1//===- ShowEnabledWarnings - diagtool tool for printing enabled flags -----===//
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#include "DiagTool.h"
10#include "DiagnosticNames.h"
11#include "clang/Basic/LLVM.h"
12#include "clang/Driver/CreateInvocationFromArgs.h"
13#include "clang/Frontend/CompilerInstance.h"
14#include "clang/Frontend/TextDiagnosticBuffer.h"
15#include "clang/Frontend/TextDiagnosticPrinter.h"
16#include "clang/Frontend/Utils.h"
17#include "llvm/Support/TargetSelect.h"
18#include "llvm/Support/VirtualFileSystem.h"
19
20DEF_DIAGTOOL("show-enabled",
21 "Show which warnings are enabled for a given command line",
22 ShowEnabledWarnings)
23
24using namespace clang;
25using namespace diagtool;
26
27namespace {
28 struct PrettyDiag {
29 StringRef Name;
30 StringRef Flag;
31 DiagnosticsEngine::Level Level;
32
33 PrettyDiag(StringRef name, StringRef flag, DiagnosticsEngine::Level level)
34 : Name(name), Flag(flag), Level(level) {}
35
36 bool operator<(const PrettyDiag &x) const { return Name < x.Name; }
37 };
38}
39
40static void printUsage() {
41 llvm::errs() << "Usage: diagtool show-enabled [<flags>] <single-input.c>\n";
42}
43
44static char getCharForLevel(DiagnosticsEngine::Level Level) {
45 switch (Level) {
46 case DiagnosticsEngine::Ignored: return ' ';
47 case DiagnosticsEngine::Note: return '-';
48 case DiagnosticsEngine::Remark: return 'R';
49 case DiagnosticsEngine::Warning: return 'W';
50 case DiagnosticsEngine::Error: return 'E';
51 case DiagnosticsEngine::Fatal: return 'F';
52 }
53
54 llvm_unreachable("Unknown diagnostic level");
55}
56
57static IntrusiveRefCntPtr<DiagnosticsEngine>
58createDiagnostics(unsigned int argc, char **argv) {
59 DiagnosticOptions DiagOpts;
60
61 // Buffer diagnostics from argument parsing so that we can output them using a
62 // well formed diagnostic object.
63 TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
64
65 // Try to build a CompilerInvocation.
66 SmallVector<const char *, 4> Args;
67 Args.push_back(Elt: "diagtool");
68 Args.append(in_start: argv, in_end: argv + argc);
69 CreateInvocationOptions CIOpts;
70 CIOpts.Diags = llvm::makeIntrusiveRefCnt<DiagnosticsEngine>(
71 A: DiagnosticIDs::create(), A&: DiagOpts, A&: DiagsBuffer);
72 std::unique_ptr<CompilerInvocation> Invocation =
73 createInvocation(Args, Opts: CIOpts);
74 if (!Invocation)
75 return nullptr;
76
77 // Build the diagnostics parser
78 IntrusiveRefCntPtr<DiagnosticsEngine> FinalDiags =
79 CompilerInstance::createDiagnostics(VFS&: *llvm::vfs::getRealFileSystem(),
80 Opts&: Invocation->getDiagnosticOpts());
81 if (!FinalDiags)
82 return nullptr;
83
84 // Flush any errors created when initializing everything. This could happen
85 // for invalid command lines, which will probably give non-sensical results.
86 DiagsBuffer->FlushDiagnostics(Diags&: *FinalDiags);
87
88 return FinalDiags;
89}
90
91int ShowEnabledWarnings::run(unsigned int argc, char **argv, raw_ostream &Out) {
92 // First check our one flag (--levels).
93 bool ShouldShowLevels = true;
94 if (argc > 0) {
95 StringRef FirstArg(*argv);
96 if (FirstArg == "--no-levels") {
97 ShouldShowLevels = false;
98 --argc;
99 ++argv;
100 } else if (FirstArg == "--levels") {
101 ShouldShowLevels = true;
102 --argc;
103 ++argv;
104 }
105 }
106
107 // Create the diagnostic engine.
108 IntrusiveRefCntPtr<DiagnosticsEngine> Diags = createDiagnostics(argc, argv);
109 if (!Diags) {
110 printUsage();
111 return EXIT_FAILURE;
112 }
113
114 // Now we have our diagnostics. Iterate through EVERY diagnostic and see
115 // which ones are turned on.
116 // FIXME: It would be very nice to print which flags are turning on which
117 // diagnostics, but this can be done with a diff.
118 std::vector<PrettyDiag> Active;
119
120 for (const DiagnosticRecord &DR : getBuiltinDiagnosticsByName()) {
121 unsigned DiagID = DR.DiagID;
122
123 if (DiagnosticIDs{}.isNote(DiagID))
124 continue;
125
126 if (!DiagnosticIDs{}.isWarningOrExtension(DiagID))
127 continue;
128
129 DiagnosticsEngine::Level DiagLevel =
130 Diags->getDiagnosticLevel(DiagID, Loc: SourceLocation());
131 if (DiagLevel == DiagnosticsEngine::Ignored)
132 continue;
133
134 StringRef WarningOpt = DiagnosticIDs{}.getWarningOptionForDiag(DiagID);
135 Active.push_back(x: PrettyDiag(DR.getName(), WarningOpt, DiagLevel));
136 }
137
138 // Print them all out.
139 for (const PrettyDiag &PD : Active) {
140 if (ShouldShowLevels)
141 Out << getCharForLevel(Level: PD.Level) << " ";
142 Out << PD.Name;
143 if (!PD.Flag.empty())
144 Out << " [-W" << PD.Flag << "]";
145 Out << '\n';
146 }
147
148 return EXIT_SUCCESS;
149}
150