kadircet created this revision.
kadircet added a reviewer: hokein.
Herald added a subscriber: arphaman.
Herald added a project: All.
kadircet requested review of this revision.
Herald added subscribers: cfe-commits, MaskRay, ilya-biryukov.
Herald added a project: clang-tools-extra.
getMemBufferCopy triggers an UB when it receives a default constructed
StringRef. Make sure that we're always passing the null-terminated string
created in ParseInputs throughout the scanPreamble.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D144708
Files:
clang-tools-extra/clangd/Preamble.cpp
Index: clang-tools-extra/clangd/Preamble.cpp
===================================================================
--- clang-tools-extra/clangd/Preamble.cpp
+++ clang-tools-extra/clangd/Preamble.cpp
@@ -332,6 +332,8 @@
EmptyFS FS;
// Build and run Preprocessor over the preamble.
ParseInputs PI;
+ // Memory buffers below expect null-terminated && non-null strings. So make
+ // sure to always use PI.Contents!
PI.Contents = Contents.str();
PI.TFS = &FS;
PI.CompileCommand = Cmd;
@@ -346,7 +348,7 @@
// elsewhere.
auto Bounds = ComputePreambleBounds(*CI->getLangOpts(), *ContentsBuffer, 0);
auto PreambleContents =
- llvm::MemoryBuffer::getMemBufferCopy(Contents.substr(0, Bounds.Size));
+ llvm::MemoryBuffer::getMemBufferCopy(PI.Contents.substr(0, Bounds.Size));
auto Clang = prepareCompilerInstance(
std::move(CI), nullptr, std::move(PreambleContents),
// Provide an empty FS to prevent preprocessor from performing IO. This
@@ -371,7 +373,7 @@
return std::move(Err);
Action.EndSourceFile();
SP.Includes = std::move(Includes.MainFileIncludes);
- llvm::append_range(SP.Lines, llvm::split(Contents, "\n"));
+ llvm::append_range(SP.Lines, llvm::split(PI.Contents, "\n"));
return SP;
}
@@ -739,9 +741,8 @@
// whole preamble, which is terribly slow.
// - If scanning for Modified fails, cannot figure out newly added ones so
// there's nothing to do but generate an empty patch.
- auto BaselineScan = scanPreamble(
- // Contents needs to be null-terminated.
- Baseline.Preamble.getContents(), Modified.CompileCommand);
+ auto BaselineScan =
+ scanPreamble(Baseline.Preamble.getContents(), Modified.CompileCommand);
if (!BaselineScan) {
elog("Failed to scan baseline of {0}: {1}", FileName,
BaselineScan.takeError());
Index: clang-tools-extra/clangd/Preamble.cpp
===================================================================
--- clang-tools-extra/clangd/Preamble.cpp
+++ clang-tools-extra/clangd/Preamble.cpp
@@ -332,6 +332,8 @@
EmptyFS FS;
// Build and run Preprocessor over the preamble.
ParseInputs PI;
+ // Memory buffers below expect null-terminated && non-null strings. So make
+ // sure to always use PI.Contents!
PI.Contents = Contents.str();
PI.TFS = &FS;
PI.CompileCommand = Cmd;
@@ -346,7 +348,7 @@
// elsewhere.
auto Bounds = ComputePreambleBounds(*CI->getLangOpts(), *ContentsBuffer, 0);
auto PreambleContents =
- llvm::MemoryBuffer::getMemBufferCopy(Contents.substr(0, Bounds.Size));
+ llvm::MemoryBuffer::getMemBufferCopy(PI.Contents.substr(0, Bounds.Size));
auto Clang = prepareCompilerInstance(
std::move(CI), nullptr, std::move(PreambleContents),
// Provide an empty FS to prevent preprocessor from performing IO. This
@@ -371,7 +373,7 @@
return std::move(Err);
Action.EndSourceFile();
SP.Includes = std::move(Includes.MainFileIncludes);
- llvm::append_range(SP.Lines, llvm::split(Contents, "\n"));
+ llvm::append_range(SP.Lines, llvm::split(PI.Contents, "\n"));
return SP;
}
@@ -739,9 +741,8 @@
// whole preamble, which is terribly slow.
// - If scanning for Modified fails, cannot figure out newly added ones so
// there's nothing to do but generate an empty patch.
- auto BaselineScan = scanPreamble(
- // Contents needs to be null-terminated.
- Baseline.Preamble.getContents(), Modified.CompileCommand);
+ auto BaselineScan =
+ scanPreamble(Baseline.Preamble.getContents(), Modified.CompileCommand);
if (!BaselineScan) {
elog("Failed to scan baseline of {0}: {1}", FileName,
BaselineScan.takeError());
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