Initial work to improve documentation for Clang's diagnostics, from Matthieu Monrocq

llvm-svn: 129614

clang/include/clang/AST/ASTDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define ASTSTART
 #include "clang/Basic/DiagnosticASTKinds.inc"
 #undef DIAG

clang/include/clang/Analysis/AnalysisDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define ANALYSISSTART
 #include "clang/Basic/DiagnosticAnalysisKinds.inc"
 #undef DIAG

clang/include/clang/Basic/CMakeLists.txt

@@ -17,6 +17,10 @@ clang_tablegen(DiagnosticGroups.inc -gen-clang-diag-groups
   SOURCE Diagnostic.td
   TARGET ClangDiagnosticGroups)
 
+clang_tablegen(DiagnosticIndexName.inc -gen-clang-diags-index-name
+  SOURCE Diagnostic.td
+  TARGET ClangDiagnosticIndexName)
+
 clang_tablegen(AttrList.inc -gen-clang-attr-list
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE Attr.td

clang/include/clang/Basic/Diagnostic.td

@@ -60,6 +60,8 @@ class Diagnostic<string text, DiagClass DC, DiagMapping defaultmapping> {
   DiagMapping DefaultMapping = defaultmapping;
   DiagGroup   Group;
   string      CategoryName = "";
+  string      Brief = "";
+  string      Explanation = "";
 }
 
 class Error<string str>     : Diagnostic<str, CLASS_ERROR, MAP_ERROR>;
@@ -77,6 +79,12 @@ class DefaultFatal  { DiagMapping DefaultMapping = MAP_FATAL; }
 class NoSFINAE { bit SFINAE = 0; }
 class AccessControl { bit AccessControl = 1; }
 
+class Brief<string str> { string Brief = str; }
+class FullExplanation<string brief, string full> {
+  string Brief = brief;
+  string Explanation = full;
+}
+
 // Definitions for Diagnostics.
 include "DiagnosticASTKinds.td"
 include "DiagnosticAnalysisKinds.td"

clang/include/clang/Basic/DiagnosticIDs.h

@@ -42,7 +42,8 @@ namespace clang {
 
     // Get typedefs for common diagnostics.
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #include "clang/Basic/DiagnosticCommonKinds.inc"
       NUM_BUILTIN_COMMON_DIAGNOSTICS
 #undef DIAG
@@ -99,7 +100,7 @@ public:
   /// issue.
   const char *getDescription(unsigned DiagID) const;
 
-  /// isNoteWarningOrExtension - Return true if the unmapped diagnostic
+  /// isBuiltinWarningOrExtension - Return true if the unmapped diagnostic
   /// level of the specified diagnostic ID is a Warning or Extension.
   /// This only works on builtin diagnostics, not custom ones, and is not legal to
   /// call on NOTEs.
@@ -130,7 +131,7 @@ public:
   /// the diagnostic, this returns null.
   static const char *getWarningOptionForDiag(unsigned DiagID);
 
-  /// getWarningOptionForDiag - Return the category number that a specified
+  /// getCategoryNumberForDiag - Return the category number that a specified
   /// DiagID belongs to, or 0 if no category.
   static unsigned getCategoryNumberForDiag(unsigned DiagID);
 
@@ -174,6 +175,20 @@ public:
   /// are not SFINAE errors.
   static SFINAEResponse getDiagnosticSFINAEResponse(unsigned DiagID);
 
+  /// getName - Given a diagnostic ID, return its name
+  static const char *getName(unsigned DiagID);
+  
+  /// getIdFromName - Given a diagnostic name, return its ID, or 0
+  static unsigned getIdFromName(char const *Name);
+  
+  /// getBriefExplanation - Given a diagnostic ID, return a brief explanation
+  /// of the issue
+  static const char *getBriefExplanation(unsigned DiagID);
+
+  /// getFullExplanation - Given a diagnostic ID, return a full explanation
+  /// of the issue
+  static const char *getFullExplanation(unsigned DiagID);
+
 private:
   /// setDiagnosticGroupMapping - Change an entire diagnostic group (e.g.
   /// "unknown-pragmas" to have the specified mapping.  This returns true and

clang/include/clang/Basic/Makefile

@@ -4,7 +4,7 @@ BUILT_SOURCES = \
 	DiagnosticCommonKinds.inc DiagnosticDriverKinds.inc \
 	DiagnosticFrontendKinds.inc DiagnosticLexKinds.inc \
 	DiagnosticParseKinds.inc DiagnosticSemaKinds.inc \
-	DiagnosticGroups.inc AttrList.inc arm_neon.inc \
+	DiagnosticIndexName.inc DiagnosticGroups.inc AttrList.inc arm_neon.inc \
 	Version.inc
 
 TABLEGEN_INC_FILES_COMMON = 1
@@ -33,6 +33,10 @@ $(ObjDir)/Diagnostic%Kinds.inc.tmp : Diagnostic.td Diagnostic%Kinds.td $(TBLGEN)
 	$(Echo) "Building Clang $(patsubst Diagnostic%Kinds.inc.tmp,%,$(@F)) diagnostic tables with tblgen"
 	$(Verb) $(TableGen) -gen-clang-diags-defs -clang-component=$(patsubst Diagnostic%Kinds.inc.tmp,%,$(@F)) -o $(call SYSPATH, $@) $<
 
+$(ObjDir)/DiagnosticIndexName.inc.tmp : Diagnostic.td $(INPUT_TDS) $(TBLGEN) $(ObjDir)/.dir
+	$(Echo) "Building Clang diagnostic name index with tblgen"
+	$(Verb) $(TableGen) -gen-clang-diags-index-name -o $(call SYSPATH, $@) $<
+
 $(ObjDir)/DiagnosticGroups.inc.tmp : Diagnostic.td DiagnosticGroups.td $(INPUT_TDS) $(TBLGEN) $(ObjDir)/.dir
 	$(Echo) "Building Clang diagnostic groups with tblgen"
 	$(Verb) $(TableGen) -gen-clang-diag-groups -o $(call SYSPATH, $@) $<

clang/include/clang/Driver/CC1Options.td

@@ -230,8 +230,10 @@ def fdiagnostics_print_source_range_info : Flag<"-fdiagnostics-print-source-rang
   HelpText<"Print source range spans in numeric form">;
 def fdiagnostics_parseable_fixits : Flag<"-fdiagnostics-parseable-fixits">,
   HelpText<"Print fix-its in machine parseable form">;
+def fdiagnostics_show_name : Flag<"-fdiagnostics-show-name">,
+  HelpText<"Print diagnostic name">;
 def fdiagnostics_show_option : Flag<"-fdiagnostics-show-option">,
-  HelpText<"Print diagnostic name with mappable diagnostics">;
+  HelpText<"Print option name with mappable diagnostics">;
 def fdiagnostics_show_category : Separate<"-fdiagnostics-show-category">,
   HelpText<"Print diagnostic category">;
 def fdiagnostics_show_note_include_stack :

clang/include/clang/Driver/DriverDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define DRIVERSTART
 #include "clang/Basic/DiagnosticDriverKinds.inc"
 #undef DIAG

clang/include/clang/Driver/Options.td

@@ -272,6 +272,7 @@ def fdiagnostics_fixit_info : Flag<"-fdiagnostics-fixit-info">, Group<f_clang_Gr
 def fdiagnostics_print_source_range_info : Flag<"-fdiagnostics-print-source-range-info">, Group<f_clang_Group>;
 def fdiagnostics_parseable_fixits : Flag<"-fdiagnostics-parseable-fixits">, Group<f_clang_Group>;
 def fdiagnostics_show_option : Flag<"-fdiagnostics-show-option">, Group<f_Group>;
+def fdiagnostics_show_name : Flag<"-fdiagnostics-show-name">, 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_clang_Group>;
 def fdollars_in_identifiers : Flag<"-fdollars-in-identifiers">, Group<f_Group>;
@@ -330,6 +331,7 @@ def fno_common : Flag<"-fno-common">, Group<f_Group>;
 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_name : Flag<"-fno-diagnostics-show-name">, 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>;

clang/include/clang/Frontend/DiagnosticOptions.h

@@ -31,7 +31,8 @@ public:
   unsigned ShowFixits : 1;       /// Show fixit information.
   unsigned ShowSourceRanges : 1; /// Show source ranges in numeric form.
   unsigned ShowParseableFixits : 1; /// Show machine parseable fix-its.
-  unsigned ShowOptionNames : 1;  /// Show the diagnostic name for mappable
+  unsigned ShowNames : 1;        /// Show the diagnostic name
+  unsigned ShowOptionNames : 1;  /// Show the option name for mappable
                                  /// diagnostics.
   unsigned ShowNoteIncludeStack : 1; /// Show include stacks for notes.
   unsigned ShowCategories : 2;   /// Show categories: 0 -> none, 1 -> Number,
@@ -82,6 +83,7 @@ public:
     ShowColumn = 1;
     ShowFixits = 1;
     ShowLocation = 1;
+    ShowNames = 0;
     ShowOptionNames = 0;
     ShowCategories = 0;
     ShowSourceRanges = 0;

clang/include/clang/Frontend/FrontendDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define FRONTENDSTART
 #include "clang/Basic/DiagnosticFrontendKinds.inc"
 #undef DIAG

clang/include/clang/Lex/LexDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define LEXSTART
 #include "clang/Basic/DiagnosticLexKinds.inc"
 #undef DIAG

clang/include/clang/Parse/ParseDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define PARSESTART
 #include "clang/Basic/DiagnosticParseKinds.inc"
 #undef DIAG

clang/include/clang/Sema/SemaDiagnostic.h

@@ -15,7 +15,8 @@
 namespace clang {
   namespace diag {
     enum {
-#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY) ENUM,
+#define DIAG(ENUM,FLAGS,DEFAULT_MAPPING,DESC,GROUP,\
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL) ENUM,
 #define SEMASTART
 #include "clang/Basic/DiagnosticSemaKinds.inc"
 #undef DIAG

clang/lib/Basic/CMakeLists.txt

@@ -40,5 +40,6 @@ add_dependencies(clangBasic
                  ClangDiagnosticGroups
                  ClangDiagnosticLex
                  ClangDiagnosticParse
-                 ClangDiagnosticSema)
+                 ClangDiagnosticSema
+                 ClangDiagnosticIndexName)
                  

clang/lib/Basic/DiagnosticIDs.cpp

@@ -46,19 +46,41 @@ struct StaticDiagInfoRec {
   unsigned AccessControl : 1;
   unsigned Category : 5;
   
+  const char *Name;
+  
   const char *Description;
   const char *OptionGroup;
 
+  const char *BriefExplanation;
+  const char *FullExplanation;
+
   bool operator<(const StaticDiagInfoRec &RHS) const {
     return DiagID < RHS.DiagID;
   }
 };
 
+struct StaticDiagNameIndexRec {
+  const char *Name;
+  unsigned short DiagID;
+  
+  bool operator<(const StaticDiagNameIndexRec &RHS) const {
+    assert(Name && RHS.Name && "Null Diagnostic Name");
+    return strcmp(Name, RHS.Name) == -1;
+  }
+  
+  bool operator==(const StaticDiagNameIndexRec &RHS) const {
+    assert(Name && RHS.Name && "Null Diagnostic Name");
+    return strcmp(Name, RHS.Name) == 0;
+  }
+};
+
 }
 
 static const StaticDiagInfoRec StaticDiagInfo[] = {
-#define DIAG(ENUM,CLASS,DEFAULT_MAPPING,DESC,GROUP,SFINAE,ACCESS,CATEGORY)    \
-  { diag::ENUM, DEFAULT_MAPPING, CLASS, SFINAE, ACCESS, CATEGORY, DESC, GROUP },
+#define DIAG(ENUM,CLASS,DEFAULT_MAPPING,DESC,GROUP,     \
+             SFINAE,ACCESS,CATEGORY,BRIEF,FULL)         \
+  { diag::ENUM, DEFAULT_MAPPING, CLASS, SFINAE,         \
+   ACCESS, CATEGORY, #ENUM, DESC, GROUP, BRIEF, FULL },
 #include "clang/Basic/DiagnosticCommonKinds.inc"
 #include "clang/Basic/DiagnosticDriverKinds.inc"
 #include "clang/Basic/DiagnosticFrontendKinds.inc"
@@ -67,20 +89,32 @@ static const StaticDiagInfoRec StaticDiagInfo[] = {
 #include "clang/Basic/DiagnosticASTKinds.inc"
 #include "clang/Basic/DiagnosticSemaKinds.inc"
 #include "clang/Basic/DiagnosticAnalysisKinds.inc"
-  { 0, 0, 0, 0, 0, 0, 0, 0}
-};
 #undef DIAG
+  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+};
+
+static const unsigned StaticDiagInfoSize =
+  sizeof(StaticDiagInfo)/sizeof(StaticDiagInfo[0])-1;
+
+/// To be sorted before first use (since it's splitted among multiple files)
+static StaticDiagNameIndexRec StaticDiagNameIndex[] = {
+#define DIAG_NAME_INDEX(ENUM) { #ENUM, diag::ENUM },
+#include "clang/Basic/DiagnosticIndexName.inc"
+#undef DIAG_NAME_INDEX
+  { 0, 0 }
+};
+
+static const unsigned StaticDiagNameIndexSize =
+  sizeof(StaticDiagNameIndex)/sizeof(StaticDiagNameIndex[0])-1;
 
 /// GetDiagInfo - Return the StaticDiagInfoRec entry for the specified DiagID,
 /// or null if the ID is invalid.
 static const StaticDiagInfoRec *GetDiagInfo(unsigned DiagID) {
-  unsigned NumDiagEntries = sizeof(StaticDiagInfo)/sizeof(StaticDiagInfo[0])-1;
-
   // If assertions are enabled, verify that the StaticDiagInfo array is sorted.
 #ifndef NDEBUG
   static bool IsFirst = true;
   if (IsFirst) {
-    for (unsigned i = 1; i != NumDiagEntries; ++i) {
+    for (unsigned i = 1; i != StaticDiagInfoSize; ++i) {
       assert(StaticDiagInfo[i-1].DiagID != StaticDiagInfo[i].DiagID &&
              "Diag ID conflict, the enums at the start of clang::diag (in "
              "DiagnosticIDs.h) probably need to be increased");
@@ -93,11 +127,11 @@ static const StaticDiagInfoRec *GetDiagInfo(unsigned DiagID) {
 #endif
 
   // Search the diagnostic table with a binary search.
-  StaticDiagInfoRec Find = { DiagID, 0, 0, 0, 0, 0, 0, 0 };
+  StaticDiagInfoRec Find = { DiagID, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
   const StaticDiagInfoRec *Found =
-    std::lower_bound(StaticDiagInfo, StaticDiagInfo + NumDiagEntries, Find);
-  if (Found == StaticDiagInfo + NumDiagEntries ||
+    std::lower_bound(StaticDiagInfo, StaticDiagInfo + StaticDiagInfoSize, Find);
+  if (Found == StaticDiagInfo + StaticDiagInfoSize ||
       Found->DiagID != DiagID)
     return 0;
 
@@ -119,7 +153,7 @@ const char *DiagnosticIDs::getWarningOptionForDiag(unsigned DiagID) {
   return 0;
 }
 
-/// getWarningOptionForDiag - Return the category number that a specified
+/// getCategoryNumberForDiag - Return the category number that a specified
 /// DiagID belongs to, or 0 if no category.
 unsigned DiagnosticIDs::getCategoryNumberForDiag(unsigned DiagID) {
   if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
@@ -167,7 +201,48 @@ DiagnosticIDs::getDiagnosticSFINAEResponse(unsigned DiagID) {
   return SFINAE_Report;
 }
 
-/// getDiagClass - Return the class field of the diagnostic.
+/// getName - Given a diagnostic ID, return its name
+const char *DiagnosticIDs::getName(unsigned DiagID) {
+  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
+    return Info->Name;
+  return 0;
+}
+
+/// getIdFromName - Given a diagnostic name, return its ID, or 0
+unsigned DiagnosticIDs::getIdFromName(char const *Name) {
+  StaticDiagNameIndexRec *StaticDiagNameIndexEnd =
+    StaticDiagNameIndex + StaticDiagNameIndexSize;
+  
+  if (Name == 0) { return diag::DIAG_UPPER_LIMIT; }
+  
+  StaticDiagNameIndexRec Find = { Name, 0 };
+  
+  const StaticDiagNameIndexRec *Found =
+    std::lower_bound( StaticDiagNameIndex, StaticDiagNameIndexEnd, Find);
+  if (Found == StaticDiagNameIndexEnd ||
+      strcmp(Found->Name, Name) != 0)
+    return diag::DIAG_UPPER_LIMIT;
+  
+  return Found->DiagID;
+}
+
+/// getBriefExplanation - Given a diagnostic ID, return a brief explanation
+/// of the issue
+const char *DiagnosticIDs::getBriefExplanation(unsigned DiagID) {
+  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
+    return Info->BriefExplanation;
+  return 0;
+}
+
+/// getFullExplanation - Given a diagnostic ID, return a full explanation
+/// of the issue
+const char *DiagnosticIDs::getFullExplanation(unsigned DiagID) {
+  if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))
+    return Info->FullExplanation;
+  return 0;
+}
+
+/// getBuiltinDiagClass - Return the class field of the diagnostic.
 ///
 static unsigned getBuiltinDiagClass(unsigned DiagID) {
   if (const StaticDiagInfoRec *Info = GetDiagInfo(DiagID))

clang/lib/Driver/Tools.cpp

@@ -1737,6 +1737,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (!Args.hasFlag(options::OPT_fdiagnostics_fixit_info,
                     options::OPT_fno_diagnostics_fixit_info))
     CmdArgs.push_back("-fno-diagnostics-fixit-info");
+  
+  // Enable -fdiagnostics-show-name by default.
+  if (Args.hasFlag(options::OPT_fdiagnostics_show_name,
+                   options::OPT_fno_diagnostics_show_name, false))
+    CmdArgs.push_back("-fdiagnostics-show-name");
 
   // Enable -fdiagnostics-show-option by default.
   if (Args.hasFlag(options::OPT_fdiagnostics_show_option,

clang/lib/Frontend/CompilerInvocation.cpp

@@ -263,6 +263,8 @@ static void DiagnosticOptsToArgs(const DiagnosticOptions &Opts,
     Res.push_back("-fcolor-diagnostics");
   if (Opts.VerifyDiagnostics)
     Res.push_back("-verify");
+  if (Opts.ShowNames)
+    Res.push_back("-fdiagnostics-show-name");
   if (Opts.ShowOptionNames)
     Res.push_back("-fdiagnostics-show-option");
   if (Opts.ShowCategories == 1)
@@ -997,6 +999,7 @@ static void ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
   Opts.ShowColumn = !Args.hasArg(OPT_fno_show_column);
   Opts.ShowFixits = !Args.hasArg(OPT_fno_diagnostics_fixit_info);
   Opts.ShowLocation = !Args.hasArg(OPT_fno_show_source_location);
+  Opts.ShowNames = Args.hasArg(OPT_fdiagnostics_show_name);
   Opts.ShowOptionNames = Args.hasArg(OPT_fdiagnostics_show_option);
 
   // Default behavior is to not to show note include stacks.

clang/lib/Frontend/TextDiagnosticPrinter.cpp

@@ -908,6 +908,13 @@ void TextDiagnosticPrinter::HandleDiagnostic(Diagnostic::Level Level,
   llvm::SmallString<100> OutStr;
   Info.FormatDiagnostic(OutStr);
 
+  if (DiagOpts->ShowNames &&
+      !DiagnosticIDs::isBuiltinNote(Info.getID())) {
+    OutStr += " [";
+    OutStr += DiagnosticIDs::getName(Info.getID());
+    OutStr += "]";
+  }
+  
   std::string OptionName;
   if (DiagOpts->ShowOptionNames) {
     // Was this a warning mapped to an error using -Werror or pragma?

clang/test/Frontend/diagnostic-name.c

@@ -0,0 +1,5 @@
+// RUN: %clang -Wunused-parameter -fdiagnostics-show-name %s 2>&1 | grep "\[warn_unused_parameter\]" | count 1
+// RUN: %clang -Wunused-parameter -fno-diagnostics-show-name %s 2>&1 | grep "\[warn_unused_parameter\]" | count 0
+int main(int argc, char *argv[]) {
+  return argc;
+}