Add template type diffing to Clang. This feature will provide a better

comparison between two templated types when they both appear in a diagnostic.
Type elision will remove indentical template arguments, which can be disabled
with -fno-elide-type.  Cyan highlighting is applied to the differing types.

For more formatting, -fdiagnostic-show-template-tree will output the template
type as an indented text tree, with differences appearing inline. Template
tree works with or without type elision.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159216 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 32 insertions, 4 deletions

diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 8a95c80e49..40328d4200 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1349,6 +1349,8 @@ bool clang::ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
   Opts.ShowSourceRanges = Args.hasArg(OPT_fdiagnostics_print_source_range_info);
   Opts.ShowParseableFixits = Args.hasArg(OPT_fdiagnostics_parseable_fixits);
   Opts.VerifyDiagnostics = Args.hasArg(OPT_verify);
+  Opts.ElideType = !Args.hasArg(OPT_fno_elide_type);
+  Opts.ShowTemplateTree = Args.hasArg(OPT_fdiagnostics_show_template_tree);
   Opts.ErrorLimit = Args.getLastArgIntValue(OPT_ferror_limit, 0, Diags);
   Opts.MacroBacktraceLimit
     = Args.getLastArgIntValue(OPT_fmacro_backtrace_limit,
diff --git a/lib/Frontend/TextDiagnostic.cpp b/lib/Frontend/TextDiagnostic.cpp
index d0c3626f3c..8b7332dbeb 100644
--- a/lib/Frontend/TextDiagnostic.cpp
+++ b/lib/Frontend/TextDiagnostic.cpp
@@ -31,12 +31,29 @@ static const enum raw_ostream::Colors caretColor =
   raw_ostream::GREEN;
 static const enum raw_ostream::Colors warningColor =
   raw_ostream::MAGENTA;
+static const enum raw_ostream::Colors templateColor =
+  raw_ostream::CYAN;
 static const enum raw_ostream::Colors errorColor = raw_ostream::RED;
 static const enum raw_ostream::Colors fatalColor = raw_ostream::RED;
 // Used for changing only the bold attribute.
 static const enum raw_ostream::Colors savedColor =
   raw_ostream::SAVEDCOLOR;
 
+/// \brief Add highlights to differences in template strings.
+static void applyTemplateHighlighting(raw_ostream &OS, StringRef Str,
+                                      bool &Normal) {
+  for (unsigned i = 0, e = Str.size(); i < e; ++i)
+    if (Str[i] != ToggleHighlight) {
+      OS << Str[i];
+    } else {
+      if (Normal)
+        OS.changeColor(templateColor, true);
+      else
+        OS.resetColor();
+      Normal = !Normal;
+    }
+}
+
 /// \brief Number of spaces to indent when word-wrapping.
 const unsigned WordWrapIndentation = 6;
 
@@ -578,6 +595,7 @@ static bool printWordWrapped(raw_ostream &OS, StringRef Str,
                              unsigned Column = 0,
                              unsigned Indentation = WordWrapIndentation) {
   const unsigned Length = std::min(Str.find('\n'), Str.size());
+  bool TextNormal = true;
 
   // The string used to indent each line.
   SmallString<16> IndentStr;
@@ -601,7 +619,8 @@ static bool printWordWrapped(raw_ostream &OS, StringRef Str,
         OS << ' ';
         Column += 1;
       }
-      OS << Str.substr(WordStart, WordLength);
+      applyTemplateHighlighting(OS, Str.substr(WordStart, WordLength),
+                                TextNormal);
       Column += WordLength;
       continue;
     }
@@ -610,13 +629,16 @@ static bool printWordWrapped(raw_ostream &OS, StringRef Str,
     // line.
     OS << '\n';
     OS.write(&IndentStr[0], Indentation);
-    OS << Str.substr(WordStart, WordLength);
+    applyTemplateHighlighting(OS, Str.substr(WordStart, WordLength),
+                              TextNormal);
     Column = Indentation + WordLength;
     Wrapped = true;
   }
 
   // Append any remaning text from the message with its existing formatting.
-  OS << Str.substr(Length);
+  applyTemplateHighlighting(OS, Str.substr(Length), TextNormal);
+
+  assert(TextNormal && "Text highlighted at end of diagnostic message.");
 
   return Wrapped;
 }
diff --git a/lib/Frontend/Warnings.cpp b/lib/Frontend/Warnings.cpp
index 24b7acacfd..b7d4a3b925 100644
--- a/lib/Frontend/Warnings.cpp
+++ b/lib/Frontend/Warnings.cpp
@@ -53,7 +53,11 @@ void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
   Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
   Diags.setShowOverloads(
     static_cast<DiagnosticsEngine::OverloadsShown>(Opts.ShowOverloads));
-  
+
+  Diags.setElideType(Opts.ElideType);
+  Diags.setPrintTemplateTree(Opts.ShowTemplateTree);
+  Diags.setShowColors(Opts.ShowColors);
+ 
   // Handle -ferror-limit
   if (Opts.ErrorLimit)
     Diags.setErrorLimit(Opts.ErrorLimit);