aclocal.m4: add defines for added CFLAGS, cleanups, PA_SYM()

Add defines for added CFLAGS.  This can be useful, for example, for
LTO or sanitizers being enabled.

Various cleanups for readability and documentation; use macros
available in current autoconf.

Add new utility function PA_SYM(), similar to AS_TR_CPP() except
collapses sequential underscores.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 31 insertions, 23 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index f216e511..ed73c33f 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1,7 +1,18 @@
 dnl --------------------------------------------------------------------------
-dnl PA_ADD_CFLAGS()
+dnl PA_SYM(prefix, string)
 dnl
-dnl Attempt to add the given option to CFLAGS, if it doesn't break compilation
+dnl Convert a (semi-) arbitrary string to a CPP symbol
+dnl --------------------------------------------------------------------------
+AC_DEFUN(PA_SYM,
+[[$1]m4_bpatsubsts(m4_toupper([$2]),[[^ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789]+],[_],[^._?\(.*\)_.$],[[\1]])])
+
+dnl --------------------------------------------------------------------------
+dnl PA_ADD_CFLAGS(flag [,actual_flag])
+dnl
+dnl Attempt to add the given option to CFLAGS, if it doesn't break
+dnl compilation.  If the option to be tested is different than the
+dnl option that should actually be added, add the option to be
+dnl actually added as a second argument.
 dnl --------------------------------------------------------------------------
 AC_DEFUN(PA_ADD_CFLAGS,
 [AC_MSG_CHECKING([if $CC accepts $1])
@@ -10,12 +21,14 @@ AC_DEFUN(PA_ADD_CFLAGS,
  AC_TRY_LINK(AC_INCLUDES_DEFAULT,
  [printf("Hello, World!\n");],
  [AC_MSG_RESULT([yes])
-  CFLAGS="$pa_add_cflags__old_cflags ifelse([$2],[],[$1],[$2])"],
+  CFLAGS="$pa_add_cflags__old_cflags ifelse([$2],[],[$1],[$2])"
+  AC_DEFINE(PA_SYM([CFLAG_],[$1]), 1,
+   [Define to 1 if compiled with the `$1' compiler flag])],
  [AC_MSG_RESULT([no])
   CFLAGS="$pa_add_cflags__old_cflags"])])
 
 dnl --------------------------------------------------------------------------
-dnl PA_ADD_CLDFLAGS()
+dnl PA_ADD_CLDFLAGS(flag [,actual_flag])
 dnl
 dnl Attempt to add the given option to CFLAGS and LDFLAGS,
 dnl if it doesn't break compilation
@@ -30,30 +43,24 @@ AC_DEFUN(PA_ADD_CLDFLAGS,
  [printf("Hello, World!\n");],
  [AC_MSG_RESULT([yes])
   CFLAGS="$pa_add_cldflags__old_cflags ifelse([$2],[],[$1],[$2])"
-  LDFLAGS="$pa_add_cldflags__old_ldflags ifelse([$2],[],[$1],[$2])"],
+  LDFLAGS="$pa_add_cldflags__old_ldflags ifelse([$2],[],[$1],[$2])"
+  AC_DEFINE(PA_SYM([CFLAG_],[$1]), 1,
+   [Define to 1 if compiled with the `$1' compiler flag])],
  [AC_MSG_RESULT([no])
   CFLAGS="$pa_add_cldflags__old_cflags"
   LDFLAGS="$pa_add_cldflags__old_ldflags"])])
 
 dnl --------------------------------------------------------------------------
-dnl PA_VAR
-dnl
-dnl Canonicalize a variable name: upper case, and fold non-C characters
-dnl to underscores.
-dnl --------------------------------------------------------------------------
-AC_DEFUN(PA_VAR, [patsubst(m4_toupper([$1]),[[^A-Za-z0-9_]],[_])])
-
-dnl --------------------------------------------------------------------------
-dnl PA_HAVE_FUNC
+dnl PA_HAVE_FUNC(func_name)
 dnl
 dnl Look for a function with the specified arguments which could be
 dnl a builtin/intrinsic function.
 dnl --------------------------------------------------------------------------
 AC_DEFUN(PA_HAVE_FUNC,
 [AC_MSG_CHECKING([for $1])
-AC_TRY_LINK(AC_INCLUDES_DEFAULT, [(void)$1$2;],
+AC_TRY_LINK([], [(void)$1$2;],
 AC_MSG_RESULT([yes])
-AC_DEFINE(PA_VAR([HAVE_$1]), [1],
+AC_DEFINE(AS_TR_CPP([HAVE_$1]), 1,
   [Define to 1 if you have the `$1' intrinsic function.]),
 AC_MSG_RESULT([no]))])
 
@@ -78,7 +85,7 @@ AC_MSG_RESULT([$LIBEXT])
 AC_SUBST([LIBEXT])])
 
 dnl --------------------------------------------------------------------------
-dnl PA_FUNC_ATTRIBUTE
+dnl PA_FUNC_ATTRIBUTE(attribute_name)
 dnl
 dnl See if this compiler supports the equivalent of a specific gcc
 dnl attribute on a function, using the __attribute__(()) syntax.
@@ -99,7 +106,7 @@ void *foo(void)
 }
  ])],
  [AC_MSG_RESULT([yes])
-  AC_DEFINE(PA_VAR([HAVE_FUNC_ATTRIBUTE_$1]), 1,
+  AC_DEFINE(PA_SYM([HAVE_FUNC_ATTRIBUTE_],[$1]), 1,
     [Define to 1 if your compiler supports __attribute__(($1)) on functions])],
  [AC_MSG_RESULT([no])])
 ])
@@ -124,14 +131,14 @@ void foo(void)
 }
  ])],
  [AC_MSG_RESULT([yes])
-  AC_DEFINE(PA_VAR([HAVE_FUNC_ATTRIBUTE_ERROR]), 1,
+  AC_DEFINE([HAVE_FUNC_ATTRIBUTE_ERROR], 1,
     [Define to 1 if your compiler supports __attribute__((error)) on functions])],
  [AC_MSG_RESULT([no])])
 ])
 
 dnl --------------------------------------------------------------------------
-dnl PA_ARG_ENABLED
-dnl PA_ARG_DISABLED
+dnl PA_ARG_ENABLED(option, helptext [,enabled_action [,disabled_action]])
+dnl PA_ARG_DISABLED(option, helptext [,disabled_action [,enabled_action]])
 dnl
 dnl  Simpler-to-use versions of AC_ARG_ENABLED, that include the
 dnl  test for $enableval and the AS_HELP_STRING definition
@@ -147,13 +154,14 @@ AC_DEFUN(PA_ARG_DISABLED,
 ])
 
 dnl --------------------------------------------------------------------------
-dnl PA_ADD_HEADERS()
+dnl PA_ADD_HEADERS(headers...)
 dnl
 dnl Call AC_CHECK_HEADERS(), and add to ac_includes_default if found
 dnl --------------------------------------------------------------------------
 AC_DEFUN(_PA_ADD_HEADER,
 [AC_CHECK_HEADERS([$1],[ac_includes_default="$ac_includes_default
-#include <$1>"])])
+#include <$1>"dnl
+])])
 
 AC_DEFUN(PA_ADD_HEADERS,
 [m4_map_args_w([$1],[_PA_ADD_HEADER(],[)])])