b
case tokenid::plus_equal: // a += b
case tokenid::minus_equal: // a -= b
case tokenid::slash_equal: // a /= b
case tokenid::less_less_equal: // a <<= b
case tokenid::greater_greater_equal: // a >>= b
case tokenid::caret_equal: // a ^= b
case tokenid::pipe_equal: // a |= b
break;
default:
return false;
}
consume();
return true;
}
bool reshadefx::parser::parse_expression(expression &exp)
{
// Parse first expression
if (!parse_expression_assignment(exp))
return false;
// Continue parsing if an expression sequence is next (in the form "a, b, c, ...")
while (accept(','))
// Overwrite 'exp' since conveniently the last expression in the sequence is the result
if (!parse_expression_assignment(exp))
return false;
return true;
}
bool reshadefx::parser::parse_expression_unary(expression &exp)
{
auto location = _token_next.location;
#pragma region Prefix Expression
// Check if a prefix operator exists
if (accept_unary_op())
{
// Remember the operator token before parsing the expression that follows it
const tokenid op = _token.id;
// Parse the actual expression
if (!parse_expression_unary(exp))
return false;
// Unary operators are only valid on basic types
if (!exp.type.is_scalar() && !exp.type.is_vector() && !exp.type.is_matrix())
return error(exp.location, 3022, "scalar, vector, or matrix expected"), false;
// Special handling for the "++" and "--" operators
if (op == tokenid::plus_plus || op == tokenid::minus_minus)
{
if (exp.type.has(type::q_const) || exp.type.has(type::q_uniform) || !exp.is_lvalue)
return error(location, 3025, "l-value specifies const object"), false;
// Create a constant one in the type of the expression
constant one = {};
for (unsigned int i = 0; i < exp.type.components(); ++i)
if (exp.type.is_floating_point()) one.as_float[i] = 1.0f; else one.as_uint[i] = 1u;
const auto value = _codegen->emit_load(exp);
const auto result = _codegen->emit_binary_op(location, op, exp.type, value,
_codegen->emit_constant(exp.type, one));
// The "++" and "--" operands modify the source variable, so store result back into it
_codegen->emit_store(exp, result);
}
else if (op != tokenid::plus) // Ignore "+" operator since it does not actually do anything
{
// The "~" bitwise operator is only valid on integral types
if (op == tokenid::tilde && !exp.type.is_integral())
return error(exp.location, 3082, "int or unsigned int type required"), false;
// The logical not operator expects a boolean type as input, so perform cast if necessary
if (op == tokenid::exclaim && !exp.type.is_boolean())
exp.add_cast_operation({ type::t_bool, exp.type.rows, exp.type.cols }); // Note: The result will be boolean as well
// Constant expressions can be evaluated at compile time
if (!exp.evaluate_constant_expression(op))
{
const auto value = _codegen->emit_load(exp);
const auto result = _codegen->emit_unary_op(location, op, exp.type, value);
exp.reset_to_rvalue(location, result, exp.type);
}
}
}
else if (accept('('))
{
// Note: This backup may get overridden in 'accept_type_class', but should point to the same token still
backup();
// Check if this is a C-style cast expression
if (type cast_type; accept_type_class(cast_type))
{
if (peek('('))
{
// This is not a C-style cast but a constructor call, so need to roll-back and parse that instead
restore();
}
else if (expect(')'))
{
// Parse the expression behind cast operator
if (!parse_expression_unary(exp))
return false;
// Check if the types already match, in which case there is nothing to do
if (exp.type == cast_type)
return true;
// Check if a cast between these types is valid
if (!type::rank(exp.type, cast_type))
return error(location, 3017, "cannot convert these types (from " + exp.type.description() + " to " + cast_type.description() + ')'), false;
exp.add_cast_operation(cast_type);
return true;
}
else
{
// Type name was not followed by a closing parenthesis
return false;
}
}
// Parse expression between the parentheses
if (!parse_expression(exp) || !expect(')'))
return false;
}
else if (accept('{'))
{
bool is_constant = true;
std::vector<expression> elements;
type composite_type = { type::t_void, 1, 1 };
while (!peek('}'))
{
// There should be a comma between arguments
if (!elements.empty() && !expect(','))
return consume_until('}'), false;
// Initializer lists might contain a comma at the end, so break out of the loop if nothing follows afterwards
if (peek('}'))
break;
// Parse the argument expression
if (!parse_expression_assignment(elements.emplace_back()))
return consume_until('}'), false;
expression &element = elements.back();
if (element.type.is_array())
return error(element.location, 3119, "arrays cannot be multi-dimensional"), consume_until('}'), false;
if (composite_type.base != type::t_void && element.type.definition != composite_type.definition)
return error(element.location, 3017, "cannot convert these types (from " + element.type.description() + " to " + composite_type.description() + ')'), false;
is_constant &= element.is_constant; // Result is only constant if all arguments are constant
composite_type = type::merge(composite_type, element.type);
}
// Constant arrays can be constructed at compile time
if (is_constant)
{
constant res = {};
for (expression &element : elements)
{
element.add_cast_operation(composite_type);
res.array_data.push_back(element.constant);
}
composite_type.array_length = static_cast<int>(elements.size());
exp.reset_to_rvalue_constant(location, std::move(res), composite_type);
}
else
{
composite_type.array_length = static_cast<int>(elements.size());
// Resolve all access chains
for (expression &element : elements)
{
element.reset_to_rvalue(element.location, _codegen->emit_load(element), element.type);
}
const auto result = _codegen->emit_construct(location, composite_type, elements);
exp.reset_to_rvalue(location, result, composite_type);
}
return expect('}');
}
else if (accept(tokenid::true_literal))
{
exp.reset_to_rvalue_constant(location, true);
}
else if (accept(tokenid::false_literal))
{
exp.reset_to_rvalue_constant(location, false);
}
else if (accept(tokenid::int_literal))
{
exp.reset_to_rvalue_constant(location, _token.literal_as_int);
}
else if (accept(tokenid::uint_literal))
{
exp.reset_to_rvalue_constant(location, _token.literal_as_uint);
}
else if (accept(tokenid::float_literal))
{
exp.reset_to_rvalue_constant(location, _token.literal_as_float);
}
else if (accept(tokenid::double_literal))
{
// Convert double literal to float literal for now
warning(location, 5000, "double literal truncated to float literal");
exp.reset_to_rvalue_constant(location, static_cast<float>(_token.literal_as_double));
}
else if (accept(tokenid::string_literal))
{
std::string value = std::move(_token.literal_as_string);
// Multiple string literals in sequence are concatenated into a single string literal
while (accept(tokenid::string_literal))
value += _token.literal_as_string;
exp.reset_to_rvalue_constant(location, std::move(value));
}
else if (type type; accept_type_class(type)) // Check if this is a constructor call expression
{
if (!expect('('))
return false;
if (!type.is_numeric())
return error(location, 3037, "constructors only defined for numeric base types"), false;
// Empty constructors do not exist
if (accept(')'))
return error(location, 3014, "incorrect number of arguments to numeric-type constructor"), false;
// Parse entire argument expression list
bool is_constant = true;
unsigned int num_components = 0;
std::vector<expression> arguments;
while (!peek(')'))
{
// There should be a comma between arguments
if (!arguments.empty() && !expect(','))
return false;
// Parse the argument expression
if (!parse_expression_assignment(arguments.emplace_back()))
return false;
expression &argument = arguments.back();
// Constructors are only defined for numeric base types
if (!argument.type.is_numeric())
return error(argument.location, 3017, "cannot convert non-numeric types"), false;
is_constant &= argument.is_constant; // Result is only constant if all arguments are constant
num_components += argument.type.components();
}
// The list should be terminated with a parenthesis
if (!expect(')'))
return false;
// The total number of argument elements needs to match the number of elements in the result type
if (num_components != type.components())
return error(location, 3014, "incorrect number of arguments to numeric-type constructor"), false;
assert(num_components > 0 && num_components <= 16 && !type.is_array());
if (is_constant) // Constants can be converted at compile time
{
constant res = {};
unsigned int i = 0;
for (expression &argument : arguments)
{
argument.add_cast_operation({ type.base, argument.type.rows, argument.type.cols });
for (unsigned int k = 0; k < argument.type.components(); ++k)
res.as_uint[i++] = argument.constant.as_uint[k];
}
exp.reset_to_rvalue_constant(location, std::move(res), type);
}
else if (arguments.size() > 1)
{
// Flatten all arguments to a list of scalars
for (auto it = arguments.begin(); it != arguments.end();)
{
// Argument is a scalar already, so only need to cast it
if (it->type.is_scalar())
{
expression &argument = *it++;
auto scalar_type = argument.type;
scalar_type.base = type.base;
argument.add_cast_operation(scalar_type);
argument.reset_to_rvalue(argument.location, _codegen->emit_load(argument), scalar_type);
}
else
{
const expression argument = *it;
it = arguments.erase(it);
// Convert to a scalar value and re-enter the loop in the next iteration (in case a cast is necessary too)
for (unsigned int i = argument.type.components(); i > 0; --i)
{
expression scalar = argument;
scalar.add_constant_index_access(i - 1);
it = arguments.insert(it, scalar);
}
}
}
const auto result = _codegen->emit_construct(location, type, arguments);
exp.reset_to_rvalue(location, result, type);
}
else // A constructor call with a single argument is identical to a cast
{
assert(!arguments.empty());
// Reset expression to only argument and add cast to expression access chain
exp = std::move(arguments[0]); exp.add_cast_operation(type);
}
}
// At this point only identifiers are left to check and resolve
else
{
scope scope;
symbol symbol;
std::string identifier;
if (!accept_symbol(identifier, scope, symbol))
return false;
// Check if this is a function call or variable reference
if (accept('('))
{
// Can only call symbols that are functions, but do not abort yet if no symbol was found since the identifier may reference an intrinsic
if (symbol.id && symbol.op != symbol_type::function)
return error(location, 3005, "identifier '" + identifier + "' represents a variable, not a function"), false;
// Parse entire argument expression list
std::vector<expression> arguments;
while (!peek(')'))
{
// There should be a comma between arguments
if (!arguments.empty() && !expect(','))
return false;
// Parse the argument expression
if (!parse_expression_assignment(arguments.emplace_back()))
return false;
}
// The list should be terminated with a parenthesis
if (!expect(')'))
return false;
// Function calls can only be made from within functions
if (!_codegen->is_in_function())
return error(location, 3005, "invalid function call outside of a function"), false;
// Try to resolve the call by searching through both function symbols and intrinsics
bool undeclared = !symbol.id, ambiguous = false;
if (!resolve_function_call(identifier, arguments, scope, symbol, ambiguous))
{
if (undeclared)
error(location, 3004, "undeclared identifier or no matching intrinsic overload for '" + identifier + '\'');
else if (ambiguous)
error(location, 3067, "ambiguous function call to '" + identifier + '\'');
else
error(location, 3013, "no matching function overload for '" + identifier + '\'');
return false;
}
assert(symbol.function != nullptr);
std::vector<expression> parameters(arguments.size());
// We need to allocate some temporary variables to pass in and load results from pointer parameters
for (size_t i = 0; i < arguments.size(); ++i)
{
const auto ¶m_type = symbol.function->parameter_list[i].type;
if (param_type.has(type::q_out) && (arguments[i].type.has(type::q_const) || arguments[i].type.has(type::q_uniform) || !arguments[i].is_lvalue))
return error(arguments[i].location, 3025, "l-value specifies const object for an 'out' parameter"), false;
if (arguments[i].type.components() > param_type.components())
warning(arguments[i].location, 3206, "implicit truncation of vector type");
if (symbol.op == symbol_type::function || param_type.has(type::q_out))
{
if (param_type.is_sampler() || param_type.is_storage() || param_type.has(type::q_groupshared) /* Special case for atomic intrinsics */)
{
if (arguments[i].type != param_type)
return error(location, 3004, "no matching intrinsic overload for '" + identifier + '\''), false;
assert(arguments[i].is_lvalue);
// Do not shadow object or pointer parameters to function calls
size_t chain_index = 0;
const auto access_chain = _codegen->emit_access_chain(arguments[i], chain_index);
parameters[i].reset_to_lvalue(arguments[i].location, access_chain, param_type);
assert(chain_index == arguments[i].chain.size());
// This is referencing a l-value, but want to avoid copying below
parameters[i].is_lvalue = false;
}
else
{
// All user-defined functions actually accept pointers as arguments, same applies to intrinsics with 'out' parameters
const auto temp_variable = _codegen->define_variable(arguments[i].location, param_type);
parameters[i].reset_to_lvalue(arguments[i].location, temp_variable, param_type);
}
}
else
{
expression arg = arguments[i];
arg.add_cast_operation(param_type);
parameters[i].reset_to_rvalue(arg.location, _codegen->emit_load(arg), param_type);
// Keep track of whether the parameter is a constant for code generation (this makes the expression invalid for all other uses)
parameters[i].is_constant = arg.is_constant;
}
}
// Copy in parameters from the argument access chains to parameter variables
for (size_t i = 0; i < arguments.size(); ++i)
{
// Only do this for pointer parameters as discovered above
if (parameters[i].is_lvalue && parameters[i].type.has(type::q_in) && !parameters[i].type.is_sampler() && !parameters[i].type.is_storage())
{
expression arg = arguments[i];
arg.add_cast_operation(parameters[i].type);
_codegen->emit_store(parameters[i], _codegen->emit_load(arg));
}
}
// Check if the call resolving found an intrinsic or function and invoke the corresponding code
const auto result = symbol.op == symbol_type::function ?
_codegen->emit_call(location, symbol.id, symbol.type, parameters) :
_codegen->emit_call_intrinsic(location, symbol.id, symbol.type, parameters);
exp.reset_to_rvalue(location, result, symbol.type);
// Copy out parameters from parameter variables back to the argument access chains
for (size_t i = 0; i < arguments.size(); ++i)
{
// Only do this for pointer parameters as discovered above
if (parameters[i].is_lvalue && parameters[i].type.has(type::q_out) && !parameters[i].type.is_sampler() && !parameters[i].type.is_storage())
{
expression arg = parameters[i];
arg.add_cast_operation(arguments[i].type);
_codegen->emit_store(arguments[i], _codegen->emit_load(arg));
}
}
}
else if (symbol.op == symbol_type::invalid)
{
// Show error if no symbol matching the identifier was found
return error(location, 3004, "undeclared identifier '" + identifier + '\''), false;
}
else if (symbol.op == symbol_type::variable)
{
assert(symbol.id != 0);
// Simply return the pointer to the variable, dereferencing is done on site where necessary
exp.reset_to_lvalue(location, symbol.id, symbol.type);
}
else if (symbol.op == symbol_type::constant)
{
// Constants are loaded into the access chain
exp.reset_to_rvalue_constant(location, symbol.constant, symbol.type);
}
else
{
// Can only reference variables and constants by name, functions need to be called
return error(location, 3005, "identifier '" + identifier + "' represents a function, not a variable"), false;
}
}
#pragma endregion
#pragma region Postfix Expression
while (!peek(tokenid::end_of_file))
{
location = _token_next.location;
// Check if a postfix operator exists
if (accept_postfix_op())
{
// Unary operators are only valid on basic types
if (!exp.type.is_scalar() && !exp.type.is_vector() && !exp.type.is_matrix())
return error(exp.location, 3022, "scalar, vector, or matrix expected"), false;
if (exp.type.has(type::q_const) || exp.type.has(type::q_uniform) || !exp.is_lvalue)
return error(exp.location, 3025, "l-value specifies const object"), false;