Files
carbon-lang/executable_semantics/interpreter/heap.cpp
T
Jon MeowandChandler Carruth f0af3cb795 Switch from llvm::errs()+exit() to FATAL_USER_ERROR() stream-based handling. (#670)
This is intended to:

- Standardize use of line_num (and highlight where no line_num is available).
- Standardize indications of runtime/compilation errors.
- Make it incrementally easier to write new errors.

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2021-07-28 10:47:33 -07:00

68 lines
1.9 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "executable_semantics/interpreter/heap.h"
#include "executable_semantics/common/error.h"
#include "llvm/ADT/StringExtras.h"
namespace Carbon {
auto Heap::AllocateValue(const Value* v) -> Address {
// Putting the following two side effects together in this function
// ensures that we don't do anything else in between, which is really bad!
// Consider whether to include a copy of the input v in this function
// or to leave it up to the caller.
CHECK(v != nullptr);
Address a(values_.size());
values_.push_back(v);
alive_.push_back(true);
return a;
}
auto Heap::Read(const Address& a, int line_num) -> const Value* {
this->CheckAlive(a, line_num);
return values_[a.index]->GetField(a.field_path, line_num);
}
void Heap::Write(const Address& a, const Value* v, int line_num) {
CHECK(v != nullptr);
this->CheckAlive(a, line_num);
values_[a.index] = values_[a.index]->SetField(a.field_path, v, line_num);
}
void Heap::CheckAlive(const Address& address, int line_num) {
if (!alive_[address.index]) {
FATAL_RUNTIME_ERROR(line_num)
<< ": undefined behavior: access to dead value "
<< *values_[address.index];
}
}
void Heap::Deallocate(const Address& address) {
CHECK(address.field_path.IsEmpty());
if (alive_[address.index]) {
alive_[address.index] = false;
} else {
FATAL_RUNTIME_ERROR_NO_LINE() << "deallocating an already dead value";
}
}
void Heap::Print(llvm::raw_ostream& out) const {
llvm::ListSeparator sep;
for (size_t i = 0; i < values_.size(); ++i) {
out << sep;
PrintAddress(Address(i), out);
}
}
void Heap::PrintAddress(const Address& a, llvm::raw_ostream& out) const {
if (!alive_[a.index]) {
out << "!!";
}
out << *values_[a.index];
}
} // namespace Carbon