config.h: separate function and function pointer attributes; automate

Separate out function and function pointer attributes, as not all
versions of all compilers support both.

Have macros related to function attributes auto-generated by
autoheader. As a result, rename config.h.in to unconfig.h, to make it
more obvious that it is really intended to be included from some C
programs.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

.gitignore

@@ -50,7 +50,7 @@ TAGS
 /asm/tokhash.c
 /asm/warnings.c
 /config/config.h
-/config/config.h.in
+/config/unconfig.h
 /config.log
 /config.status
 /configure

asm/listing.h

@@ -102,7 +102,7 @@ struct lfmt {
     /*
      * Called on a warning or error, with the error message.
      */
-    void printf_func(2, 3) (*error)(errflags severity, const char *fmt, ...);
+    void printf_func_ptr(2, 3) (*error)(errflags severity, const char *fmt, ...);
 
     /*
      * Update the current offset.  Used to give the listing generator

autoconf/gitignore

@@ -1,10 +0,0 @@
-/autoconf/aclocal.m4
-/autoconf/compile
-/autoconf/config.*
-/autoconf/install-sh
-/config/config.h
-/config/config.h.in
-/config.log
-/config.status
-/configure
-/Makefile

autoconf/m4/pa_func_attribute.m4

@@ -4,14 +4,23 @@ dnl
 dnl See if this compiler supports the equivalent of a specific gcc
 dnl attribute on a function, using the __attribute__(()) syntax.
 dnl All arguments except the attribute name are optional.
+dnl
 dnl PA_FUNC_ATTRIBUTE(attribute, attribute_opts, return_type,
-dnl                   prototype_args, call_args)
+dnl                   prototype_args, call_args, altname)
+dnl
+dnl This tests the attribute both on a function pointer and on a
+dnl direct function, as some gcc [and others?] versions have problems
+dnl with attributes on function pointers, and we might as well check both.
 dnl --------------------------------------------------------------------------
-AC_DEFUN([PA_FUNC_ATTRIBUTE],
+AC_DEFUN([_PA_FUNC_ATTRIBUTE],
 [AC_MSG_CHECKING([if $CC supports the $1 function attribute])
+ m4_define([_pa_faa],ifelse([$2],[],[],[($2)]))
+ m4_define([_pa_fam],ifelse([$2],[],[],[(m4_join([,],m4_for(_pa_n,1,m4_count($2),1,[m4_quote([x]_pa_n),])))]))
+ m4_define([_pa_suf],ifelse([$2],[],[],[m4_count($2)]))
+ m4_define([_pa_mac],ifelse([$6],[],[$1_func]_pa_suf,[$6]))
  AC_COMPILE_IFELSE([AC_LANG_SOURCE([
 AC_INCLUDES_DEFAULT
-extern ifelse([$3],[],[void *],[$3])  __attribute__(($1$2))
+extern ifelse([$3],[],[void *],[$3])  __attribute__(([$1]_pa_faa))
   bar(ifelse([$4],[],[int],[$4]));
 ifelse([$3],[],[void *],[$3]) foo(void);
 ifelse([$3],[],[void *],[$3]) foo(void)
@@ -21,7 +30,60 @@ ifelse([$3],[],[void *],[$3]) foo(void)
 }
  ])],
  [AC_MSG_RESULT([yes])
-  AC_DEFINE(PA_SYM([HAVE_FUNC_ATTRIBUTE_],[$1]), 1,
+  AC_DEFINE(PA_SYM([HAVE_FUNC_ATTRIBUTE],_pa_suf,[_$1]), 1,
     [Define to 1 if your compiler supports __attribute__(($1)) on functions])],
  [AC_MSG_RESULT([no])])
+ AH_BOTTOM(m4_quote(m4_join([],
+ [#ifndef ],_pa_mac,[
+# ifdef ],PA_SYM([HAVE_FUNC_ATTRIBUTE],_pa_suf,[_$1]),[
+#  define ],_pa_mac,m4_quote(_pa_fam),[ __attribute__(($1],m4_quote(_pa_fam),[))
+# else
+#  define ],_pa_mac,m4_quote(_pa_fam),[
+# endif
+#endif])))
 ])
+
+AC_DEFUN([_PA_FUNC_PTR_ATTRIBUTE],
+[AC_MSG_CHECKING([if $CC supports the $1 function attribute on pointers])
+ m4_define([_pa_faa],ifelse([$2],[],[],[($2)]))
+ m4_define([_pa_fam],ifelse([$2],[],[],[(m4_join([,],m4_for(_pa_n,1,m4_count($2),1,[m4_quote([x]_pa_n),])))]))
+ m4_define([_pa_suf],ifelse([$2],[],[],[m4_count($2)]))
+ m4_define([_pa_mac],ifelse([$6],[],[$1_func]_pa_suf,[$6])_ptr)
+ AC_COMPILE_IFELSE([AC_LANG_SOURCE([
+AC_INCLUDES_DEFAULT
+extern ifelse([$3],[],[void *],[$3])  __attribute__(([$1]_pa_faa))
+  (*bar1)(ifelse([$4],[],[int],[$4]));
+ifelse([$3],[],[void *],[$3]) foo1(void);
+ifelse([$3],[],[void *],[$3]) foo1(void)
+{
+	ifelse([$3],[void],[],[return])
+		bar1(ifelse([$5],[],[1],[$5]));
+}
+
+typedef ifelse([$3],[],[void *],[$3])  __attribute__(([$1]_pa_faa))
+  (*bar_t)(ifelse([$4],[],[int],[$4]));
+extern bar_t bar2;
+ifelse([$3],[],[void *],[$3]) foo2(void);
+ifelse([$3],[],[void *],[$3]) foo2(void)
+{
+	ifelse([$3],[void],[],[return])
+		bar2(ifelse([$5],[],[1],[$5]));
+}
+ ])],
+ [AC_MSG_RESULT([yes])
+  AC_DEFINE(PA_SYM([HAVE_FUNC_PTR_ATTRIBUTE],_pa_suf,[_$1]), 1,
+    [Define to 1 if your compiler supports __attribute__(($1)) on function pointers])],
+ [AC_MSG_RESULT([no])])
+ AH_BOTTOM(m4_quote(m4_join([],
+ [#ifndef ],_pa_mac,[
+# ifdef ],PA_SYM([HAVE_FUNC_PTR_ATTRIBUTE],_pa_suf,[_$1]),[
+#  define ],_pa_mac,m4_quote(_pa_fam),[ __attribute__(($1],m4_quote(_pa_fam),[))
+# else
+#  define ],_pa_mac,m4_quote(_pa_fam),[
+# endif
+#endif])))
+])
+
+AC_DEFUN([PA_FUNC_ATTRIBUTE],
+[_PA_FUNC_ATTRIBUTE([$1],[$2],[$3],[$4],[$5],[$6])
+ _PA_FUNC_PTR_ATTRIBUTE([$1],[$2],[$3],[$4],[$5],[$6])])

autoconf/m4/pa_func_attribute_error.m4

@@ -4,6 +4,9 @@ dnl
 dnl See if this compiler supports __attribute__((error("foo")))
 dnl The generic version of this doesn't work as it makes the compiler
 dnl throw an error by design.
+dnl
+dnl This doesn't use a function pointer because there is no need:
+dnl the error function will never be a function pointer.
 dnl --------------------------------------------------------------------------
 AC_DEFUN([PA_FUNC_ATTRIBUTE_ERROR],
 [AC_MSG_CHECKING([if $CC supports the error function attribute])

autoconf/m4/pa_sym.m4

@@ -4,4 +4,5 @@ dnl
 dnl Convert a (semi-) arbitrary string to a CPP symbol
 dnl --------------------------------------------------------------------------
 AC_DEFUN([PA_SYM],
-[m4_normalize([$1])m4_bpatsubsts(m4_toupper([$2]),[[^ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789]+],[_],[^._?\(.*\)_.$],[[\1]])])
+[m4_bpatsubsts(m4_quote(m4_toupper([$*])),
+ [,],[],[[^ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789]+],[_],[^._?\(.*\)_.$],[[\1]])])

config/msvc.h

@@ -35,7 +35,7 @@
  * config/msvc.h
  *
  * Compiler definitions for Microsoft Visual C++;
- * instead of config.h.in.  See config.h.in for the
+ * instead of unconfig.h.  See config.h.in for the
  * variables which can be defined here.
  *
  * MSDN seems to have information back to Visual Studio 2003, so aim

configure.ac

@@ -1,8 +1,8 @@
 dnl Process this file with autoconf 2.69 or later to produce
 dnl a configure script.
 AC_PREREQ(2.69)
-AC_INIT(config/config.h.in)
-AC_CONFIG_HEADERS(config/config.h)
+AC_INIT([config/undef.h])
+AC_CONFIG_HEADERS([config/config.h:config/unconfig.h])
 AC_PREFIX_PROGRAM(nasm)
 AC_CONFIG_AUX_DIR(autoconf/helpers)
 
@@ -225,14 +225,15 @@ dnl some other features of gcc.
 dnl
 PA_ADD_CFLAGS([-Werror=attributes])
 PA_FUNC_ATTRIBUTE(noreturn)
-PA_FUNC_ATTRIBUTE(returns_nonnull)
+PA_FUNC_ATTRIBUTE(returns_nonnull,,,,,never_null)
 PA_FUNC_ATTRIBUTE(malloc)
-PA_FUNC_ATTRIBUTE(alloc_size, (1))
-PA_FUNC_ATTRIBUTE(sentinel,,, [const char *, ...], ["a","b",NULL])
-PA_FUNC_ATTRIBUTE(format, [(printf,1,2)], int, [const char *, ...], ["%d",1])
+PA_FUNC_ATTRIBUTE(alloc_size,[1])
+PA_FUNC_ATTRIBUTE(alloc_size,[1,2])
+PA_FUNC_ATTRIBUTE(sentinel,,, [const char *, ...], ["a","b",NULL],end_with_null)
+PA_FUNC_ATTRIBUTE(format, [printf,1,2], int, [const char *, ...], ["%d",1])
 PA_FUNC_ATTRIBUTE(const)
 PA_FUNC_ATTRIBUTE(pure)
-PA_FUNC_ATTRIBUTE(cold)
+PA_FUNC_ATTRIBUTE(cold,,,,,unlikely_func)
 PA_FUNC_ATTRIBUTE_ERROR
 
 dnl

include/compiler.h

@@ -56,12 +56,16 @@
 
 #ifdef HAVE_CONFIG_H
 # include "config/config.h"
-#elif defined(_MSC_VER) && (_MSC_VER >= 1310)
-# include "config/msvc.h"
-#elif defined(__WATCOMC__)
-# include "config/watcom.h"
 #else
-# include "config/unknown.h"
+# if defined(_MSC_VER) && (_MSC_VER >= 1310)
+#  include "config/msvc.h"
+# elif defined(__WATCOMC__)
+#  include "config/watcom.h"
+# else
+#  include "config/unknown.h"
+# endif
+/* This unconditionally defines some macros we really want */
+# include "config/unconfig.h"
 #endif /* Configuration file */
 
 /* This is required to get the standard <inttypes.h> macros when compiling
@@ -271,36 +275,15 @@ static inline void *mempcpy(void *dst, const void *src, size_t n)
 # define unlikely(x)	(!!(x))
 #endif
 
-/*
- * Hints about malloc-like functions that never return NULL
- */
-#ifdef HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL
-# define never_null __attribute__((returns_nonnull))
-#else
-# define never_null
-#endif
+#define safe_alloc     never_null     malloc_func
+#define safe_alloc_ptr never_null_ptr malloc_func_ptr
 
-#ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
-# define safe_alloc never_null __attribute__((malloc))
-#else
-# define safe_alloc never_null
-#endif
-
-#ifdef HAVE_FUNC_ATTRIBUTE_ALLOC_SIZE
-# define safe_malloc(s) safe_alloc __attribute__((alloc_size(s)))
-# define safe_malloc2(s1,s2) safe_alloc __attribute__((alloc_size(s1,s2)))
-# define safe_realloc(s) never_null __attribute__((alloc_size(s)))
-#else
-# define safe_malloc(s) safe_alloc
-# define safe_malloc2(s1,s2) safe_alloc
-# define safe_realloc(s) never_null
-#endif
-
-#ifdef HAVE_FUNC_ATTRIBUTE_SENTINEL
-# define end_with_null __attribute__((sentinel))
-#else
-# define end_with_null
-#endif
+#define safe_malloc(s)          safe_alloc     alloc_size_func1(s)
+#define safe_malloc2(s1,s2)     safe_alloc     alloc_size_func2(s1,s2)
+#define safe_realloc(s)         never_null     alloc_size_func1(s)
+#define safe_malloc_ptr(s)      safe_alloc_ptr alloc_size_func1_ptr(s)
+#define safe_malloc2_ptr(s1,s2) safe_alloc_ptr alloc_size_func2_ptr(s1,s2)
+#define safe_realloc_ptr(s)     never_null_ptr alloc_size_func1_ptr(s)
 
 /*
  * How to tell the compiler that a function doesn't return
@@ -308,59 +291,23 @@ static inline void *mempcpy(void *dst, const void *src, size_t n)
 #ifdef HAVE_STDNORETURN_H
 # include <stdnoreturn.h>
 # define no_return noreturn void
-#elif defined(HAVE_FUNC_ATTRIBUTE_NORETURN)
-# define no_return void __attribute__((noreturn))
 #elif defined(_MSC_VER)
 # define no_return __declspec(noreturn) void
 #else
-# define no_return void
-#endif
-
-/*
- * How to tell the compiler that a function is unlikely to be executed.
- * This differs from unlikely() in that it is applied to a function call,
- * not a boolean condition.
- */
-#ifdef HAVE_FUNC_ATTRIBUTE_COLD
-# define unlikely_func __attribute__((cold))
-#else
-# define unlikely_func
+# define no_return void noreturn_func
 #endif
 
 /*
  * A fatal function is both unlikely and no_return
  */
-#define fatal_func no_return unlikely_func
+#define fatal_func     no_return unlikely_func
+#define fatal_func_ptr no_return unlikely_func_ptr
 
 /*
  * How to tell the compiler that a function takes a printf-like string
  */
-#ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
-# define printf_func(fmt, list) __attribute__((format(printf, fmt, list)))
-#else
-# define printf_func(fmt, list)
-#endif
-
-/*
- * How to tell the compiler that a function is pure arithmetic
- */
-#ifdef HAVE_FUNC_ATTRIBUTE_CONST
-# define const_func __attribute__((const))
-#else
-# define const_func
-#endif
-
-/*
- * This function has no side effects, but depends on its arguments,
- * memory pointed to by its arguments, or global variables.
- * NOTE: functions that return a value by modifying memory pointed to
- * by a pointer argument are *NOT* considered pure.
- */
-#ifdef HAVE_FUNC_ATTRIBUTE_PURE
-# define pure_func __attribute__((pure))
-#else
-# define pure_func
-#endif
+#define printf_func(fmt, list)     format_func3(printf,fmt,list)
+#define printf_func_ptr(fmt, list) format_func3_ptr(printf,fmt,list)
 
 /* Determine probabilistically if something is a compile-time constant */
 #ifdef HAVE___BUILTIN_CONSTANT_P