Prior to this, a BSS declaration such as:
int foo;
static int bar;
Generates:
.global foo
.local foo
.comm foo,4,4
.local bar
.comm bar,4,4
Creating symbols:
0000000000000000 b foo
0000000000000004 b bar
Both symbols are local. However, libbpf bpf_object__variable_offset
rquires symbols to be STB_GLOBAL & STT_OBJECT for data section lookup.
This patch makes the same declaration generate:
.global foo
.type foo, @object
.lcomm foo,4,4
.local bar
.comm bar,4,4
Creating symbols:
0000000000000000 B foo
0000000000000004 b bar
And libbpf will be okay with looking up the global symbol "foo".
2021-04-22 YiFei Zhu <zhuyifei1...@gmail.com>
gcc/
* config/bpf/bpf.h (ASM_OUTPUT_ALIGNED_BSS): Use .type and .lcomm.
---
gcc/config/bpf/bpf.h | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/gcc/config/bpf/bpf.h b/gcc/config/bpf/bpf.h
index 7ff2f310d583..55beecbcb364 100644
--- a/gcc/config/bpf/bpf.h
+++ b/gcc/config/bpf/bpf.h
@@ -414,9 +414,15 @@ enum reg_class
Try to use asm_output_aligned_bss to implement this macro. */
#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
- do { \
- ASM_OUTPUT_ALIGNED_LOCAL (FILE, NAME, SIZE, ALIGN); \
- } while (0)
+ do \
+ { \
+ ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object");
\
+ fprintf ((FILE), "%s", "\t.lcomm\t"); \
+ assemble_name ((FILE), (NAME)); \
+ fprintf ((FILE), "," HOST_WIDE_INT_PRINT_UNSIGNED ",%u\n", \
+ (SIZE), (ALIGN) / BITS_PER_UNIT); \
+ } \
+ while (0)
/*** Output and Generation of Labels. */
--
2.31.1
