Fix port to 32-bit AIX with xlc.

This doesn't fix Bug#17598, but it does fix a regression since Emacs
built with xlc until recently, and perhaps it'll help us fix Bug#17598.
* configure.ac (GC_SETJMP_WORKS): Define for AIX, too.
Merge from gnulib, incorporating:
2014-05-30 ftoastr: work around compiler bug in IBM xlc 12.1
* lib/ftoastr.c: Update from gnulib.
* src/alloc.c (gdb_make_enums_visible): Remove FLOAT_TO_STRING_BUFSIZE.
* src/conf_post.h (FLEXIBLE_ARRAY_MEMBER) [__IBMC__]: Don't define to empty.
* src/lisp.h (FLOAT_TO_STRING_BUFSIZE): Make it a macro, instead of an enum,
to work around a compiler bug in IBM xlc 12.1.

7 files changed, 32 insertions, 13 deletions

diff --git a/ChangeLog b/ChangeLog
index 3789203527c..30561d6ac13 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2014-05-30  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Fix port to 32-bit AIX with xlc (Bug#17598).
+        This doesn't fix Bug#17598, but it does fix a regression since Emacs
+        built with xlc until recently, and perhaps it'll help us fix Bug#17598.
+        * configure.ac (GC_SETJMP_WORKS): Define for AIX, too.
+        Merge from gnulib, incorporating:
+        2014-05-30 ftoastr: work around compiler bug in IBM xlc 12.1
+        * lib/ftoastr.c: Update from gnulib.
+
 2014-05-22  Paul Eggert  <eggert@cs.ucla.edu>
 
         Fix port to 32-bit AIX (Bug#17540).
diff --git a/configure.ac b/configure.ac
index 0f4351fcd5d..3de3cb97c04 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4380,7 +4380,7 @@ if test x$GCC = xyes; then
 else
   case $opsys in
     dnl irix: Tested on Irix 6.5.  SCM worked on earlier versions.
-    dragonfly | freebsd | netbsd | openbsd | irix6-5 | sol2* )
+    aix* | dragonfly | freebsd | netbsd | openbsd | irix6-5 | sol2* )
       AC_DEFINE(GC_SETJMP_WORKS, 1)
       ;;
   esac
diff --git a/lib/ftoastr.h b/lib/ftoastr.h
index 6236292d9d9..26cad7369ce 100644
--- a/lib/ftoastr.h
+++ b/lib/ftoastr.h
@@ -72,12 +72,13 @@ enum
 
 /* _GL_FLT_PREC_BOUND is an upper bound on the precision needed to
    represent a float value without losing information.  Likewise for
-   _GL_DBL_PREC_BOUND and double, and _GL_LDBL_PREC_BOUND and long double.  */
+   _GL_DBL_PREC_BOUND and double, and _GL_LDBL_PREC_BOUND and long double.
+   These are macros, not enums, to work around a bug in IBM xlc 12.1.  */
 
 #if FLT_RADIX == 10 /* decimal floating point */
- enum {  _GL_FLT_PREC_BOUND =  FLT_MANT_DIG };
- enum {  _GL_DBL_PREC_BOUND =  DBL_MANT_DIG };
- enum { _GL_LDBL_PREC_BOUND = LDBL_MANT_DIG };
+# define  _GL_FLT_PREC_BOUND  FLT_MANT_DIG
+# define  _GL_DBL_PREC_BOUND  DBL_MANT_DIG
+# define _GL_LDBL_PREC_BOUND LDBL_MANT_DIG
 #else
 
 /* An upper bound on the number of bits needed to represent a single
@@ -95,13 +96,13 @@ enum
    DIG digits.  For why the "+ 1" is needed, see "Binary to Decimal
    Conversion" in David Goldberg's paper "What Every Computer
    Scientist Should Know About Floating-Point Arithmetic"
-   <http://docs.sun.com/source/806-3568/ncg_goldberg.html>.  */
+   <http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html>.  */
 # define _GL_FLOAT_PREC_BOUND(dig) \
    (INT_BITS_STRLEN_BOUND ((dig) * _GL_FLOAT_DIG_BITS_BOUND) + 1)
 
- enum {  _GL_FLT_PREC_BOUND = _GL_FLOAT_PREC_BOUND ( FLT_MANT_DIG) };
- enum {  _GL_DBL_PREC_BOUND = _GL_FLOAT_PREC_BOUND ( DBL_MANT_DIG) };
- enum { _GL_LDBL_PREC_BOUND = _GL_FLOAT_PREC_BOUND (LDBL_MANT_DIG) };
+# define  _GL_FLT_PREC_BOUND _GL_FLOAT_PREC_BOUND ( FLT_MANT_DIG)
+# define  _GL_DBL_PREC_BOUND _GL_FLOAT_PREC_BOUND ( DBL_MANT_DIG)
+# define _GL_LDBL_PREC_BOUND _GL_FLOAT_PREC_BOUND (LDBL_MANT_DIG)
 #endif
 
 
diff --git a/src/ChangeLog b/src/ChangeLog
index a07daee1669..522f1ad965a 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,11 @@
+2014-05-30  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Fix port to 32-bit AIX with xlc (Bug#17598).
+        * alloc.c (gdb_make_enums_visible): Remove FLOAT_TO_STRING_BUFSIZE.
+        * conf_post.h (FLEXIBLE_ARRAY_MEMBER) [__IBMC__]: Don't define to empty.
+        * lisp.h (FLOAT_TO_STRING_BUFSIZE): Make it a macro, instead of an enum,
+        to work around a compiler bug in IBM xlc 12.1.
+
 2014-05-29  Eli Zaretskii  <eliz@gnu.org>
 
         * xterm.c (x_update_window_end): Don't invalidate the entire
diff --git a/src/alloc.c b/src/alloc.c
index ccb955a547b..12b3d4ba165 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -7003,7 +7003,6 @@ union
   enum CHECK_LISP_OBJECT_TYPE CHECK_LISP_OBJECT_TYPE;
   enum DEFAULT_HASH_SIZE DEFAULT_HASH_SIZE;
   enum enum_USE_LSB_TAG enum_USE_LSB_TAG;
-  enum FLOAT_TO_STRING_BUFSIZE FLOAT_TO_STRING_BUFSIZE;
   enum Lisp_Bits Lisp_Bits;
   enum Lisp_Compiled Lisp_Compiled;
   enum maxargs maxargs;
diff --git a/src/conf_post.h b/src/conf_post.h
index 312f2389415..446c8275613 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -297,8 +297,9 @@ extern void _DebPrint (const char *fmt, ...);
 
 /* To use the struct hack with N elements, declare the struct like this:
      struct s { ...; t name[FLEXIBLE_ARRAY_MEMBER]; };
-   and allocate (offsetof (struct s, name) + N * sizeof (t)) bytes.  */
-#if 199901 <= __STDC_VERSION__
+   and allocate (offsetof (struct s, name) + N * sizeof (t)) bytes.
+   IBM xlc 12.1 claims to do C99 but mishandles flexible array members.  */
+#if 199901 <= __STDC_VERSION__ && !defined __IBMC__
 # define FLEXIBLE_ARRAY_MEMBER
 #elif __GNUC__ && !defined __STRICT_ANSI__
 # define FLEXIBLE_ARRAY_MEMBER 0
diff --git a/src/lisp.h b/src/lisp.h
index af54887a51a..a92d7694a3b 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3815,7 +3815,7 @@ extern void print_error_message (Lisp_Object, Lisp_Object, const char *,
                                  Lisp_Object);
 extern Lisp_Object internal_with_output_to_temp_buffer
         (const char *, Lisp_Object (*) (Lisp_Object), Lisp_Object);
-enum FLOAT_TO_STRING_BUFSIZE { FLOAT_TO_STRING_BUFSIZE = 350 };
+#define FLOAT_TO_STRING_BUFSIZE 350
 extern int float_to_string (char *, double);
 extern void init_print_once (void);
 extern void syms_of_print (void);