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author | David Lamparter <equinox@diac24.net> | 2019-11-26 17:05:47 +0100 |
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committer | David Lamparter <equinox@diac24.net> | 2019-11-26 17:14:03 +0100 |
commit | 50db10a162f5929784f448152c1c0bca11dcd517 (patch) | |
tree | fe8af160232ead065fcf4879b73187ae00ddcdb8 | |
parent | Merge pull request #5408 from donaldsharp/scan7 (diff) | |
download | frr-50db10a162f5929784f448152c1c0bca11dcd517.tar.xz frr-50db10a162f5929784f448152c1c0bca11dcd517.zip |
lib: add gcc 4.x workaround for frr_interface_info
gcc 4.x does not properly support structs with variable length array
members. Specifically, for global variables, it completely ignores the
array, coming up with a size much smaller than what is correct. This is
broken for both sizeof() as well as ELF object size.
This breaks for frr_interface_info since this variable is in some cases
copy relocated by the linker. (The linker does this to make the address
of the variable a "constant" for the main program.) This copying uses
the ELF object size, thereby copying only the non-array part of the
struct.
Breakage ensues...
(This fix is a bit ugly, but it's limited to very old gcc, and it's
better than changing the array to "nodes[1000]" and wasting memory...)
Fixes: #4563
Fixes: #5074
Signed-off-by: David Lamparter <equinox@diac24.net>
-rw-r--r-- | lib/if.c | 10 |
1 files changed, 10 insertions, 0 deletions
@@ -1677,3 +1677,13 @@ const struct frr_yang_module_info frr_interface_info = { }, } }; + +#if defined(__GNUC__) && ((__GNUC__ - 0) < 5) && !defined(__clang__) +/* gcc versions before 5.x miscalculate the size for structs with variable + * length arrays (they just count it as size 0) + * + * NB: the "." below means "current position", i.e. this line must be + * immediately after the frr_interface_info variable! + */ +__asm__(".size\tfrr_interface_info, .-frr_interface_info\n"); +#endif |