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/Basic/DiagnosticOptions.h" 26 #include "clang/Frontend/FrontendDiagnostic.h" 27 #include "clang/Lex/LexDiagnostic.h" 28 #include "clang/Sema/SemaDiagnostic.h" 29 #include <algorithm> 30 #include <cstring> 31 #include <utility> 32 using namespace clang; 33 34 // EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning 35 // opts 36 static void EmitUnknownDiagWarning(DiagnosticsEngine &Diags, 37 StringRef Prefix, StringRef Opt, 38 bool isPositive) { 39 StringRef Suggestion = DiagnosticIDs::getNearestWarningOption(Opt); 40 if (!Suggestion.empty()) 41 Diags.Report(isPositive? diag::warn_unknown_warning_option_suggest : 42 diag::warn_unknown_negative_warning_option_suggest) 43 << (Prefix.str() += Opt) << (Prefix.str() += Suggestion); 44 else 45 Diags.Report(isPositive? diag::warn_unknown_warning_option : 46 diag::warn_unknown_negative_warning_option) 47 << (Prefix.str() += Opt); 48 } 49 50 void clang::ProcessWarningOptions(DiagnosticsEngine &Diags, 51 const DiagnosticOptions &Opts, 52 bool ReportDiags) { 53 Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers 54 Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings); 55 Diags.setShowOverloads(Opts.getShowOverloads()); 56 57 Diags.setElideType(Opts.ElideType); 58 Diags.setPrintTemplateTree(Opts.ShowTemplateTree); 59 Diags.setWarnOnSpellCheck(Opts.WarnOnSpellCheck); 60 Diags.setShowColors(Opts.ShowColors); 61 62 // Handle -ferror-limit 63 if (Opts.ErrorLimit) 64 Diags.setErrorLimit(Opts.ErrorLimit); 65 if (Opts.TemplateBacktraceLimit) 66 Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit); 67 if (Opts.ConstexprBacktraceLimit) 68 Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit); 69 70 // If -pedantic or -pedantic-errors was specified, then we want to map all 71 // extension diagnostics onto WARNING or ERROR unless the user has futz'd 72 // around with them explicitly. 73 if (Opts.PedanticErrors) 74 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Error); 75 else if (Opts.Pedantic) 76 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Warn); 77 else 78 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Ignore); 79 80 SmallVector<diag::kind, 10> _Diags; 81 const IntrusiveRefCntPtr< DiagnosticIDs > DiagIDs = 82 Diags.getDiagnosticIDs(); 83 // We parse the warning options twice. The first pass sets diagnostic state, 84 // while the second pass reports warnings/errors. This has the effect that 85 // we follow the more canonical "last option wins" paradigm when there are 86 // conflicting options. 87 for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) { 88 bool SetDiagnostic = (Report == 0); 89 90 // If we've set the diagnostic state and are not reporting diagnostics then 91 // we're done. 92 if (!SetDiagnostic && !ReportDiags) 93 break; 94 95 for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) { 96 StringRef Opt = Opts.Warnings[i]; 97 StringRef OrigOpt = Opts.Warnings[i]; 98 99 // Treat -Wformat=0 as an alias for -Wno-format. 100 if (Opt == "format=0") 101 Opt = "no-format"; 102 103 // Check to see if this warning starts with "no-", if so, this is a 104 // negative form of the option. 105 bool isPositive = true; 106 if (Opt.startswith("no-")) { 107 isPositive = false; 108 Opt = Opt.substr(3); 109 } 110 111 // Figure out how this option affects the warning. If -Wfoo, map the 112 // diagnostic to a warning, if -Wno-foo, map it to ignore. 113 diag::Mapping Mapping = isPositive ? diag::MAP_WARNING : diag::MAP_IGNORE; 114 115 // -Wsystem-headers is a special case, not driven by the option table. It 116 // cannot be controlled with -Werror. 117 if (Opt == "system-headers") { 118 if (SetDiagnostic) 119 Diags.setSuppressSystemWarnings(!isPositive); 120 continue; 121 } 122 123 // -Weverything is a special case as well. It implicitly enables all 124 // warnings, including ones not explicitly in a warning group. 125 if (Opt == "everything") { 126 if (SetDiagnostic) { 127 if (isPositive) { 128 Diags.setEnableAllWarnings(true); 129 } else { 130 Diags.setEnableAllWarnings(false); 131 Diags.setMappingToAllDiagnostics(diag::MAP_IGNORE); 132 } 133 } 134 continue; 135 } 136 137 // -Werror/-Wno-error is a special case, not controlled by the option 138 // table. It also has the "specifier" form of -Werror=foo and -Werror-foo. 139 if (Opt.startswith("error")) { 140 StringRef Specifier; 141 if (Opt.size() > 5) { // Specifier must be present. 142 if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) { 143 if (Report) 144 Diags.Report(diag::warn_unknown_warning_specifier) 145 << "-Werror" << ("-W" + OrigOpt.str()); 146 continue; 147 } 148 Specifier = Opt.substr(6); 149 } 150 151 if (Specifier.empty()) { 152 if (SetDiagnostic) 153 Diags.setWarningsAsErrors(isPositive); 154 continue; 155 } 156 157 if (SetDiagnostic) { 158 // Set the warning as error flag for this specifier. 159 Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive); 160 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) { 161 EmitUnknownDiagWarning(Diags, "-Werror=", Specifier, isPositive); 162 } 163 continue; 164 } 165 166 // -Wfatal-errors is yet another special case. 167 if (Opt.startswith("fatal-errors")) { 168 StringRef Specifier; 169 if (Opt.size() != 12) { 170 if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) { 171 if (Report) 172 Diags.Report(diag::warn_unknown_warning_specifier) 173 << "-Wfatal-errors" << ("-W" + OrigOpt.str()); 174 continue; 175 } 176 Specifier = Opt.substr(13); 177 } 178 179 if (Specifier.empty()) { 180 if (SetDiagnostic) 181 Diags.setErrorsAsFatal(isPositive); 182 continue; 183 } 184 185 if (SetDiagnostic) { 186 // Set the error as fatal flag for this specifier. 187 Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive); 188 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) { 189 EmitUnknownDiagWarning(Diags, "-Wfatal-errors=", Specifier, 190 isPositive); 191 } 192 continue; 193 } 194 195 if (Report) { 196 if (DiagIDs->getDiagnosticsInGroup(Opt, _Diags)) 197 EmitUnknownDiagWarning(Diags, isPositive ? "-W" : "-Wno-", Opt, 198 isPositive); 199 } else { 200 Diags.setDiagnosticGroupMapping(Opt, Mapping); 201 } 202 } 203 } 204 } 205