>Number: 5354
>Category: c
>Synopsis: function call with two statement expressions yields incorrect result
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: wrong-code
>Submitter-Id: net
>Arrival-Date: Thu Jan 10 16:26:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator: Ben Liblit <[EMAIL PROTECTED]>
>Release: 3.1 20020110 (experimental)
>Organization:
Computer Science Division, UC Berkeley
>Environment:
System: Linux brawnix.CS.Berkeley.EDU 2.4.17 #4 Fri Dec 28 23:34:16 PST 2001 i686
unknown
Architecture: i686
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../src/configure --prefix=/var/local/liblit/gcc-cvs/install
>Description:
When calling a function where two arguments are computed using ({...})
statement expressions, the generated code computes the incorrect
value for one of the arguments. Specifically, it appears that
whichever statement expression is computed *last* is taken as the
value for *both* arguments.
>How-To-Repeat:
Compile and run the following code:
------------------------------------------------------------------------
extern int printf(__const char *__restrict __format, ...);
void f(int x, int y)
{
printf("f(%d, %d)\n", x, y);
}
int main()
{
f(({ int temp1 = 1; temp1; }),
({ int temp2 = 2; temp2; }));
return 0;
}
------------------------------------------------------------------------
gcc-2.96 produces the correct output:
f(1, 2)
gcc-3.0.1, which computes the arguments for the call to g from right
to left, produces the following incorrect output:
f(1, 1)
gcc CVS snapshot as of 10-Jan-2002, which computes the arguments for
the call to g from left to right, produces the following incorrect
output:
f(2, 2)
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
