arm: move check for BX to its own header

As Will noticed, the header this check is currently done in
is asm-only, and is not meant to be included from C code.
This breaks compilation when compiled for a Thumb2-aware CPU.

Move the BX check to its own header, and revert 7a246fd.

Reported-by: Will Newton <will.newton@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Will Newton <will.newton@gmail.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

8 files changed, 40 insertions, 9 deletions

diff --git a/libc/sysdeps/linux/arm/__longjmp.S b/libc/sysdeps/linux/arm/__longjmp.S
index b6e4961b3..853b906f8 100644
--- a/libc/sysdeps/linux/arm/__longjmp.S
+++ b/libc/sysdeps/linux/arm/__longjmp.S
@@ -18,6 +18,7 @@
 
 #include <features.h>
 #include <bits/arm_asm.h>
+#include <bits/arm_bx.h>
 
 .global __longjmp
 .type __longjmp,%function
diff --git a/libc/sysdeps/linux/arm/bits/arm_asm.h b/libc/sysdeps/linux/arm/bits/arm_asm.h
index 14d26341f..04664b376 100644
--- a/libc/sysdeps/linux/arm/bits/arm_asm.h
+++ b/libc/sysdeps/linux/arm/bits/arm_asm.h
@@ -26,12 +26,4 @@
 #define THUMB1_ONLY 1
 #endif
 
-#if defined(__USE_BX__)
-# if (   defined (__ARM_ARCH_2__)  || defined (__ARM_ARCH_3__) \
-      || defined (__ARM_ARCH_3M__) || defined (__ARM_ARCH_4__) \
-     )
-#  error Use of BX was requested, but is not available on the target processor.
-# endif /* ARCH level */
-#endif /* __USE_BX__ */
-
 #endif /* _ARM_ASM_H */
diff --git a/libc/sysdeps/linux/arm/bits/arm_bx.h b/libc/sysdeps/linux/arm/bits/arm_bx.h
new file mode 100644
index 000000000..321490e55
--- /dev/null
+++ b/libc/sysdeps/linux/arm/bits/arm_bx.h
@@ -0,0 +1,34 @@
+/* Copyright (C) 2013 Yann E. MORIN <yann.morin.1998@free.fr>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the GNU C Library; if not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _ARM_BX_H
+#define _ARM_BX_H
+
+/* We need features.h first */
+#if !defined _FEATURES_H
+#error Please include features.h first
+#endif /* features.h not yet included */
+
+#if defined(__USE_BX__)
+# if (   defined (__ARM_ARCH_2__)  || defined (__ARM_ARCH_3__) \
+      || defined (__ARM_ARCH_3M__) || defined (__ARM_ARCH_4__) \
+     )
+#  error Use of BX was requested, but is not available on the target processor.
+# endif /* ARCH level */
+#endif /* __USE_BX__ */
+
+#endif /* _ARM_BX_H */
diff --git a/libc/sysdeps/linux/arm/clone.S b/libc/sysdeps/linux/arm/clone.S
index e73ddb6a4..03cd10e62 100644
--- a/libc/sysdeps/linux/arm/clone.S
+++ b/libc/sysdeps/linux/arm/clone.S
@@ -24,6 +24,7 @@
 #include <bits/errno.h>
 #include <sys/syscall.h>
 #include <bits/arm_asm.h>
+#include <bits/arm_bx.h>
 
 #if defined(__NR_clone)
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
diff --git a/libc/sysdeps/linux/arm/mmap64.S b/libc/sysdeps/linux/arm/mmap64.S
index 3b66ef31a..f4c491aac 100644
--- a/libc/sysdeps/linux/arm/mmap64.S
+++ b/libc/sysdeps/linux/arm/mmap64.S
@@ -20,6 +20,7 @@
 #include <bits/errno.h>
 #include <sys/syscall.h>
 #include <bits/arm_asm.h>
+#include <bits/arm_bx.h>
 
 #ifdef __NR_mmap2
 
diff --git a/libc/sysdeps/linux/arm/syscall-eabi.S b/libc/sysdeps/linux/arm/syscall-eabi.S
index 56439044f..005cfe357 100644
--- a/libc/sysdeps/linux/arm/syscall-eabi.S
+++ b/libc/sysdeps/linux/arm/syscall-eabi.S
@@ -17,6 +17,7 @@
 
 #include <sys/syscall.h>
 #include <bits/arm_asm.h>
+#include <bits/arm_bx.h>
 
 /* In the EABI syscall interface, we don't need a special syscall to
    implement syscall().  It won't work reliably with 64-bit arguments
diff --git a/libc/sysdeps/linux/arm/sysdep.h b/libc/sysdeps/linux/arm/sysdep.h
index 5c751f544..64f40407e 100644
--- a/libc/sysdeps/linux/arm/sysdep.h
+++ b/libc/sysdeps/linux/arm/sysdep.h
@@ -20,7 +20,7 @@
 #define _LINUX_ARM_SYSDEP_H 1
 
 #include <common/sysdep.h>
-#include <bits/arm_asm.h>
+#include <bits/arm_bx.h>
 
 #include <sys/syscall.h>
 /* For Linux we can use the system call table in the header file
diff --git a/libc/sysdeps/linux/arm/vfork.S b/libc/sysdeps/linux/arm/vfork.S
index 6a1c65e09..99fb6cb1f 100644
--- a/libc/sysdeps/linux/arm/vfork.S
+++ b/libc/sysdeps/linux/arm/vfork.S
@@ -7,6 +7,7 @@
 
 #include <features.h>
 #include <bits/arm_asm.h>
+#include <bits/arm_bx.h>
 
 #define _ERRNO_H
 #include <bits/errno.h>