Revert "[modules] Do not cache invalid state for modules that we attempted to load."
As per comment on https://reviews.llvm.org/D72860, it is suggested to
revert this change in the meantime, since it has introduced regression.
This reverts commit 83f4c3af021cd5322ea10fd1c4e839874c1dae49.
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index b5ca1e1..63c817b 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4502,7 +4502,7 @@
if (ShouldFinalizePCM)
MC.finalizePCM(FileName);
else
- MC.tryToRemovePCM(FileName);
+ MC.tryToDropPCM(FileName);
});
ModuleFile &F = *M;
BitstreamCursor &Stream = F.Stream;
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index bf893c7..1278841 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4317,7 +4317,7 @@
WritingAST = false;
if (ShouldCacheASTInMemory) {
// Construct MemoryBuffer and update buffer manager.
- ModuleCache.addFinalPCM(OutputFile,
+ ModuleCache.addBuiltPCM(OutputFile,
llvm::MemoryBuffer::getMemBufferCopy(
StringRef(Buffer.begin(), Buffer.size())));
}
diff --git a/clang/lib/Serialization/InMemoryModuleCache.cpp b/clang/lib/Serialization/InMemoryModuleCache.cpp
index 68d9411..d35fa2a 100644
--- a/clang/lib/Serialization/InMemoryModuleCache.cpp
+++ b/clang/lib/Serialization/InMemoryModuleCache.cpp
@@ -11,6 +11,16 @@
using namespace clang;
+InMemoryModuleCache::State
+InMemoryModuleCache::getPCMState(llvm::StringRef Filename) const {
+ auto I = PCMs.find(Filename);
+ if (I == PCMs.end())
+ return Unknown;
+ if (I->second.IsFinal)
+ return Final;
+ return I->second.Buffer ? Tentative : ToBuild;
+}
+
llvm::MemoryBuffer &
InMemoryModuleCache::addPCM(llvm::StringRef Filename,
std::unique_ptr<llvm::MemoryBuffer> Buffer) {
@@ -20,11 +30,11 @@
}
llvm::MemoryBuffer &
-InMemoryModuleCache::addFinalPCM(llvm::StringRef Filename,
+InMemoryModuleCache::addBuiltPCM(llvm::StringRef Filename,
std::unique_ptr<llvm::MemoryBuffer> Buffer) {
auto &PCM = PCMs[Filename];
assert(!PCM.IsFinal && "Trying to override finalized PCM?");
- assert(!PCM.Buffer && "Already has a non-final PCM");
+ assert(!PCM.Buffer && "Trying to override tentative PCM?");
PCM.Buffer = std::move(Buffer);
PCM.IsFinal = true;
return *PCM.Buffer;
@@ -39,21 +49,24 @@
}
bool InMemoryModuleCache::isPCMFinal(llvm::StringRef Filename) const {
- auto I = PCMs.find(Filename);
- if (I == PCMs.end())
- return false;
- return I->second.IsFinal;
+ return getPCMState(Filename) == Final;
}
-bool InMemoryModuleCache::tryToRemovePCM(llvm::StringRef Filename) {
+bool InMemoryModuleCache::shouldBuildPCM(llvm::StringRef Filename) const {
+ return getPCMState(Filename) == ToBuild;
+}
+
+bool InMemoryModuleCache::tryToDropPCM(llvm::StringRef Filename) {
auto I = PCMs.find(Filename);
assert(I != PCMs.end() && "PCM to remove is unknown...");
auto &PCM = I->second;
+ assert(PCM.Buffer && "PCM to remove is scheduled to be built...");
+
if (PCM.IsFinal)
return true;
- PCMs.erase(I);
+ PCM.Buffer.reset();
return false;
}
diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index 9b326d2..2656220 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -163,7 +163,7 @@
// Load the contents of the module
if (std::unique_ptr<llvm::MemoryBuffer> Buffer = lookupBuffer(FileName)) {
// The buffer was already provided for us.
- NewModule->Buffer = &ModuleCache->addFinalPCM(FileName, std::move(Buffer));
+ NewModule->Buffer = &ModuleCache->addBuiltPCM(FileName, std::move(Buffer));
// Since the cached buffer is reused, it is safe to close the file
// descriptor that was opened while stat()ing the PCM in
// lookupModuleFile() above, it won't be needed any longer.
@@ -173,6 +173,11 @@
NewModule->Buffer = Buffer;
// As above, the file descriptor is no longer needed.
Entry->closeFile();
+ } else if (getModuleCache().shouldBuildPCM(FileName)) {
+ // Report that the module is out of date, since we tried (and failed) to
+ // import it earlier.
+ Entry->closeFile();
+ return OutOfDate;
} else {
// Open the AST file.
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buf((std::error_code()));
@@ -180,9 +185,7 @@
Buf = llvm::MemoryBuffer::getSTDIN();
} else {
// Get a buffer of the file and close the file descriptor when done.
- // The file is volatile because in a parallel build we expect multiple
- // compiler processes to use the same module file rebuilding it if needed.
- Buf = FileMgr.getBufferForFile(NewModule->File, /*isVolatile=*/true);
+ Buf = FileMgr.getBufferForFile(NewModule->File, /*isVolatile=*/false);
}
if (!Buf) {