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/Basic/AllDiagnostics.h"
24 #include "clang/Basic/Diagnostic.h"
25 #include "clang/Basic/DiagnosticOptions.h"
26 #include <algorithm>
27 #include <cstring>
28 #include <utility>
29 using namespace clang;
30
31 // EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning
32 // opts
EmitUnknownDiagWarning(DiagnosticsEngine & Diags,StringRef Prefix,StringRef Opt,bool isPositive)33 static void EmitUnknownDiagWarning(DiagnosticsEngine &Diags,
34 StringRef Prefix, StringRef Opt,
35 bool isPositive) {
36 StringRef Suggestion = DiagnosticIDs::getNearestWarningOption(Opt);
37 if (!Suggestion.empty())
38 Diags.Report(isPositive? diag::warn_unknown_warning_option_suggest :
39 diag::warn_unknown_negative_warning_option_suggest)
40 << (Prefix.str() += Opt) << (Prefix.str() += Suggestion);
41 else
42 Diags.Report(isPositive? diag::warn_unknown_warning_option :
43 diag::warn_unknown_negative_warning_option)
44 << (Prefix.str() += Opt);
45 }
46
ProcessWarningOptions(DiagnosticsEngine & Diags,const DiagnosticOptions & Opts,bool ReportDiags)47 void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
48 const DiagnosticOptions &Opts,
49 bool ReportDiags) {
50 Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers
51 Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
52 Diags.setShowOverloads(Opts.getShowOverloads());
53
54 Diags.setElideType(Opts.ElideType);
55 Diags.setPrintTemplateTree(Opts.ShowTemplateTree);
56 Diags.setShowColors(Opts.ShowColors);
57
58 // Handle -ferror-limit
59 if (Opts.ErrorLimit)
60 Diags.setErrorLimit(Opts.ErrorLimit);
61 if (Opts.TemplateBacktraceLimit)
62 Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
63 if (Opts.ConstexprBacktraceLimit)
64 Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit);
65
66 // If -pedantic or -pedantic-errors was specified, then we want to map all
67 // extension diagnostics onto WARNING or ERROR unless the user has futz'd
68 // around with them explicitly.
69 if (Opts.PedanticErrors)
70 Diags.setExtensionHandlingBehavior(diag::Severity::Error);
71 else if (Opts.Pedantic)
72 Diags.setExtensionHandlingBehavior(diag::Severity::Warning);
73 else
74 Diags.setExtensionHandlingBehavior(diag::Severity::Ignored);
75
76 SmallVector<diag::kind, 10> _Diags;
77 const IntrusiveRefCntPtr< DiagnosticIDs > DiagIDs =
78 Diags.getDiagnosticIDs();
79 // We parse the warning options twice. The first pass sets diagnostic state,
80 // while the second pass reports warnings/errors. This has the effect that
81 // we follow the more canonical "last option wins" paradigm when there are
82 // conflicting options.
83 for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) {
84 bool SetDiagnostic = (Report == 0);
85
86 // If we've set the diagnostic state and are not reporting diagnostics then
87 // we're done.
88 if (!SetDiagnostic && !ReportDiags)
89 break;
90
91 for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) {
92 StringRef Opt = Opts.Warnings[i];
93 StringRef OrigOpt = Opts.Warnings[i];
94
95 // Treat -Wformat=0 as an alias for -Wno-format.
96 if (Opt == "format=0")
97 Opt = "no-format";
98
99 // Check to see if this warning starts with "no-", if so, this is a
100 // negative form of the option.
101 bool isPositive = true;
102 if (Opt.startswith("no-")) {
103 isPositive = false;
104 Opt = Opt.substr(3);
105 }
106
107 // Figure out how this option affects the warning. If -Wfoo, map the
108 // diagnostic to a warning, if -Wno-foo, map it to ignore.
109 diag::Severity Mapping =
110 isPositive ? diag::Severity::Warning : diag::Severity::Ignored;
111
112 // -Wsystem-headers is a special case, not driven by the option table. It
113 // cannot be controlled with -Werror.
114 if (Opt == "system-headers") {
115 if (SetDiagnostic)
116 Diags.setSuppressSystemWarnings(!isPositive);
117 continue;
118 }
119
120 // -Weverything is a special case as well. It implicitly enables all
121 // warnings, including ones not explicitly in a warning group.
122 if (Opt == "everything") {
123 if (SetDiagnostic) {
124 if (isPositive) {
125 Diags.setEnableAllWarnings(true);
126 } else {
127 Diags.setEnableAllWarnings(false);
128 Diags.setSeverityForAll(diag::Severity::Ignored);
129 }
130 }
131 continue;
132 }
133
134 // -Werror/-Wno-error is a special case, not controlled by the option
135 // table. It also has the "specifier" form of -Werror=foo and -Werror-foo.
136 if (Opt.startswith("error")) {
137 StringRef Specifier;
138 if (Opt.size() > 5) { // Specifier must be present.
139 if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) {
140 if (Report)
141 Diags.Report(diag::warn_unknown_warning_specifier)
142 << "-Werror" << ("-W" + OrigOpt.str());
143 continue;
144 }
145 Specifier = Opt.substr(6);
146 }
147
148 if (Specifier.empty()) {
149 if (SetDiagnostic)
150 Diags.setWarningsAsErrors(isPositive);
151 continue;
152 }
153
154 if (SetDiagnostic) {
155 // Set the warning as error flag for this specifier.
156 Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive);
157 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) {
158 EmitUnknownDiagWarning(Diags, "-Werror=", Specifier, isPositive);
159 }
160 continue;
161 }
162
163 // -Wfatal-errors is yet another special case.
164 if (Opt.startswith("fatal-errors")) {
165 StringRef Specifier;
166 if (Opt.size() != 12) {
167 if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) {
168 if (Report)
169 Diags.Report(diag::warn_unknown_warning_specifier)
170 << "-Wfatal-errors" << ("-W" + OrigOpt.str());
171 continue;
172 }
173 Specifier = Opt.substr(13);
174 }
175
176 if (Specifier.empty()) {
177 if (SetDiagnostic)
178 Diags.setErrorsAsFatal(isPositive);
179 continue;
180 }
181
182 if (SetDiagnostic) {
183 // Set the error as fatal flag for this specifier.
184 Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive);
185 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) {
186 EmitUnknownDiagWarning(Diags, "-Wfatal-errors=", Specifier,
187 isPositive);
188 }
189 continue;
190 }
191
192 if (Report) {
193 if (DiagIDs->getDiagnosticsInGroup(Opt, _Diags))
194 EmitUnknownDiagWarning(Diags, isPositive ? "-W" : "-Wno-", Opt,
195 isPositive);
196 } else {
197 Diags.setSeverityForGroup(Opt, Mapping);
198 }
199 }
200 }
201 }
202