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>
22using namespace clang;
23
24TextDiagnosticPrinter::TextDiagnosticPrinter(raw_ostream &os,
25 DiagnosticOptions *diags,
26 bool _OwnsOutputStream)
27 : OS(os), DiagOpts(diags),
28 OwnsOutputStream(_OwnsOutputStream) {
29}
30
31TextDiagnosticPrinter::~TextDiagnosticPrinter() {
32 if (OwnsOutputStream)
33 delete &OS;
34}
35
36void TextDiagnosticPrinter::BeginSourceFile(const LangOptions &LO,
37 const Preprocessor *PP) {
38 // Build the TextDiagnostic utility.
39 TextDiag.reset(p: new TextDiagnostic(OS, LO, &*DiagOpts, PP));
40}
41
42void 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: " [...]".
51static 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(DiagID: Info.getID()) &&
74 !DiagnosticIDs::isDefaultMappingAsError(DiagID: Info.getID())) {
75 OS << " [-Werror";
76 Started = true;
77 }
78
79 StringRef Opt = DiagnosticIDs::getWarningOptionForDiag(DiagID: Info.getID());
80 if (!Opt.empty()) {
81 OS << (Started ? "," : " [")
82 << (Level == DiagnosticsEngine::Remark ? "-R" : "-W") << Opt;
83 StringRef OptValue = Info.getDiags()->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(DiagID: 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(CategoryID: DiagCategory);
102 }
103 }
104 }
105 if (Started)
106 OS << ']';
107}
108
109void TextDiagnosticPrinter::HandleDiagnostic(DiagnosticsEngine::Level Level,
110 const Diagnostic &Info) {
111 // Default implementation (Warnings/errors count).
112 DiagnosticConsumer::HandleDiagnostic(DiagLevel: 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(OS&: DiagMessageStream, Level, Info, DiagOpts: *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, ShowColors: DiagOpts->ShowColors);
137 TextDiagnostic::printDiagnosticMessage(
138 OS, /*IsSupplemental=*/Level == DiagnosticsEngine::Note,
139 Message: DiagMessageStream.str(), CurrentColumn: OS.tell() - StartOfLocationInfo,
140 Columns: DiagOpts->MessageLength, ShowColors: 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 Loc: FullSourceLoc(Info.getLocation(), Info.getSourceManager()), Level,
153 Message: DiagMessageStream.str(), Ranges: Info.getRanges(), FixItHints: Info.getFixItHints());
154
155 OS.flush();
156}
157

source code of clang/lib/Frontend/TextDiagnosticPrinter.cpp