[PATCH v3 1/1] libbpf: fix broken gcc SEC pragma macro

From: James Hilliard
Date: Thu Jun 09 2022 - 02:24:33 EST


It seems the gcc preprocessor breaks unless pragmas are wrapped
individually inside macros when surrounding __attribute__.

Fixes errors like:
error: expected identifier or '(' before '#pragma'
106 | SEC("cgroup/bind6")
| ^~~

error: expected '=', ',', ';', 'asm' or '__attribute__' before '#pragma'
114 | char _license[] SEC("license") = "GPL";
| ^~~

Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
---
Changes v2 -> v3:
- just fix SEC pragma
Changes v1 -> v2:
- replace typeof with __typeof__ instead of changing pragma macros
---
tools/lib/bpf/bpf_helpers.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index fb04eaf367f1..66d23c47c206 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -22,11 +22,12 @@
* To allow use of SEC() with externs (e.g., for extern .maps declarations),
* make sure __attribute__((unused)) doesn't trigger compilation warning.
*/
+#define DO_PRAGMA(x) _Pragma(#x)
#define SEC(name) \
- _Pragma("GCC diagnostic push") \
- _Pragma("GCC diagnostic ignored \"-Wignored-attributes\"") \
+ DO_PRAGMA("GCC diagnostic push") \
+ DO_PRAGMA("GCC diagnostic ignored \"-Wignored-attributes\"") \
__attribute__((section(name), used)) \
- _Pragma("GCC diagnostic pop") \
+ DO_PRAGMA("GCC diagnostic pop") \

/* Avoid 'linux/stddef.h' definition of '__always_inline'. */
#undef __always_inline
--
2.25.1