llvm-project/clang/lib/Basic/Warnings.cpp
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

230 lines
8.6 KiB
C++

//===--- Warnings.cpp - C-Language Front-end ------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Command line warning options handler.
//
//===----------------------------------------------------------------------===//
//
// This file is responsible for handling all warning options. This includes
// a number of -Wfoo options and their variants, which are driven by TableGen-
// generated data, and the special cases -pedantic, -pedantic-errors, -w,
// -Werror and -Wfatal-errors.
//
// Each warning option controls any number of actual warnings.
// Given a warning option 'foo', the following are valid:
// -Wfoo, -Wno-foo, -Werror=foo, -Wfatal-errors=foo
//
// Remark options are also handled here, analogously, except that they are much
// simpler because a remark can't be promoted to an error.
#include "clang/Basic/AllDiagnostics.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticOptions.h"
#include <algorithm>
#include <cstring>
#include <utility>
using namespace clang;
// EmitUnknownDiagWarning - Emit a warning and typo hint for unknown warning
// opts
static void EmitUnknownDiagWarning(DiagnosticsEngine &Diags,
diag::Flavor Flavor, StringRef Prefix,
StringRef Opt) {
StringRef Suggestion = DiagnosticIDs::getNearestOption(Flavor, Opt);
Diags.Report(diag::warn_unknown_diag_option)
<< (Flavor == diag::Flavor::WarningOrError ? 0 : 1) << (Prefix.str() += Opt)
<< !Suggestion.empty() << (Prefix.str() += Suggestion);
}
void clang::ProcessWarningOptions(DiagnosticsEngine &Diags,
const DiagnosticOptions &Opts,
bool ReportDiags) {
Diags.setSuppressSystemWarnings(true); // Default to -Wno-system-headers
Diags.setIgnoreAllWarnings(Opts.IgnoreWarnings);
Diags.setShowOverloads(Opts.getShowOverloads());
Diags.setElideType(Opts.ElideType);
Diags.setPrintTemplateTree(Opts.ShowTemplateTree);
Diags.setShowColors(Opts.ShowColors);
// Handle -ferror-limit
if (Opts.ErrorLimit)
Diags.setErrorLimit(Opts.ErrorLimit);
if (Opts.TemplateBacktraceLimit)
Diags.setTemplateBacktraceLimit(Opts.TemplateBacktraceLimit);
if (Opts.ConstexprBacktraceLimit)
Diags.setConstexprBacktraceLimit(Opts.ConstexprBacktraceLimit);
// If -pedantic or -pedantic-errors was specified, then we want to map all
// extension diagnostics onto WARNING or ERROR unless the user has futz'd
// around with them explicitly.
if (Opts.PedanticErrors)
Diags.setExtensionHandlingBehavior(diag::Severity::Error);
else if (Opts.Pedantic)
Diags.setExtensionHandlingBehavior(diag::Severity::Warning);
else
Diags.setExtensionHandlingBehavior(diag::Severity::Ignored);
SmallVector<diag::kind, 10> _Diags;
const IntrusiveRefCntPtr< DiagnosticIDs > DiagIDs =
Diags.getDiagnosticIDs();
// We parse the warning options twice. The first pass sets diagnostic state,
// while the second pass reports warnings/errors. This has the effect that
// we follow the more canonical "last option wins" paradigm when there are
// conflicting options.
for (unsigned Report = 0, ReportEnd = 2; Report != ReportEnd; ++Report) {
bool SetDiagnostic = (Report == 0);
// If we've set the diagnostic state and are not reporting diagnostics then
// we're done.
if (!SetDiagnostic && !ReportDiags)
break;
for (unsigned i = 0, e = Opts.Warnings.size(); i != e; ++i) {
const auto Flavor = diag::Flavor::WarningOrError;
StringRef Opt = Opts.Warnings[i];
StringRef OrigOpt = Opts.Warnings[i];
// Treat -Wformat=0 as an alias for -Wno-format.
if (Opt == "format=0")
Opt = "no-format";
// Check to see if this warning starts with "no-", if so, this is a
// negative form of the option.
bool isPositive = true;
if (Opt.startswith("no-")) {
isPositive = false;
Opt = Opt.substr(3);
}
// Figure out how this option affects the warning. If -Wfoo, map the
// diagnostic to a warning, if -Wno-foo, map it to ignore.
diag::Severity Mapping =
isPositive ? diag::Severity::Warning : diag::Severity::Ignored;
// -Wsystem-headers is a special case, not driven by the option table. It
// cannot be controlled with -Werror.
if (Opt == "system-headers") {
if (SetDiagnostic)
Diags.setSuppressSystemWarnings(!isPositive);
continue;
}
// -Weverything is a special case as well. It implicitly enables all
// warnings, including ones not explicitly in a warning group.
if (Opt == "everything") {
if (SetDiagnostic) {
if (isPositive) {
Diags.setEnableAllWarnings(true);
} else {
Diags.setEnableAllWarnings(false);
Diags.setSeverityForAll(Flavor, diag::Severity::Ignored);
}
}
continue;
}
// -Werror/-Wno-error is a special case, not controlled by the option
// table. It also has the "specifier" form of -Werror=foo and -Werror-foo.
if (Opt.startswith("error")) {
StringRef Specifier;
if (Opt.size() > 5) { // Specifier must be present.
if ((Opt[5] != '=' && Opt[5] != '-') || Opt.size() == 6) {
if (Report)
Diags.Report(diag::warn_unknown_warning_specifier)
<< "-Werror" << ("-W" + OrigOpt.str());
continue;
}
Specifier = Opt.substr(6);
}
if (Specifier.empty()) {
if (SetDiagnostic)
Diags.setWarningsAsErrors(isPositive);
continue;
}
if (SetDiagnostic) {
// Set the warning as error flag for this specifier.
Diags.setDiagnosticGroupWarningAsError(Specifier, isPositive);
} else if (DiagIDs->getDiagnosticsInGroup(Flavor, Specifier, _Diags)) {
EmitUnknownDiagWarning(Diags, Flavor, "-Werror=", Specifier);
}
continue;
}
// -Wfatal-errors is yet another special case.
if (Opt.startswith("fatal-errors")) {
StringRef Specifier;
if (Opt.size() != 12) {
if ((Opt[12] != '=' && Opt[12] != '-') || Opt.size() == 13) {
if (Report)
Diags.Report(diag::warn_unknown_warning_specifier)
<< "-Wfatal-errors" << ("-W" + OrigOpt.str());
continue;
}
Specifier = Opt.substr(13);
}
if (Specifier.empty()) {
if (SetDiagnostic)
Diags.setErrorsAsFatal(isPositive);
continue;
}
if (SetDiagnostic) {
// Set the error as fatal flag for this specifier.
Diags.setDiagnosticGroupErrorAsFatal(Specifier, isPositive);
} else if (DiagIDs->getDiagnosticsInGroup(Flavor, Specifier, _Diags)) {
EmitUnknownDiagWarning(Diags, Flavor, "-Wfatal-errors=", Specifier);
}
continue;
}
if (Report) {
if (DiagIDs->getDiagnosticsInGroup(Flavor, Opt, _Diags))
EmitUnknownDiagWarning(Diags, Flavor, isPositive ? "-W" : "-Wno-",
Opt);
} else {
Diags.setSeverityForGroup(Flavor, Opt, Mapping);
}
}
for (unsigned i = 0, e = Opts.Remarks.size(); i != e; ++i) {
StringRef Opt = Opts.Remarks[i];
const auto Flavor = diag::Flavor::Remark;
// Check to see if this warning starts with "no-", if so, this is a
// negative form of the option.
bool IsPositive = !Opt.startswith("no-");
if (!IsPositive) Opt = Opt.substr(3);
auto Severity = IsPositive ? diag::Severity::Remark
: diag::Severity::Ignored;
// -Reverything sets the state of all remarks. Note that all remarks are
// in remark groups, so we don't need a separate 'all remarks enabled'
// flag.
if (Opt == "everything") {
if (SetDiagnostic)
Diags.setSeverityForAll(Flavor, Severity);
continue;
}
if (Report) {
if (DiagIDs->getDiagnosticsInGroup(Flavor, Opt, _Diags))
EmitUnknownDiagWarning(Diags, Flavor, IsPositive ? "-R" : "-Rno-",
Opt);
} else {
Diags.setSeverityForGroup(Flavor, Opt,
IsPositive ? diag::Severity::Remark
: diag::Severity::Ignored);
}
}
}
}