clang/lib/Frontend/TextDiagnosticPrinter.cpp

   1 //===--- TextDiagnosticPrinter.cpp - Diagnostic Printer -------------------===//
   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 // This diagnostic client prints out their diagnostic messages.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "clang/Frontend/TextDiagnosticPrinter.h"
  14 #include "clang/Basic/DiagnosticOptions.h"
  15 #include "clang/Basic/SourceManager.h"
  16 #include "clang/Frontend/TextDiagnostic.h"
  17 #include "clang/Lex/Lexer.h"
  18 #include "llvm/ADT/SmallString.h"
  19 #include "llvm/Support/ErrorHandling.h"
  20 #include "llvm/Support/raw_ostream.h"
  21 #include <algorithm>
  22 using namespace clang;
  23
  24 TextDiagnosticPrinter::TextDiagnosticPrinter(raw_ostream &os,
  25                                              DiagnosticOptions *diags,
  26                                              bool _OwnsOutputStream)
  27   : OS(os), DiagOpts(diags),
  28     OwnsOutputStream(_OwnsOutputStream) {
  29 }
  30
  31 TextDiagnosticPrinter::~TextDiagnosticPrinter() {
  32   if (OwnsOutputStream)
  33     delete &OS;
  34 }
  35
  36 void TextDiagnosticPrinter::BeginSourceFile(const LangOptions &LO,
  37                                             const Preprocessor *PP) {
  38   // Build the TextDiagnostic utility.
  39   TextDiag.reset(new TextDiagnostic(OS, LO, &*DiagOpts, PP));
  40 }
  41
  42 void TextDiagnosticPrinter::EndSourceFile() {
  43   TextDiag.reset();
  44 }
  45
  46 /// Print any diagnostic option information to a raw_ostream.
  47 ///
  48 /// This implements all of the logic for adding diagnostic options to a message
  49 /// (via OS). Each relevant option is comma separated and all are enclosed in
  50 /// the standard bracketing: " [...]".
  51 static void printDiagnosticOptions(raw_ostream &OS,
  52                                    DiagnosticsEngine::Level Level,
  53                                    const Diagnostic &Info,
  54                                    const DiagnosticOptions &DiagOpts) {
  55   bool Started = false;
  56   if (DiagOpts.ShowOptionNames) {
  57     // Handle special cases for non-warnings early.
  58     if (Info.getID() == diag::fatal_too_many_errors) {
  59       OS << " [-ferror-limit=]";
  60       return;
  61     }
  62
  63     // The code below is somewhat fragile because we are essentially trying to
  64     // report to the user what happened by inferring what the diagnostic engine
  65     // did. Eventually it might make more sense to have the diagnostic engine
  66     // include some "why" information in the diagnostic.
  67
  68     // If this is a warning which has been mapped to an error by the user (as
  69     // inferred by checking whether the default mapping is to an error) then
  70     // flag it as such. Note that diagnostics could also have been mapped by a
  71     // pragma, but we don't currently have a way to distinguish this.
  72     if (Level == DiagnosticsEngine::Error &&
  73         DiagnosticIDs::isBuiltinWarningOrExtension(Info.getID()) &&
  74         !DiagnosticIDs::isDefaultMappingAsError(Info.getID())) {
  75       OS << " [-Werror";
  76       Started = true;
  77     }
  78
  79     StringRef Opt = DiagnosticIDs::getWarningOptionForDiag(Info.getID());
  80     if (!Opt.empty()) {
  81       OS << (Started ? "," : " [")
  82          << (Level == DiagnosticsEngine::Remark ? "-R" : "-W") << Opt;
  83       StringRef OptValue = Info.getFlagValue();
  84       if (!OptValue.empty())
  85         OS << "=" << OptValue;
  86       Started = true;
  87     }
  88   }
  89
  90   // If the user wants to see category information, include it too.
  91   if (DiagOpts.ShowCategories) {
  92     unsigned DiagCategory =
  93       DiagnosticIDs::getCategoryNumberForDiag(Info.getID());
  94     if (DiagCategory) {
  95       OS << (Started ? "," : " [");
  96       Started = true;
  97       if (DiagOpts.ShowCategories == 1)
  98         OS << DiagCategory;
  99       else {
 100         assert(DiagOpts.ShowCategories == 2 && "Invalid ShowCategories value");
 101         OS << DiagnosticIDs::getCategoryNameFromID(DiagCategory);
 102       }
 103     }
 104   }
 105   if (Started)
 106     OS << ']';
 107 }
 108
 109 void TextDiagnosticPrinter::HandleDiagnostic(DiagnosticsEngine::Level Level,
 110                                              const Diagnostic &Info) {
 111   // Default implementation (Warnings/errors count).
 112   DiagnosticConsumer::HandleDiagnostic(Level, Info);
 113
 114   // Render the diagnostic message into a temporary buffer eagerly. We'll use
 115   // this later as we print out the diagnostic to the terminal.
 116   SmallString<100> OutStr;
 117   Info.FormatDiagnostic(OutStr);
 118
 119   llvm::raw_svector_ostream DiagMessageStream(OutStr);
 120   printDiagnosticOptions(DiagMessageStream, Level, Info, *DiagOpts);
 121
 122   // Keeps track of the starting position of the location
 123   // information (e.g., "foo.c:10:4:") that precedes the error
 124   // message. We use this information to determine how long the
 125   // file+line+column number prefix is.
 126   uint64_t StartOfLocationInfo = OS.tell();
 127
 128   if (!Prefix.empty())
 129     OS << Prefix << ": ";
 130
 131   // Use a dedicated, simpler path for diagnostics without a valid location.
 132   // This is important as if the location is missing, we may be emitting
 133   // diagnostics in a context that lacks language options, a source manager, or
 134   // other infrastructure necessary when emitting more rich diagnostics.
 135   if (!Info.getLocation().isValid()) {
 136     TextDiagnostic::printDiagnosticLevel(OS, Level, DiagOpts->ShowColors);
 137     TextDiagnostic::printDiagnosticMessage(
 138         OS, /*IsSupplemental=*/Level == DiagnosticsEngine::Note,
 139         DiagMessageStream.str(), OS.tell() - StartOfLocationInfo,
 140         DiagOpts->MessageLength, DiagOpts->ShowColors);
 141     OS.flush();
 142     return;
 143   }
 144
 145   // Assert that the rest of our infrastructure is setup properly.
 146   assert(DiagOpts && "Unexpected diagnostic without options set");
 147   assert(Info.hasSourceManager() &&
 148          "Unexpected diagnostic with no source manager");
 149   assert(TextDiag && "Unexpected diagnostic outside source file processing");
 150
 151   TextDiag->emitDiagnostic(
 152       FullSourceLoc(Info.getLocation(), Info.getSourceManager()), Level,
 153       DiagMessageStream.str(), Info.getRanges(), Info.getFixItHints());
 154
 155   OS.flush();
 156 }