http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55681
Bug #: 55681
Summary: Qualifiers on asm statements are order-dependent
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: josh.m.con...@gmail.com
The syntax that is accepted for asm statement qualifiers is:
asm {volatile | const | restrict} {goto}
(this can easily be seen by looking at the code in c_parser_asm_statement).
This means, for example, that gcc isn't particularly orthogonal in what it
chooses to accept and reject:
asm volatile ("nop"); // accepted
asm const ("nop"); // accepted with warning
asm __restrict ("nop"); // accepted with warning
asm const volatile ("nop"); // parse error
asm const __restrict ("nop"); // parse error
asm volatile goto ("nop" : : : : label); // accepted
asm goto volatile ("nop" : : : : label); // parse error
This is probably rarely a problem, since most of the statements that would
result in an error are not likely to be seen (I came across this when adding a
new qualifier for our local port, which exacerbated the problem), but I thought
I would mention it anyway -- the fix is relatively straightforward since the
qualifiers are independent.
