[PATCH 7/7] gdbserver: add fallback implementation for memmem

[Mircea Gherzan <mircea dot gherzan at intel dot com>]

The memmem() function is a GNU extension.

2013-06-26  Mircea Gherzan  <mircea.gherzan@intel.com>

gdbserver/

	* configure.ac (AC_CHECK_FUNCS): Add memmem.
	* configure: Rebuild.
	* config.in: Rebuild.
	* server.c (memmem): New function, included only if it's not
	already provided by the system.

Signed-off-by: Mircea Gherzan <mircea.gherzan@intel.com>
---
 gdb/gdbserver/config.in    |  3 +++
 gdb/gdbserver/configure    |  2 +-
 gdb/gdbserver/configure.ac |  2 +-
 gdb/gdbserver/server.c     | 23 +++++++++++++++++++++++
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 4a5a51d..5ed56c3 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -97,6 +97,9 @@
 /* Define to 1 if you have the <malloc.h> header file. */
 #undef HAVE_MALLOC_H
 
+/* Define to 1 if you have the `memmem' function. */
+#undef HAVE_MEMMEM
+
 /* Define to 1 if you have the <memory.h> header file. */
 #undef HAVE_MEMORY_H
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 5df8fe3..874a899 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -4795,7 +4795,7 @@ fi
 
 done
 
-for ac_func in pread pwrite pread64 readlink fdwalk pipe2
+for ac_func in pread pwrite pread64 readlink fdwalk pipe2 memmem
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index 8142e91..7cbc6ea 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -70,7 +70,7 @@ AC_CHECK_HEADERS(sgtty.h termio.h termios.h sys/reg.h string.h dnl
 		 sys/ioctl.h netinet/in.h sys/socket.h netdb.h dnl
 		 netinet/tcp.h arpa/inet.h sys/wait.h wait.h sys/un.h dnl
 		 linux/perf_event.h sys/time.h sys/param.h)
-AC_CHECK_FUNCS(pread pwrite pread64 readlink fdwalk pipe2)
+AC_CHECK_FUNCS(pread pwrite pread64 readlink fdwalk pipe2 memmem)
 AC_REPLACE_FUNCS(vasprintf vsnprintf)
 
 # Check for UST
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 4a1d1dc..99c2229 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -761,6 +761,29 @@ gdb_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
     }
 }
 
+#ifndef HAVE_MEMMEM
+
+/* Find the NEEDLE in the HAYSTACK and return its position.  */
+
+static void *
+memmem (const void *haystack, size_t haystack_len, const void *needle,
+	size_t needle_len)
+{
+  size_t i;
+  const gdb_byte *p;
+
+  for (i = 0; i <= haystack_len - needle_len; i++)
+    {
+      p = (gdb_byte *)haystack + i;
+      if (memcmp (p, needle, needle_len) == 0)
+	return p;
+    }
+
+  return NULL;
+}
+
+#endif
+
 /* Subroutine of handle_search_memory to simplify it.  */
 
 static int
-- 
1.7.12.4