1 //===-- sanitizer_printf.cc -----------------------------------------------===//
3 // This file is distributed under the University of Illinois Open Source
4 // License. See LICENSE.TXT for details.
6 //===----------------------------------------------------------------------===//
8 // This file is shared between AddressSanitizer and ThreadSanitizer.
10 // Internal printf function, used inside run-time libraries.
11 // We can't use libc printf because we intercept some of the functions used
13 //===----------------------------------------------------------------------===//
16 #include "sanitizer_common.h"
17 #include "sanitizer_libc.h"
22 namespace __sanitizer
{
24 static int AppendChar(char **buff
, const char *buff_end
, char c
) {
25 if (*buff
< buff_end
) {
32 // Appends number in a given base to buffer. If its length is less than
33 // "minimal_num_length", it is padded with leading zeroes.
34 static int AppendUnsigned(char **buff
, const char *buff_end
, u64 num
,
35 u8 base
, u8 minimal_num_length
) {
36 uptr
const kMaxLen
= 30;
37 RAW_CHECK(base
== 10 || base
== 16);
38 RAW_CHECK(minimal_num_length
< kMaxLen
);
39 uptr num_buffer
[kMaxLen
];
42 RAW_CHECK_MSG(pos
< kMaxLen
, "appendNumber buffer overflow");
43 num_buffer
[pos
++] = num
% base
;
46 if (pos
< minimal_num_length
) {
47 // Make sure compiler doesn't insert call to memset here.
48 internal_memset(&num_buffer
[pos
], 0,
49 sizeof(num_buffer
[0]) * (minimal_num_length
- pos
));
50 pos
= minimal_num_length
;
54 uptr digit
= num_buffer
[pos
];
55 result
+= AppendChar(buff
, buff_end
, (digit
< 10) ? '0' + digit
61 static int AppendSignedDecimal(char **buff
, const char *buff_end
, s64 num
,
62 u8 minimal_num_length
) {
65 result
+= AppendChar(buff
, buff_end
, '-');
67 if (minimal_num_length
)
70 result
+= AppendUnsigned(buff
, buff_end
, (u64
)num
, 10, minimal_num_length
);
74 static int AppendString(char **buff
, const char *buff_end
, const char *s
) {
79 result
+= AppendChar(buff
, buff_end
, *s
);
84 static int AppendPointer(char **buff
, const char *buff_end
, u64 ptr_value
) {
86 result
+= AppendString(buff
, buff_end
, "0x");
87 result
+= AppendUnsigned(buff
, buff_end
, ptr_value
, 16,
88 (SANITIZER_WORDSIZE
== 64) ? 12 : 8);
92 int VSNPrintf(char *buff
, int buff_length
,
93 const char *format
, va_list args
) {
94 static const char *kPrintfFormatsHelp
=
95 "Supported Printf formats: %(0[0-9]*)?(z|ll)?{d,u,x}; %p; %s; %c\n";
97 RAW_CHECK(buff_length
> 0);
98 const char *buff_end
= &buff
[buff_length
- 1];
99 const char *cur
= format
;
101 for (; *cur
; cur
++) {
103 result
+= AppendChar(&buff
, buff_end
, *cur
);
107 bool have_width
= (*cur
== '0');
110 while (*cur
>= '0' && *cur
<= '9') {
112 width
= width
* 10 + *cur
++ - '0';
115 bool have_z
= (*cur
== 'z');
117 bool have_ll
= !have_z
&& (cur
[0] == 'l' && cur
[1] == 'l');
121 bool have_flags
= have_width
| have_z
| have_ll
;
124 dval
= have_ll
? va_arg(args
, s64
)
125 : have_z
? va_arg(args
, sptr
)
127 result
+= AppendSignedDecimal(&buff
, buff_end
, dval
, width
);
132 uval
= have_ll
? va_arg(args
, u64
)
133 : have_z
? va_arg(args
, uptr
)
134 : va_arg(args
, unsigned);
135 result
+= AppendUnsigned(&buff
, buff_end
, uval
,
136 (*cur
== 'u') ? 10 : 16, width
);
140 RAW_CHECK_MSG(!have_flags
, kPrintfFormatsHelp
);
141 result
+= AppendPointer(&buff
, buff_end
, va_arg(args
, uptr
));
145 RAW_CHECK_MSG(!have_flags
, kPrintfFormatsHelp
);
146 result
+= AppendString(&buff
, buff_end
, va_arg(args
, char*));
150 RAW_CHECK_MSG(!have_flags
, kPrintfFormatsHelp
);
151 result
+= AppendChar(&buff
, buff_end
, va_arg(args
, int));
155 RAW_CHECK_MSG(!have_flags
, kPrintfFormatsHelp
);
156 result
+= AppendChar(&buff
, buff_end
, '%');
160 RAW_CHECK_MSG(false, kPrintfFormatsHelp
);
164 RAW_CHECK(buff
<= buff_end
);
165 AppendChar(&buff
, buff_end
+ 1, '\0');
169 static void (*PrintfAndReportCallback
)(const char *);
170 void SetPrintfAndReportCallback(void (*callback
)(const char *)) {
171 PrintfAndReportCallback
= callback
;
174 void Printf(const char *format
, ...) {
175 const int kLen
= 16 * 1024;
176 InternalScopedBuffer
<char> buffer(kLen
);
178 va_start(args
, format
);
179 int needed_length
= VSNPrintf(buffer
.data(), kLen
, format
, args
);
181 RAW_CHECK_MSG(needed_length
< kLen
, "Buffer in Printf is too short!\n");
182 RawWrite(buffer
.data());
183 if (PrintfAndReportCallback
)
184 PrintfAndReportCallback(buffer
.data());
187 // Writes at most "length" symbols to "buffer" (including trailing '\0').
188 // Returns the number of symbols that should have been written to buffer
189 // (not including trailing '\0'). Thus, the string is truncated
190 // iff return value is not less than "length".
191 int internal_snprintf(char *buffer
, uptr length
, const char *format
, ...) {
193 va_start(args
, format
);
194 int needed_length
= VSNPrintf(buffer
, length
, format
, args
);
196 return needed_length
;
199 // Like Printf, but prints the current PID before the output string.
200 void Report(const char *format
, ...) {
201 const int kLen
= 16 * 1024;
202 InternalScopedBuffer
<char> buffer(kLen
);
203 int needed_length
= internal_snprintf(buffer
.data(),
204 kLen
, "==%d== ", GetPid());
205 RAW_CHECK_MSG(needed_length
< kLen
, "Buffer in Report is too short!\n");
207 va_start(args
, format
);
208 needed_length
+= VSNPrintf(buffer
.data() + needed_length
,
209 kLen
- needed_length
, format
, args
);
211 RAW_CHECK_MSG(needed_length
< kLen
, "Buffer in Report is too short!\n");
212 RawWrite(buffer
.data());
213 if (PrintfAndReportCallback
)
214 PrintfAndReportCallback(buffer
.data());
217 } // namespace __sanitizer