Allow string literals as module names.

In order to make the migration to modules easier, it seems to be helpful
to allow a 1:1 mapping between target names of a current build system
and the corresponding C++ modules. As  such targets commonly contain
characters like "-". ":" and "/", allowing arbitrary quote-escaped
strings seems to be a straightforward option.

After several offline discussions, the precise mechanisms for C++
module names especially regarding submodules and import statements has
yet to be determined. Thus, this patch only enables string literals as
names inside the module map files which can be used by automatic module
import (through #include).

Also improve the error message on missing use-declarations.

llvm-svn: 196573

2 files changed, 3 insertions, 21 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index f4dfa12854a..3ce0def1d1c 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -1066,7 +1066,7 @@ void ModuleMapParser::skipUntil(MMToken::TokenKind K) {
 bool ModuleMapParser::parseModuleId(ModuleId &Id) {
   Id.clear();
   do {
-    if (Tok.is(MMToken::Identifier)) {
+    if (Tok.is(MMToken::Identifier) || Tok.is(MMToken::StringLiteral)) {
       Id.push_back(std::make_pair(Tok.getString(), Tok.getLocation()));
       consumeToken();
     } else {
@@ -1687,25 +1687,7 @@ void ModuleMapParser::parseUseDecl() {
   consumeToken();
   // Parse the module-id.
   ModuleId ParsedModuleId;
-
-  do {
-    if (Tok.is(MMToken::Identifier)) {
-      ParsedModuleId.push_back(
-          std::make_pair(Tok.getString(), Tok.getLocation()));
-      consumeToken();
-
-      if (Tok.is(MMToken::Period)) {
-        consumeToken();
-        continue;
-      }
-
-      break;
-    }
-
-    Diags.Report(Tok.getLocation(), diag::err_mmap_module_id);
-    HadError = true;
-    return;
-  } while (true);
+  parseModuleId(ParsedModuleId);
 
   ActiveModule->UnresolvedDirectUses.push_back(ParsedModuleId);
 }
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 7d4c788f660..70c32c3dc69 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -610,7 +610,7 @@ void Preprocessor::verifyModuleInclude(SourceLocation FilenameLoc,
   if (RequestingModule && getLangOpts().ModulesDeclUse &&
       violatesUseDeclarations(RequestingModule, RequestedModule.getModule()))
     Diag(FilenameLoc, diag::error_undeclared_use_of_module)
-        << Filename;
+        << RequestingModule->getFullModuleName() << Filename;
 }
 
 const FileEntry *Preprocessor::LookupFile(