1 //===-- sanitizer_printf.cc -----------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is shared between AddressSanitizer and ThreadSanitizer.
12 // Internal printf function, used inside run-time libraries.
13 // We can't use libc printf because we intercept some of the functions used
15 //===----------------------------------------------------------------------===//
17 #include "sanitizer_common.h"
18 #include "sanitizer_flags.h"
19 #include "sanitizer_libc.h"
24 #if SANITIZER_WINDOWS && defined(_MSC_VER) && _MSC_VER < 1800 && \
26 # define va_copy(dst, src) ((dst) = (src))
29 namespace __sanitizer {
31 static int AppendChar(char **buff, const char *buff_end, char c) {
32 if (*buff < buff_end) {
39 // Appends number in a given base to buffer. If its length is less than
40 // |minimal_num_length|, it is padded with leading zeroes or spaces, depending
41 // on the value of |pad_with_zero|.
42 static int AppendNumber(char **buff, const char *buff_end, u64 absolute_value,
43 u8 base, u8 minimal_num_length, bool pad_with_zero,
44 bool negative, bool uppercase) {
45 uptr const kMaxLen = 30;
46 RAW_CHECK(base == 10 || base == 16);
47 RAW_CHECK(base == 10 || !negative);
48 RAW_CHECK(absolute_value || !negative);
49 RAW_CHECK(minimal_num_length < kMaxLen);
51 if (negative && minimal_num_length)
53 if (negative && pad_with_zero)
54 result += AppendChar(buff, buff_end, '-');
55 uptr num_buffer[kMaxLen];
58 RAW_CHECK_MSG((uptr)pos < kMaxLen, "AppendNumber buffer overflow");
59 num_buffer[pos++] = absolute_value % base;
60 absolute_value /= base;
61 } while (absolute_value > 0);
62 if (pos < minimal_num_length) {
63 // Make sure compiler doesn't insert call to memset here.
64 internal_memset(&num_buffer[pos], 0,
65 sizeof(num_buffer[0]) * (minimal_num_length - pos));
66 pos = minimal_num_length;
70 for (; pos >= 0 && num_buffer[pos] == 0; pos--) {
71 char c = (pad_with_zero || pos == 0) ? '0' : ' ';
72 result += AppendChar(buff, buff_end, c);
74 if (negative && !pad_with_zero) result += AppendChar(buff, buff_end, '-');
75 for (; pos >= 0; pos--) {
76 char digit = static_cast<char>(num_buffer[pos]);
77 digit = (digit < 10) ? '0' + digit : (uppercase ? 'A' : 'a') + digit - 10;
78 result += AppendChar(buff, buff_end, digit);
83 static int AppendUnsigned(char **buff, const char *buff_end, u64 num, u8 base,
84 u8 minimal_num_length, bool pad_with_zero,
86 return AppendNumber(buff, buff_end, num, base, minimal_num_length,
87 pad_with_zero, false /* negative */, uppercase);
90 static int AppendSignedDecimal(char **buff, const char *buff_end, s64 num,
91 u8 minimal_num_length, bool pad_with_zero) {
92 bool negative = (num < 0);
93 return AppendNumber(buff, buff_end, (u64)(negative ? -num : num), 10,
94 minimal_num_length, pad_with_zero, negative,
95 false /* uppercase */);
98 static int AppendString(char **buff, const char *buff_end, int precision,
104 if (precision >= 0 && result >= precision)
106 result += AppendChar(buff, buff_end, *s);
111 static int AppendPointer(char **buff, const char *buff_end, u64 ptr_value) {
113 result += AppendString(buff, buff_end, -1, "0x");
114 result += AppendUnsigned(buff, buff_end, ptr_value, 16,
115 SANITIZER_POINTER_FORMAT_LENGTH,
116 true /* pad_with_zero */, false /* uppercase */);
120 int VSNPrintf(char *buff, int buff_length,
121 const char *format, va_list args) {
122 static const char *kPrintfFormatsHelp =
123 "Supported Printf formats: %([0-9]*)?(z|ll)?{d,u,x,X}; %p; %(\\.\\*)?s; "
126 RAW_CHECK(buff_length > 0);
127 const char *buff_end = &buff[buff_length - 1];
128 const char *cur = format;
130 for (; *cur; cur++) {
132 result += AppendChar(&buff, buff_end, *cur);
136 bool have_width = (*cur >= '0' && *cur <= '9');
137 bool pad_with_zero = (*cur == '0');
140 while (*cur >= '0' && *cur <= '9') {
141 width = width * 10 + *cur++ - '0';
144 bool have_precision = (cur[0] == '.' && cur[1] == '*');
146 if (have_precision) {
148 precision = va_arg(args, int);
150 bool have_z = (*cur == 'z');
152 bool have_ll = !have_z && (cur[0] == 'l' && cur[1] == 'l');
156 bool have_flags = have_width | have_z | have_ll;
157 // Only %s supports precision for now
158 CHECK(!(precision >= 0 && *cur != 's'));
161 dval = have_ll ? va_arg(args, s64)
162 : have_z ? va_arg(args, sptr)
164 result += AppendSignedDecimal(&buff, buff_end, dval, width,
171 uval = have_ll ? va_arg(args, u64)
172 : have_z ? va_arg(args, uptr)
173 : va_arg(args, unsigned);
174 bool uppercase = (*cur == 'X');
175 result += AppendUnsigned(&buff, buff_end, uval, (*cur == 'u') ? 10 : 16,
176 width, pad_with_zero, uppercase);
180 RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp);
181 result += AppendPointer(&buff, buff_end, va_arg(args, uptr));
185 RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp);
186 result += AppendString(&buff, buff_end, precision, va_arg(args, char*));
190 RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp);
191 result += AppendChar(&buff, buff_end, va_arg(args, int));
195 RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp);
196 result += AppendChar(&buff, buff_end, '%');
200 RAW_CHECK_MSG(false, kPrintfFormatsHelp);
204 RAW_CHECK(buff <= buff_end);
205 AppendChar(&buff, buff_end + 1, '\0');
209 static void (*PrintfAndReportCallback)(const char *);
210 void SetPrintfAndReportCallback(void (*callback)(const char *)) {
211 PrintfAndReportCallback = callback;
214 // Can be overriden in frontend.
215 #if SANITIZER_GO && defined(TSAN_EXTERNAL_HOOKS)
216 // Implementation must be defined in frontend.
217 extern "C" void OnPrint(const char *str);
219 SANITIZER_INTERFACE_WEAK_DEF(void, OnPrint, const char *str) {
224 static void CallPrintfAndReportCallback(const char *str) {
226 if (PrintfAndReportCallback)
227 PrintfAndReportCallback(str);
230 static void NOINLINE SharedPrintfCodeNoBuffer(bool append_pid,
236 va_copy(args2, args);
237 const int kLen = 16 * 1024;
239 char *buffer = local_buffer;
240 // First try to print a message using a local buffer, and then fall back to
242 for (int use_mmap = 0; use_mmap < 2; use_mmap++) {
245 va_copy(args, args2);
246 buffer = (char*)MmapOrDie(kLen, "Report");
250 // Check that data fits into the current buffer.
251 # define CHECK_NEEDED_LENGTH \
252 if (needed_length >= buffer_size) { \
253 if (!use_mmap) continue; \
254 RAW_CHECK_MSG(needed_length < kLen, \
255 "Buffer in Report is too short!\n"); \
257 // Fuchsia's logging infrastructure always keeps track of the logging
258 // process, thread, and timestamp, so never prepend such information.
259 if (!SANITIZER_FUCHSIA && append_pid) {
260 int pid = internal_getpid();
261 const char *exe_name = GetProcessName();
262 if (common_flags()->log_exe_name && exe_name) {
263 needed_length += internal_snprintf(buffer, buffer_size,
267 needed_length += internal_snprintf(
268 buffer + needed_length, buffer_size - needed_length, "==%d==", pid);
271 needed_length += VSNPrintf(buffer + needed_length,
272 buffer_size - needed_length, format, args);
274 // If the message fit into the buffer, print it and exit.
276 # undef CHECK_NEEDED_LENGTH
280 // Remove color sequences from the message.
281 RemoveANSIEscapeSequencesFromString(buffer);
282 CallPrintfAndReportCallback(buffer);
283 LogMessageOnPrintf(buffer);
285 // If we had mapped any memory, clean up.
286 if (buffer != local_buffer)
287 UnmapOrDie((void *)buffer, buffer_size);
291 static void NOINLINE SharedPrintfCode(bool append_pid, const char *format,
293 // |local_buffer| is small enough not to overflow the stack and/or violate
294 // the stack limit enforced by TSan (-Wframe-larger-than=512). On the other
295 // hand, the bigger the buffer is, the more the chance the error report will
297 char local_buffer[400];
298 SharedPrintfCodeNoBuffer(append_pid, local_buffer, ARRAY_SIZE(local_buffer),
303 void Printf(const char *format, ...) {
305 va_start(args, format);
306 SharedPrintfCode(false, format, args);
310 // Like Printf, but prints the current PID before the output string.
312 void Report(const char *format, ...) {
314 va_start(args, format);
315 SharedPrintfCode(true, format, args);
319 // Writes at most "length" symbols to "buffer" (including trailing '\0').
320 // Returns the number of symbols that should have been written to buffer
321 // (not including trailing '\0'). Thus, the string is truncated
322 // iff return value is not less than "length".
324 int internal_snprintf(char *buffer, uptr length, const char *format, ...) {
326 va_start(args, format);
327 int needed_length = VSNPrintf(buffer, length, format, args);
329 return needed_length;
333 void InternalScopedString::append(const char *format, ...) {
334 CHECK_LT(length_, size());
336 va_start(args, format);
337 VSNPrintf(data() + length_, size() - length_, format, args);
339 length_ += internal_strlen(data() + length_);
340 CHECK_LT(length_, size());
343 } // namespace __sanitizer