[clang] 2ad6917 - [modules] Accept equivalent module caches from different symlink (#90925)
via cfe-commits
cfe-commits at lists.llvm.org
Tue May 7 13:55:50 PDT 2024
Author: Ellis Hoag
Date: 2024-05-07T13:55:44-07:00
New Revision: 2ad6917c4c524576405f2146424911fd9adb3528
URL: https://github.com/llvm/llvm-project/commit/2ad6917c4c524576405f2146424911fd9adb3528
DIFF: https://github.com/llvm/llvm-project/commit/2ad6917c4c524576405f2146424911fd9adb3528.diff
LOG: [modules] Accept equivalent module caches from different symlink (#90925)
Use `VFS.equivalent()`, which follows symlinks, to check if two module
cache paths are equivalent. This prevents a PCH error when building from
a different path that is a symlink of the original.
```
error: PCH was compiled with module cache path '/home/foo/blah/ModuleCache/2IBP1TNT8OR8D', but the path is currently '/data/users/foo/blah/ModuleCache/2IBP1TNT8OR8D'
1 error generated.
```
Added:
clang/test/Modules/module-symlink.m
Modified:
clang/lib/Serialization/ASTReader.cpp
llvm/include/llvm/Support/VirtualFileSystem.h
llvm/lib/Support/VirtualFileSystem.cpp
Removed:
################################################################################
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index b4b2f999d2259..856c743086c51 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -829,36 +829,37 @@ bool SimpleASTReaderListener::ReadPreprocessorOptions(
OptionValidateNone);
}
-/// Check the header search options deserialized from the control block
-/// against the header search options in an existing preprocessor.
+/// Check that the specified and the existing module cache paths are equivalent.
///
/// \param Diags If non-null, produce diagnostics for any mismatches incurred.
-static bool checkHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
- StringRef SpecificModuleCachePath,
- StringRef ExistingModuleCachePath,
- DiagnosticsEngine *Diags,
- const LangOptions &LangOpts,
- const PreprocessorOptions &PPOpts) {
- if (LangOpts.Modules) {
- if (SpecificModuleCachePath != ExistingModuleCachePath &&
- !PPOpts.AllowPCHWithDifferentModulesCachePath) {
- if (Diags)
- Diags->Report(diag::err_pch_modulecache_mismatch)
- << SpecificModuleCachePath << ExistingModuleCachePath;
- return true;
- }
- }
-
- return false;
+/// \returns true when the module cache paths
diff er.
+static bool checkModuleCachePath(llvm::vfs::FileSystem &VFS,
+ StringRef SpecificModuleCachePath,
+ StringRef ExistingModuleCachePath,
+ DiagnosticsEngine *Diags,
+ const LangOptions &LangOpts,
+ const PreprocessorOptions &PPOpts) {
+ if (!LangOpts.Modules || PPOpts.AllowPCHWithDifferentModulesCachePath ||
+ SpecificModuleCachePath == ExistingModuleCachePath)
+ return false;
+ auto EqualOrErr =
+ VFS.equivalent(SpecificModuleCachePath, ExistingModuleCachePath);
+ if (EqualOrErr && *EqualOrErr)
+ return false;
+ if (Diags)
+ Diags->Report(diag::err_pch_modulecache_mismatch)
+ << SpecificModuleCachePath << ExistingModuleCachePath;
+ return true;
}
bool PCHValidator::ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
StringRef SpecificModuleCachePath,
bool Complain) {
- return checkHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
- PP.getHeaderSearchInfo().getModuleCachePath(),
- Complain ? &Reader.Diags : nullptr,
- PP.getLangOpts(), PP.getPreprocessorOpts());
+ return checkModuleCachePath(Reader.getFileManager().getVirtualFileSystem(),
+ SpecificModuleCachePath,
+ PP.getHeaderSearchInfo().getModuleCachePath(),
+ Complain ? &Reader.Diags : nullptr,
+ PP.getLangOpts(), PP.getPreprocessorOpts());
}
void PCHValidator::ReadCounter(const ModuleFile &M, unsigned Value) {
@@ -5376,9 +5377,9 @@ namespace {
bool ReadHeaderSearchOptions(const HeaderSearchOptions &HSOpts,
StringRef SpecificModuleCachePath,
bool Complain) override {
- return checkHeaderSearchOptions(HSOpts, SpecificModuleCachePath,
- ExistingModuleCachePath, nullptr,
- ExistingLangOpts, ExistingPPOpts);
+ return checkModuleCachePath(
+ FileMgr.getVirtualFileSystem(), SpecificModuleCachePath,
+ ExistingModuleCachePath, nullptr, ExistingLangOpts, ExistingPPOpts);
}
bool ReadPreprocessorOptions(const PreprocessorOptions &PPOpts,
diff --git a/clang/test/Modules/module-symlink.m b/clang/test/Modules/module-symlink.m
new file mode 100644
index 0000000000000..efdaf3db0dfef
--- /dev/null
+++ b/clang/test/Modules/module-symlink.m
@@ -0,0 +1,14 @@
+// REQUIRES: shell
+
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules-cache-path=%t/modules -fmodules -fimplicit-module-maps -I %S/Inputs -emit-pch -o %t.pch %s -verify
+
+// RUN: ln -s %t/modules %t/modules.symlink
+// RUN: %clang_cc1 -fmodules-cache-path=%t/modules.symlink -fmodules -fimplicit-module-maps -I %S/Inputs -include-pch %t.pch %s -verify
+// RUN: not %clang_cc1 -fmodules-cache-path=%t/modules.dne -fmodules -fimplicit-module-maps -I %S/Inputs -include-pch %t.pch %s -verify
+
+// expected-no-diagnostics
+
+ at import ignored_macros;
+
+struct Point p;
diff --git a/llvm/include/llvm/Support/VirtualFileSystem.h b/llvm/include/llvm/Support/VirtualFileSystem.h
index 49e67e7555a0d..a1e38de74dfcc 100644
--- a/llvm/include/llvm/Support/VirtualFileSystem.h
+++ b/llvm/include/llvm/Support/VirtualFileSystem.h
@@ -320,6 +320,10 @@ class FileSystem : public llvm::ThreadSafeRefCountedBase<FileSystem>,
/// platform-specific error_code.
virtual std::error_code makeAbsolute(SmallVectorImpl<char> &Path) const;
+ /// \returns true if \p A and \p B represent the same file, or an error or
+ /// false if they do not.
+ llvm::ErrorOr<bool> equivalent(const Twine &A, const Twine &B);
+
enum class PrintType { Summary, Contents, RecursiveContents };
void print(raw_ostream &OS, PrintType Type = PrintType::Contents,
unsigned IndentLevel = 0) const {
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index 152fcfe695b29..54b9c38f76095 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -151,6 +151,16 @@ bool FileSystem::exists(const Twine &Path) {
return Status && Status->exists();
}
+llvm::ErrorOr<bool> FileSystem::equivalent(const Twine &A, const Twine &B) {
+ auto StatusA = status(A);
+ if (!StatusA)
+ return StatusA.getError();
+ auto StatusB = status(B);
+ if (!StatusB)
+ return StatusB.getError();
+ return StatusA->equivalent(*StatusB);
+}
+
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void FileSystem::dump() const { print(dbgs(), PrintType::RecursiveContents); }
#endif
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