[llvm] dcac5a2 - Revert "Cache memory buffer's name length"
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 29 05:23:13 PST 2022
Author: Florian Hahn
Date: 2022-11-29T13:22:52Z
New Revision: dcac5a2f7a58f6c66520a1147c0bf3d24177c30b
URL: https://github.com/llvm/llvm-project/commit/dcac5a2f7a58f6c66520a1147c0bf3d24177c30b
DIFF: https://github.com/llvm/llvm-project/commit/dcac5a2f7a58f6c66520a1147c0bf3d24177c30b.diff
LOG: Revert "Cache memory buffer's name length"
This reverts commit 1824432174b3166b40bce59477beb5821170748e.
The change triggers an assertion when building clang on macOS:
FAILED: tools/clang/include/clang/Tooling/Syntax/Nodes.inc
cd /Users/florianhahn/projects/llvm-project/builds/release-with-assertions/ccache-stage1 && /Users/florianhahn/projects/llvm-project/builds/release-with-assertions/ccache-stage1/bin/clang-tblgen -gen-clang-syntax-node-list -I /Users/florianhahn/projects/llvm-project/clang/include/clang/Tooling/Syntax -I/Users/florianhahn/projects/llvm-project/clang/include -I/Users/florianhahn/projects/llvm-project/builds/release-with-assertions/ccache-stage1/tools/clang/include -I/Users/florianhahn/projects/llvm-project/builds/release-with-assertions/ccache-stage1/include -I/Users/florianhahn/projects/llvm-project/llvm/include /Users/florianhahn/projects/llvm-project/clang/include/clang/Tooling/Syntax/Nodes.td --write-if-changed -o tools/clang/include/clang/Tooling/Syntax/Nodes.inc -d tools/clang/include/clang/Tooling/Syntax/Nodes.inc.d
Assertion failed: ((!RequiresNullTerminator || BufEnd[0] == 0) && "Buffer is not null terminated!"), function init, file MemoryBuffer.cpp, line 52.
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0 clang-tblgen 0x000000010466b68c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1 clang-tblgen 0x000000010466a808 llvm::sys::RunSignalHandlers() + 64
2 clang-tblgen 0x000000010466bd60 SignalHandler(int) + 344
3 libsystem_platform.dylib 0x00000001877a92a4 _sigtramp + 56
4 libsystem_pthread.dylib 0x000000018777acec pthread_kill + 288
5 libsystem_c.dylib 0x00000001876b42c8 abort + 180
6 libsystem_c.dylib 0x00000001876b3620 err + 0
7 clang-tblgen 0x00000001046ce150 llvm::ErrorOr<std::__1::unique_ptr<llvm::MemoryBuffer, std::__1::default_delete<llvm::MemoryBuffer>>> getOpenFileImpl<llvm::MemoryBuffer>(int, llvm::Twine const&, unsigned long long, unsigned long long, long long, bool, bool, llvm::Optional<llvm::Align>) (.cold.1) + 0
8 clang-tblgen 0x000000010464a548 llvm::WritableMemoryBuffer::getNewUninitMemBuffer(unsigned long, llvm::Twine const&, llvm::Optional<llvm::Align>) + 496
9 clang-tblgen 0x000000010464a7a0 llvm::ErrorOr<std::__1::unique_ptr<llvm::MemoryBuffer, std::__1::default_delete<llvm::MemoryBuffer>>> getOpenFileImpl<llvm::MemoryBuffer>(int, llvm::Twine const&, unsigned long long, unsigned long long, long long, bool, bool, llvm::Optional<llvm::Align>) + 528
10 clang-tblgen 0x000000010464a254 llvm::ErrorOr<std::__1::unique_ptr<llvm::MemoryBuffer, std::__1::default_delete<llvm::MemoryBuffer>>> getFileAux<llvm::MemoryBuffer>(llvm::Twine const&, unsigned long long, unsigned long long, bool, bool, bool, llvm::Optional<llvm::Align>) + 176
11 clang-tblgen 0x000000010466fbbc llvm::TableGenMain(char const*, bool (*)(llvm::raw_ostream&, llvm::RecordKeeper&)) + 1428
12 clang-tblgen 0x0000000104626114 main + 156
13 dyld 0x0000000187453e50 start + 2544
Added:
Modified:
llvm/lib/Support/MemoryBuffer.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
index 8f123a41473e..6bb046e9b3db 100644
--- a/llvm/lib/Support/MemoryBuffer.cpp
+++ b/llvm/lib/Support/MemoryBuffer.cpp
@@ -58,10 +58,12 @@ void MemoryBuffer::init(const char *BufStart, const char *BufEnd,
// MemoryBufferMem implementation.
//===----------------------------------------------------------------------===//
-/// CopyStringRef - Copies contents of a StringRef into a block of memory.
+/// CopyStringRef - Copies contents of a StringRef into a block of memory and
+/// null-terminates it.
static void CopyStringRef(char *Memory, StringRef Data) {
if (!Data.empty())
memcpy(Memory, Data.data(), Data.size());
+ Memory[Data.size()] = 0; // Null terminate string.
}
namespace {
@@ -75,10 +77,8 @@ void *operator new(size_t N, const NamedBufferAlloc &Alloc) {
SmallString<256> NameBuf;
StringRef NameRef = Alloc.Name.toStringRef(NameBuf);
- char *Mem =
- static_cast<char *>(operator new(N + sizeof(size_t) + NameRef.size()));
- *reinterpret_cast<size_t *>(Mem + N) = NameRef.size();
- CopyStringRef(Mem + N + sizeof(size_t), NameRef);
+ char *Mem = static_cast<char *>(operator new(N + NameRef.size() + 1));
+ CopyStringRef(Mem + N, NameRef);
return Mem;
}
@@ -98,8 +98,7 @@ class MemoryBufferMem : public MB {
StringRef getBufferIdentifier() const override {
// The name is stored after the class itself.
- return StringRef(reinterpret_cast<const char *>(this + 1) + sizeof(size_t),
- *reinterpret_cast<const size_t *>(this + 1));
+ return StringRef(reinterpret_cast<const char *>(this + 1));
}
MemoryBuffer::BufferKind getBufferKind() const override {
@@ -222,8 +221,7 @@ class MemoryBufferMMapFile : public MB {
StringRef getBufferIdentifier() const override {
// The name is stored after the class itself.
- return StringRef(reinterpret_cast<const char *>(this + 1) + sizeof(size_t),
- *reinterpret_cast<const size_t *>(this + 1));
+ return StringRef(reinterpret_cast<const char *>(this + 1));
}
MemoryBuffer::BufferKind getBufferKind() const override {
@@ -303,8 +301,7 @@ WritableMemoryBuffer::getNewUninitMemBuffer(size_t Size,
// that MemoryBuffer and data are aligned so PointerIntPair works with them.
SmallString<256> NameBuf;
StringRef NameRef = BufferName.toStringRef(NameBuf);
-
- size_t StringLen = sizeof(MemBuffer) + sizeof(size_t) + NameRef.size();
+ size_t StringLen = sizeof(MemBuffer) + NameRef.size() + 1;
size_t RealLen = StringLen + Size + 1 + BufAlign.value();
if (RealLen <= Size) // Check for rollover.
return nullptr;
@@ -313,15 +310,13 @@ WritableMemoryBuffer::getNewUninitMemBuffer(size_t Size,
return nullptr;
// The name is stored after the class itself.
- *reinterpret_cast<size_t *>(Mem + sizeof(MemBuffer)) =
- NameRef.size(); // Null terminate buffer.
- CopyStringRef(Mem + sizeof(MemBuffer) + sizeof(size_t), NameRef);
+ CopyStringRef(Mem + sizeof(MemBuffer), NameRef);
// The buffer begins after the name and must be aligned.
char *Buf = (char *)alignAddr(Mem + StringLen, BufAlign);
+ Buf[Size] = 0; // Null terminate buffer.
auto *Ret = new (Mem) MemBuffer(StringRef(Buf, Size), true);
- Buf[Size] = 0; // Null terminate buffer.
return std::unique_ptr<WritableMemoryBuffer>(Ret);
}
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