Re: Make more macro checks ARMv8-M baseline proof

[Christophe Lyon <christophe dot lyon at linaro dot org>]

I forgot that the suitable format in this project is via git
format-patch, so here is the same patch in that format.

Christophe

On Mon, 1 Apr 2019 at 16:42, Christophe Lyon <christophe.lyon@linaro.org> wrote:
>
> Hi,
>
> After Thomas' patch
> (https://sourceware.org/ml/newlib/2016/msg00017.html), it seems that
> some changes committed to libgloss are missing in newlib.
> I noticed the problem when building a toolchain where GCC is
> configured --with-cpu=cortex-m{0,23}.
>
> This small patch brings the necessary changes from libgloss to newlib.
> With this, the GCC toolchain build completes.
>
> OK?
>
> Thanks,
>
> Christophe

From 1ea9c597edbece03bce084afe33b45f1ee9ff67f Mon Sep 17 00:00:00 2001
From: Christophe Lyon <christophe.lyon@linaro.org>
Date: Mon, 1 Apr 2019 17:30:53 +0000
Subject: [PATCH 1/1] Make more macro checks ARMv8-M baseline proof.

Commit 69f4c4029183fb26d2fcae00790881620c1978a3 improved most
macro checks to be ARMv8-M baseline proof, but missed a few
occurrences which otherwise fail to build when using a CPU setting
such as cortex-m0 or cortex-m23. This patch brings the same
changes as the ones that were committed to libgloss at that time.

	newlib:
	* libc/sys/arm/crt0.S: Use THUMB1_ONLY rather than
	__ARM_ARCH_6M__.
	* libc/sys/arm/trap.S: Use PREFER_THUMB rather than __thumb2__.
---
 newlib/libc/sys/arm/crt0.S | 8 ++++----
 newlib/libc/sys/arm/trap.S | 3 ++-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/newlib/libc/sys/arm/crt0.S b/newlib/libc/sys/arm/crt0.S
index 64d4259..8c9f7be 100644
--- a/newlib/libc/sys/arm/crt0.S
+++ b/newlib/libc/sys/arm/crt0.S
@@ -85,7 +85,7 @@
 
 	/*  Stack limit is at end of data.  */
 	/*  Allow slop for stack overflow handling and small frames.  */
-#ifdef __ARM_ARCH_6M__
+#ifdef THUMB1_ONLY
 	ldr	r0, .LC2
 	adds	r0, #128
 	adds	r0, #128
@@ -137,7 +137,7 @@
 	beq	.LC27
 
 	/*  Allow slop for stack overflow handling and small frames.  */
-#ifdef __ARM_ARCH_6M__
+#ifdef THUMB1_ONLY
 	adds	r2, #128
 	adds	r2, #128
 	mov	sl, r2
@@ -164,7 +164,7 @@
 #ifdef __thumb2__
 	it	eq
 #endif	
-#ifdef __ARM_ARCH_6M__
+#ifdef THUMB1_ONLY
 	bne	.LC28
 	ldr	r3, .LC0
 .LC28:
@@ -219,7 +219,7 @@
 	   this default 64k is enough for the program being executed.
 	   However, it ensures that this simple crt0 world will not
 	   immediately cause an overflow event:  */
-#ifdef __ARM_ARCH_6M__
+#ifdef THUMB1_ONLY
 	movs	r2, #64
 	lsls	r2, r2, #10
 	subs	r2, r3, r2
diff --git a/newlib/libc/sys/arm/trap.S b/newlib/libc/sys/arm/trap.S
index 21b6937..d854b57 100644
--- a/newlib/libc/sys/arm/trap.S
+++ b/newlib/libc/sys/arm/trap.S
@@ -1,5 +1,6 @@
+#include "arm.h"
         /* Run-time exception support */
-#if !defined(__thumb2__)
+#ifndef PREFER_THUMB
 #include "swi.h"
 
 /* .text is used instead of .section .text so it works with arm-aout too.  */
-- 
2.7.4