Reinstate r223753, reverted in r223759 due to breakage of clang-tools-extra.

Original commit message:

[modules] Add experimental -fmodule-map-file-home-is-cwd flag to -cc1.

For files named by -fmodule-map-file=, and files found by 'extern module'
directives, this flag specifies that we should resolve filenames relative to
the current working directory rather than relative to the directory in which
the module map file resides. This is aimed at fixing path handling, in
particular for relative -I paths, when building modules that represent
components of the current project (rather than libraries installed on the
current system, which the current project has as dependencies, where we'd
typically expect the module map files to be looked up implicitly).

llvm-svn: 223913

1 files changed, 11 insertions, 15 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 9ac554a..c5e317a 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -19,6 +19,7 @@
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/HeaderSearchOptions.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/Lexer.h"
 #include "clang/Lex/LiteralSupport.h"
@@ -648,7 +649,7 @@ ModuleMap::inferFrameworkModule(StringRef ModuleName,
           bool IsFrameworkDir = Parent.endswith(".framework");
           if (const FileEntry *ModMapFile =
                 HeaderInfo.lookupModuleMapFile(ParentDir, IsFrameworkDir)) {
-            parseModuleMapFile(ModMapFile, IsSystem);
+            parseModuleMapFile(ModMapFile, IsSystem, ParentDir);
             inferred = InferredDirectories.find(ParentDir);
           }
 
@@ -1024,7 +1025,8 @@ namespace clang {
     /// \brief The current module map file.
     const FileEntry *ModuleMapFile;
     
-    /// \brief The directory that this module map resides in.
+    /// \brief The directory that file names in this module map file should
+    /// be resolved relative to.
     const DirectoryEntry *Directory;
 
     /// \brief The directory containing Clang-supplied headers.
@@ -1591,7 +1593,11 @@ void ModuleMapParser::parseExternModuleDecl() {
     FileNameRef = ModuleMapFileName.str();
   }
   if (const FileEntry *File = SourceMgr.getFileManager().getFile(FileNameRef))
-    Map.parseModuleMapFile(File, /*IsSystem=*/false);
+    Map.parseModuleMapFile(
+        File, /*IsSystem=*/false,
+        Map.HeaderInfo.getHeaderSearchOpts().ModuleMapFileHomeIsCwd
+            ? Directory
+            : File->getDir());
 }
 
 /// \brief Parse a requires declaration.
@@ -2333,7 +2339,8 @@ bool ModuleMapParser::parseModuleMapFile() {
   } while (true);
 }
 
-bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem) {
+bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem,
+                                   const DirectoryEntry *Dir) {
   llvm::DenseMap<const FileEntry *, bool>::iterator Known
     = ParsedModuleMap.find(File);
   if (Known != ParsedModuleMap.end())
@@ -2346,17 +2353,6 @@ bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem) {
   if (!Buffer)
     return ParsedModuleMap[File] = true;
 
-  // Find the directory for the module. For frameworks, that may require going
-  // up from the 'Modules' directory.
-  const DirectoryEntry *Dir = File->getDir();
-  StringRef DirName(Dir->getName());
-  if (llvm::sys::path::filename(DirName) == "Modules") {
-    DirName = llvm::sys::path::parent_path(DirName);
-    if (DirName.endswith(".framework"))
-      Dir = SourceMgr.getFileManager().getDirectory(DirName);
-    assert(Dir && "parent must exist");
-  }
-  
   // Parse this module map file.
   Lexer L(ID, SourceMgr.getBuffer(ID), SourceMgr, MMapLangOpts);
   ModuleMapParser Parser(L, SourceMgr, Target, Diags, *this, File, Dir,