clang  6.0.0svn
Warnings.cpp
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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 // Remark options are also handled here, analogously, except that they are much
24 // simpler because a remark can't be promoted to an error.
26 #include "clang/Basic/Diagnostic.h"
28 #include <algorithm>
29 #include <cstring>
30 #include <utility>
31 using namespace clang;
32 
33 // EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning
34 // opts
36  diag::Flavor Flavor, StringRef Prefix,
37  StringRef Opt) {
38  StringRef Suggestion = DiagnosticIDs::getNearestOption(Flavor, Opt);
39  Diags.Report(diag::warn_unknown_diag_option)
40  << (Flavor == diag::Flavor::WarningOrError ? 0 : 1) << (Prefix.str() += Opt)
41  << !Suggestion.empty() << (Prefix.str() += Suggestion);
42 }
43 
45  const DiagnosticOptions &Opts,
46  bool ReportDiags) {
47  Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers
48  Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
49  Diags.setShowOverloads(Opts.getShowOverloads());
50 
51  Diags.setElideType(Opts.ElideType);
52  Diags.setPrintTemplateTree(Opts.ShowTemplateTree);
53  Diags.setShowColors(Opts.ShowColors);
54 
55  // Handle -ferror-limit
56  if (Opts.ErrorLimit)
57  Diags.setErrorLimit(Opts.ErrorLimit);
58  if (Opts.TemplateBacktraceLimit)
59  Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
60  if (Opts.ConstexprBacktraceLimit)
61  Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit);
62 
63  // If -pedantic or -pedantic-errors was specified, then we want to map all
64  // extension diagnostics onto WARNING or ERROR unless the user has futz'd
65  // around with them explicitly.
66  if (Opts.PedanticErrors)
68  else if (Opts.Pedantic)
70  else
72 
75  Diags.getDiagnosticIDs();
76  // We parse the warning options twice. The first pass sets diagnostic state,
77  // while the second pass reports warnings/errors. This has the effect that
78  // we follow the more canonical "last option wins" paradigm when there are
79  // conflicting options.
80  for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) {
81  bool SetDiagnostic = (Report == 0);
82 
83  // If we've set the diagnostic state and are not reporting diagnostics then
84  // we're done.
85  if (!SetDiagnostic && !ReportDiags)
86  break;
87 
88  for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) {
90  StringRef Opt = Opts.Warnings[i];
91  StringRef OrigOpt = Opts.Warnings[i];
92 
93  // Treat -Wformat=0 as an alias for -Wno-format.
94  if (Opt == "format=0")
95  Opt = "no-format";
96 
97  // Check to see if this warning starts with "no-", if so, this is a
98  // negative form of the option.
99  bool isPositive = true;
100  if (Opt.startswith("no-")) {
101  isPositive = false;
102  Opt = Opt.substr(3);
103  }
104 
105  // Figure out how this option affects the warning. If -Wfoo, map the
106  // diagnostic to a warning, if -Wno-foo, map it to ignore.
107  diag::Severity Mapping =
109 
110  // -Wsystem-headers is a special case, not driven by the option table. It
111  // cannot be controlled with -Werror.
112  if (Opt == "system-headers") {
113  if (SetDiagnostic)
114  Diags.setSuppressSystemWarnings(!isPositive);
115  continue;
116  }
117 
118  // -Weverything is a special case as well. It implicitly enables all
119  // warnings, including ones not explicitly in a warning group.
120  if (Opt == "everything") {
121  if (SetDiagnostic) {
122  if (isPositive) {
123  Diags.setEnableAllWarnings(true);
124  } else {
125  Diags.setEnableAllWarnings(false);
127  }
128  }
129  continue;
130  }
131 
132  // -Werror/-Wno-error is a special case, not controlled by the option
133  // table. It also has the "specifier" form of -Werror=foo and -Werror-foo.
134  if (Opt.startswith("error")) {
135  StringRef Specifier;
136  if (Opt.size() > 5) { // Specifier must be present.
137  if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) {
138  if (Report)
139  Diags.Report(diag::warn_unknown_warning_specifier)
140  << "-Werror" << ("-W" + OrigOpt.str());
141  continue;
142  }
143  Specifier = Opt.substr(6);
144  }
145 
146  if (Specifier.empty()) {
147  if (SetDiagnostic)
148  Diags.setWarningsAsErrors(isPositive);
149  continue;
150  }
151 
152  if (SetDiagnostic) {
153  // Set the warning as error flag for this specifier.
154  Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive);
155  } else if (DiagIDs->getDiagnosticsInGroup(Flavor, Specifier, _Diags)) {
156  EmitUnknownDiagWarning(Diags, Flavor, "-Werror=", Specifier);
157  }
158  continue;
159  }
160 
161  // -Wfatal-errors is yet another special case.
162  if (Opt.startswith("fatal-errors")) {
163  StringRef Specifier;
164  if (Opt.size() != 12) {
165  if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) {
166  if (Report)
167  Diags.Report(diag::warn_unknown_warning_specifier)
168  << "-Wfatal-errors" << ("-W" + OrigOpt.str());
169  continue;
170  }
171  Specifier = Opt.substr(13);
172  }
173 
174  if (Specifier.empty()) {
175  if (SetDiagnostic)
176  Diags.setErrorsAsFatal(isPositive);
177  continue;
178  }
179 
180  if (SetDiagnostic) {
181  // Set the error as fatal flag for this specifier.
182  Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive);
183  } else if (DiagIDs->getDiagnosticsInGroup(Flavor, Specifier, _Diags)) {
184  EmitUnknownDiagWarning(Diags, Flavor, "-Wfatal-errors=", Specifier);
185  }
186  continue;
187  }
188 
189  if (Report) {
190  if (DiagIDs->getDiagnosticsInGroup(Flavor, Opt, _Diags))
191  EmitUnknownDiagWarning(Diags, Flavor, isPositive ? "-W" : "-Wno-",
192  Opt);
193  } else {
194  Diags.setSeverityForGroup(Flavor, Opt, Mapping);
195  }
196  }
197 
198  for (unsigned i = 0, e = Opts.Remarks.size(); i != e; ++i) {
199  StringRef Opt = Opts.Remarks[i];
200  const auto Flavor = diag::Flavor::Remark;
201 
202  // Check to see if this warning starts with "no-", if so, this is a
203  // negative form of the option.
204  bool IsPositive = !Opt.startswith("no-");
205  if (!IsPositive) Opt = Opt.substr(3);
206 
207  auto Severity = IsPositive ? diag::Severity::Remark
209 
210  // -Reverything sets the state of all remarks. Note that all remarks are
211  // in remark groups, so we don't need a separate 'all remarks enabled'
212  // flag.
213  if (Opt == "everything") {
214  if (SetDiagnostic)
216  continue;
217  }
218 
219  if (Report) {
220  if (DiagIDs->getDiagnosticsInGroup(Flavor, Opt, _Diags))
221  EmitUnknownDiagWarning(Diags, Flavor, IsPositive ? "-R" : "-Rno-",
222  Opt);
223  } else {
224  Diags.setSeverityForGroup(Flavor, Opt,
225  IsPositive ? diag::Severity::Remark
227  }
228  }
229  }
230 }
A diagnostic that indicates a problem or potential problem.
void setSeverityForAll(diag::Flavor Flavor, diag::Severity Map, SourceLocation Loc=SourceLocation())
Add the specified mapping to all diagnostics of the specified flavor.
Definition: Diagnostic.cpp:362
void setShowColors(bool Val=false)
Set color printing, so the type diffing will inject color markers into the output.
Definition: Diagnostic.h:565
void setShowOverloads(OverloadsShown Val)
Specify which overload candidates to show when overload resolution fails.
Definition: Diagnostic.h:572
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1205
const NestedNameSpecifier * Specifier
bool setDiagnosticGroupWarningAsError(StringRef Group, bool Enabled)
Set the warning-as-error flag for the given diagnostic group.
Definition: Diagnostic.cpp:301
Severity
Enum values that allow the client to map NOTEs, WARNINGs, and EXTENSIONs to either Ignore (nothing)...
Definition: DiagnosticIDs.h:80
void setTemplateBacktraceLimit(unsigned Limit)
Specify the maximum number of template instantiation notes to emit along with a given diagnostic...
Definition: Diagnostic.h:478
Includes all the separate Diagnostic headers & some related helpers.
bool setDiagnosticGroupErrorAsFatal(StringRef Group, bool Enabled)
Set the error-as-fatal flag for the given diagnostic group.
Definition: Diagnostic.cpp:332
void setExtensionHandlingBehavior(diag::Severity H)
Controls whether otherwise-unmapped extension diagnostics are mapped onto ignore/warning/error.
Definition: Diagnostic.h:598
void setPrintTemplateTree(bool Val=false)
Set tree printing, to outputting the template difference in a tree format.
Definition: Diagnostic.h:560
static StringRef getNearestOption(diag::Flavor Flavor, StringRef Group)
Get the diagnostic option with the closest edit distance to the given group name. ...
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:147
bool setSeverityForGroup(diag::Flavor Flavor, StringRef Group, diag::Severity Map, SourceLocation Loc=SourceLocation())
Change an entire diagnostic group (e.g.
Definition: Diagnostic.cpp:286
Defines the Diagnostic-related interfaces.
Present this diagnostic as an error.
std::vector< std::string > Warnings
The list of -W...
void setElideType(bool Val=true)
Set type eliding, to skip outputting same types occurring in template types.
Definition: Diagnostic.h:555
void setEnableAllWarnings(bool Val)
When set to true, any unmapped ignored warnings are no longer ignored.
Definition: Diagnostic.h:514
void setSuppressSystemWarnings(bool Val)
When set to true mask warnings that come from system headers.
Definition: Diagnostic.h:538
Options for controlling the compiler diagnostics engine.
void ProcessWarningOptions(DiagnosticsEngine &Diags, const DiagnosticOptions &Opts, bool ReportDiags=true)
ProcessWarningOptions - Initialize the diagnostic client and process the warning options specified on...
Definition: Warnings.cpp:44
std::vector< std::string > Remarks
The list of -R...
Flavor
Flavors of diagnostics we can emit.
Definition: DiagnosticIDs.h:91
void setErrorLimit(unsigned Limit)
Specify a limit for the number of errors we should emit before giving up.
Definition: Diagnostic.h:474
void setIgnoreAllWarnings(bool Val)
When set to true, any unmapped warnings are ignored.
Definition: Diagnostic.h:503
Dataflow Directional Tag Classes.
Present this diagnostic as a remark.
void setErrorsAsFatal(bool Val)
When set to true, any error reported is made a fatal error.
Definition: Diagnostic.h:530
void setWarningsAsErrors(bool Val)
When set to true, any warnings reported are issued as errors.
Definition: Diagnostic.h:522
void setConstexprBacktraceLimit(unsigned Limit)
Specify the maximum number of constexpr evaluation notes to emit along with a given diagnostic...
Definition: Diagnostic.h:490
const IntrusiveRefCntPtr< DiagnosticIDs > & getDiagnosticIDs() const
Definition: Diagnostic.h:412
Do not present this diagnostic, ignore it.
A diagnostic that indicates normal progress through compilation.
Present this diagnostic as a warning.
static void EmitUnknownDiagWarning(DiagnosticsEngine &Diags, diag::Flavor Flavor, StringRef Prefix, StringRef Opt)
Definition: Warnings.cpp:35