xref: /llvm-project/clang-tools-extra/clang-tidy/modernize/UseStdPrintCheck.cpp (revision 43fa7ea9df3a7b3bdc9d0129bcc3bed4db52dba0)
1 //===--- UseStdPrintCheck.cpp - clang-tidy-----------------------*- C++ -*-===//
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 "UseStdPrintCheck.h"
10 #include "../utils/FormatStringConverter.h"
11 #include "../utils/Matchers.h"
12 #include "../utils/OptionsUtils.h"
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14 #include "clang/Lex/Lexer.h"
15 #include "clang/Tooling/FixIt.h"
16 
17 using namespace clang::ast_matchers;
18 
19 namespace clang::tidy::modernize {
20 
21 namespace {
22 AST_MATCHER(StringLiteral, isOrdinary) { return Node.isOrdinary(); }
23 } // namespace
24 
25 UseStdPrintCheck::UseStdPrintCheck(StringRef Name, ClangTidyContext *Context)
26     : ClangTidyCheck(Name, Context),
27       StrictMode(Options.getLocalOrGlobal("StrictMode", false)),
28       PrintfLikeFunctions(utils::options::parseStringList(
29           Options.get("PrintfLikeFunctions", ""))),
30       FprintfLikeFunctions(utils::options::parseStringList(
31           Options.get("FprintfLikeFunctions", ""))),
32       ReplacementPrintFunction(
33           Options.get("ReplacementPrintFunction", "std::print")),
34       ReplacementPrintlnFunction(
35           Options.get("ReplacementPrintlnFunction", "std::println")),
36       IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",
37                                                utils::IncludeSorter::IS_LLVM),
38                       areDiagsSelfContained()),
39       MaybeHeaderToInclude(Options.get("PrintHeader")) {
40 
41   if (PrintfLikeFunctions.empty() && FprintfLikeFunctions.empty()) {
42     PrintfLikeFunctions.push_back("::printf");
43     PrintfLikeFunctions.push_back("absl::PrintF");
44     FprintfLikeFunctions.push_back("::fprintf");
45     FprintfLikeFunctions.push_back("absl::FPrintF");
46   }
47 
48   if (!MaybeHeaderToInclude && (ReplacementPrintFunction == "std::print" ||
49                                 ReplacementPrintlnFunction == "std::println"))
50     MaybeHeaderToInclude = "<print>";
51 }
52 
53 void UseStdPrintCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
54   using utils::options::serializeStringList;
55   Options.store(Opts, "StrictMode", StrictMode);
56   Options.store(Opts, "PrintfLikeFunctions",
57                 serializeStringList(PrintfLikeFunctions));
58   Options.store(Opts, "FprintfLikeFunctions",
59                 serializeStringList(FprintfLikeFunctions));
60   Options.store(Opts, "ReplacementPrintFunction", ReplacementPrintFunction);
61   Options.store(Opts, "ReplacementPrintlnFunction", ReplacementPrintlnFunction);
62   Options.store(Opts, "IncludeStyle", IncludeInserter.getStyle());
63   if (MaybeHeaderToInclude)
64     Options.store(Opts, "PrintHeader", *MaybeHeaderToInclude);
65 }
66 
67 void UseStdPrintCheck::registerPPCallbacks(const SourceManager &SM,
68                                            Preprocessor *PP,
69                                            Preprocessor *ModuleExpanderPP) {
70   IncludeInserter.registerPreprocessor(PP);
71 }
72 
73 void UseStdPrintCheck::registerMatchers(MatchFinder *Finder) {
74   if (!PrintfLikeFunctions.empty())
75     Finder->addMatcher(
76         callExpr(argumentCountAtLeast(1),
77                  hasArgument(0, stringLiteral(isOrdinary())),
78                  callee(functionDecl(
79                             unless(cxxMethodDecl()),
80                             matchers::matchesAnyListedName(PrintfLikeFunctions))
81                             .bind("func_decl")))
82             .bind("printf"),
83         this);
84 
85   if (!FprintfLikeFunctions.empty())
86     Finder->addMatcher(
87         callExpr(argumentCountAtLeast(2),
88                  hasArgument(1, stringLiteral(isOrdinary())),
89                  callee(functionDecl(unless(cxxMethodDecl()),
90                                      matchers::matchesAnyListedName(
91                                          FprintfLikeFunctions))
92                             .bind("func_decl")))
93             .bind("fprintf"),
94         this);
95 }
96 
97 void UseStdPrintCheck::check(const MatchFinder::MatchResult &Result) {
98   unsigned FormatArgOffset = 0;
99   const auto *OldFunction = Result.Nodes.getNodeAs<FunctionDecl>("func_decl");
100   const auto *Printf = Result.Nodes.getNodeAs<CallExpr>("printf");
101   if (!Printf) {
102     Printf = Result.Nodes.getNodeAs<CallExpr>("fprintf");
103     FormatArgOffset = 1;
104   }
105 
106   utils::FormatStringConverter Converter(
107       Result.Context, Printf, FormatArgOffset, StrictMode, getLangOpts());
108   const Expr *PrintfCall = Printf->getCallee();
109   const StringRef ReplacementFunction = Converter.usePrintNewlineFunction()
110                                             ? ReplacementPrintlnFunction
111                                             : ReplacementPrintFunction;
112   if (!Converter.canApply()) {
113     diag(PrintfCall->getBeginLoc(),
114          "unable to use '%0' instead of %1 because %2")
115         << ReplacementFunction << OldFunction->getIdentifier()
116         << Converter.conversionNotPossibleReason();
117     return;
118   }
119 
120   DiagnosticBuilder Diag =
121       diag(PrintfCall->getBeginLoc(), "use '%0' instead of %1")
122       << ReplacementFunction << OldFunction->getIdentifier();
123 
124   Diag << FixItHint::CreateReplacement(
125       CharSourceRange::getTokenRange(PrintfCall->getBeginLoc(),
126                                      PrintfCall->getEndLoc()),
127       ReplacementFunction);
128   Converter.applyFixes(Diag, *Result.SourceManager);
129 
130   if (MaybeHeaderToInclude)
131     Diag << IncludeInserter.createIncludeInsertion(
132         Result.Context->getSourceManager().getFileID(PrintfCall->getBeginLoc()),
133         *MaybeHeaderToInclude);
134 }
135 
136 } // namespace clang::tidy::modernize
137