[libbacktrace] Factor out read_string

Factor out new function read_string in dwarf.c.

Bootstrapped and reg-tested on x86_64.

2018-11-21  Tom de Vries  <tdevries@suse.de>

	* dwarf.c (read_string): Factor out of ...
	(read_attribute, read_line_header, read_line_program): ... here.

From-SVN: r266339
This commit is contained in:
Tom de Vries 2018-11-21 08:31:04 +00:00 committed by Tom de Vries
parent 25baeeb36e
commit 171125708a
2 changed files with 33 additions and 11 deletions

View File

@ -1,3 +1,8 @@
2018-11-21 Tom de Vries <tdevries@suse.de>
* dwarf.c (read_string): Factor out of ...
(read_attribute, read_line_header, read_line_program): ... here.
2018-10-31 Joseph Myers <joseph@codesourcery.com>
PR bootstrap/82856

View File

@ -411,6 +411,25 @@ advance (struct dwarf_buf *buf, size_t count)
return 1;
}
/* Read one zero-terminated string from BUF and advance past the string. */
static const char *
read_string (struct dwarf_buf *buf)
{
const char *p = (const char *)buf->buf;
size_t len = strnlen (p, buf->left);
/* - If len == left, we ran out of buffer before finding the zero terminator.
Generate an error by advancing len + 1.
- If len < left, advance by len + 1 to skip past the zero terminator. */
size_t count = len + 1;
if (!advance (buf, count))
return NULL;
return p;
}
/* Read one byte from BUF and advance 1 byte. */
static unsigned char
@ -694,8 +713,8 @@ read_attribute (enum dwarf_form form, struct dwarf_buf *buf,
return 1;
case DW_FORM_string:
val->encoding = ATTR_VAL_STRING;
val->u.string = (const char *) buf->buf;
return advance (buf, strnlen ((const char *) buf->buf, buf->left) + 1);
val->u.string = read_string (buf);
return val->u.string == NULL ? 0 : 1;
case DW_FORM_block:
val->encoding = ATTR_VAL_BLOCK;
return advance (buf, read_uleb128 (buf));
@ -1649,11 +1668,10 @@ read_line_header (struct backtrace_state *state, struct unit *u,
if (hdr_buf.reported_underflow)
return 0;
hdr->dirs[i] = (const char *) hdr_buf.buf;
++i;
if (!advance (&hdr_buf,
strnlen ((const char *) hdr_buf.buf, hdr_buf.left) + 1))
hdr->dirs[i] = read_string (&hdr_buf);
if (hdr->dirs[i] == NULL)
return 0;
++i;
}
if (!advance (&hdr_buf, 1))
return 0;
@ -1687,9 +1705,8 @@ read_line_header (struct backtrace_state *state, struct unit *u,
if (hdr_buf.reported_underflow)
return 0;
filename = (const char *) hdr_buf.buf;
if (!advance (&hdr_buf,
strnlen ((const char *) hdr_buf.buf, hdr_buf.left) + 1))
filename = read_string (&hdr_buf);
if (filename == NULL)
return 0;
dir_index = read_uleb128 (&hdr_buf);
if (IS_ABSOLUTE_PATH (filename)
@ -1808,8 +1825,8 @@ read_line_program (struct backtrace_state *state, struct dwarf_data *ddata,
const char *f;
unsigned int dir_index;
f = (const char *) line_buf->buf;
if (!advance (line_buf, strnlen (f, line_buf->left) + 1))
f = read_string (line_buf);
if (f == NULL)
return 0;
dir_index = read_uleb128 (line_buf);
/* Ignore that time and length. */