From: Tom Tromey <tromey@adacore.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tromey@adacore.com>
Subject: [PATCH 2/4] Rewrite target_read_string
Date: Fri, 12 Jun 2020 15:53:54 -0600 [thread overview]
Message-ID: <20200612215356.22145-3-tromey@adacore.com> (raw)
In-Reply-To: <20200612215356.22145-1-tromey@adacore.com>
This rewrites target_read_string in terms of read_string.
gdb/ChangeLog
2020-06-02 Tom Tromey <tromey@adacore.com>
* valprint.c (read_string): Update comment.
* target.c (MIN): Remove.
(target_read_string): Rewrite.
---
gdb/ChangeLog | 6 +++++
gdb/target.c | 71 +++++++-------------------------------------------
gdb/valprint.c | 8 +-----
3 files changed, 16 insertions(+), 69 deletions(-)
diff --git a/gdb/target.c b/gdb/target.c
index 82c405a8491..14c494688e0 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -803,9 +803,6 @@ target_xfer_status_to_string (enum target_xfer_status status)
};
-#undef MIN
-#define MIN(A, B) (((A) <= (B)) ? (A) : (B))
-
/* target_read_string -- read a null terminated string, up to LEN bytes,
from MEMADDR in target. Set *ERRNOP to the errno code, or 0 if successful.
Set *STRING to a pointer to malloc'd memory containing the data; the caller
@@ -816,68 +813,18 @@ int
target_read_string (CORE_ADDR memaddr, gdb::unique_xmalloc_ptr<char> *string,
int len, int *errnop)
{
- int tlen, offset, i;
- gdb_byte buf[4];
- int errcode = 0;
- char *buffer;
- int buffer_allocated;
- char *bufptr;
- unsigned int nbytes_read = 0;
-
- gdb_assert (string);
-
- /* Small for testing. */
- buffer_allocated = 4;
- buffer = (char *) xmalloc (buffer_allocated);
- bufptr = buffer;
-
- while (len > 0)
- {
- tlen = MIN (len, 4 - (memaddr & 3));
- offset = memaddr & 3;
+ int bytes_read;
+ gdb::unique_xmalloc_ptr<gdb_byte> buffer;
- errcode = target_read_memory (memaddr & ~3, buf, sizeof buf);
- if (errcode != 0)
- {
- /* The transfer request might have crossed the boundary to an
- unallocated region of memory. Retry the transfer, requesting
- a single byte. */
- tlen = 1;
- offset = 0;
- errcode = target_read_memory (memaddr, buf, 1);
- if (errcode != 0)
- goto done;
- }
-
- if (bufptr - buffer + tlen > buffer_allocated)
- {
- unsigned int bytes;
+ /* Note that the endian-ness does not matter here. */
+ int errcode = read_string (memaddr, -1, 1, len, BFD_ENDIAN_LITTLE,
+ &buffer, &bytes_read);
- bytes = bufptr - buffer;
- buffer_allocated *= 2;
- buffer = (char *) xrealloc (buffer, buffer_allocated);
- bufptr = buffer + bytes;
- }
-
- for (i = 0; i < tlen; i++)
- {
- *bufptr++ = buf[i + offset];
- if (buf[i + offset] == '\000')
- {
- nbytes_read += i + 1;
- goto done;
- }
- }
-
- memaddr += tlen;
- len -= tlen;
- nbytes_read += tlen;
- }
-done:
- string->reset (buffer);
- if (errnop != NULL)
+ if (errnop != nullptr)
*errnop = errcode;
- return nbytes_read;
+
+ string->reset ((char *) buffer.release ());
+ return bytes_read;
}
struct target_section_table *
diff --git a/gdb/valprint.c b/gdb/valprint.c
index d5490898b9b..f2549805268 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -2027,13 +2027,7 @@ partial_memory_read (CORE_ADDR memaddr, gdb_byte *myaddr,
Unless an exception is thrown, BUFFER will always be allocated, even on
failure. In this case, some characters might have been read before the
- failure happened. Check BYTES_READ to recognize this situation.
-
- Note: There was a FIXME asking to make this code use target_read_string,
- but this function is more general (can read past null characters, up to
- given LEN). Besides, it is used much more often than target_read_string
- so it is more tested. Perhaps callers of target_read_string should use
- this function instead? */
+ failure happened. Check BYTES_READ to recognize this situation. */
int
read_string (CORE_ADDR addr, int len, int width, unsigned int fetchlimit,
--
2.21.3
next prev parent reply other threads:[~2020-06-12 21:53 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-12 21:53 [PATCH 0/4] Unify string-reading APIs Tom Tromey
2020-06-12 21:53 ` [PATCH 1/4] Remove read_memory_string Tom Tromey
2020-06-13 14:19 ` Simon Marchi
2020-06-15 12:37 ` Pedro Alves
2020-06-12 21:53 ` Tom Tromey [this message]
2020-06-12 21:53 ` [PATCH 3/4] Remove a use of target_read_string Tom Tromey
2020-06-13 3:04 ` Sergio Durigan Junior
2020-06-15 12:13 ` Tom Tromey
2020-06-12 21:53 ` [PATCH 4/4] Change target_read_string API Tom Tromey
2020-06-13 14:40 ` Simon Marchi
2020-06-13 14:40 ` [PATCH 0/4] Unify string-reading APIs Simon Marchi
2020-06-15 12:27 ` Tom Tromey
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