1 //===--- TextDiagnosticPrinter.cpp - Diagnostic Printer -------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This diagnostic client prints out their diagnostic messages.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Frontend/TextDiagnosticPrinter.h"
15 #include "clang/Basic/DiagnosticOptions.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Frontend/TextDiagnostic.h"
18 #include "clang/Lex/Lexer.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include <algorithm>
23 using namespace clang;
24 
25 TextDiagnosticPrinter::TextDiagnosticPrinter(raw_ostream &os,
26                                              DiagnosticOptions *diags,
27                                              bool _OwnsOutputStream)
28   : OS(os), DiagOpts(diags),
29     OwnsOutputStream(_OwnsOutputStream) {
30 }
31 
32 TextDiagnosticPrinter::~TextDiagnosticPrinter() {
33   if (OwnsOutputStream)
34     delete &OS;
35 }
36 
37 void TextDiagnosticPrinter::BeginSourceFile(const LangOptions &LO,
38                                             const Preprocessor *PP) {
39   // Build the TextDiagnostic utility.
40   TextDiag.reset(new TextDiagnostic(OS, LO, &*DiagOpts));
41 }
42 
43 void TextDiagnosticPrinter::EndSourceFile() {
44   TextDiag.reset();
45 }
46 
47 /// Print any diagnostic option information to a raw_ostream.
48 ///
49 /// This implements all of the logic for adding diagnostic options to a message
50 /// (via OS). Each relevant option is comma separated and all are enclosed in
51 /// the standard bracketing: " [...]".
52 static void printDiagnosticOptions(raw_ostream &OS,
53                                    DiagnosticsEngine::Level Level,
54                                    const Diagnostic &Info,
55                                    const DiagnosticOptions &DiagOpts) {
56   bool Started = false;
57   if (DiagOpts.ShowOptionNames) {
58     // Handle special cases for non-warnings early.
59     if (Info.getID() == diag::fatal_too_many_errors) {
60       OS << " [-ferror-limit=]";
61       return;
62     }
63 
64     // The code below is somewhat fragile because we are essentially trying to
65     // report to the user what happened by inferring what the diagnostic engine
66     // did. Eventually it might make more sense to have the diagnostic engine
67     // include some "why" information in the diagnostic.
68 
69     // If this is a warning which has been mapped to an error by the user (as
70     // inferred by checking whether the default mapping is to an error) then
71     // flag it as such. Note that diagnostics could also have been mapped by a
72     // pragma, but we don't currently have a way to distinguish this.
73     if (Level == DiagnosticsEngine::Error &&
74         DiagnosticIDs::isBuiltinWarningOrExtension(Info.getID()) &&
75         !DiagnosticIDs::isDefaultMappingAsError(Info.getID())) {
76       OS << " [-Werror";
77       Started = true;
78     }
79 
80     StringRef Opt = DiagnosticIDs::getWarningOptionForDiag(Info.getID());
81     if (!Opt.empty()) {
82       OS << (Started ? "," : " [")
83          << (Level == DiagnosticsEngine::Remark ? "-R" : "-W") << Opt;
84       StringRef OptValue = Info.getDiags()->getFlagValue();
85       if (!OptValue.empty())
86         OS << "=" << OptValue;
87       Started = true;
88     }
89   }
90 
91   // If the user wants to see category information, include it too.
92   if (DiagOpts.ShowCategories) {
93     unsigned DiagCategory =
94       DiagnosticIDs::getCategoryNumberForDiag(Info.getID());
95     if (DiagCategory) {
96       OS << (Started ? "," : " [");
97       Started = true;
98       if (DiagOpts.ShowCategories == 1)
99         OS << DiagCategory;
100       else {
101         assert(DiagOpts.ShowCategories == 2 && "Invalid ShowCategories value");
102         OS << DiagnosticIDs::getCategoryNameFromID(DiagCategory);
103       }
104     }
105   }
106   if (Started)
107     OS << ']';
108 }
109 
110 void TextDiagnosticPrinter::HandleDiagnostic(DiagnosticsEngine::Level Level,
111                                              const Diagnostic &Info) {
112   // Default implementation (Warnings/errors count).
113   DiagnosticConsumer::HandleDiagnostic(Level, Info);
114 
115   // Render the diagnostic message into a temporary buffer eagerly. We'll use
116   // this later as we print out the diagnostic to the terminal.
117   SmallString<100> OutStr;
118   Info.FormatDiagnostic(OutStr);
119 
120   llvm::raw_svector_ostream DiagMessageStream(OutStr);
121   printDiagnosticOptions(DiagMessageStream, Level, Info, *DiagOpts);
122 
123   // Keeps track of the starting position of the location
124   // information (e.g., "foo.c:10:4:") that precedes the error
125   // message. We use this information to determine how long the
126   // file+line+column number prefix is.
127   uint64_t StartOfLocationInfo = OS.tell();
128 
129   if (!Prefix.empty())
130     OS << Prefix << ": ";
131 
132   // Use a dedicated, simpler path for diagnostics without a valid location.
133   // This is important as if the location is missing, we may be emitting
134   // diagnostics in a context that lacks language options, a source manager, or
135   // other infrastructure necessary when emitting more rich diagnostics.
136   if (!Info.getLocation().isValid()) {
137     TextDiagnostic::printDiagnosticLevel(OS, Level, DiagOpts->ShowColors,
138                                          DiagOpts->CLFallbackMode);
139     TextDiagnostic::printDiagnosticMessage(OS, Level, DiagMessageStream.str(),
140                                            OS.tell() - StartOfLocationInfo,
141                                            DiagOpts->MessageLength,
142                                            DiagOpts->ShowColors);
143     OS.flush();
144     return;
145   }
146 
147   // Assert that the rest of our infrastructure is setup properly.
148   assert(DiagOpts && "Unexpected diagnostic without options set");
149   assert(Info.hasSourceManager() &&
150          "Unexpected diagnostic with no source manager");
151   assert(TextDiag && "Unexpected diagnostic outside source file processing");
152 
153   TextDiag->emitDiagnostic(
154       FullSourceLoc(Info.getLocation(), Info.getSourceManager()), Level,
155       DiagMessageStream.str(), Info.getRanges(), Info.getFixItHints());
156 
157   OS.flush();
158 }
159