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> 32using namespace clang; 33 34// EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning 35// opts 36static 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 50void 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 Diags.setElideType(Opts.ElideType); 58 Diags.setPrintTemplateTree(Opts.ShowTemplateTree); 59 Diags.setShowColors(Opts.ShowColors); 60 61 // Handle -ferror-limit 62 if (Opts.ErrorLimit) 63 Diags.setErrorLimit(Opts.ErrorLimit); 64 if (Opts.TemplateBacktraceLimit) 65 Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit); 66 if (Opts.ConstexprBacktraceLimit) 67 Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit); 68 69 // If -pedantic or -pedantic-errors was specified, then we want to map all 70 // extension diagnostics onto WARNING or ERROR unless the user has futz'd 71 // around with them explicitly. 72 if (Opts.PedanticErrors) 73 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Error); 74 else if (Opts.Pedantic) 75 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Warn); 76 else 77 Diags.setExtensionHandlingBehavior(DiagnosticsEngine::Ext_Ignore); 78 79 llvm::SmallVector<diag::kind, 10> _Diags; 80 const IntrusiveRefCntPtr< DiagnosticIDs > DiagIDs = 81 Diags.getDiagnosticIDs(); 82 // We parse the warning options twice. The first pass sets diagnostic state, 83 // while the second pass reports warnings/errors. This has the effect that 84 // we follow the more canonical "last option wins" paradigm when there are 85 // conflicting options. 86 for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) { 87 bool SetDiagnostic = (Report == 0); 88 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::Mapping Mapping = isPositive ? diag::MAP_WARNING : diag::MAP_IGNORE; 107 108 // -Wsystem-headers is a special case, not driven by the option table. It 109 // cannot be controlled with -Werror. 110 if (Opt == "system-headers") { 111 if (SetDiagnostic) 112 Diags.setSuppressSystemWarnings(!isPositive); 113 continue; 114 } 115 116 // -Weverything is a special case as well. It implicitly enables all 117 // warnings, including ones not explicitly in a warning group. 118 if (Opt == "everything") { 119 if (SetDiagnostic) { 120 if (isPositive) { 121 Diags.setEnableAllWarnings(true); 122 } else { 123 Diags.setEnableAllWarnings(false); 124 Diags.setMappingToAllDiagnostics(diag::MAP_IGNORE); 125 } 126 } 127 continue; 128 } 129 130 // -Werror/-Wno-error is a special case, not controlled by the option 131 // table. It also has the "specifier" form of -Werror=foo and -Werror-foo. 132 if (Opt.startswith("error")) { 133 StringRef Specifier; 134 if (Opt.size() > 5) { // Specifier must be present. 135 if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) { 136 if (Report) 137 Diags.Report(diag::warn_unknown_warning_specifier) 138 << "-Werror" << ("-W" + OrigOpt.str()); 139 continue; 140 } 141 Specifier = Opt.substr(6); 142 } 143 144 if (Specifier.empty()) { 145 if (SetDiagnostic) 146 Diags.setWarningsAsErrors(isPositive); 147 continue; 148 } 149 150 if (SetDiagnostic) { 151 // Set the warning as error flag for this specifier. 152 Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive); 153 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) { 154 EmitUnknownDiagWarning(Diags, "-Werror=", Specifier, isPositive); 155 } 156 continue; 157 } 158 159 // -Wfatal-errors is yet another special case. 160 if (Opt.startswith("fatal-errors")) { 161 StringRef Specifier; 162 if (Opt.size() != 12) { 163 if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) { 164 if (Report) 165 Diags.Report(diag::warn_unknown_warning_specifier) 166 << "-Wfatal-errors" << ("-W" + OrigOpt.str()); 167 continue; 168 } 169 Specifier = Opt.substr(13); 170 } 171 172 if (Specifier.empty()) { 173 if (SetDiagnostic) 174 Diags.setErrorsAsFatal(isPositive); 175 continue; 176 } 177 178 if (SetDiagnostic) { 179 // Set the error as fatal flag for this specifier. 180 Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive); 181 } else if (DiagIDs->getDiagnosticsInGroup(Specifier, _Diags)) { 182 EmitUnknownDiagWarning(Diags, "-Wfatal-errors=", Specifier, 183 isPositive); 184 } 185 continue; 186 } 187 188 if (Report) { 189 if (DiagIDs->getDiagnosticsInGroup(Opt, _Diags)) 190 EmitUnknownDiagWarning(Diags, isPositive ? "-W" : "-Wno-", Opt, 191 isPositive); 192 } else { 193 Diags.setDiagnosticGroupMapping(Opt, Mapping); 194 } 195 } 196 } 197} 198