Following example haven't been linearized correctly:
static void *inc_ptr(void *a) {
return ++a;
}
test-linearize:
<entry-point>
add.32 %r2 <- %arg1, $-1
ret.32 %r2
Apparently, something went wrong with -1 value to be added to the original
pointer. When void* substituted for int*, the result is as expected
(considering 32b int):
<entry-point>
add.32 %r2 <- %arg1, $4
ret.32 %r2
The proposed patch turns post-ops on void* operand into an error
(taking the same route as with function operand).
When running check with C=2 on my old linux-3.0.6 configuration,
this detected a few occurencies:
drivers/scsi/scsi_proc.c:405:31: error: bad argument type for ++/--
drivers/scsi/scsi_proc.c:413:23: error: bad argument type for ++/--
net/bluetooth/hci_core.c:1545:29: error: bad argument type for ++/--
net/bluetooth/l2cap_core.c:1825:37: error: bad argument type for ++/--
net/bluetooth/bnep/core.c:239:13: error: bad argument type for ++/--
lib/sort.c:25:27: error: bad argument type for ++/--
lib/sort.c:26:27: error: bad argument type for ++/--
lib/check_signature.c:21:24: error: bad argument type for ++/--
All of them seems trivially fixable.
Alternatively, I can turn it to emit an warning only (should be
configurable/default?). To be noted that GCC will only emit an warning,
and only if -pedantic or -Wpointer-arith specified, but I consider
it rather a convenient exception.
When this gets clear, I'll add also the respective test-case.
Signed-off-by: Jan Pokorny <pokorny_jan@xxxxxxxxx>
---
evaluate.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/evaluate.c b/evaluate.c
index bebe968..b6d706b 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -1711,7 +1711,8 @@ static struct symbol *evaluate_postop(struct expression *expr)
multiply = 1;
} else if (class == TYPE_PTR) {
struct symbol *target = examine_pointer_target(ctype);
- if (!is_function(target))
+ /* beside function, reject also void* (due to sizeof(void)) */
+ if (target != &void_ctype && !is_function(target))
multiply = bits_to_bytes(target->bit_size);
}
--
1.7.3.4
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