tools/clang/plugins/SuppressibleDiagnosticBuilder.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef TOOLS_CLANG_PLUGINS_HESIENDIAGNOSTICBUILDER_H_
   6 #define TOOLS_CLANG_PLUGINS_HESIENDIAGNOSTICBUILDER_H_
   7
   8 #include "clang/Basic/Diagnostic.h"
   9 #include "clang/Basic/SourceLocation.h"
  10
  11 namespace chrome_checker {
  12
  13 // A simple wrapper around DiagnosticBuilder that allows a diagnostic to be
  14 // suppressed. The intended use case is for helper functions that return a
  15 // DiagnosticBuilder, but only want to emit the diagnostic if some conditions
  16 // are met.
  17 class SuppressibleDiagnosticBuilder : public clang::DiagnosticBuilder {
  18  public:
  19   SuppressibleDiagnosticBuilder(clang::DiagnosticsEngine* diagnostics,
  20                                 clang::SourceLocation loc,
  21                                 unsigned diagnostic_id,
  22                                 bool suppressed)
  23       : DiagnosticBuilder(diagnostics->Report(loc, diagnostic_id)),
  24         diagnostics_(diagnostics),
  25         suppressed_(suppressed) {}
  26
  27   ~SuppressibleDiagnosticBuilder() {
  28     if (suppressed_) {
  29       // Clear the counts and underlying data, so the base class destructor
  30       // doesn't try to emit the diagnostic.
  31       FlushCounts();
  32       Clear();
  33       // Also clear the current diagnostic being processed by the
  34       // DiagnosticsEngine, since it won't be emitted.
  35       diagnostics_->Clear();
  36     }
  37   }
  38
  39   template <typename T>
  40   friend const SuppressibleDiagnosticBuilder& operator<<(
  41       const SuppressibleDiagnosticBuilder& builder,
  42       const T& value) {
  43     const DiagnosticBuilder& base_builder = builder;
  44     base_builder << value;
  45     return builder;
  46   }
  47
  48  private:
  49   clang::DiagnosticsEngine* const diagnostics_;
  50   const bool suppressed_;
  51 };
  52
  53 }  // namespace chrome_checker
  54
  55 #endif  // TOOLS_CLANG_PLUGINS_HESIENDIAGNOSTICBUILDER_H_