1//===----- FormatStringParsing.h - Format String Parsing --------*- 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// This provides some shared functions between printf and scanf format string
10// parsing code.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LIB_ANALYSIS_FORMATSTRINGPARSING_H
15#define LLVM_CLANG_LIB_ANALYSIS_FORMATSTRINGPARSING_H
16
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/Type.h"
19#include "clang/AST/FormatString.h"
20
21namespace clang {
22
23class LangOptions;
24
25template <typename T>
26class UpdateOnReturn {
27 T &ValueToUpdate;
28 const T &ValueToCopy;
29public:
30 UpdateOnReturn(T &valueToUpdate, const T &valueToCopy)
31 : ValueToUpdate(valueToUpdate), ValueToCopy(valueToCopy) {}
32
33 ~UpdateOnReturn() {
34 ValueToUpdate = ValueToCopy;
35 }
36};
37
38namespace analyze_format_string {
39
40OptionalAmount ParseAmount(const char *&Beg, const char *E);
41OptionalAmount ParseNonPositionAmount(const char *&Beg, const char *E,
42 unsigned &argIndex);
43
44OptionalAmount ParsePositionAmount(FormatStringHandler &H,
45 const char *Start, const char *&Beg,
46 const char *E, PositionContext p);
47
48bool ParseFieldWidth(FormatStringHandler &H,
49 FormatSpecifier &CS,
50 const char *Start, const char *&Beg, const char *E,
51 unsigned *argIndex);
52
53bool ParseArgPosition(FormatStringHandler &H,
54 FormatSpecifier &CS, const char *Start,
55 const char *&Beg, const char *E);
56
57bool ParseVectorModifier(FormatStringHandler &H,
58 FormatSpecifier &FS, const char *&Beg, const char *E,
59 const LangOptions &LO);
60
61/// Returns true if a LengthModifier was parsed and installed in the
62/// FormatSpecifier& argument, and false otherwise.
63bool ParseLengthModifier(FormatSpecifier &FS, const char *&Beg, const char *E,
64 const LangOptions &LO, bool IsScanf = false);
65
66/// Returns true if the invalid specifier in \p SpecifierBegin is a UTF-8
67/// string; check that it won't go further than \p FmtStrEnd and write
68/// up the total size in \p Len.
69bool ParseUTF8InvalidSpecifier(const char *SpecifierBegin,
70 const char *FmtStrEnd, unsigned &Len);
71
72template <typename T> class SpecifierResult {
73 T FS;
74 const char *Start;
75 bool Stop;
76public:
77 SpecifierResult(bool stop = false)
78 : Start(nullptr), Stop(stop) {}
79 SpecifierResult(const char *start,
80 const T &fs)
81 : FS(fs), Start(start), Stop(false) {}
82
83 const char *getStart() const { return Start; }
84 bool shouldStop() const { return Stop; }
85 bool hasValue() const { return Start != nullptr; }
86 const T &getValue() const {
87 assert(hasValue());
88 return FS;
89 }
90 const T &getValue() { return FS; }
91};
92
93} // end analyze_format_string namespace
94} // end clang namespace
95
96#endif
97