clang/tools/diagtool/ShowEnabledWarnings.cpp

   1 //===- ShowEnabledWarnings - diagtool tool for printing enabled flags -----===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "DiagTool.h"
  10 #include "DiagnosticNames.h"
  11 #include "clang/Basic/LLVM.h"
  12 #include "clang/Frontend/CompilerInstance.h"
  13 #include "clang/Frontend/TextDiagnosticBuffer.h"
  14 #include "clang/Frontend/TextDiagnosticPrinter.h"
  15 #include "clang/Frontend/Utils.h"
  16 #include "llvm/Support/TargetSelect.h"
  17
  18 DEF_DIAGTOOL("show-enabled",
  19              "Show which warnings are enabled for a given command line",
  20              ShowEnabledWarnings)
  21
  22 using namespace clang;
  23 using namespace diagtool;
  24
  25 namespace {
  26   struct PrettyDiag {
  27     StringRef Name;
  28     StringRef Flag;
  29     DiagnosticsEngine::Level Level;
  30
  31     PrettyDiag(StringRef name, StringRef flag, DiagnosticsEngine::Level level)
  32     : Name(name), Flag(flag), Level(level) {}
  33
  34     bool operator<(const PrettyDiag &x) const { return Name < x.Name; }
  35   };
  36 }
  37
  38 static void printUsage() {
  39   llvm::errs() << "Usage: diagtool show-enabled [<flags>] <single-input.c>\n";
  40 }
  41
  42 static char getCharForLevel(DiagnosticsEngine::Level Level) {
  43   switch (Level) {
  44   case DiagnosticsEngine::Ignored: return ' ';
  45   case DiagnosticsEngine::Note:    return '-';
  46   case DiagnosticsEngine::Remark:  return 'R';
  47   case DiagnosticsEngine::Warning: return 'W';
  48   case DiagnosticsEngine::Error:   return 'E';
  49   case DiagnosticsEngine::Fatal:   return 'F';
  50   }
  51
  52   llvm_unreachable("Unknown diagnostic level");
  53 }
  54
  55 static IntrusiveRefCntPtr<DiagnosticsEngine>
  56 createDiagnostics(unsigned int argc, char **argv) {
  57   IntrusiveRefCntPtr<DiagnosticIDs> DiagIDs(new DiagnosticIDs());
  58
  59   // Buffer diagnostics from argument parsing so that we can output them using a
  60   // well formed diagnostic object.
  61   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
  62
  63   // Try to build a CompilerInvocation.
  64   SmallVector<const char *, 4> Args;
  65   Args.push_back("diagtool");
  66   Args.append(argv, argv + argc);
  67   CreateInvocationOptions CIOpts;
  68   CIOpts.Diags =
  69       new DiagnosticsEngine(DiagIDs, new DiagnosticOptions(), DiagsBuffer);
  70   std::unique_ptr<CompilerInvocation> Invocation =
  71       createInvocation(Args, CIOpts);
  72   if (!Invocation)
  73     return nullptr;
  74
  75   // Build the diagnostics parser
  76   IntrusiveRefCntPtr<DiagnosticsEngine> FinalDiags =
  77     CompilerInstance::createDiagnostics(&Invocation->getDiagnosticOpts());
  78   if (!FinalDiags)
  79     return nullptr;
  80
  81   // Flush any errors created when initializing everything. This could happen
  82   // for invalid command lines, which will probably give non-sensical results.
  83   DiagsBuffer->FlushDiagnostics(*FinalDiags);
  84
  85   return FinalDiags;
  86 }
  87
  88 int ShowEnabledWarnings::run(unsigned int argc, char **argv, raw_ostream &Out) {
  89   // First check our one flag (--levels).
  90   bool ShouldShowLevels = true;
  91   if (argc > 0) {
  92     StringRef FirstArg(*argv);
  93     if (FirstArg.equals("--no-levels")) {
  94       ShouldShowLevels = false;
  95       --argc;
  96       ++argv;
  97     } else if (FirstArg.equals("--levels")) {
  98       ShouldShowLevels = true;
  99       --argc;
 100       ++argv;
 101     }
 102   }
 103
 104   // Create the diagnostic engine.
 105   IntrusiveRefCntPtr<DiagnosticsEngine> Diags = createDiagnostics(argc, argv);
 106   if (!Diags) {
 107     printUsage();
 108     return EXIT_FAILURE;
 109   }
 110
 111   // Now we have our diagnostics. Iterate through EVERY diagnostic and see
 112   // which ones are turned on.
 113   // FIXME: It would be very nice to print which flags are turning on which
 114   // diagnostics, but this can be done with a diff.
 115   std::vector<PrettyDiag> Active;
 116
 117   for (const DiagnosticRecord &DR : getBuiltinDiagnosticsByName()) {
 118     unsigned DiagID = DR.DiagID;
 119
 120     if (DiagnosticIDs::isBuiltinNote(DiagID))
 121       continue;
 122
 123     if (!DiagnosticIDs::isBuiltinWarningOrExtension(DiagID))
 124       continue;
 125
 126     DiagnosticsEngine::Level DiagLevel =
 127       Diags->getDiagnosticLevel(DiagID, SourceLocation());
 128     if (DiagLevel == DiagnosticsEngine::Ignored)
 129       continue;
 130
 131     StringRef WarningOpt = DiagnosticIDs::getWarningOptionForDiag(DiagID);
 132     Active.push_back(PrettyDiag(DR.getName(), WarningOpt, DiagLevel));
 133   }
 134
 135   // Print them all out.
 136   for (const PrettyDiag &PD : Active) {
 137     if (ShouldShowLevels)
 138       Out << getCharForLevel(PD.Level) << "  ";
 139     Out << PD.Name;
 140     if (!PD.Flag.empty())
 141       Out << " [-W" << PD.Flag << "]";
 142     Out << '\n';
 143   }
 144
 145   return EXIT_SUCCESS;
 146 }