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 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 Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers 53 Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings); 54 Diags.setShowOverloads( 55 static_cast<DiagnosticsEngine::OverloadsShown>(Opts.ShowOverloads)); 56 57 // Handle -ferror-limit 58 if (Opts.ErrorLimit) 59 Diags.setErrorLimit(Opts.ErrorLimit); 60 if (Opts.TemplateBacktraceLimit) 61 Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit); 62 if (Opts.ConstexprBacktraceLimit) 63 Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit); 64 65 // If -pedantic or -pedantic-errors was specified, then we want to map all 66 // extension diagnostics onto WARNING or ERROR unless the user has futz'd 67 // around with them explicitly. 68 if (Opts.PedanticErrors) 69 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Error); 70 else if (Opts.Pedantic) 71 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Warn); 72 else 73 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Ignore); 74 75 llvm::SmallVector<diag::kind, 10> _Diags; 76 const IntrusiveRefCntPtr< DiagnosticIDs > DiagIDs = 77 Diags.getDiagnosticIDs(); 78 // We parse the warning options twice. The first pass sets diagnostic state, 79 // while the second pass reports warnings/errors. This has the effect that 80 // we follow the more canonical "last option wins" paradigm when there are 81 // conflicting options. 82 for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) { 83 bool SetDiagnostic = (Report == 0); 84 for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) { 85 StringRef Opt = Opts.Warnings[i]; 86 87 // Treat -Wformat=0 as an alias for -Wno-format. 88 if (Opt == "format=0") 89 Opt = "no-format"; 90 91 // Check to see if this warning starts with "no-", if so, this is a 92 // negative form of the option. 93 bool isPositive = true; 94 if (Opt.startswith("no-")) { 95 isPositive = false; 96 Opt = Opt.substr(3); 97 } 98 99 // Figure out how this option affects the warning. If -Wfoo, map the 100 // diagnostic to a warning, if -Wno-foo, map it to ignore. 101 diag::Mapping Mapping = isPositive ? diag::MAP_WARNING : diag::MAP_IGNORE; 102 103 // -Wsystem-headers is a special case, not driven by the option table. It 104 // cannot be controlled with -Werror. 105 if (Opt == "system-headers") { 106 if (SetDiagnostic) 107 Diags.setSuppressSystemWarnings(!isPositive); 108 continue; 109 } 110 111 // -Weverything is a special case as well. It implicitly enables all 112 // warnings, including ones not explicitly in a warning group. 113 if (Opt == "everything") { 114 if (SetDiagnostic) { 115 if (isPositive) { 116 Diags.setEnableAllWarnings(true); 117 } else { 118 Diags.setEnableAllWarnings(false); 119 Diags.setMappingToAllDiagnostics(diag::MAP_IGNORE); 120 } 121 } 122 continue; 123 } 124 125 // -Werror/-Wno-error is a special case, not controlled by the option 126 // table. It also has the "specifier" form of -Werror=foo and -Werror-foo. 127 if (Opt.startswith("error")) { 128 StringRef Specifier; 129 if (Opt.size() > 5) { // Specifier must be present. 130 if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) { 131 if (Report) 132 Diags.Report(diag::warn_unknown_warning_specifier) 133 << "-Werror" << ("-W" + Opt.str()); 134 continue; 135 } 136 Specifier = Opt.substr(6); 137 } 138 139 if (Specifier.empty()) { 140 if (SetDiagnostic) 141 Diags.setWarningsAsErrors(isPositive); 142 continue; 143 } 144 145 if (SetDiagnostic) { 146 // Set the warning as error flag for this specifier. 147 Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive); 148 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) { 149 EmitUnknownDiagWarning(Diags, "-Werror=", Specifier, isPositive); 150 } 151 continue; 152 } 153 154 // -Wfatal-errors is yet another special case. 155 if (Opt.startswith("fatal-errors")) { 156 StringRef Specifier; 157 if (Opt.size() != 12) { 158 if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) { 159 if (Report) 160 Diags.Report(diag::warn_unknown_warning_specifier) 161 << "-Wfatal-errors" << ("-W" + Opt.str()); 162 continue; 163 } 164 Specifier = Opt.substr(13); 165 } 166 167 if (Specifier.empty()) { 168 if (SetDiagnostic) 169 Diags.setErrorsAsFatal(isPositive); 170 continue; 171 } 172 173 if (SetDiagnostic) { 174 // Set the error as fatal flag for this specifier. 175 Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive); 176 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) { 177 EmitUnknownDiagWarning(Diags, "-Wfatal-errors=", Specifier, 178 isPositive); 179 } 180 continue; 181 } 182 183 if (Report) { 184 if (DiagIDs->getDiagnosticsInGroup(Opt, _Diags)) 185 EmitUnknownDiagWarning(Diags, "-W", Opt, isPositive); 186 } else { 187 Diags.setDiagnosticGroupMapping(Opt, Mapping); 188 } 189 } 190 } 191 } 192
