Adding support for #pragma include_alias in MS compatibility mode. This implements PR 10705.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151949 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 50 insertions, 0 deletions

diff --git a/include/clang/Basic/DiagnosticLexKinds.td b/include/clang/Basic/DiagnosticLexKinds.td
index 46e0bebb3e..12f23cea50 100644
--- a/include/clang/Basic/DiagnosticLexKinds.td
+++ b/include/clang/Basic/DiagnosticLexKinds.td
@@ -292,6 +292,19 @@ def warn_has_warning_invalid_option :
    ExtWarn<"__has_warning expected option name (e.g. \"-Wundef\")">,
    InGroup<MalformedWarningCheck>;
 
+def warn_pragma_include_alias_mismatch_angle :
+   ExtWarn<"angle-bracketed include <%0> cannot be aliased to double-quoted "
+   "include \"%1\"">, InGroup<UnknownPragmas>;
+def warn_pragma_include_alias_mismatch_quote :
+   ExtWarn<"double-quoted include \"%0\" cannot be aliased to angle-bracketed "
+   "include <%1>">, InGroup<UnknownPragmas>;
+def warn_pragma_include_alias_expected :
+   ExtWarn<"pragma include_alias expected '%0'">,
+   InGroup<UnknownPragmas>;
+def warn_pragma_include_alias_expected_filename :
+   ExtWarn<"pragma include_alias expected include filename">,
+   InGroup<UnknownPragmas>;
+
 def err__Pragma_malformed : Error<
   "_Pragma takes a parenthesized string literal">;
 def err_pragma_comment_malformed : Error<
diff --git a/include/clang/Lex/HeaderSearch.h b/include/clang/Lex/HeaderSearch.h
index 84bb37da3a..8ed2ec3362 100644
--- a/include/clang/Lex/HeaderSearch.h
+++ b/include/clang/Lex/HeaderSearch.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/Allocator.h"
+#include "llvm/ADT/OwningPtr.h"
 #include <vector>
 
 namespace clang {
@@ -154,6 +155,13 @@ class HeaderSearch {
   llvm::StringMap<const DirectoryEntry *, llvm::BumpPtrAllocator>
     FrameworkMap;
 
+  /// IncludeAliases - maps include file names (including the quotes or
+  /// angle brackets) to other include file names.  This is used to support the
+  /// include_alias pragma for Microsoft compatibility.
+  typedef llvm::StringMap<std::string, llvm::BumpPtrAllocator>
+    IncludeAliasMap;
+  OwningPtr<IncludeAliasMap> IncludeAliases;
+
   /// HeaderMaps - This is a mapping from FileEntry -> HeaderMap, uniquing
   /// headermaps.  This vector owns the headermap.
   std::vector<std::pair<const FileEntry*, const HeaderMap*> > HeaderMaps;
@@ -217,6 +225,34 @@ public:
     SystemDirIdx++;
   }
 
+  /// HasIncludeAliasMap - Checks whether the map exists or not
+  bool HasIncludeAliasMap() const {
+    return IncludeAliases;
+  }
+
+  /// AddIncludeAlias - Map the source include name to the dest include name.
+  /// The Source should include the angle brackets or quotes, the dest 
+  /// should not.  This allows for distinction between <> and "" headers.
+  void AddIncludeAlias(StringRef Source, StringRef Dest) {
+    if (!IncludeAliases)
+      IncludeAliases.reset(new IncludeAliasMap);
+    (*IncludeAliases)[Source] = Dest;
+  }
+
+  /// MapHeaderToIncludeAlias - Maps one header file name to a different header
+  /// file name, for use with the include_alias pragma.  Note that the source
+  /// file name should include the angle brackets or quotes.  Returns StringRef
+  /// as null if the header cannot be mapped.
+  StringRef MapHeaderToIncludeAlias(StringRef Source) {
+    assert(IncludeAliases && "Trying to map headers when there's no map");
+
+    // Do any filename replacements before anything else
+    IncludeAliasMap::const_iterator Iter = IncludeAliases->find(Source);
+    if (Iter != IncludeAliases->end())
+      return Iter->second;
+    return StringRef();
+  }
+
   /// \brief Set the path to the module cache.
   void setModuleCachePath(StringRef CachePath) {
     ModuleCachePath = CachePath;
diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index feed6a8bfa..9ee9e82529 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -1262,6 +1262,7 @@ public:
   void HandlePragmaMessage(Token &MessageTok);
   void HandlePragmaPushMacro(Token &Tok);
   void HandlePragmaPopMacro(Token &Tok);
+  void HandlePragmaIncludeAlias(Token &Tok);
   IdentifierInfo *ParsePragmaPushOrPopMacro(Token &Tok);
 
   // Return true and store the first token only if any CommentHandler