[Modules] Don't eagerly load and associate all the module header files.
In a module-enabled Cocoa PCH file, we spend a lot of time stat'ing the headers
in order to associate the FileEntries with their modules and support implicit
module import.
Use a more lazy scheme by enhancing HeaderInfoTable to store extra info about
the module that a header belongs to, and associate it with its module only when
there is a request for loading the header info for a particular file.
Part of rdar://13391765
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176976 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 8f48d58..088e7a3 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1384,14 +1384,15 @@
// Trait used for the on-disk hash table of header search information.
class HeaderFileInfoTrait {
ASTWriter &Writer;
+ const HeaderSearch &HS;
// Keep track of the framework names we've used during serialization.
SmallVector<char, 128> FrameworkStringData;
llvm::StringMap<unsigned> FrameworkNameOffset;
public:
- HeaderFileInfoTrait(ASTWriter &Writer)
- : Writer(Writer) { }
+ HeaderFileInfoTrait(ASTWriter &Writer, const HeaderSearch &HS)
+ : Writer(Writer), HS(HS) { }
struct key_type {
const FileEntry *FE;
@@ -1415,6 +1416,8 @@
unsigned KeyLen = strlen(key.Filename) + 1 + 8 + 8;
clang::io::Emit16(Out, KeyLen);
unsigned DataLen = 1 + 2 + 4 + 4;
+ if (Data.isModuleHeader)
+ DataLen += 4;
clang::io::Emit8(Out, DataLen);
return std::make_pair(KeyLen, DataLen);
}
@@ -1427,7 +1430,7 @@
Out.write(key.Filename, KeyLen);
}
- void EmitData(raw_ostream &Out, key_type_ref,
+ void EmitData(raw_ostream &Out, key_type_ref key,
data_type_ref Data, unsigned DataLen) {
using namespace clang::io;
uint64_t Start = Out.tell(); (void)Start;
@@ -1461,7 +1464,12 @@
Offset = Pos->second;
}
Emit32(Out, Offset);
-
+
+ if (Data.isModuleHeader) {
+ Module *Mod = HS.findModuleForHeader(key.FE);
+ Emit32(Out, Writer.getExistingSubmoduleID(Mod));
+ }
+
assert(Out.tell() - Start == DataLen && "Wrong data length");
}
@@ -1480,7 +1488,7 @@
if (FilesByUID.size() > HS.header_file_size())
FilesByUID.resize(HS.header_file_size());
- HeaderFileInfoTrait GeneratorTrait(*this);
+ HeaderFileInfoTrait GeneratorTrait(*this, HS);
OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
SmallVector<const char *, 4> SavedStrings;
unsigned NumHeaderSearchEntries = 0;
@@ -2020,6 +2028,18 @@
return SubmoduleIDs[Mod] = NextSubmoduleID++;
}
+unsigned ASTWriter::getExistingSubmoduleID(Module *Mod) const {
+ if (!Mod)
+ return 0;
+
+ llvm::DenseMap<Module *, unsigned>::const_iterator
+ Known = SubmoduleIDs.find(Mod);
+ if (Known != SubmoduleIDs.end())
+ return Known->second;
+
+ return 0;
+}
+
/// \brief Compute the number of modules within the given tree (including the
/// given module).
static unsigned getNumberOfModules(Module *Mod) {