1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
| //===-- string_utils.cpp ----------------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "string_utils.h"
#include "common.h"
#include <stdarg.h>
#include <string.h>
namespace scudo {
static int appendChar(char **Buffer, const char *BufferEnd, char C) {
if (*Buffer < BufferEnd) {
**Buffer = C;
(*Buffer)++;
}
return 1;
}
// Appends number in a given Base to buffer. If its length is less than
// |MinNumberLength|, it is padded with leading zeroes or spaces, depending
// on the value of |PadWithZero|.
static int appendNumber(char **Buffer, const char *BufferEnd, u64 AbsoluteValue,
u8 Base, u8 MinNumberLength, bool PadWithZero,
bool Negative, bool Upper) {
constexpr uptr MaxLen = 30;
RAW_CHECK(Base == 10 || Base == 16);
RAW_CHECK(Base == 10 || !Negative);
RAW_CHECK(AbsoluteValue || !Negative);
RAW_CHECK(MinNumberLength < MaxLen);
int Res = 0;
if (Negative && MinNumberLength)
--MinNumberLength;
if (Negative && PadWithZero)
Res += appendChar(Buffer, BufferEnd, '-');
uptr NumBuffer[MaxLen];
int Pos = 0;
do {
RAW_CHECK_MSG(static_cast<uptr>(Pos) < MaxLen,
"appendNumber buffer overflow");
NumBuffer[Pos++] = static_cast<uptr>(AbsoluteValue % Base);
AbsoluteValue /= Base;
} while (AbsoluteValue > 0);
if (Pos < MinNumberLength) {
memset(&NumBuffer[Pos], 0,
sizeof(NumBuffer[0]) * static_cast<uptr>(MinNumberLength - Pos));
Pos = MinNumberLength;
}
RAW_CHECK(Pos > 0);
Pos--;
for (; Pos >= 0 && NumBuffer[Pos] == 0; Pos--) {
char c = (PadWithZero || Pos == 0) ? '0' : ' ';
Res += appendChar(Buffer, BufferEnd, c);
}
if (Negative && !PadWithZero)
Res += appendChar(Buffer, BufferEnd, '-');
for (; Pos >= 0; Pos--) {
char Digit = static_cast<char>(NumBuffer[Pos]);
Digit = static_cast<char>((Digit < 10) ? '0' + Digit
: (Upper ? 'A' : 'a') + Digit - 10);
Res += appendChar(Buffer, BufferEnd, Digit);
}
return Res;
}
static int appendUnsigned(char **Buffer, const char *BufferEnd, u64 Num,
u8 Base, u8 MinNumberLength, bool PadWithZero,
bool Upper) {
return appendNumber(Buffer, BufferEnd, Num, Base, MinNumberLength,
PadWithZero, /*Negative=*/false, Upper);
}
static int appendSignedDecimal(char **Buffer, const char *BufferEnd, s64 Num,
u8 MinNumberLength, bool PadWithZero) {
const bool Negative = (Num < 0);
return appendNumber(Buffer, BufferEnd,
static_cast<u64>(Negative ? -Num : Num), 10,
MinNumberLength, PadWithZero, Negative,
/*Upper=*/false);
}
// Use the fact that explicitly requesting 0 Width (%0s) results in UB and
// interpret Width == 0 as "no Width requested":
// Width == 0 - no Width requested
// Width < 0 - left-justify S within and pad it to -Width chars, if necessary
// Width > 0 - right-justify S, not implemented yet
static int appendString(char **Buffer, const char *BufferEnd, int Width,
int MaxChars, const char *S) {
if (!S)
S = "<null>";
int Res = 0;
for (; *S; S++) {
if (MaxChars >= 0 && Res >= MaxChars)
break;
Res += appendChar(Buffer, BufferEnd, *S);
}
// Only the left justified strings are supported.
while (Width < -Res)
Res += appendChar(Buffer, BufferEnd, ' ');
return Res;
}
static int appendPointer(char **Buffer, const char *BufferEnd, u64 ptr_value) {
int Res = 0;
Res += appendString(Buffer, BufferEnd, 0, -1, "0x");
Res += appendUnsigned(Buffer, BufferEnd, ptr_value, 16,
SCUDO_POINTER_FORMAT_LENGTH, /*PadWithZero=*/true,
/*Upper=*/false);
return Res;
}
int formatString(char *Buffer, uptr BufferLength, const char *Format,
va_list Args) {
static const char *PrintfFormatsHelp =
"Supported formatString formats: %([0-9]*)?(z|ll)?{d,u,x,X}; %p; "
"%[-]([0-9]*)?(\\.\\*)?s; %c\n";
RAW_CHECK(Format);
RAW_CHECK(BufferLength > 0);
const char *BufferEnd = &Buffer[BufferLength - 1];
const char *Cur = Format;
int Res = 0;
for (; *Cur; Cur++) {
if (*Cur != '%') {
Res += appendChar(&Buffer, BufferEnd, *Cur);
continue;
}
Cur++;
const bool LeftJustified = *Cur == '-';
if (LeftJustified)
Cur++;
bool HaveWidth = (*Cur >= '0' && *Cur <= '9');
const bool PadWithZero = (*Cur == '0');
u8 Width = 0;
if (HaveWidth) {
while (*Cur >= '0' && *Cur <= '9')
Width = static_cast<u8>(Width * 10 + *Cur++ - '0');
}
const bool HavePrecision = (Cur[0] == '.' && Cur[1] == '*');
int Precision = -1;
if (HavePrecision) {
Cur += 2;
Precision = va_arg(Args, int);
}
const bool HaveZ = (*Cur == 'z');
Cur += HaveZ;
const bool HaveLL = !HaveZ && (Cur[0] == 'l' && Cur[1] == 'l');
Cur += HaveLL * 2;
s64 DVal;
u64 UVal;
const bool HaveLength = HaveZ || HaveLL;
const bool HaveFlags = HaveWidth || HaveLength;
// At the moment only %s supports precision and left-justification.
CHECK(!((Precision >= 0 || LeftJustified) && *Cur != 's'));
switch (*Cur) {
case 'd': {
DVal = HaveLL ? va_arg(Args, s64)
: HaveZ ? va_arg(Args, sptr) : va_arg(Args, int);
Res += appendSignedDecimal(&Buffer, BufferEnd, DVal, Width, PadWithZero);
break;
}
case 'u':
case 'x':
case 'X': {
UVal = HaveLL ? va_arg(Args, u64)
: HaveZ ? va_arg(Args, uptr) : va_arg(Args, unsigned);
const bool Upper = (*Cur == 'X');
Res += appendUnsigned(&Buffer, BufferEnd, UVal, (*Cur == 'u') ? 10 : 16,
Width, PadWithZero, Upper);
break;
}
case 'p': {
RAW_CHECK_MSG(!HaveFlags, PrintfFormatsHelp);
Res += appendPointer(&Buffer, BufferEnd, va_arg(Args, uptr));
break;
}
case 's': {
RAW_CHECK_MSG(!HaveLength, PrintfFormatsHelp);
// Only left-justified Width is supported.
CHECK(!HaveWidth || LeftJustified);
Res += appendString(&Buffer, BufferEnd, LeftJustified ? -Width : Width,
Precision, va_arg(Args, char *));
break;
}
case 'c': {
RAW_CHECK_MSG(!HaveFlags, PrintfFormatsHelp);
Res +=
appendChar(&Buffer, BufferEnd, static_cast<char>(va_arg(Args, int)));
break;
}
case '%': {
RAW_CHECK_MSG(!HaveFlags, PrintfFormatsHelp);
Res += appendChar(&Buffer, BufferEnd, '%');
break;
}
default: {
RAW_CHECK_MSG(false, PrintfFormatsHelp);
}
}
}
RAW_CHECK(Buffer <= BufferEnd);
appendChar(&Buffer, BufferEnd + 1, '\0');
return Res;
}
void ScopedString::append(const char *Format, va_list Args) {
DCHECK_LT(Length, String.size());
va_list ArgsCopy;
va_copy(ArgsCopy, Args);
// formatString doesn't currently support a null buffer or zero buffer length,
// so in order to get the resulting formatted string length, we use a one-char
// buffer.
char C[1];
const uptr AdditionalLength =
static_cast<uptr>(formatString(C, sizeof(C), Format, Args)) + 1;
String.resize(Length + AdditionalLength);
formatString(String.data() + Length, AdditionalLength, Format, ArgsCopy);
Length = strlen(String.data());
CHECK_LT(Length, String.size());
}
FORMAT(2, 3)
void ScopedString::append(const char *Format, ...) {
va_list Args;
va_start(Args, Format);
append(Format, Args);
va_end(Args);
}
FORMAT(1, 2)
void Printf(const char *Format, ...) {
va_list Args;
va_start(Args, Format);
ScopedString Msg(1024);
Msg.append(Format, Args);
outputRaw(Msg.data());
va_end(Args);
}
} // namespace scudo
|