Files
llvm-project/llvm/lib/Support/ProgramStack.cpp
Michael Spencer 227d8d33c6 [llvm][clang] Revert split stacks implementation from runOnNewStack (#181743)
This was potentially causing Clang to emit out of stack space warnings
in rare cases, so I'm reverting it until I can verify the issue. This
keeps the API change as that's known not to be the issue.
2026-02-16 13:38:40 -08:00

60 lines
1.8 KiB
C++

//===--- RunOnNewStack.cpp - Crash Recovery -------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/ProgramStack.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
#ifdef LLVM_ON_UNIX
# include <sys/resource.h> // for getrlimit
#endif
#ifdef _MSC_VER
# include <intrin.h> // for _AddressOfReturnAddress
#endif
#include "llvm/Support/thread.h"
using namespace llvm;
uintptr_t llvm::getStackPointer() {
#if __GNUC__ || __has_builtin(__builtin_frame_address)
return (uintptr_t)__builtin_frame_address(0);
#elif defined(_MSC_VER)
return (uintptr_t)_AddressOfReturnAddress();
#else
volatile char CharOnStack = 0;
// The volatile store here is intended to escape the local variable, to
// prevent the compiler from optimizing CharOnStack into anything other
// than a char on the stack.
//
// Tested on: MSVC 2015 - 2019, GCC 4.9 - 9, Clang 3.2 - 9, ICC 13 - 19.
char *volatile Ptr = &CharOnStack;
return (uintptr_t)Ptr;
#endif
}
unsigned llvm::getDefaultStackSize() {
#ifdef LLVM_ON_UNIX
rlimit RL;
getrlimit(RLIMIT_STACK, &RL);
return RL.rlim_cur;
#else
// Clang recursively parses, instantiates templates, and evaluates constant
// expressions. We've found 8MiB to be a reasonable stack size given the way
// Clang works and the way C++ is commonly written.
return 8 << 20;
#endif
}
void llvm::runOnNewStack(unsigned StackSize, function_ref<void()> Fn) {
llvm::thread Thread(
StackSize == 0 ? std::nullopt : std::optional<unsigned>(StackSize), Fn);
Thread.join();
}