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[PATCH] Refine read_string
- From: Yao Qi <yao at codesourcery dot com>
- To: <gdb-patches at sourceware dot org>
- Date: Thu, 21 Aug 2014 10:09:03 +0800
- Subject: [PATCH] Refine read_string
- Authentication-results: sourceware.org; auth=none
In read_string, we have this line
chunksize = (len == -1 ? min (8, fetchlimit) : fetchlimit);
but chunksize is only used in the block that lne == -1, so IWBN to
move chunksize to the block in which it is used, and simplify the
condition setting chunksize. This patch also moves 'found_nul' to
inner block. This patch also splits a paragraph of comment into two,
and move them to different condition blocks (len > 0 and len == -1)
respectively.
Rebuild GDB on x86-linux. Is it OK?
gdb:
2014-08-21 Yao Qi <yao@codesourcery.com>
* valprint.c (read_string): Move local variables 'found_nul',
'chunksize' and 'limit' to inner scope. Update comments.
---
gdb/valprint.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 8cb5c74..315e455 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -1794,36 +1794,23 @@ int
read_string (CORE_ADDR addr, int len, int width, unsigned int fetchlimit,
enum bfd_endian byte_order, gdb_byte **buffer, int *bytes_read)
{
- int found_nul; /* Non-zero if we found the nul char. */
int errcode; /* Errno returned from bad reads. */
unsigned int nfetch; /* Chars to fetch / chars fetched. */
- unsigned int chunksize; /* Size of each fetch, in chars. */
gdb_byte *bufptr; /* Pointer to next available byte in
buffer. */
- gdb_byte *limit; /* First location past end of fetch buffer. */
struct cleanup *old_chain = NULL; /* Top of the old cleanup chain. */
- /* Decide how large of chunks to try to read in one operation. This
- is also pretty simple. If LEN >= zero, then we want fetchlimit chars,
- so we might as well read them all in one operation. If LEN is -1, we
- are looking for a NUL terminator to end the fetching, so we might as
- well read in blocks that are large enough to be efficient, but not so
- large as to be slow if fetchlimit happens to be large. So we choose the
- minimum of 8 and fetchlimit. We used to use 200 instead of 8 but
- 200 is way too big for remote debugging over a serial line. */
-
- chunksize = (len == -1 ? min (8, fetchlimit) : fetchlimit);
-
/* Loop until we either have all the characters, or we encounter
some error, such as bumping into the end of the address space. */
- found_nul = 0;
*buffer = NULL;
old_chain = make_cleanup (free_current_contents, buffer);
if (len > 0)
{
+ /* We want fetchlimit chars, so we might as well read them all in
+ one operation. */
unsigned int fetchlen = min (len, fetchlimit);
*buffer = (gdb_byte *) xmalloc (fetchlen * width);
@@ -1837,6 +1824,18 @@ read_string (CORE_ADDR addr, int len, int width, unsigned int fetchlimit,
else if (len == -1)
{
unsigned long bufsize = 0;
+ unsigned int chunksize; /* Size of each fetch, in chars. */
+ int found_nul; /* Non-zero if we found the nul char. */
+ gdb_byte *limit; /* First location past end of fetch buffer. */
+
+ found_nul = 0;
+ /* We are looking for a NUL terminator to end the fetching, so we
+ might as well read in blocks that are large enough to be efficient,
+ but not so large as to be slow if fetchlimit happens to be large.
+ So we choose the minimum of 8 and fetchlimit. We used to use 200
+ instead of 8 but 200 is way too big for remote debugging over a
+ serial line. */
+ chunksize = min (8, fetchlimit);
do
{
--
1.9.3