[git commit] libbb: constify *bb_common_bufsiz1 (if it is compiled to be a pointer)
Denys Vlasenko
vda.linux at googlemail.com
Thu Apr 21 19:47:45 UTC 2016
commit: https://git.busybox.net/busybox/commit/?id=93e1aaa1c7e5ed6d2704262700ec28837bdfc9b7
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
This lets gcc optimize much better:
text data bss dec hex filename
922846 910 13056 936812 e4b6c busybox_unstripped.nonconst
920255 910 13056 934221 e414d busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
libbb/common_bufsiz.c | 4 ++--
scripts/generate_BUFSIZ.sh | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/libbb/common_bufsiz.c b/libbb/common_bufsiz.c
index 26faafc..1a35851 100644
--- a/libbb/common_bufsiz.c
+++ b/libbb/common_bufsiz.c
@@ -58,11 +58,11 @@ char bb_common_bufsiz1[COMMON_BUFSIZE] ALIGNED(sizeof(long long));
* It is not defined as a dummy macro.
* It means we have to provide this function.
*/
-char* bb_common_bufsiz1;
+char *const bb_common_bufsiz1 __attribute__ ((section (".data")));
void setup_common_bufsiz(void)
{
if (!bb_common_bufsiz1)
- bb_common_bufsiz1 = xzalloc(COMMON_BUFSIZE);
+ *(char**)&bb_common_bufsiz1 = xzalloc(COMMON_BUFSIZE);
}
# else
# ifndef bb_common_bufsiz1
diff --git a/scripts/generate_BUFSIZ.sh b/scripts/generate_BUFSIZ.sh
index d541425..1914fa0 100755
--- a/scripts/generate_BUFSIZ.sh
+++ b/scripts/generate_BUFSIZ.sh
@@ -77,7 +77,7 @@ if test $REM -lt 1024; then
# users will need to malloc it.
{
echo "enum { COMMON_BUFSIZE = 1024 };"
- echo "extern char *bb_common_bufsiz1;"
+ echo "extern char *const bb_common_bufsiz1;"
echo "void setup_common_bufsiz(void);"
} | regenerate "$common_bufsiz_h"
# Check that we aren't left with a buggy binary:
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