Hi Paul,
> > CCLD ebrowse
> > cc: "ebrowse.c", line 281: error 1687: Illegal use of flexible array:
> > structs with FAMs cannot be members of other structs.
>
> This suggests that the HP-UX cc flexible array member bug is as follows: if a
> struct X contains a 'struct Y *' member where 'struct Y' has a flexible array
> member, the compiler incorrectly rejects the definition of struct X.
Confirmed:
$ cat foo.c
struct Y {
int a;
char b[];
};
struct X {
int b;
struct Y *p;
};
$ cc -AC99 -c foo.c
cc: "foo.c", line 6: error 1687: Illegal use of flexible array: structs with
FAMs cannot be members of other structs.
> Does the
> attached Gnulib patch suffice to detect the HP-UX cc bug?
Yes. Output before your patch:
checking for flexible array member... yes
and after your patch:
checking for flexible array member... no
> For the problem with __attribute__ ((__aligned__ (8))), does it suffice to
> put
> the declaration after the identifier? E.g., does this compile:
>
> int foo __attribute__ ((__aligned__ (8))) = 10;
>
> whereas this does not compile?
>
> int __attribute__ ((__aligned__ (8))) bar = 20;
No, nothing like this works.
$ cat foo.c
int aa __attribute__ ((__aligned__ (8))) = 10;
int ab __attribute__ ((aligned (8))) = 10;
int __attribute__ ((__aligned__ (8))) ac = 10;
int __attribute__ ((aligned (8))) ad = 10;
__attribute__ ((__aligned__ (8))) int ae = 10;
__attribute__ ((aligned (8))) int af = 10;
$ cc -AC99 -c foo.c
cc: "foo.c", line 1: error 1000: Unexpected symbol: "8".
cc: "foo.c", line 1: error 1670: Illegal attribute __aligned__ specified.
cc: "foo.c", line 3: error 1000: Unexpected symbol: "8".
cc: "foo.c", line 3: error 1670: Illegal attribute aligned specified.
cc: "foo.c", line 5: error 1000: Unexpected symbol: "8".
cc: "foo.c", line 5: error 1670: Illegal attribute __aligned__ specified.
cc: "foo.c", line 7: error 1000: Unexpected symbol: "8".
cc: "foo.c", line 7: error 1670: Illegal attribute aligned specified.
cc: "foo.c", line 9: error 1000: Unexpected symbol: "8".
cc: "foo.c", line 9: error 1670: Illegal attribute __aligned__ specified.
cc: "foo.c", line 11: error 1000: Unexpected symbol: "8".
cc: "foo.c", line 11: error 1670: Illegal attribute aligned specified.
> Also, in your build of Emacs 25.1, is the symbol
> HAVE_STRUCT_ATTRIBUTE_ALIGNED
> defined in src/config.h?
No, it's #undef'ed.
> (although we'd also need to fix m4/stdalign.m4 to keep it in sync with
> lib/stdalign.in.h).
Good point. Here's a revised proposed patch.
2017-03-17 Bruno Haible <br...@clisp.org>
stdalign: Make it work with HP-UX cc.
* lib/stdalign.in.h (_Alignas): Don't define for HP-UX cc.
* m4/stdalign.m4 (gl_STDALIGN_H): No need to enable the extra test
for HP-UX cc.
diff --git a/lib/stdalign.in.h b/lib/stdalign.in.h
index c2b791e..f6f4190 100644
--- a/lib/stdalign.in.h
+++ b/lib/stdalign.in.h
@@ -103,7 +103,7 @@
# elif ((defined __APPLE__ && defined __MACH__ \
? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \
: __GNUC__) \
- || 061200 <= __HP_cc || 061200 <= __HP_aCC \
+ || 061200 <= __HP_aCC \
|| __ICC || 0x590 <= __SUNPRO_C || 0x0600 <= __xlC__)
# define _Alignas(a) __attribute__ ((__aligned__ (a)))
# elif 1300 <= _MSC_VER
diff --git a/m4/stdalign.m4 b/m4/stdalign.m4
index 3a12658..5c15ef0 100644
--- a/m4/stdalign.m4
+++ b/m4/stdalign.m4
@@ -35,7 +35,7 @@ AC_DEFUN([gl_STDALIGN_H],
|| (defined __APPLE__ && defined __MACH__ \
? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \
: __GNUC__) \
- || __HP_cc || __HP_aCC || __IBMC__ || __IBMCPP__ \
+ || __HP_aCC || __IBMC__ || __IBMCPP__ \
|| __ICC || 0x5110 <= __SUNPRO_C \
|| 1300 <= _MSC_VER)
struct alignas_test { char c; char alignas (8) alignas_8; };
