| Summary: | archival/libarchive/decompress_gunzip.c:1139:2: error: size of unnamed array is negative, -mms-bitfields influences non-bitfield struct layout | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Wen Yang <yellowriver2010> |
| Component: | target | Assignee: | Not yet assigned to anyone <unassigned> |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | normal | Keywords: | ABI |
| Priority: | P3 | ||
| Version: | 6.2.0 | ||
| Target Milestone: | --- | ||
| Host: | Target: | x86_64-*-*, i?86-*-* | |
| Build: | Known to work: | ||
| Known to fail: | 6.2.0, 6.4.0, 7.2.0 | Last reconfirmed: | 2018-09-18 00:00:00 |
| Attachments: |
compile.sh
decompress_gunzip.i decompress_gunzip.i |
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Created attachment 44711 [details]
decompress_gunzip.i
Created attachment 44712 [details]
decompress_gunzip.i
Confirmed with your gazillion command line flags, works fine with plain -Os. Maybe you can remove the ones not necessary, it's hard to see if there's a stupid user error. It's -mms-bitfields which appearantly influences layout of the following struct:
union {
unsigned char raw[8];
struct {
uint8_t gz_method;
uint8_t flags;
uint32_t mtime;
uint8_t xtra_flags_UNUSED;
uint8_t os_flags_UNUSED;
} __attribute__ ((__packed__)) formatted;
} header;
((void)sizeof(char[1 - 2*!!(sizeof(header) != 8)]));
Not sure if the difference is intended.
|
Created attachment 44710 [details] compile.sh # ./compile.sh archival/libarchive/decompress_gunzip.c:1:0: warning: this target machine does not have delayed branches [enabled by default] archival/libarchive/decompress_gunzip.c:1:0: warning: -fassociative-math disabled; other options take precedence [enabled by default] archival/libarchive/decompress_gunzip.c: In function ‘check_header_gzip’: archival/libarchive/decompress_gunzip.c:1139:2: error: size of unnamed array is negative The orignal code is: 1126 static int check_header_gzip(STATE_PARAM transformer_state_t *xstate) 1127 { 1128 union { 1129 unsigned char raw[8]; 1130 struct { 1131 uint8_t gz_method; 1132 uint8_t flags; 1133 uint32_t mtime; 1134 uint8_t xtra_flags_UNUSED; 1135 uint8_t os_flags_UNUSED; 1136 } PACKED formatted; 1137 } header; 1138 1139 BUILD_BUG_ON(sizeof(header) != 8); The preprocessed code is: 11347 static int check_header_gzip(state_t *state, transformer_state_t *xstate) 11348 { 11349 union { 11350 unsigned char raw[8]; 11351 struct { 11352 uint8_t gz_method; 11353 uint8_t flags; 11354 uint32_t mtime; 11355 uint8_t xtra_flags_UNUSED; 11356 uint8_t os_flags_UNUSED; 11357 } __attribute__ ((__packed__)) formatted; 11358 } header; 11359 11360 ((void)sizeof(char[1 - 2*!!(sizeof(header) != 8)]));