binutils-gdb/ld/testsuite/ld-x86-64/pr18900c.c

extern void foo (void);

typedef void (*func_p) (void);

func_p p1 = &foo;
Skip PLT for function pointer initialization We use its PLT entry to initialize function pointer at run-time. If there is no other usage for the PLT entry, we can generate run-time function pointer relocations in read-write section, which can be resolved by dynamic linker, to initialize function pointers. It avoids the extra indirect branch overhead in PLT. bfd/ PR ld/18900 * elf32-i386.c (elf_i386_link_hash_entry): Add func_pointer_refcount. (elf_i386_link_hash_newfunc): Clear func_pointer_refcount. (elf_i386_get_local_sym_hash): Likewise. (elf_i386_copy_indirect_symbol): Also copy func_pointer_refcount. (elf_i386_check_relocs): Increment func_pointer_refcount. (elf_i386_gc_sweep_hook): Decrement func_pointer_refcount. (elf_i386_allocate_dynrelocs): Don't create the PLT entry if there are only function pointer relocations which can be resolved at run-time. Keep dynanamic relocations for run-time function pointer initialization. (elf_i386_relocate_section): Copy dynamic function pointer relocations. * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add func_pointer_refcount. (elf_x86_64_link_hash_newfunc): Clear func_pointer_refcount. (elf_x86_64_get_local_sym_hash): Likewise. (elf_x86_64_copy_indirect_symbol): Also copy func_pointer_refcount. (elf_x86_64_check_relocs): Increment func_pointer_refcount. (elf_x86_64_gc_sweep_hook): Decrement func_pointer_refcount. (elf_x86_64_allocate_dynrelocs): Don't create the PLT entry if there are only function pointer relocations which can be resolved at run-time. Keep dynanamic relocations for run-time function pointer initialization. (elf_x86_64_relocate_section): Copy dynamic function pointer relocations. ld/testsuite/ PR ld/18900 * ld-i386/i386.exp: Run tests for PR ld/18900. * ld-x86-64/x86-64.exp: Likewise. * ld-i386/pr18900.out: New file. * ld-i386/pr18900a.c: Likewise. * ld-i386/pr18900a.c: Likewise. * ld-i386/pr18900a.rd: Likewise. * ld-i386/pr18900b.c: Likewise. * ld-i386/pr18900b.rd: Likewise. * ld-i386/pr18900c.c: Likewise. * ld-x86-64/pr18900.out: Likewise. * ld-x86-64/pr18900a.c: Likewise. * ld-x86-64/pr18900a.rd: Likewise. * ld-x86-64/pr18900b.c: Likewise. * ld-x86-64/pr18900b.rd: Likewise. * ld-x86-64/pr18900c.c: Likewise. * ld-x86-64/mpx3.dd: Updated. 2015-09-01 20:06:16 +08:00			`extern void foo (void);`

			`typedef void (*func_p) (void);`

			`func_p p1 = &foo;`