5156b2455
YU Jincheng
2021-10-09
Subject
Make const ptr assign as function call in clang
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Commit Diff GitHub →
coreutils/test.c +1 -1include/libbb.h +15 -6libbb/Kbuild.src +1 -0libbb/appletlib.c +1 -1libbb/const_hack.c +16 -0libbb/lineedit.c +1 -1shell/ash.c +3 -3
coreutils/test.c+1 -1
| @@ -446,7 +446,7 @@ extern struct test_statics *BB_GLOBAL_CONST test_ptr_to_statics; | |
| #define leaving (S.leaving ) | |
| #define INIT_S() do { \ | |
| - | ASSIGN_CONST_PTR(test_ptr_to_statics, xzalloc(sizeof(S))); \ |
| + | XZALLOC_CONST_PTR(&test_ptr_to_statics, sizeof(S)); \ |
| } while (0) | |
| #define DEINIT_S() do { \ | |
| free(group_array); \ | |
include/libbb.h+15 -6
| @@ -2280,6 +2280,7 @@ extern const char bb_PATH_root_path[] ALIGN1; /* BB_PATH_ROOT_PATH */ | |
| extern const int const_int_0; | |
| //extern const int const_int_1; | |
| + | |
| /* This struct is deliberately not defined. */ | |
| /* See docs/keep_data_small.txt */ | |
| struct globals; | |
| @@ -2304,23 +2305,31 @@ static ALWAYS_INLINE void* not_const_pp(const void *p) | |
| ); | |
| return pp; | |
| } | |
| + | # define ASSIGN_CONST_PTR(pptr, v) do { \ |
| + | *(void**)not_const_pp(pptr) = (void*)(v); \ |
| + | barrier(); \ |
| + | } while (0) |
| + | /* XZALLOC_CONST_PTR() is an out-of-line function to prevent |
| + | * clang from reading pointer before it is assigned. |
| + | */ |
| + | void XZALLOC_CONST_PTR(const void *pptr, size_t size) FAST_FUNC; |
| #else | |
| - | static ALWAYS_INLINE void* not_const_pp(const void *p) { return (void*)p; } |
| - | #endif |
| - | |
| - | #define ASSIGN_CONST_PTR(p, v) do { \ |
| - | *(void**)not_const_pp(&p) = (void*)(v); \ |
| + | # define ASSIGN_CONST_PTR(pptr, v) do { \ |
| + | *(void**)(pptr) = (void*)(v); \ |
| /* At least gcc 3.4.6 on mipsel needs optimization barrier */ \ | |
| barrier(); \ | |
| } while (0) | |
| + | # define XZALLOC_CONST_PTR(pptr, size) ASSIGN_CONST_PTR(pptr, xzalloc(size)) |
| + | #endif |
| - | #define SET_PTR_TO_GLOBALS(x) ASSIGN_CONST_PTR(ptr_to_globals, x) |
| + | #define SET_PTR_TO_GLOBALS(x) ASSIGN_CONST_PTR(&ptr_to_globals, x) |
| #define FREE_PTR_TO_GLOBALS() do { \ | |
| if (ENABLE_FEATURE_CLEAN_UP) { \ | |
| free(ptr_to_globals); \ | |
| } \ | |
| } while (0) | |
| + | |
| /* You can change LIBBB_DEFAULT_LOGIN_SHELL, but don't use it, | |
| * use bb_default_login_shell and following defines. | |
| * If you change LIBBB_DEFAULT_LOGIN_SHELL, | |
libbb/Kbuild.src+1 -0
| @@ -24,6 +24,7 @@ lib-y += chomp.o | |
| lib-y += compare_string_array.o | |
| lib-y += concat_path_file.o | |
| lib-y += concat_subpath_file.o | |
| + | lib-y += const_hack.o |
| lib-y += copy_file.o | |
| lib-y += copyfd.o | |
| lib-y += crc32.o | |
libbb/appletlib.c+1 -1
| @@ -247,7 +247,7 @@ void lbb_prepare(const char *applet | |
| IF_FEATURE_INDIVIDUAL(, char **argv)) | |
| { | |
| #ifdef bb_cached_errno_ptr | |
| - | ASSIGN_CONST_PTR(bb_errno, get_perrno()); |
| + | ASSIGN_CONST_PTR(&bb_errno, get_perrno()); |
| #endif | |
| applet_name = applet; | |
libbb/const_hack.c+16 -0
| @@ -0,0 +1,16 @@ | |
| + | /* vi: set sw=4 ts=4: */ |
| + | /* |
| + | * Trick to assign a const ptr with barrier for clang |
| + | * |
| + | * Copyright (C) 2021 by YU Jincheng <[email protected]> |
| + | * |
| + | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| + | */ |
| + | #include "libbb.h" |
| + | |
| + | #if defined(__clang_major__) && __clang_major__ >= 9 |
| + | void FAST_FUNC XZALLOC_CONST_PTR(const void *pptr, size_t size) |
| + | { |
| + | ASSIGN_CONST_PTR(pptr, xzalloc(size)); |
| + | } |
| + | #endif |
libbb/lineedit.c+1 -1
| @@ -214,7 +214,7 @@ extern struct lineedit_statics *BB_GLOBAL_CONST lineedit_ptr_to_statics; | |
| #define delbuf (S.delbuf ) | |
| #define INIT_S() do { \ | |
| - | ASSIGN_CONST_PTR(lineedit_ptr_to_statics, xzalloc(sizeof(S))); \ |
| + | XZALLOC_CONST_PTR(&lineedit_ptr_to_statics, sizeof(S)); \ |
| } while (0) | |
| static void deinit_S(void) | |
shell/ash.c+3 -3
| @@ -504,7 +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 { \ | |
| - | ASSIGN_CONST_PTR(ash_ptr_to_globals_misc, xzalloc(sizeof(G_misc))); \ |
| + | XZALLOC_CONST_PTR(&ash_ptr_to_globals_misc, sizeof(G_misc)); \ |
| savestatus = -1; \ | |
| curdir = nullstr; \ | |
| physdir = nullstr; \ | |
| @@ -1582,7 +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 { \ | |
| - | ASSIGN_CONST_PTR(ash_ptr_to_globals_memstack, xzalloc(sizeof(G_memstack))); \ |
| + | XZALLOC_CONST_PTR(&ash_ptr_to_globals_memstack, sizeof(G_memstack)); \ |
| g_stackp = &stackbase; \ | |
| g_stacknxt = stackbase.space; \ | |
| g_stacknleft = MINSIZE; \ | |
| @@ -2213,7 +2213,7 @@ extern struct globals_var *BB_GLOBAL_CONST ash_ptr_to_globals_var; | |
| #endif | |
| #define INIT_G_var() do { \ | |
| unsigned i; \ | |
| - | ASSIGN_CONST_PTR(ash_ptr_to_globals_var, xzalloc(sizeof(G_var))); \ |
| + | XZALLOC_CONST_PTR(&ash_ptr_to_globals_var, 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; \ | |