[PATCH] MIPS: tools: Fix relocs tool compiler warnings

From: Harvey Hunt
Date: Thu Jun 16 2016 - 11:35:51 EST


When using clang as HOSTCC, the following warnings appear:

In file included from arch/mips/boot/tools/relocs_64.c:27:0:
arch/mips/boot/tools/relocs.c: In function âread_relocsâ:
arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
ELF_R_SYM(rel->r_info) = elf32_to_cpu(ELF_R_SYM(rel->r_info));
^~~~~~~~~
arch/mips/boot/tools/relocs.c:397:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
arch/mips/boot/tools/relocs.c: In function âwalk_relocsâ:
arch/mips/boot/tools/relocs.c:491:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
^~~~~~~
arch/mips/boot/tools/relocs.c: In function âdo_relocâ:
arch/mips/boot/tools/relocs.c:502:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
unsigned r_type = ELF_R_TYPE(rel->r_info);
^~~~~~~~
arch/mips/boot/tools/relocs.c: In function âdo_reloc_infoâ:
arch/mips/boot/tools/relocs.c:641:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
rel_type(ELF_R_TYPE(rel->r_info)),
^~~~~~~~

Fix them by making Elf64_Mips_Rela a union

Signed-off-by: Harvey Hunt <harvey.hunt@xxxxxxxxxx>
Cc: Matt Redfearn <matt.redfearn@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
arch/mips/boot/tools/relocs_64.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/mips/boot/tools/relocs_64.c b/arch/mips/boot/tools/relocs_64.c
index b671b5e..06066e6a 100644
--- a/arch/mips/boot/tools/relocs_64.c
+++ b/arch/mips/boot/tools/relocs_64.c
@@ -9,17 +9,20 @@

typedef uint8_t Elf64_Byte;

-typedef struct {
- Elf64_Word r_sym; /* Symbol index. */
- Elf64_Byte r_ssym; /* Special symbol. */
- Elf64_Byte r_type3; /* Third relocation. */
- Elf64_Byte r_type2; /* Second relocation. */
- Elf64_Byte r_type; /* First relocation. */
+typedef union {
+ struct {
+ Elf64_Word r_sym; /* Symbol index. */
+ Elf64_Byte r_ssym; /* Special symbol. */
+ Elf64_Byte r_type3; /* Third relocation. */
+ Elf64_Byte r_type2; /* Second relocation. */
+ Elf64_Byte r_type; /* First relocation. */
+ } fields;
+ Elf64_Xword unused;
} Elf64_Mips_Rela;

#define ELF_CLASS ELFCLASS64
-#define ELF_R_SYM(val) (((Elf64_Mips_Rela *)(&val))->r_sym)
-#define ELF_R_TYPE(val) (((Elf64_Mips_Rela *)(&val))->r_type)
+#define ELF_R_SYM(val) (((Elf64_Mips_Rela *)(&val))->fields.r_sym)
+#define ELF_R_TYPE(val) (((Elf64_Mips_Rela *)(&val))->fields.r_type)
#define ELF_ST_TYPE(o) ELF64_ST_TYPE(o)
#define ELF_ST_BIND(o) ELF64_ST_BIND(o)
#define ELF_ST_VISIBILITY(o) ELF64_ST_VISIBILITY(o)
--
2.8.3