Re: WCHAR_WIDTH with HP-UX cc

[Bruno Haible]

Hi Paul,

> We could do that as a special case if __HP_cc is defined, as we know that 
> particular compiler doesn't work with other-width integers. Does the attached 
> (untested) patch work for you?

With it, the initialization

  int aa = WCHAR_WIDTH;

no longer produces an error "Incorrect initialization." That's good.

But the error in the 'verify' line is still there:
cc: "test-stdint.c", line 419: error 1511: Bit-field size must be a constant.
cc: "test-stdint.c", line 419: error 1613: Zero-sized struct.
cc: "test-stdint.c", line 419: warning 504: The sizeof operator applied to a 
zero-sized object.

I can see from a compilation to .s the following values:
  WCHAR_WIDTH = 0x00000020
  WCHAR_MIN = 0x00000000
  WCHAR_MAX = 0xFFFFFFFF

The following line fails:
extern int (*_gl_verify_function419 (void)) [(!!sizeof (struct { unsigned int 
_gl_verify_error_if_negative: (((((((0u) + 1) << ((32) ? (32) - 1 - (0) : 0)) - 
1) * 2 + 1)) >> (((((((((0u) + 1) << ((32) ? (32) - 1 - (0) : 0)) - 1) * 2 + 
1)) >> 31 >> 1 ? 64 : ((((((0u) + 1) << ((32) ? (32) - 1 - (0) : 0)) - 1) * 2 + 
1)) >> 16 ? 32 : ((((((0u) + 1) << ((32) ? (32) - 1 - (0) : 0)) - 1) * 2 + 1)) 
>> 8 ? 16 : 8)) - 1 - ((((0) ? ~ (((((0u) + 1) << ((32) ? (32) - 1 - (0) : 0)) 
- 1) * 2 + 1) : (0u))) < 0)) == 1) ? 1 : -1; }))] ;

I did successive simplifications:

FAILS:
struct foo { unsigned int _gl_verify_error_if_negative: ((0xffffffffu) >> 
(((0x0u ? 64 : (0xffffu) ? 32 : (0xffffffu) ? 16 : 8)) - 1 - ((((0) ? ~ 
0xffffffffu : (0u))) < 0)) == 1) ? 1 : -1; } ;
SUCCEEDS:
struct foo { unsigned int _gl_verify_error_if_negative: ((0xffffffffu) >> 
(((0x0u ? 64 : (0xffffu) ? 32 : (0xffffffu) ? 16 : 8)) - 1 - ((((0u))) < 0)) == 
1) ? 1 : -1; } ;

FAILS:
struct foo { unsigned int _gl_verify_error_if_negative: (0xffffffffu >> (31 - 
((0 ? 0x0u : 0u) < 0)) == 1) ? 1 : -1; } ;
SUCCEEDS:
struct foo { unsigned int _gl_verify_error_if_negative: (0xffffffffu >> (31 - 
((0u) < 0)) == 1) ? 1 : -1; } ;

So, conditional expressions inside arithmetic expressions inside bit field sizes
are apparently the problem.

Adding

#undef WCHAR_MIN
#define WCHAR_MIN 0u

makes the error go away. But even a seemingly innocent replacement

#undef WCHAR_MIN
#define WCHAR_MIN (0 * 0u)

produces the error.

It seems that this compiler has problem with type inference inside constant
expressions and that the "Bit-field size must be a constant" message is a
manifestation of some kind of internal compiler error.

I'm pushing this fix. It's a little bit more ugly than the previous code,
but it's still generic.

And with it, no change to _GL_INTEGER_WIDTH is needed. The problem in
  # define WCHAR_WIDTH _GL_INTEGER_WIDTH (WCHAR_MIN, WCHAR_MAX)
was apparently due to the WCHAR_MIN macro, not the _GL_INTEGER_WIDTH macro.


2017-03-16  Bruno Haible  <address@hidden>

        stdint: Fix test compilation failure with HP-UX 11 cc.
        * lib/stdint.in.h (_STDINT_MIN): Remove macro.
        (_STDINT_UNSIGNED_MIN, _STDINT_SIGNED_MIN): New macros.
        (PTRDIFF_MIN, SIG_ATOMIC_MIN, WCHAR_MIN, WINT_MIN): Define using
        _STDINT_UNSIGNED_MIN, _STDINT_SIGNED_MIN.

diff --git a/lib/stdint.in.h b/lib/stdint.in.h
index 7535962..9583fd9 100644
--- a/lib/stdint.in.h
+++ b/lib/stdint.in.h
@@ -128,8 +128,13 @@
    Return an unspecified value if BITS == 0, adding a check to pacify
    picky compilers.  */
 
-# define _STDINT_MIN(signed, bits, zero) \
-    ((signed) ? ~ _STDINT_MAX (signed, bits, zero) : (zero))
+/* These are separate macros, because if you try to merge these macros into
+   a single one, HP-UX cc rejects the resulting expression in constant
+   expressions.  */
+# define _STDINT_UNSIGNED_MIN(bits, zero) \
+    (zero)
+# define _STDINT_SIGNED_MIN(bits, zero) \
+    (~ _STDINT_MAX (1, bits, zero))
 
 # define _STDINT_MAX(signed, bits, zero) \
     (((((zero) + 1) << ((bits) ? (bits) - 1 - (signed) : 0)) - 1) * 2 + 1)
@@ -512,15 +517,15 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == 
sizeof (uintmax_t)
 # undef PTRDIFF_MAX
 # if @APPLE_UNIVERSAL_BUILD@
 #  ifdef _LP64
-#   define PTRDIFF_MIN  _STDINT_MIN (1, 64, 0l)
+#   define PTRDIFF_MIN  _STDINT_SIGNED_MIN (64, 0l)
 #   define PTRDIFF_MAX  _STDINT_MAX (1, 64, 0l)
 #  else
-#   define PTRDIFF_MIN  _STDINT_MIN (1, 32, 0)
+#   define PTRDIFF_MIN  _STDINT_SIGNED_MIN (32, 0)
 #   define PTRDIFF_MAX  _STDINT_MAX (1, 32, 0)
 #  endif
 # else
 #  define PTRDIFF_MIN  \
-    _STDINT_MIN (1, @BITSIZEOF_PTRDIFF_T@, address@hidden@)
+    _STDINT_SIGNED_MIN (@BITSIZEOF_PTRDIFF_T@, address@hidden@)
 #  define PTRDIFF_MAX  \
     _STDINT_MAX (1, @BITSIZEOF_PTRDIFF_T@, address@hidden@)
 # endif
@@ -528,9 +533,13 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == 
sizeof (uintmax_t)
 /* sig_atomic_t limits */
 # undef SIG_ATOMIC_MIN
 # undef SIG_ATOMIC_MAX
-# define SIG_ATOMIC_MIN  \
-   _STDINT_MIN (@HAVE_SIGNED_SIG_ATOMIC_T@, @BITSIZEOF_SIG_ATOMIC_T@, \
-                address@hidden@)
+# if @HAVE_SIGNED_SIG_ATOMIC_T@
+#  define SIG_ATOMIC_MIN  \
+    _STDINT_SIGNED_MIN (@BITSIZEOF_SIG_ATOMIC_T@, address@hidden@)
+# else
+#  define SIG_ATOMIC_MIN  \
+    _STDINT_UNSIGNED_MIN (@BITSIZEOF_SIG_ATOMIC_T@, address@hidden@)
+# endif
 # define SIG_ATOMIC_MAX  \
    _STDINT_MAX (@HAVE_SIGNED_SIG_ATOMIC_T@, @BITSIZEOF_SIG_ATOMIC_T@, \
                 address@hidden@)
@@ -566,16 +575,26 @@ typedef int _verify_intmax_size[sizeof (intmax_t) == 
sizeof (uintmax_t)
 # endif
 # undef WCHAR_MIN
 # undef WCHAR_MAX
-# define WCHAR_MIN  \
-   _STDINT_MIN (@HAVE_SIGNED_WCHAR_T@, @BITSIZEOF_WCHAR_T@, address@hidden@)
+# if @HAVE_SIGNED_WCHAR_T@
+#  define WCHAR_MIN  \
+    _STDINT_SIGNED_MIN (@BITSIZEOF_WCHAR_T@, address@hidden@)
+# else
+#  define WCHAR_MIN  \
+    _STDINT_UNSIGNED_MIN (@BITSIZEOF_WCHAR_T@, address@hidden@)
+# endif
 # define WCHAR_MAX  \
    _STDINT_MAX (@HAVE_SIGNED_WCHAR_T@, @BITSIZEOF_WCHAR_T@, address@hidden@)
 
 /* wint_t limits */
 # undef WINT_MIN
 # undef WINT_MAX
-# define WINT_MIN  \
-   _STDINT_MIN (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, address@hidden@)
+# if @HAVE_SIGNED_WINT_T@
+#  define WINT_MIN  \
+    _STDINT_SIGNED_MIN (@BITSIZEOF_WINT_T@, address@hidden@)
+# else
+#  define WINT_MIN  \
+    _STDINT_UNSIGNED_MIN (@BITSIZEOF_WINT_T@, address@hidden@)
+# endif
 # define WINT_MAX  \
    _STDINT_MAX (@HAVE_SIGNED_WINT_T@, @BITSIZEOF_WINT_T@, address@hidden@)