Add an option to suppress include stack printing on note diagnostics.

These stacks are often less important than those on primary diagnostics.

As the number of notes grows, this becomes increasingly important. The
include stack printing is clever and doesn't print stacks for adjacent
diagnostics from the same file, but when a note is in between a sequence
of errors in a header file, and the notes all refer to some other file,
we end up getting a worst-case ping-pong of include stacks that take up
a great deal of vertical space.

Still, for now, the default behavior isn't changed. We can evaluate user
feedback with the flag.

Patch by Richard Trieu, a couple of style tweaks from me.

llvm-svn: 128371

7 files changed, 45 insertions, 14 deletions

diff --git a/clang/include/clang/Driver/CC1Options.td b/clang/include/clang/Driver/CC1Options.td
index b29d73fd026..6e1c61c99f5 100644
--- a/clang/include/clang/Driver/CC1Options.td
+++ b/clang/include/clang/Driver/CC1Options.td
@@ -210,6 +210,9 @@ def fno_caret_diagnostics : Flag<"-fno-caret-diagnostics">,
   HelpText<"Do not include source line and caret with diagnostics">;
 def fno_diagnostics_fixit_info : Flag<"-fno-diagnostics-fixit-info">,
   HelpText<"Do not include fixit information in diagnostics">;
+def fno_diagnostics_show_note_include_stack :
+  Flag<"-fno-diagnostics-show-note-include-stack">,
+  HelpText<"Display include stacks for diagnostic notes">;
 def w : Flag<"-w">, HelpText<"Suppress all warnings">;
 def pedantic : Flag<"-pedantic">;
 def pedantic_errors : Flag<"-pedantic-errors">;
@@ -227,7 +230,9 @@ def fdiagnostics_show_option : Flag<"-fdiagnostics-show-option">,
   HelpText<"Print diagnostic name with mappable diagnostics">;
 def fdiagnostics_show_category : Separate<"-fdiagnostics-show-category">,
   HelpText<"Print diagnostic category">;
-
+def fdiagnostics_show_note_include_stack :
+  Flag<"-fdiagnostics-show-note-include-stack">,
+  HelpText<"Display include stacks for diagnostic notes">;
 def ftabstop : Separate<"-ftabstop">, MetaVarName<"<N>">,
   HelpText<"Set the tab stop distance.">;
 def ferror_limit : Separate<"-ferror-limit">, MetaVarName<"<N>">,
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6cd5645cdff..b831c9193f7 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -271,6 +271,7 @@ def fdiagnostics_fixit_info : Flag<"-fdiagnostics-fixit-info">, Group<f_Group>;
 def fdiagnostics_print_source_range_info : Flag<"-fdiagnostics-print-source-range-info">, Group<f_Group>;
 def fdiagnostics_parseable_fixits : Flag<"-fdiagnostics-parseable-fixits">, Group<f_Group>;
 def fdiagnostics_show_option : Flag<"-fdiagnostics-show-option">, Group<f_Group>;
+def fdiagnostics_show_note_include_stack : Flag<"-fdiagnostics-show-note-include-stack">, Group<f_Group>;
 def fdiagnostics_show_category_EQ : Joined<"-fdiagnostics-show-category=">, Group<f_Group>;
 def fdollars_in_identifiers : Flag<"-fdollars-in-identifiers">, Group<f_Group>;
 def felide_constructors : Flag<"-felide-constructors">, Group<f_Group>;
@@ -329,6 +330,7 @@ def fno_constant_cfstrings : Flag<"-fno-constant-cfstrings">, Group<f_Group>;
 def fno_cxx_exceptions: Flag<"-fno-cxx-exceptions">, Group<f_Group>;
 def fno_diagnostics_fixit_info : Flag<"-fno-diagnostics-fixit-info">, Group<f_Group>;
 def fno_diagnostics_show_option : Flag<"-fno-diagnostics-show-option">, Group<f_Group>;
+def fno_diagnostics_show_note_include_stack : Flag<"-fno-diagnostics-show-note-include-stack">, Group<f_Group>;
 def fno_dollars_in_identifiers : Flag<"-fno-dollars-in-identifiers">, Group<f_Group>;
 def fno_elide_constructors : Flag<"-fno-elide-constructors">, Group<f_Group>;
 def fno_eliminate_unused_debug_symbols : Flag<"-fno-eliminate-unused-debug-symbols">, Group<f_Group>;
diff --git a/clang/include/clang/Frontend/DiagnosticOptions.h b/clang/include/clang/Frontend/DiagnosticOptions.h
index f7f498bff02..4e46b4fbf02 100644
--- a/clang/include/clang/Frontend/DiagnosticOptions.h
+++ b/clang/include/clang/Frontend/DiagnosticOptions.h
@@ -33,6 +33,7 @@ public:
   unsigned ShowParseableFixits : 1; /// Show machine parseable fix-its.
   unsigned ShowOptionNames : 1;  /// Show the diagnostic name for mappable
                                  /// diagnostics.
+  unsigned ShowNoteIncludeStack : 1; /// Show include stacks for notes.
   unsigned ShowCategories : 2;   /// Show categories: 0 -> none, 1 -> Number,
                                  /// 2 -> Full Name.
   unsigned ShowColors : 1;       /// Show diagnostics with ANSI color sequences.
diff --git a/clang/include/clang/Frontend/TextDiagnosticPrinter.h b/clang/include/clang/Frontend/TextDiagnosticPrinter.h
index f5302947a59..d7d2692cb54 100644
--- a/clang/include/clang/Frontend/TextDiagnosticPrinter.h
+++ b/clang/include/clang/Frontend/TextDiagnosticPrinter.h
@@ -53,7 +53,8 @@ public:
     LangOpts = 0;
   }
 
-  void PrintIncludeStack(SourceLocation Loc, const SourceManager &SM);
+  void PrintIncludeStack(Diagnostic::Level Level, SourceLocation Loc,
+                         const SourceManager &SM);
 
   void HighlightRange(const CharSourceRange &R,
                       const SourceManager &SrcMgr,
@@ -61,7 +62,7 @@ public:
                       std::string &CaretLine,
                       const std::string &SourceLine);
 
-  void EmitCaretDiagnostic(SourceLocation Loc,
+  void EmitCaretDiagnostic(Diagnostic::Level Level, SourceLocation Loc,
                            CharSourceRange *Ranges, unsigned NumRanges,
                            const SourceManager &SM,
                            const FixItHint *Hints,
@@ -71,7 +72,7 @@ public:
                            unsigned MacroSkipStart,
                            unsigned MacroSkipEnd);
 
-  virtual void HandleDiagnostic(Diagnostic::Level DiagLevel,
+  virtual void HandleDiagnostic(Diagnostic::Level Level,
                                 const DiagnosticInfo &Info);
 };
 
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 81585c85674..721117071ba 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1732,6 +1732,16 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(A->getValue(Args));
   }
 
+  if (Arg *A = Args.getLastArg(
+      options::OPT_fdiagnostics_show_note_include_stack,
+      options::OPT_fno_diagnostics_show_note_include_stack)) {
+    if (A->getOption().matches(
+        options::OPT_fdiagnostics_show_note_include_stack))
+      CmdArgs.push_back("-fdiagnostics-show-note-include-stack");
+    else
+      CmdArgs.push_back("-fno-diagnostics-show-note-include-stack");
+  }
+
   // Color diagnostics are the default, unless the terminal doesn't support
   // them.
   if (Args.hasFlag(options::OPT_fcolor_diagnostics,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 980c75200e7..431f5f4d2f4 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -989,6 +989,13 @@ static void ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
   Opts.ShowLocation = !Args.hasArg(OPT_fno_show_source_location);
   Opts.ShowOptionNames = Args.hasArg(OPT_fdiagnostics_show_option);
 
+  // Default behavior is to show note include stacks.
+  Opts.ShowNoteIncludeStack = true;
+  if (Arg *A = Args.getLastArg(OPT_fdiagnostics_show_note_include_stack,
+                               OPT_fno_diagnostics_show_note_include_stack))
+    if (A->getOption().matches(OPT_fno_diagnostics_show_note_include_stack))
+      Opts.ShowNoteIncludeStack = false;
+
   llvm::StringRef ShowOverloads =
     Args.getLastArgValue(OPT_fshow_overloads_EQ, "all");
   if (ShowOverloads == "best")
diff --git a/clang/lib/Frontend/TextDiagnosticPrinter.cpp b/clang/lib/Frontend/TextDiagnosticPrinter.cpp
index 084915311dc..867d919fb30 100644
--- a/clang/lib/Frontend/TextDiagnosticPrinter.cpp
+++ b/clang/lib/Frontend/TextDiagnosticPrinter.cpp
@@ -53,8 +53,11 @@ TextDiagnosticPrinter::~TextDiagnosticPrinter() {
     delete &OS;
 }
 
-void TextDiagnosticPrinter::
-PrintIncludeStack(SourceLocation Loc, const SourceManager &SM) {
+void TextDiagnosticPrinter::PrintIncludeStack(Diagnostic::Level Level,
+                                              SourceLocation Loc,
+                                              const SourceManager &SM) {
+  if (!DiagOpts->ShowNoteIncludeStack && Level == Diagnostic::Note) return;
+
   if (Loc.isInvalid()) return;
 
   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
@@ -62,7 +65,7 @@ PrintIncludeStack(SourceLocation Loc, const SourceManager &SM) {
     return;
   
   // Print out the other include frames first.
-  PrintIncludeStack(PLoc.getIncludeLoc(), SM);
+  PrintIncludeStack(Level, PLoc.getIncludeLoc(), SM);
 
   if (DiagOpts->ShowLocation)
     OS << "In file included from " << PLoc.getFilename()
@@ -289,7 +292,8 @@ static void SelectInterestingSourceRegion(std::string &SourceLine,
   }
 }
 
-void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
+void TextDiagnosticPrinter::EmitCaretDiagnostic(Diagnostic::Level Level,
+                                                SourceLocation Loc,
                                                 CharSourceRange *Ranges,
                                                 unsigned NumRanges,
                                                 const SourceManager &SM,
@@ -313,7 +317,7 @@ void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
 
     SourceLocation OneLevelUp = SM.getImmediateInstantiationRange(Loc).first;
     // FIXME: Map ranges?
-    EmitCaretDiagnostic(OneLevelUp, Ranges, NumRanges, SM, 0, 0, Columns,
+    EmitCaretDiagnostic(Level, OneLevelUp, Ranges, NumRanges, SM, 0, 0, Columns,
                         OnMacroInst + 1, MacroSkipStart, MacroSkipEnd);
     
     // Map the location.
@@ -339,7 +343,7 @@ void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
       // "included from" lines.
       if (LastWarningLoc != PLoc.getIncludeLoc()) {
         LastWarningLoc = PLoc.getIncludeLoc();
-        PrintIncludeStack(LastWarningLoc, SM);
+        PrintIncludeStack(Level, LastWarningLoc, SM);
       }
 
       if (DiagOpts->ShowLocation) {
@@ -351,8 +355,9 @@ void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
       }
       OS << "note: instantiated from:\n";
       
-      EmitCaretDiagnostic(Loc, Ranges, NumRanges, SM, Hints, NumHints, Columns,
-                          OnMacroInst + 1, MacroSkipStart, MacroSkipEnd);
+      EmitCaretDiagnostic(Level, Loc, Ranges, NumRanges, SM, Hints, NumHints,
+                          Columns, OnMacroInst + 1, MacroSkipStart,
+                          MacroSkipEnd);
       return;
     }
     
@@ -805,7 +810,7 @@ void TextDiagnosticPrinter::HandleDiagnostic(Diagnostic::Level Level,
       // "included from" lines.
       if (LastWarningLoc != PLoc.getIncludeLoc()) {
         LastWarningLoc = PLoc.getIncludeLoc();
-        PrintIncludeStack(LastWarningLoc, SM);
+        PrintIncludeStack(Level, LastWarningLoc, SM);
         StartOfLocationInfo = OS.tell();
       }
 
@@ -1034,7 +1039,7 @@ void TextDiagnosticPrinter::HandleDiagnostic(Diagnostic::Level Level,
       }
     }        
     
-    EmitCaretDiagnostic(LastLoc, Ranges, NumRanges, LastLoc.getManager(),
+    EmitCaretDiagnostic(Level, LastLoc, Ranges, NumRanges, LastLoc.getManager(),
                         Info.getFixItHints(),
                         Info.getNumFixItHints(),
                         DiagOpts->MessageLength,