Extend configure script to check for environ declaration in stdlib.h.

[openocd.git] / configure.in

diff --git a/configure.in b/configure.in
index 3b1d49e4f2bed99888f8181ed20318ca4b558dd1..a6177e1d9d60fb9c46e942f470c25fba4ed0ff2d 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -8,13 +8,16 @@ AC_CANONICAL_HOST
 AC_SEARCH_LIBS([ioperm], [ioperm])
 AC_SEARCH_LIBS([dlopen], [dl])
 
+AC_CHECK_HEADERS(elf.h)
+AC_CHECK_HEADERS(ifaddrs.h)
 AC_CHECK_HEADERS(jtag_minidriver.h)
+AC_CHECK_HEADERS(malloc.h)
+AC_CHECK_HEADERS(pthread.h)
+AC_CHECK_HEADERS(stdbool.h)
+AC_CHECK_HEADERS(strings.h)
 AC_CHECK_HEADERS(sys/param.h)
 AC_CHECK_HEADERS(sys/time.h)
 AC_CHECK_HEADERS(sys/select.h)
-AC_CHECK_HEADERS(elf.h)
-AC_CHECK_HEADERS(strings.h)
-AC_CHECK_HEADERS(stdbool.h)
 
 AC_HEADER_TIME
 
@@ -781,9 +784,42 @@ AM_CONDITIONAL(BITQ, test $build_bitq = yes)
 
 AC_LANG_C
 AC_PROG_CC
+AC_PROG_CC_C99
 AM_PROG_CC_C_O
 AC_PROG_RANLIB
 
+# Look for environ alternatives.  Possibility #1: is environ in unistd.h or stdlib.h?
+AC_MSG_CHECKING([for environ in unistd.h and stdlib.h])
+AC_COMPILE_IFELSE([
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <stdlib.h>
+int main(int argc, char **argv) { char **ep = environ; }
+  ], [
+    AC_MSG_RESULT([yes])
+    has_environ=yes
+  ], [
+    AC_MSG_RESULT([no])
+
+    # Possibility #2: can environ be found in an available library?
+    AC_MSG_CHECKING([for extern environ])
+    AC_LINK_IFELSE([
+extern char **environ;
+int main(int argc, char **argv) { char **ep = environ; }
+      ], [
+        AC_DEFINE(NEED_ENVIRON_EXTERN, [1], [Must declare 'environ' to use it.])
+        has_environ=yes
+      ], [
+        has_environ=no
+      ])
+    AC_MSG_RESULT([${has_environ}])
+  ])
+
+if test "${has_environ}" != "yes" ; then
+     AC_MSG_FAILURE([Could not find 'environ' in unistd.h or available libraries.]) 
+fi
+
+
 # set default gcc warnings
 GCC_WARNINGS="-Wall -Wstrict-prototypes -Wformat-security"
 if test "${gcc_wextra}" = yes; then