From: Bakul Shah <bakul@bitblocks.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: [9fans] A compiler bug
Date: Wed, 1 Aug 2018 00:21:27 -0700 [thread overview]
Message-ID: <20180801072134.DEB31156E400@mail.bitblocks.com> (raw)
Consider:
% cat x.c
#include <u.h>
uintptr foo[3];
uintptr bar=&foo[2];
% 8c -c x.c # this works.
% 5c -c x.c # this fails
x.c:3 initializer is not a constant: bar
If I change the last line to
uintptr* bar=&foo[2];
Both compilers compile it fine. But if I change the last line
to
uintptr bar=(uintptr)&foo[2];
both compilers fail. Note that the last two examples are
type correct.
uintptr is the same size as int* so there should be no runtime
cost and we already know from the second example that &foo[2]
is a link time constant.
Similar code to the last two examples compiles on gcc/clang.
This seems like a compiler bug.
next reply other threads:[~2018-08-01 7:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 7:21 Bakul Shah [this message]
2018-08-01 23:35 ` Charles Forsyth
2018-08-02 0:27 ` Bakul Shah
2018-08-02 9:38 ` Charles Forsyth
2018-08-02 13:28 ` Benjamin Purcell
2018-08-02 14:20 cinap_lenrek
2018-08-05 14:53 ` Charles Forsyth
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