r177194 - <rdar://problem/13426257> Introduce SDKSettings.plist as an input file dependency for PCH/modules.
Douglas Gregor
dgregor at apple.com
Fri Mar 15 16:36:26 PDT 2013
On Mar 15, 2013, at 4:33 PM, Jean-Daniel Dupas <devlists at shadowlab.org> wrote:
> Out of curiosity, what happen while compiling on Darwin without specifying an sdkroot as in such case, it uses headers from /System directly and will not be able to locate a SDKSettings.plist file.
If there is no SDKSettings.plist file, then we won't add a dependency on it. The net effect is that modules will not automatically rebuild if you (say) hack your system headers.
- Doug
>
>
> Le 15 mars 2013 à 23:15, Douglas Gregor <dgregor at apple.com> a écrit :
>
>> Author: dgregor
>> Date: Fri Mar 15 17:15:07 2013
>> New Revision: 177194
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=177194&view=rev
>> Log:
>> <rdar://problem/13426257> Introduce SDKSettings.plist as an input file dependency for PCH/modules.
>>
>> When we're building a precompiled header or module against an SDK on
>> Darwin, there will be a file SDKSettings.plist in the sysroot. Since
>> stat()'ing every system header on which a module or PCH file depends
>> is performance suicide, we instead stat() just SDKSettings.plist. This
>> hack works well on Darwin; it's unclear how we want to handle this on
>> other platforms. If there is a canonical file, we should use it; if
>> not, we either have to take the performance hit of stat()'ing system
>> headers repeatedly or roll the dice by not checking anything.
>>
>> Modified:
>> cfe/trunk/include/clang/Serialization/ASTWriter.h
>> cfe/trunk/lib/Serialization/ASTWriter.cpp
>>
>> Modified: cfe/trunk/include/clang/Serialization/ASTWriter.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Serialization/ASTWriter.h?rev=177194&r1=177193&r2=177194&view=diff
>> ==============================================================================
>> --- cfe/trunk/include/clang/Serialization/ASTWriter.h (original)
>> +++ cfe/trunk/include/clang/Serialization/ASTWriter.h Fri Mar 15 17:15:07 2013
>> @@ -48,6 +48,7 @@ class CXXCtorInitializer;
>> class FileEntry;
>> class FPOptions;
>> class HeaderSearch;
>> +class HeaderSearchOptions;
>> class IdentifierResolver;
>> class MacroDefinition;
>> class OpaqueValueExpr;
>> @@ -416,7 +417,9 @@ private:
>> void WriteBlockInfoBlock();
>> void WriteControlBlock(Preprocessor &PP, ASTContext &Context,
>> StringRef isysroot, const std::string &OutputFile);
>> - void WriteInputFiles(SourceManager &SourceMgr, StringRef isysroot);
>> + void WriteInputFiles(SourceManager &SourceMgr,
>> + HeaderSearchOptions &HSOpts,
>> + StringRef isysroot);
>> void WriteSourceManagerBlock(SourceManager &SourceMgr,
>> const Preprocessor &PP,
>> StringRef isysroot);
>>
>> Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=177194&r1=177193&r2=177194&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/Serialization/ASTWriter.cpp (original)
>> +++ cfe/trunk/lib/Serialization/ASTWriter.cpp Fri Mar 15 17:15:07 2013
>> @@ -1213,11 +1213,24 @@ void ASTWriter::WriteControlBlock(Prepro
>> Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
>> }
>>
>> - WriteInputFiles(Context.SourceMgr, isysroot);
>> + WriteInputFiles(Context.SourceMgr,
>> + PP.getHeaderSearchInfo().getHeaderSearchOpts(),
>> + isysroot);
>> Stream.ExitBlock();
>> }
>>
>> -void ASTWriter::WriteInputFiles(SourceManager &SourceMgr, StringRef isysroot) {
>> +namespace {
>> + /// \brief An input file.
>> + struct InputFileEntry {
>> + const FileEntry *File;
>> + bool IsSystemFile;
>> + bool BufferOverridden;
>> + };
>> +}
>> +
>> +void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
>> + HeaderSearchOptions &HSOpts,
>> + StringRef isysroot) {
>> using namespace llvm;
>> Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
>> RecordData Record;
>> @@ -1234,7 +1247,7 @@ void ASTWriter::WriteInputFiles(SourceMa
>>
>> // Get all ContentCache objects for files, sorted by whether the file is a
>> // system one or not. System files go at the back, users files at the front.
>> - std::deque<const SrcMgr::ContentCache *> SortedFiles;
>> + std::deque<InputFileEntry> SortedFiles;
>> for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
>> // Get this source location entry.
>> const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
>> @@ -1247,20 +1260,38 @@ void ASTWriter::WriteInputFiles(SourceMa
>> if (!Cache->OrigEntry)
>> continue;
>>
>> + InputFileEntry Entry;
>> + Entry.File = Cache->OrigEntry;
>> + Entry.IsSystemFile = Cache->IsSystemFile;
>> + Entry.BufferOverridden = Cache->BufferOverridden;
>> if (Cache->IsSystemFile)
>> - SortedFiles.push_back(Cache);
>> + SortedFiles.push_back(Entry);
>> else
>> - SortedFiles.push_front(Cache);
>> + SortedFiles.push_front(Entry);
>> + }
>> +
>> + // If we have an isysroot for a Darwin SDK, include its SDKSettings.plist in
>> + // the set of (non-system) input files. This is simple heuristic for
>> + // detecting whether the system headers may have changed, because it is too
>> + // expensive to stat() all of the system headers.
>> + FileManager &FileMgr = SourceMgr.getFileManager();
>> + if (!HSOpts.Sysroot.empty()) {
>> + llvm::SmallString<128> SDKSettingsFileName(HSOpts.Sysroot);
>> + llvm::sys::path::append(SDKSettingsFileName, "SDKSettings.plist");
>> + if (const FileEntry *SDKSettingsFile = FileMgr.getFile(SDKSettingsFileName)) {
>> + InputFileEntry Entry = { SDKSettingsFile, false, false };
>> + SortedFiles.push_front(Entry);
>> + }
>> }
>>
>> unsigned UserFilesNum = 0;
>> // Write out all of the input files.
>> std::vector<uint32_t> InputFileOffsets;
>> - for (std::deque<const SrcMgr::ContentCache *>::iterator
>> + for (std::deque<InputFileEntry>::iterator
>> I = SortedFiles.begin(), E = SortedFiles.end(); I != E; ++I) {
>> - const SrcMgr::ContentCache *Cache = *I;
>> + const InputFileEntry &Entry = *I;
>>
>> - uint32_t &InputFileID = InputFileIDs[Cache->OrigEntry];
>> + uint32_t &InputFileID = InputFileIDs[Entry.File];
>> if (InputFileID != 0)
>> continue; // already recorded this file.
>>
>> @@ -1269,7 +1300,7 @@ void ASTWriter::WriteInputFiles(SourceMa
>>
>> InputFileID = InputFileOffsets.size();
>>
>> - if (!Cache->IsSystemFile)
>> + if (!Entry.IsSystemFile)
>> ++UserFilesNum;
>>
>> Record.clear();
>> @@ -1277,19 +1308,19 @@ void ASTWriter::WriteInputFiles(SourceMa
>> Record.push_back(InputFileOffsets.size());
>>
>> // Emit size/modification time for this file.
>> - Record.push_back(Cache->OrigEntry->getSize());
>> - Record.push_back(Cache->OrigEntry->getModificationTime());
>> + Record.push_back(Entry.File->getSize());
>> + Record.push_back(Entry.File->getModificationTime());
>>
>> // Whether this file was overridden.
>> - Record.push_back(Cache->BufferOverridden);
>> + Record.push_back(Entry.BufferOverridden);
>>
>> // Turn the file name into an absolute path, if it isn't already.
>> - const char *Filename = Cache->OrigEntry->getName();
>> + const char *Filename = Entry.File->getName();
>> SmallString<128> FilePath(Filename);
>>
>> // Ask the file manager to fixup the relative path for us. This will
>> // honor the working directory.
>> - SourceMgr.getFileManager().FixupRelativePath(FilePath);
>> + FileMgr.FixupRelativePath(FilePath);
>>
>> // FIXME: This call to make_absolute shouldn't be necessary, the
>> // call to FixupRelativePath should always return an absolute path.
>> @@ -1300,7 +1331,7 @@ void ASTWriter::WriteInputFiles(SourceMa
>>
>> Stream.EmitRecordWithBlob(IFAbbrevCode, Record, Filename);
>> }
>> -
>> +
>> Stream.ExitBlock();
>>
>> // Create input file offsets abbreviation.
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>
> -- Jean-Daniel
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