07deaf8464
Reland https://github.com/llvm/llvm-project/pull/133173 Clang spawns a new thread to avoid running out of stack space. This can make debugging and performance analysis more difficult as how the threads are connected is difficult to recover. This patch introduces `runOnNewStack` and applies it in Clang. On platforms that have good support for it this allocates a new stack and moves to it using assembly. Doing split stacks like this actually runs on most platforms, but many debuggers and unwinders reject the large or backwards stack offsets that occur. Apple platforms and tools are known to support this, so this only enables it there for now.
36 lines
1.1 KiB
C++
36 lines
1.1 KiB
C++
//===- unittest/Support/ProgramStackTest.cpp ------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Support/ProgramStack.h"
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#include "llvm/Support/Process.h"
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#include "gtest/gtest.h"
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using namespace llvm;
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static uintptr_t func(int &A) {
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A = 7;
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return getStackPointer();
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}
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static void func2(int &A) {
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A = 5;
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}
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TEST(ProgramStackTest, runOnNewStack) {
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int A = 0;
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uintptr_t Stack = runOnNewStack(0, function_ref<uintptr_t(int &)>(func), A);
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EXPECT_EQ(A, 7);
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intptr_t StackDiff = (intptr_t)llvm::getStackPointer() - (intptr_t)Stack;
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size_t StackDistance = (size_t)std::abs(StackDiff);
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// Page size is used as it's large enough to guarantee were not on the same
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// stack but not too large to cause spurious failures.
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EXPECT_GT(StackDistance, llvm::sys::Process::getPageSizeEstimate());
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runOnNewStack(0, function_ref<void(int &)>(func2), A);
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EXPECT_EQ(A, 5);
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}
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