When we ran `make hdr-check` with the following patch
diff --git a/Makefile b/Makefile
index f879697ea3..d8df4e316b 100644
--- a/Makefile
+++ b/Makefile
@@ -2773,7 +2773,7 @@ CHK_HDRS = $(filter-out $(EXCEPT_HDRS),$(patsubst
./%,%,$(LIB_H)))
HCO = $(patsubst %.h,%.hco,$(CHK_HDRS))
$(HCO): %.hco: %.h FORCE
- $(QUIET_HDR)$(CC) -include git-compat-util.h -I. -o /dev/null
-c -xc $<
+ $(QUIET_HDR)$(CC) -include git-compat-util.h -I. -o /dev/null
-c -xc $(ALL_CFLAGS) $<
.PHONY: hdr-check $(HCO)
hdr-check: $(HCO)
and with `DEVELOPER=1`, we got the following warning on Arch Linux:
pack-bitmap.h:20:19: error: ‘BITMAP_IDX_SIGNATURE’ defined but not used
[-Werror=unused-const-variable=]
20 | static const char BITMAP_IDX_SIGNATURE[] = {'B', 'I', 'T', 'M'};
| ^~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
"Use" the BITMAP_IDX_SIGNATURE variable by making the size of
bitmap_disk_header.magic equal to the size of BITMAP_IDX_SIGNATURE,
thereby eliminating the magic number (4).
An alternative was to simply add MAYBE_UNUSED, however that does not
eliminate the magic number.
Another alternative was to change the definition to
extern const char BITMAP_IDX_SIGNATURE[4];
However, this design was also not chosen as the static definition allows
us to keep the declaration together for readability along with removing
the magic number.
Signed-off-by: Denton Liu <liu.den...@gmail.com>
---
pack-bitmap.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/pack-bitmap.h b/pack-bitmap.h
index 00de3ec8e4..466c5afa09 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -9,16 +9,16 @@ struct commit;
struct repository;
struct rev_info;
+static const char BITMAP_IDX_SIGNATURE[] = {'B', 'I', 'T', 'M'};
+
struct bitmap_disk_header {
- char magic[4];
+ char magic[ARRAY_SIZE(BITMAP_IDX_SIGNATURE)];
uint16_t version;
uint16_t options;
uint32_t entry_count;
unsigned char checksum[GIT_MAX_RAWSZ];
};
-static const char BITMAP_IDX_SIGNATURE[] = {'B', 'I', 'T', 'M'};
-
#define NEEDS_BITMAP (1u<<22)
enum pack_bitmap_opts {
--
2.23.0.248.g3a9dd8fb08
