1 //===--- Warnings.cpp - C-Language Front-end ------------------------------===//
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 // Command line warning options handler.
11 //
12 //===----------------------------------------------------------------------===//
13 //
14 // This file is responsible for handling all warning options. This includes
15 // a number of -Wfoo options and their variants, which are driven by TableGen-
16 // generated data, and the special cases -pedantic, -pedantic-errors, -w,
17 // -Werror and -Wfatal-errors.
18 //
19 // Each warning option controls any number of actual warnings.
20 // Given a warning option 'foo', the following are valid:
21 // -Wfoo, -Wno-foo, -Werror=foo, -Wfatal-errors=foo
22 //
23 #include "clang/Frontend/Utils.h"
24 #include "clang/Basic/Diagnostic.h"
25 #include "clang/Sema/SemaDiagnostic.h"
26 #include "clang/Lex/LexDiagnostic.h"
27 #include "clang/Frontend/DiagnosticOptions.h"
28 #include "clang/Frontend/FrontendDiagnostic.h"
29 #include <cstring>
30 #include <utility>
31 #include <algorithm>
32 using namespace clang;
33
ProcessWarningOptions(Diagnostic & Diags,const DiagnosticOptions & Opts)34 void clang::ProcessWarningOptions(Diagnostic &Diags,
35 const DiagnosticOptions &Opts) {
36 Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers
37 Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
38 Diags.setShowOverloads(
39 static_cast<Diagnostic::OverloadsShown>(Opts.ShowOverloads));
40
41 // Handle -ferror-limit
42 if (Opts.ErrorLimit)
43 Diags.setErrorLimit(Opts.ErrorLimit);
44 if (Opts.TemplateBacktraceLimit)
45 Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
46
47 // If -pedantic or -pedantic-errors was specified, then we want to map all
48 // extension diagnostics onto WARNING or ERROR unless the user has futz'd
49 // around with them explicitly.
50 if (Opts.PedanticErrors)
51 Diags.setExtensionHandlingBehavior(Diagnostic::Ext_Error);
52 else if (Opts.Pedantic)
53 Diags.setExtensionHandlingBehavior(Diagnostic::Ext_Warn);
54 else
55 Diags.setExtensionHandlingBehavior(Diagnostic::Ext_Ignore);
56
57 for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) {
58 llvm::StringRef Opt = Opts.Warnings[i];
59
60 // Check to see if this warning starts with "no-", if so, this is a negative
61 // form of the option.
62 bool isPositive = true;
63 if (Opt.startswith("no-")) {
64 isPositive = false;
65 Opt = Opt.substr(3);
66 }
67
68 // Figure out how this option affects the warning. If -Wfoo, map the
69 // diagnostic to a warning, if -Wno-foo, map it to ignore.
70 diag::Mapping Mapping = isPositive ? diag::MAP_WARNING : diag::MAP_IGNORE;
71
72 // -Wsystem-headers is a special case, not driven by the option table. It
73 // cannot be controlled with -Werror.
74 if (Opt == "system-headers") {
75 Diags.setSuppressSystemWarnings(!isPositive);
76 continue;
77 }
78
79 // -Werror/-Wno-error is a special case, not controlled by the option table.
80 // It also has the "specifier" form of -Werror=foo and -Werror-foo.
81 if (Opt.startswith("error")) {
82 llvm::StringRef Specifier;
83 if (Opt.size() > 5) { // Specifier must be present.
84 if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) {
85 Diags.Report(diag::warn_unknown_warning_specifier)
86 << "-Werror" << ("-W" + Opt.str());
87 continue;
88 }
89 Specifier = Opt.substr(6);
90 }
91
92 if (Specifier.empty()) {
93 Diags.setWarningsAsErrors(isPositive);
94 continue;
95 }
96
97 // -Werror=foo maps foo to Error, -Wno-error=foo maps it to Warning.
98 Mapping = isPositive ? diag::MAP_ERROR : diag::MAP_WARNING_NO_WERROR;
99 Opt = Specifier;
100 }
101
102 // -Wfatal-errors is yet another special case.
103 if (Opt.startswith("fatal-errors")) {
104 llvm::StringRef Specifier;
105 if (Opt.size() != 12) {
106 if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) {
107 Diags.Report(diag::warn_unknown_warning_specifier)
108 << "-Wfatal-errors" << ("-W" + Opt.str());
109 continue;
110 }
111 Specifier = Opt.substr(13);
112 }
113
114 if (Specifier.empty()) {
115 Diags.setErrorsAsFatal(isPositive);
116 continue;
117 }
118
119 // -Wfatal-errors=foo maps foo to Fatal, -Wno-fatal-errors=foo
120 // maps it to Error.
121 Mapping = isPositive ? diag::MAP_FATAL : diag::MAP_ERROR_NO_WFATAL;
122 Opt = Specifier;
123 }
124
125 if (Diags.setDiagnosticGroupMapping(Opt, Mapping))
126 Diags.Report(isPositive ? diag::warn_unknown_warning_option :
127 diag::warn_unknown_negative_warning_option)
128 << ("-W" + Opt.str());
129 }
130 }
131