[Preprocessor] Support for '-dI' flag

Re-introduce r285411.

Implement the -dI as supported by GCC: Output ‘#include’ directives in addition
to the result of preprocessing.

This change aims to add this option, pass it through to the preprocessor via
the options class, and when inclusions occur we output some information (+ test
cases).

Patch by Steve O'Brien!

Differential Revision: https://reviews.llvm.org/D26089

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@287275 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 8 deletions

diff --git a/lib/Frontend/PrintPreprocessedOutput.cpp b/lib/Frontend/PrintPreprocessedOutput.cpp
index 77b80e612f..d48b952ef2 100644
--- a/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -93,13 +93,16 @@ private:
   bool Initialized;
   bool DisableLineMarkers;
   bool DumpDefines;
+  bool DumpIncludeDirectives;
   bool UseLineDirectives;
   bool IsFirstFileEntered;
 public:
   PrintPPOutputPPCallbacks(Preprocessor &pp, raw_ostream &os, bool lineMarkers,
-                           bool defines, bool UseLineDirectives)
+                           bool defines, bool DumpIncludeDirectives,
+                           bool UseLineDirectives)
       : PP(pp), SM(PP.getSourceManager()), ConcatInfo(PP), OS(os),
         DisableLineMarkers(lineMarkers), DumpDefines(defines),
+        DumpIncludeDirectives(DumpIncludeDirectives),
         UseLineDirectives(UseLineDirectives) {
     CurLine = 0;
     CurFilename += "<uninit>";
@@ -320,10 +323,10 @@ void PrintPPOutputPPCallbacks::InclusionDirective(SourceLocation HashLoc,
                                                   StringRef SearchPath,
                                                   StringRef RelativePath,
                                                   const Module *Imported) {
-  // When preprocessing, turn implicit imports into @imports.
-  // FIXME: This is a stop-gap until a more comprehensive "preprocessing with
-  // modules" solution is introduced.
   if (Imported) {
+    // When preprocessing, turn implicit imports into @imports.
+    // FIXME: This is a stop-gap until a more comprehensive "preprocessing with
+    // modules" solution is introduced.
     startNewLineIfNeeded();
     MoveToLine(HashLoc);
     if (PP.getLangOpts().ObjC2) {
@@ -331,9 +334,9 @@ void PrintPPOutputPPCallbacks::InclusionDirective(SourceLocation HashLoc,
          << " /* clang -E: implicit import for \"" << File->getName()
          << "\" */";
     } else {
-      // FIXME: Preseve whether this was a
-      // #include/#include_next/#include_macros/#import.
-      OS << "#include "
+      const std::string TokenText = PP.getSpelling(IncludeTok);
+      assert(!TokenText.empty());
+      OS << "#" << TokenText << " "
          << (IsAngled ? '<' : '"')
          << FileName
          << (IsAngled ? '>' : '"')
@@ -344,6 +347,20 @@ void PrintPPOutputPPCallbacks::InclusionDirective(SourceLocation HashLoc,
     // line immediately.
     EmittedTokensOnThisLine = true;
     startNewLineIfNeeded();
+  } else {
+    // Not a module import; it's a more vanilla inclusion of some file using one
+    // of: #include, #import, #include_next, #include_macros.
+    if (DumpIncludeDirectives) {
+      startNewLineIfNeeded();
+      MoveToLine(HashLoc);
+      const std::string TokenText = PP.getSpelling(IncludeTok);
+      assert(!TokenText.empty());
+      OS << "#" << TokenText << " "
+         << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
+         << " /* clang -E -dI */";
+      setEmittedDirectiveOnThisLine();
+      startNewLineIfNeeded();
+    }
   }
 }
 
@@ -751,7 +768,8 @@ void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
   PP.SetCommentRetentionState(Opts.ShowComments, Opts.ShowMacroComments);
 
   PrintPPOutputPPCallbacks *Callbacks = new PrintPPOutputPPCallbacks(
-      PP, *OS, !Opts.ShowLineMarkers, Opts.ShowMacros, Opts.UseLineDirectives);
+      PP, *OS, !Opts.ShowLineMarkers, Opts.ShowMacros,
+      Opts.ShowIncludeDirectives, Opts.UseLineDirectives);
 
   // Expand macros in pragmas with -fms-extensions.  The assumption is that
   // the majority of pragmas in such a file will be Microsoft pragmas.