1//===--- FormatStringConverter.h - 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/// \file
10/// Declaration of the FormatStringConverter class which is used to convert
11/// printf format strings to C++ std::formatter format strings.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_FORMATSTRINGCONVERTER_H
16#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_FORMATSTRINGCONVERTER_H
17
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/FormatString.h"
20#include "clang/ASTMatchers/ASTMatchers.h"
21#include <string>
22
23namespace clang::tidy::utils {
24
25/// Convert a printf-style format string to a std::formatter-style one, and
26/// prepare any casts that are required to wrap the arguments to retain printf
27/// compatibility. This class is expecting to work on the already-cooked format
28/// string (i.e. all the escapes have been converted) so we have to convert them
29/// back. This means that we might not convert them back using the same form.
30class FormatStringConverter
31 : public clang::analyze_format_string::FormatStringHandler {
32public:
33 using ConversionSpecifier = clang::analyze_format_string::ConversionSpecifier;
34 using PrintfSpecifier = analyze_printf::PrintfSpecifier;
35
36 struct Configuration {
37 bool StrictMode = false;
38 bool AllowTrailingNewlineRemoval = false;
39 };
40
41 FormatStringConverter(ASTContext *Context, const CallExpr *Call,
42 unsigned FormatArgOffset, Configuration Config,
43 const LangOptions &LO, SourceManager &SM,
44 Preprocessor &PP);
45
46 bool canApply() const { return ConversionNotPossibleReason.empty(); }
47 const std::string &conversionNotPossibleReason() const {
48 return ConversionNotPossibleReason;
49 }
50 void applyFixes(DiagnosticBuilder &Diag, SourceManager &SM);
51 bool usePrintNewlineFunction() const { return UsePrintNewlineFunction; }
52
53private:
54 ASTContext *Context;
55 const Configuration Config;
56 const bool CastMismatchedIntegerTypes;
57 const Expr *const *Args;
58 const unsigned NumArgs;
59 unsigned ArgsOffset;
60 const LangOptions &LangOpts;
61 std::string ConversionNotPossibleReason;
62 bool FormatStringNeededRewriting = false;
63 bool UsePrintNewlineFunction = false;
64 size_t PrintfFormatStringPos = 0U;
65 StringRef PrintfFormatString;
66
67 /// Lazily-created c_str() call matcher
68 std::optional<clang::ast_matchers::StatementMatcher>
69 StringCStrCallExprMatcher;
70
71 const StringLiteral *FormatExpr;
72 std::string StandardFormatString;
73
74 /// Casts to be used to wrap arguments to retain printf compatibility.
75 struct ArgumentFix {
76 unsigned ArgIndex;
77 std::string Fix;
78
79 // We currently need this for emplace_back. Roll on C++20.
80 explicit ArgumentFix(unsigned ArgIndex, std::string Fix)
81 : ArgIndex(ArgIndex), Fix(std::move(Fix)) {}
82 };
83
84 std::vector<ArgumentFix> ArgFixes;
85 std::vector<clang::ast_matchers::BoundNodes> ArgCStrRemovals;
86
87 // Argument rotations to cope with the fact that std::print puts the value to
88 // be formatted first and the width and precision afterwards whereas printf
89 // puts the width and preicision first.
90 std::vector<std::tuple<unsigned, unsigned>> ArgRotates;
91
92 void emitAlignment(const PrintfSpecifier &FS, std::string &FormatSpec);
93 void emitSign(const PrintfSpecifier &FS, std::string &FormatSpec);
94 void emitAlternativeForm(const PrintfSpecifier &FS, std::string &FormatSpec);
95 void emitFieldWidth(const PrintfSpecifier &FS, std::string &FormatSpec);
96 void emitPrecision(const PrintfSpecifier &FS, std::string &FormatSpec);
97 void emitStringArgument(unsigned ArgIndex, const Expr *Arg);
98 bool emitIntegerArgument(ConversionSpecifier::Kind ArgKind, const Expr *Arg,
99 unsigned ArgIndex, std::string &FormatSpec);
100
101 bool emitType(const PrintfSpecifier &FS, const Expr *Arg,
102 std::string &FormatSpec);
103 bool convertArgument(const PrintfSpecifier &FS, const Expr *Arg,
104 std::string &StandardFormatString);
105
106 void maybeRotateArguments(const PrintfSpecifier &FS);
107
108 bool HandlePrintfSpecifier(const PrintfSpecifier &FS,
109 const char *StartSpecifier, unsigned SpecifierLen,
110 const TargetInfo &Target) override;
111
112 void appendFormatText(StringRef Text);
113 void finalizeFormatText();
114 static std::optional<StringRef>
115 formatStringContainsUnreplaceableMacro(const CallExpr *CallExpr,
116 const StringLiteral *FormatExpr,
117 SourceManager &SM, Preprocessor &PP);
118 bool conversionNotPossible(std::string Reason) {
119 ConversionNotPossibleReason = std::move(Reason);
120 return false;
121 }
122};
123
124} // namespace clang::tidy::utils
125
126#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_FORMATSTRINGCONVERTER_H
127

source code of clang-tools-extra/clang-tidy/utils/FormatStringConverter.h