>Submitter-Id: net
>Originator: Matthias Klose
>Organization:
>Confidential: no
>Synopsis: _Pragma within macros is improperly expanded
>Severity: serious
>Priority: medium
>Category: preprocessor
>Class: sw-bug
>Release: 3.2.1 2002-11-03
>Environment:
System: Linux smile 2.4.18-xfs #1 Tue Mar 12 22:42:02 CET 2002 i686 unknown
Architecture: i686
host: i386-pc-linux-gnu
build: i386-pc-linux-gnu
target: i386-pc-linux-gnu
>Description:
The original report from the Debian BTS, fix applied to head and branch:
[EMAIL PROTECTED]:~$ cat foo.c
_Pragma("foo"); int y;
#define FOO _Pragma("foo"); int x;
FOO
[EMAIL PROTECTED]:~$ cpp-3.2 foo.c
# 1 "foo.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "foo.c"
# 1 "foo.c"
#pragma foo
# 1 "foo.c"
; int y;
# 3 "foo.c"
#pragma ; int x;foo
The first line is expanded correctly; the third is not (rendering
_Pragma almost completely useless).
Fixed by Neil:
* cpphash.h (FIRST, LAST, CUR, RLIMIT): Fix definitions.
* cpplib.c (destringize_and_run): Kludge around getting
tokens from in-progress macros.
(_cpp_do__Pragma): Simplify. testsuite:
* gcc.dg/cpp/_Pragma4.c: New test.
Bug submitter claims:
Nope, still not right. Here's a new case where it breaks:
[EMAIL PROTECTED]:~/tmp$ cat foo.c
#define ALPHA(A) alpha_ ## A
#define BETA(B) beta_ ## B
#define GAMMA(C) _Pragma("moose") ALPHA(C) BETA(C)
GAMMA(baz);
[EMAIL PROTECTED]:~/tmp$ cpp-3.2 foo.c
# 1 "foo.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "foo.c"
# 4 "foo.c"
#pragma moose=20
# 4 "foo.c"
alpha_baz beta_alpha_baz;
[EMAIL PROTECTED]:~/tmp$ cpp-2.95 foo.c
# 1 "foo.c"
_Pragma("moose") alpha_baz beta_baz ;
=3D=3D
Note how beta_baz has become beta_alpha_baz in 3.2. This only happens
when the _Pragma is present, so I presume it's the same bug in another
form.
But wait! It gets better:
[EMAIL PROTECTED]:~/tmp$ cat foo.c
#define ALPHA
#define BETA(B) beta_ ## B
#define GAMMA(C) _Pragma("moose") ALPHA BETA(C)
GAMMA(baz);
[EMAIL PROTECTED]:~/tmp$ cpp-3.2 foo.c
# 1 "foo.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "foo.c"
# 4 "foo.c"
#pragma moose=20
# 4 "foo.c"
cpp-3.2: Internal error: Aborted (program cpp0)
Please submit a full bug report.
>How-To-Repeat:
>Fix:
