---
coreutils/test.c | 7 ++-----
include/libbb.h | 34 +++++++++++++++++++++++++++++-----
libbb/appletlib.c | 3 +--
libbb/lineedit.c | 7 ++-----
shell/ash.c | 23 +++--------------------
5 files changed, 37 insertions(+), 37 deletions(-)
diff --git a/coreutils/test.c b/coreutils/test.c
index 7c6574334..3a91de407 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -435,7 +435,7 @@ struct test_statics {
};
/* See test_ptr_hack.c */
-extern struct test_statics *const test_ptr_to_statics;
+extern struct test_statics *BB_GLOBAL_CONST test_ptr_to_statics;
#define S (*test_ptr_to_statics)
#define args (S.args )
@@ -445,10 +445,7 @@ extern struct test_statics *const test_ptr_to_statics;
#define bash_test2 (S.bash_test2 )
#define leaving (S.leaving )
-#define INIT_S() do { \
- (*(struct
test_statics**)not_const_pp(&test_ptr_to_statics)) = xzalloc(sizeof(S)); \
- barrier(); \
-} while (0)
+#define INIT_S() ASSIGN_CONST_PTR(test_ptr_to_statics, xzalloc(sizeof(S)))
#define DEINIT_S() do { \
free(group_array); \
free(test_ptr_to_statics); \
diff --git a/include/libbb.h b/include/libbb.h
index dfcaa05ec..cdc8bd271 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -365,10 +365,24 @@ struct BUG_off_t_size_is_misdetected {
#endif
#endif
+/* We use a trick to have more optimized code (fewer pointer reloads
+ * and reduce binary size by a few kilobytes) like:
+ * ash.c: extern struct globals *const ash_ptr_to_globals;
+ * ash_ptr_hack.c: struct globals *ash_ptr_to_globals;
+ * This way, compiler in ash.c knows the pointer can not change.
+ *
+ * However, this may break on weird arches or toolchains. In this case,
+ * set "-DBB_GLOBAL_CONST=''" in CONFIG_EXTRA_CFLAGS to disable
+ * this optimization.
+ */
+#ifndef BB_GLOBAL_CONST
+# define BB_GLOBAL_CONST const
+#endif
+
#if defined(errno)
/* If errno is a define, assume it's "define errno (*__errno_location())"
* and we will cache it's result in this variable */
-extern int *const bb_errno;
+extern int *BB_GLOBAL_CONST bb_errno;
#undef errno
#define errno (*bb_errno)
#define bb_cached_errno_ptr 1
@@ -2284,16 +2298,26 @@ static ALWAYS_INLINE void* not_const_pp(const
void *p)
);
return pp;
}
+#ifndef ASSIGN_CONST_PTR
+#define ASSIGN_CONST_PTR(p, v) \
+_Pragma("clang diagnostic push"); \
+_Pragma("clang diagnostic ignored \"-Wshadow\""); \
+ __typeof__(p) p = ({*(void**)not_const_pp(&p) = (void*)(v);});
+_Pragma("clang diagnostic pop")
+#endif
#else
static ALWAYS_INLINE void* not_const_pp(const void *p) { return (void*)p; }
+#ifndef ASSIGN_CONST_PTR
+#define ASSIGN_CONST_PTR(p, v) do { \
+ (*(void**)not_const_pp(&p)) = (void*)(v); \
+ barrier(); \
+} while (0)
+#endif
#endif
/* At least gcc 3.4.6 on mipsel system needs optimization barrier */
#define barrier() __asm__ __volatile__("":::"memory")
-#define SET_PTR_TO_GLOBALS(x) do { \
- (*(struct globals**)not_const_pp(&ptr_to_globals)) =
(void*)(x); \
- barrier(); \
-} while (0)
+#define SET_PTR_TO_GLOBALS(x) ASSIGN_CONST_PTR(ptr_to_globals, x)
#define FREE_PTR_TO_GLOBALS() do { \
if (ENABLE_FEATURE_CLEAN_UP) { \
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 14be33603..8b4c0f0e7 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -247,8 +247,7 @@ void lbb_prepare(const char *applet
IF_FEATURE_INDIVIDUAL(, char **argv))
{
#ifdef bb_cached_errno_ptr
- (*(int **)not_const_pp(&bb_errno)) = get_perrno();
- barrier();
+ ASSIGN_CONST_PTR(bb_errno, get_perrno());
#endif
applet_name = applet;
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index a7a3ee103..73194282c 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -192,7 +192,7 @@ struct lineedit_statics {
};
/* See lineedit_ptr_hack.c */
-extern struct lineedit_statics *const lineedit_ptr_to_statics;
+extern struct lineedit_statics *BB_GLOBAL_CONST lineedit_ptr_to_statics;
#define S (*lineedit_ptr_to_statics)
#define state (S.state )
@@ -213,10 +213,7 @@ extern struct lineedit_statics *const
lineedit_ptr_to_statics;
#define newdelflag (S.newdelflag )
#define delbuf (S.delbuf )
-#define INIT_S() do { \
- (*(struct
lineedit_statics**)not_const_pp(&lineedit_ptr_to_statics)) =
xzalloc(sizeof(S)); \
- barrier(); \
-} while (0)
+#define INIT_S() ASSIGN_CONST_PTR(lineedit_ptr_to_statics,
xzalloc(sizeof(S)))
static void deinit_S(void)
{
diff --git a/shell/ash.c b/shell/ash.c
index 4bc4f55d0..c8a20ab94 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -303,20 +303,6 @@ typedef long arith_t;
# error "Do not even bother, ash will not run on NOMMU machine"
#endif
-/* We use a trick to have more optimized code (fewer pointer reloads):
- * ash.c: extern struct globals *const ash_ptr_to_globals;
- * ash_ptr_hack.c: struct globals *ash_ptr_to_globals;
- * This way, compiler in ash.c knows the pointer can not change.
- *
- * However, this may break on weird arches or toolchains. In this case,
- * set "-DBB_GLOBAL_CONST=''" in CONFIG_EXTRA_CFLAGS to disable
- * this optimization.
- */
-#ifndef BB_GLOBAL_CONST
-# define BB_GLOBAL_CONST const
-#endif
-
-
/* ============ Hash table sizes. Configurable. */
#define VTABSIZE 39
@@ -518,8 +504,7 @@ extern struct globals_misc *BB_GLOBAL_CONST
ash_ptr_to_globals_misc;
#define random_gen (G_misc.random_gen )
#define backgndpid (G_misc.backgndpid )
#define INIT_G_misc() do { \
- (*(struct
globals_misc**)not_const_pp(&ash_ptr_to_globals_misc)) =
xzalloc(sizeof(G_misc)); \
- barrier(); \
+ ASSIGN_CONST_PTR(ash_ptr_to_globals_misc,
xzalloc(sizeof(G_misc))); \
savestatus = -1; \
curdir = nullstr; \
physdir = nullstr; \
@@ -1597,8 +1582,7 @@ extern struct globals_memstack *BB_GLOBAL_CONST
ash_ptr_to_globals_memstack;
#define g_stacknleft (G_memstack.g_stacknleft)
#define stackbase (G_memstack.stackbase )
#define INIT_G_memstack() do { \
- (*(struct
globals_memstack**)not_const_pp(&ash_ptr_to_globals_memstack)) =
xzalloc(sizeof(G_memstack)); \
- barrier(); \
+ ASSIGN_CONST_PTR(ash_ptr_to_globals_memstack,
xzalloc(sizeof(G_memstack))); \
g_stackp = &stackbase; \
g_stacknxt = stackbase.space; \
g_stacknleft = MINSIZE; \
@@ -2229,8 +2213,7 @@ extern struct globals_var *BB_GLOBAL_CONST
ash_ptr_to_globals_var;
#endif
#define INIT_G_var() do { \
unsigned i; \
- (*(struct
globals_var**)not_const_pp(&ash_ptr_to_globals_var)) =
xzalloc(sizeof(G_var)); \
- barrier(); \
+ ASSIGN_CONST_PTR(ash_ptr_to_globals_var,
xzalloc(sizeof(G_var))); \
for (i = 0; i < ARRAY_SIZE(varinit_data); i++) { \
varinit[i].flags = varinit_data[i].flags; \
varinit[i].var_text =
varinit_data[i].var_text; \
--
2.25.1
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