Implement dependency analysis for the precompiled preamble. If any of
the files in the precompiled preamble have changed since it was build,
force the preamble to be rebuilt.
llvm-svn: 109937
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 7f42fa9..d7597bc 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -36,6 +36,7 @@
#include "llvm/Support/Timer.h"
#include <cstdlib>
#include <cstdio>
+#include <sys/stat.h>
using namespace clang;
ASTUnit::ASTUnit(bool _MainFileIsAST)
@@ -626,14 +627,72 @@
NewPreamble.second.first) == 0) {
// The preamble has not changed. We may be able to re-use the precompiled
// preamble.
- // FIXME: Check that none of the files used by the preamble have changed.
+ // Check that none of the files used by the preamble have changed.
+ bool AnyFileChanged = false;
+
+ // First, make a record of those files that have been overridden via
+ // remapping or unsaved_files.
+ llvm::StringMap<std::pair<off_t, time_t> > OverriddenFiles;
+ for (PreprocessorOptions::remapped_file_iterator
+ R = PreprocessorOpts.remapped_file_begin(),
+ REnd = PreprocessorOpts.remapped_file_end();
+ !AnyFileChanged && R != REnd;
+ ++R) {
+ struct stat StatBuf;
+ if (stat(R->second.c_str(), &StatBuf)) {
+ // If we can't stat the file we're remapping to, assume that something
+ // horrible happened.
+ AnyFileChanged = true;
+ break;
+ }
- // Okay! Re-use the precompiled preamble.
- return CreatePaddedMainFileBuffer(NewPreamble.first,
- CreatedPreambleBuffer,
- PreambleReservedSize,
- FrontendOpts.Inputs[0].second);
+ OverriddenFiles[R->first] = std::make_pair(StatBuf.st_size,
+ StatBuf.st_mtime);
+ }
+ for (PreprocessorOptions::remapped_file_buffer_iterator
+ R = PreprocessorOpts.remapped_file_buffer_begin(),
+ REnd = PreprocessorOpts.remapped_file_buffer_end();
+ !AnyFileChanged && R != REnd;
+ ++R) {
+ // FIXME: Should we actually compare the contents of file->buffer
+ // remappings?
+ OverriddenFiles[R->first] = std::make_pair(R->second->getBufferSize(),
+ 0);
+ }
+
+ // Check whether anything has changed.
+ for (llvm::StringMap<std::pair<off_t, time_t> >::iterator
+ F = FilesInPreamble.begin(), FEnd = FilesInPreamble.end();
+ !AnyFileChanged && F != FEnd;
+ ++F) {
+ llvm::StringMap<std::pair<off_t, time_t> >::iterator Overridden
+ = OverriddenFiles.find(F->first());
+ if (Overridden != OverriddenFiles.end()) {
+ // This file was remapped; check whether the newly-mapped file
+ // matches up with the previous mapping.
+ if (Overridden->second != F->second)
+ AnyFileChanged = true;
+ continue;
+ }
+
+ // The file was not remapped; check whether it has changed on disk.
+ struct stat StatBuf;
+ if (stat(F->first(), &StatBuf)) {
+ // If we can't stat the file, assume that something horrible happened.
+ AnyFileChanged = true;
+ } else if (StatBuf.st_size != F->second.first ||
+ StatBuf.st_mtime != F->second.second)
+ AnyFileChanged = true;
+ }
+
+ if (!AnyFileChanged) {
+ // Okay! Re-use the precompiled preamble.
+ return CreatePaddedMainFileBuffer(NewPreamble.first,
+ CreatedPreambleBuffer,
+ PreambleReservedSize,
+ FrontendOpts.Inputs[0].second);
+ }
}
// We can't reuse the previously-computed preamble. Build a new one.
@@ -768,14 +827,31 @@
delete NewPreamble.first;
if (PreambleTimer)
PreambleTimer->stopTimer();
- if (PreambleTimer)
- PreambleTimer->stopTimer();
return 0;
}
// Keep track of the preamble we precompiled.
PreambleFile = FrontendOpts.OutputFile;
+
+ // Keep track of all of the files that the source manager knows about,
+ // so we can verify whether they have changed or not.
+ FilesInPreamble.clear();
+ SourceManager &SourceMgr = Clang.getSourceManager();
+ const llvm::MemoryBuffer *MainFileBuffer
+ = SourceMgr.getBuffer(SourceMgr.getMainFileID());
+ for (SourceManager::fileinfo_iterator F = SourceMgr.fileinfo_begin(),
+ FEnd = SourceMgr.fileinfo_end();
+ F != FEnd;
+ ++F) {
+ const FileEntry *File = F->second->Entry;
+ if (!File || F->second->getRawBuffer() == MainFileBuffer)
+ continue;
+
+ FilesInPreamble[File->getName()]
+ = std::make_pair(F->second->getSize(), File->getModificationTime());
+ }
+
if (PreambleTimer)
PreambleTimer->stopTimer();
@@ -913,6 +989,13 @@
Timers.push_back(ReparsingTimer);
}
+ // Remap files.
+ // FIXME: Do we want to remove old mappings for these files?
+ Invocation->getPreprocessorOpts().clearRemappedFiles();
+ for (unsigned I = 0; I != NumRemappedFiles; ++I)
+ Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
+ RemappedFiles[I].second);
+
// If we have a preamble file lying around, build or reuse the precompiled
// preamble.
llvm::MemoryBuffer *OverrideMainBuffer = 0;
@@ -922,12 +1005,6 @@
// Clear out the diagnostics state.
getDiagnostics().Reset();
- // Remap files.
- Invocation->getPreprocessorOpts().clearRemappedFiles();
- for (unsigned I = 0; I != NumRemappedFiles; ++I)
- Invocation->getPreprocessorOpts().addRemappedFile(RemappedFiles[I].first,
- RemappedFiles[I].second);
-
// Parse the sources
bool Result = Parse(OverrideMainBuffer);
if (ReparsingTimer)