Fix format_number.
I broke this the other day when silencing x86 gcc warnings.
Bug: 7904160
Change-Id: I8e60cc1f8cbaff95248c8738d84e515413d839e4
diff --git a/linker/linker_format.cpp b/linker/linker_format.cpp
index c56d8a1..e631ca1 100644
--- a/linker/linker_format.cpp
+++ b/linker/linker_format.cpp
@@ -30,14 +30,16 @@
// compile under GCC 4.7
#undef _FORTIFY_SOURCE
-#include <assert.h>
-#include <stdarg.h>
-#include <string.h>
-#include <errno.h>
-#include <unistd.h>
-#include <stdint.h>
-#include <stddef.h>
#include "linker_format.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
#include "linker_debug.h"
/* define UNIT_TESTS to build this file as a single executable that runs
@@ -357,49 +359,49 @@
return result;
}
-/* write an octal/decimal/number into a bounded buffer.
- * assumes that bufsize > 0, and 'digits' is a string of
- * digits of at least 'base' values.
- */
-static void
-format_number(char *buffer, size_t bufsize, uint64_t value, int base, const char *digits)
-{
- char *pos = buffer;
- char *end = buffer + bufsize - 1;
+// Writes number 'value' in base 'base' into buffer 'buf' of size 'buf_size' bytes.
+// Assumes that buf_size > 0.
+static void format_number(char* buf, size_t buf_size, uint64_t value, int base, bool caps) {
+ char* p = buf;
+ char* end = buf + buf_size - 1;
- /* generate digit string in reverse order */
- while (value) {
- unsigned d = value % base;
- value /= base;
- if (pos != end) {
- *pos++ = digits[d];
- }
+ // Generate digit string in reverse order.
+ while (value) {
+ unsigned d = value % base;
+ value /= base;
+ if (p != end) {
+ char ch;
+ if (d < 10) {
+ ch = '0' + d;
+ } else {
+ ch = (caps ? 'A' : 'a') + (d - 10);
+ }
+ *p++ = ch;
}
+ }
- /* special case for 0 */
- if (pos == buffer) {
- if (pos != end) {
- *pos++ = '0';
- }
+ // Special case for 0.
+ if (p == buf) {
+ if (p != end) {
+ *p++ = '0';
}
- pos[0] = '\0';
+ }
+ *p = '\0';
- /* now reverse digit string in-place */
- end = pos - 1;
- pos = buffer;
- while (pos != end) {
- int ch = pos[0];
- pos[0] = end[0];
- end[0] = (char) ch;
- pos++;
- end--;
- }
+ // Reverse digit string in-place.
+ size_t length = p - buf;
+ for (size_t i = 0, j = length - 1; i < j; ++i, --j) {
+ char ch = buf[i];
+ buf[i] = buf[j];
+ buf[j] = ch;
+ }
}
/* Write an integer (octal or decimal) into a buffer, assumes buffsize > 2 */
static void
format_integer(char *buffer, size_t buffsize, uint64_t value, int base, int isSigned)
{
+ // TODO: this is incorrect for MIN_INT.
if (isSigned && (int64_t)value < 0) {
buffer[0] = '-';
buffer += 1;
@@ -407,17 +409,12 @@
value = (uint64_t)(-(int64_t)value);
}
- format_number(buffer, buffsize, value, base, "0123456789");
+ format_number(buffer, buffsize, value, base, false);
}
-/* Write an hexadecimal into a buffer, isCap is true for capital alphas.
- * Assumes bufsize > 2 */
-static void
-format_hex(char *buffer, size_t buffsize, uint64_t value, int isCap)
-{
- const char *digits = isCap ? "0123456789ABCDEF" : "0123456789abcdef";
-
- format_number(buffer, buffsize, value, 16, digits);
+// Assumes buf_size > 2.
+static void format_hex(char* buf, size_t buf_size, uint64_t value, bool caps) {
+ format_number(buf, buf_size, value, 16, caps);
}
@@ -543,7 +540,7 @@
uint64_t value = (uintptr_t) va_arg(args, void*);
buffer[0] = '0';
buffer[1] = 'x';
- format_hex(buffer + 2, sizeof buffer-2, value, 0);
+ format_hex(buffer + 2, sizeof buffer-2, value, false);
str = buffer;
} else {
/* integers - first read value from stack */
