[modules] Add ability to specify module name to module file mapping (reapply)
Extend the -fmodule-file option to support the [<name>=]<file> value format.
If the name is omitted, then the old semantics is preserved (the module file
is loaded whether needed or not). If the name is specified, then the mapping
is treated as just another prebuilt module search mechanism, similar to
-fprebuilt-module-path, and the module file is only loaded if actually used
(e.g., via import). With one exception: this mapping also overrides module
file references embedded in other modules (which can be useful if module files
are moved/renamed as often happens during remote compilation).
This override semantics requires some extra work: we now store the module name
in addition to the file name in the serialized AST representation.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D35020
llvm-svn: 312220
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 62c9fb4..0d45b27 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1505,6 +1505,7 @@
for (auto I : M.Signature)
Record.push_back(I);
+ AddString(M.ModuleName, Record);
AddPath(M.FileName, Record);
}
Stream.EmitRecord(IMPORTS, Record);
@@ -4779,7 +4780,8 @@
// each of those modules were mapped into our own offset/ID space, so that
// the reader can build the appropriate mapping to its own offset/ID space.
// The map consists solely of a blob with the following format:
- // *(module-name-len:i16 module-name:len*i8
+ // *(module-kind:i8
+ // module-name-len:i16 module-name:len*i8
// source-location-offset:i32
// identifier-id:i32
// preprocessed-entity-id:i32
@@ -4790,6 +4792,10 @@
// c++-base-specifiers-id:i32
// type-id:i32)
//
+ // module-kind is the ModuleKind enum value. If it is MK_PrebuiltModule or
+ // MK_ExplicitModule, then the module-name is the module name. Otherwise,
+ // it is the module file name.
+ //
auto Abbrev = std::make_shared<BitCodeAbbrev>();
Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
@@ -4800,9 +4806,13 @@
for (ModuleFile &M : Chain->ModuleMgr) {
using namespace llvm::support;
endian::Writer<little> LE(Out);
- StringRef FileName = M.FileName;
- LE.write<uint16_t>(FileName.size());
- Out.write(FileName.data(), FileName.size());
+ LE.write<uint8_t>(static_cast<uint8_t>(M.Kind));
+ StringRef Name =
+ M.Kind == MK_PrebuiltModule || M.Kind == MK_ExplicitModule
+ ? M.ModuleName
+ : M.FileName;
+ LE.write<uint16_t>(Name.size());
+ Out.write(Name.data(), Name.size());
// Note: if a base ID was uint max, it would not be possible to load
// another module after it or have more than one entity inside it.