clang  10.0.0svn
Warnings.cpp
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1 //===--- Warnings.cpp - C-Language Front-end ------------------------------===//
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 // Command line warning options handler.
10 //
11 //===----------------------------------------------------------------------===//
12 //
13 // This file is responsible for handling all warning options. This includes
14 // a number of -Wfoo options and their variants, which are driven by TableGen-
15 // generated data, and the special cases -pedantic, -pedantic-errors, -w,
16 // -Werror and -Wfatal-errors.
17 //
18 // Each warning option controls any number of actual warnings.
19 // Given a warning option 'foo', the following are valid:
20 // -Wfoo, -Wno-foo, -Werror=foo, -Wfatal-errors=foo
21 //
22 // Remark options are also handled here, analogously, except that they are much
23 // simpler because a remark can't be promoted to an error.
25 #include "clang/Basic/Diagnostic.h"
27 #include <algorithm>
28 #include <cstring>
29 #include <utility>
30 using namespace clang;
31 
32 // EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning
33 // opts
35  diag::Flavor Flavor, StringRef Prefix,
36  StringRef Opt) {
37  StringRef Suggestion = DiagnosticIDs::getNearestOption(Flavor, Opt);
38  Diags.Report(diag::warn_unknown_diag_option)
39  << (Flavor == diag::Flavor::WarningOrError ? 0 : 1) << (Prefix.str() += Opt)
40  << !Suggestion.empty() << (Prefix.str() += Suggestion);
41 }
42 
44  const DiagnosticOptions &Opts,
45  bool ReportDiags) {
46  Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers
47  Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
48  Diags.setShowOverloads(Opts.getShowOverloads());
49 
50  Diags.setElideType(Opts.ElideType);
51  Diags.setPrintTemplateTree(Opts.ShowTemplateTree);
52  Diags.setShowColors(Opts.ShowColors);
53 
54  // Handle -ferror-limit
55  if (Opts.ErrorLimit)
56  Diags.setErrorLimit(Opts.ErrorLimit);
57  if (Opts.TemplateBacktraceLimit)
58  Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
59  if (Opts.ConstexprBacktraceLimit)
60  Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit);
61 
62  // If -pedantic or -pedantic-errors was specified, then we want to map all
63  // extension diagnostics onto WARNING or ERROR unless the user has futz'd
64  // around with them explicitly.
65  if (Opts.PedanticErrors)
67  else if (Opts.Pedantic)
69  else
71 
74  Diags.getDiagnosticIDs();
75  // We parse the warning options twice. The first pass sets diagnostic state,
76  // while the second pass reports warnings/errors. This has the effect that
77  // we follow the more canonical "last option wins" paradigm when there are
78  // conflicting options.
79  for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) {
80  bool SetDiagnostic = (Report == 0);
81 
82  // If we've set the diagnostic state and are not reporting diagnostics then
83  // we're done.
84  if (!SetDiagnostic && !ReportDiags)
85  break;
86 
87  for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) {
89  StringRef Opt = Opts.Warnings[i];
90  StringRef OrigOpt = Opts.Warnings[i];
91 
92  // Treat -Wformat=0 as an alias for -Wno-format.
93  if (Opt == "format=0")
94  Opt = "no-format";
95 
96  // Check to see if this warning starts with "no-", if so, this is a
97  // negative form of the option.
98  bool isPositive = true;
99  if (Opt.startswith("no-")) {
100  isPositive = false;
101  Opt = Opt.substr(3);
102  }
103 
104  // Figure out how this option affects the warning. If -Wfoo, map the
105  // diagnostic to a warning, if -Wno-foo, map it to ignore.
106  diag::Severity Mapping =
108 
109  // -Wsystem-headers is a special case, not driven by the option table. It
110  // cannot be controlled with -Werror.
111  if (Opt == "system-headers") {
112  if (SetDiagnostic)
113  Diags.setSuppressSystemWarnings(!isPositive);
114  continue;
115  }
116 
117  // -Weverything is a special case as well. It implicitly enables all
118  // warnings, including ones not explicitly in a warning group.
119  if (Opt == "everything") {
120  if (SetDiagnostic) {
121  if (isPositive) {
122  Diags.setEnableAllWarnings(true);
123  } else {
124  Diags.setEnableAllWarnings(false);
126  }
127  }
128  continue;
129  }
130 
131  // -Werror/-Wno-error is a special case, not controlled by the option
132  // table. It also has the "specifier" form of -Werror=foo and -Werror-foo.
133  if (Opt.startswith("error")) {
134  StringRef Specifier;
135  if (Opt.size() > 5) { // Specifier must be present.
136  if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) {
137  if (Report)
138  Diags.Report(diag::warn_unknown_warning_specifier)
139  << "-Werror" << ("-W" + OrigOpt.str());
140  continue;
141  }
142  Specifier = Opt.substr(6);
143  }
144 
145  if (Specifier.empty()) {
146  if (SetDiagnostic)
147  Diags.setWarningsAsErrors(isPositive);
148  continue;
149  }
150 
151  if (SetDiagnostic) {
152  // Set the warning as error flag for this specifier.
153  Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive);
154  } else if (DiagIDs->getDiagnosticsInGroup(Flavor, Specifier, _Diags)) {
155  EmitUnknownDiagWarning(Diags, Flavor, "-Werror=", Specifier);
156  }
157  continue;
158  }
159 
160  // -Wfatal-errors is yet another special case.
161  if (Opt.startswith("fatal-errors")) {
162  StringRef Specifier;
163  if (Opt.size() != 12) {
164  if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) {
165  if (Report)
166  Diags.Report(diag::warn_unknown_warning_specifier)
167  << "-Wfatal-errors" << ("-W" + OrigOpt.str());
168  continue;
169  }
170  Specifier = Opt.substr(13);
171  }
172 
173  if (Specifier.empty()) {
174  if (SetDiagnostic)
175  Diags.setErrorsAsFatal(isPositive);
176  continue;
177  }
178 
179  if (SetDiagnostic) {
180  // Set the error as fatal flag for this specifier.
181  Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive);
182  } else if (DiagIDs->getDiagnosticsInGroup(Flavor, Specifier, _Diags)) {
183  EmitUnknownDiagWarning(Diags, Flavor, "-Wfatal-errors=", Specifier);
184  }
185  continue;
186  }
187 
188  if (Report) {
189  if (DiagIDs->getDiagnosticsInGroup(Flavor, Opt, _Diags))
190  EmitUnknownDiagWarning(Diags, Flavor, isPositive ? "-W" : "-Wno-",
191  Opt);
192  } else {
193  Diags.setSeverityForGroup(Flavor, Opt, Mapping);
194  }
195  }
196 
197  for (unsigned i = 0, e = Opts.Remarks.size(); i != e; ++i) {
198  StringRef Opt = Opts.Remarks[i];
199  const auto Flavor = diag::Flavor::Remark;
200 
201  // Check to see if this warning starts with "no-", if so, this is a
202  // negative form of the option.
203  bool IsPositive = !Opt.startswith("no-");
204  if (!IsPositive) Opt = Opt.substr(3);
205 
206  auto Severity = IsPositive ? diag::Severity::Remark
208 
209  // -Reverything sets the state of all remarks. Note that all remarks are
210  // in remark groups, so we don't need a separate 'all remarks enabled'
211  // flag.
212  if (Opt == "everything") {
213  if (SetDiagnostic)
215  continue;
216  }
217 
218  if (Report) {
219  if (DiagIDs->getDiagnosticsInGroup(Flavor, Opt, _Diags))
220  EmitUnknownDiagWarning(Diags, Flavor, IsPositive ? "-R" : "-Rno-",
221  Opt);
222  } else {
223  Diags.setSeverityForGroup(Flavor, Opt,
224  IsPositive ? diag::Severity::Remark
226  }
227  }
228  }
229 }
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:458
void setShowOverloads(OverloadsShown Val)
Specify which overload candidates to show when overload resolution fails.
Definition: Diagnostic.h:657
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1290
const NestedNameSpecifier * Specifier
bool setDiagnosticGroupWarningAsError(StringRef Group, bool Enabled)
Set the warning-as-error flag for the given diagnostic group.
Definition: Diagnostic.cpp:397
Severity
Enum values that allow the client to map NOTEs, WARNINGs, and EXTENSIONs to either Ignore (nothing)...
Definition: DiagnosticIDs.h:79
void setTemplateBacktraceLimit(unsigned Limit)
Specify the maximum number of template instantiation notes to emit along with a given diagnostic...
Definition: Diagnostic.h:563
Includes all the separate Diagnostic headers & some related helpers.
void setElideType(bool Val)
Set type eliding, to skip outputting same types occurring in template types.
Definition: Diagnostic.h:640
bool setDiagnosticGroupErrorAsFatal(StringRef Group, bool Enabled)
Set the error-as-fatal flag for the given diagnostic group.
Definition: Diagnostic.cpp:428
void setExtensionHandlingBehavior(diag::Severity H)
Controls whether otherwise-unmapped extension diagnostics are mapped onto ignore/warning/error.
Definition: Diagnostic.h:685
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:149
bool setSeverityForGroup(diag::Flavor Flavor, StringRef Group, diag::Severity Map, SourceLocation Loc=SourceLocation())
Change an entire diagnostic group (e.g.
Definition: Diagnostic.cpp:382
Defines the Diagnostic-related interfaces.
Present this diagnostic as an error.
std::vector< std::string > Warnings
The list of -W...
void setEnableAllWarnings(bool Val)
When set to true, any unmapped ignored warnings are no longer ignored.
Definition: Diagnostic.h:599
void setSuppressSystemWarnings(bool Val)
When set to true mask warnings that come from system headers.
Definition: Diagnostic.h:625
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:43
std::vector< std::string > Remarks
The list of -R...
Flavor
Flavors of diagnostics we can emit.
Definition: DiagnosticIDs.h:90
void setErrorLimit(unsigned Limit)
Specify a limit for the number of errors we should emit before giving up.
Definition: Diagnostic.h:559
void setIgnoreAllWarnings(bool Val)
When set to true, any unmapped warnings are ignored.
Definition: Diagnostic.h:588
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:615
void setPrintTemplateTree(bool Val)
Set tree printing, to outputting the template difference in a tree format.
Definition: Diagnostic.h:645
void setShowColors(bool Val)
Set color printing, so the type diffing will inject color markers into the output.
Definition: Diagnostic.h:650
void setWarningsAsErrors(bool Val)
When set to true, any warnings reported are issued as errors.
Definition: Diagnostic.h:607
void setConstexprBacktraceLimit(unsigned Limit)
Specify the maximum number of constexpr evaluation notes to emit along with a given diagnostic...
Definition: Diagnostic.h:575
const IntrusiveRefCntPtr< DiagnosticIDs > & getDiagnosticIDs() const
Definition: Diagnostic.h:495
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:34