system/gcc: Make ARMv7 unwind macros functions

This workaround is already needed upstream for FreeBSD.  Let's go ahead
and use the same workaround for musl.  We also ensure they are not
declared `inline` so that they are available as library functions.

We also have a hack in place for the stage1 Ada driver due to their own
hack pulling in the Arm unwind functions directly without linking.

Fixes: #866 (and probably more as we continue building packages)

1 files changed, 53 insertions, 0 deletions

diff --git a/system/gcc/206-arm-unwind-functionise.patch b/system/gcc/206-arm-unwind-functionise.patch
new file mode 100644
index 000000000..0cee39e54
--- /dev/null
+++ b/system/gcc/206-arm-unwind-functionise.patch
@@ -0,0 +1,53 @@
+--- gcc-8.5.0/libgcc/config/arm/unwind-arm.c.old	2021-05-14 03:42:10.000000000 -0500
++++ gcc-8.5.0/libgcc/config/arm/unwind-arm.c	2022-12-24 20:04:04.085095067 -0600
+@@ -510,22 +510,22 @@
+   return __gnu_unwind_pr_common (state, ucbp, context, 2);
+ }
+ 
+-#ifdef __FreeBSD__
+-/* FreeBSD expects these to be functions */
+-inline _Unwind_Ptr
++#if !defined(IN_STAGE1_ADA) && (defined(__FreeBSD__) || defined(linux))
++/* Some packages expect these to be functions */
++_Unwind_Ptr
+ _Unwind_GetIP (struct _Unwind_Context *context)
+ {
+   return _Unwind_GetGR (context, 15) & ~(_Unwind_Word)1;
+ }
+ 
+-inline _Unwind_Ptr
++_Unwind_Ptr
+ _Unwind_GetIPInfo (struct _Unwind_Context *context, int *ip_before_insn)
+ {
+   *ip_before_insn = 0;
+   return _Unwind_GetIP (context);
+ }
+ 
+-inline void
++void
+ _Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val)
+ {
+   _Unwind_SetGR (context, 15, val | (_Unwind_GetGR (context, 15) & 1));
+--- gcc-8.5.0/libgcc/config/arm/unwind-arm.h.old	2021-05-14 03:42:10.000000000 -0500
++++ gcc-8.5.0/libgcc/config/arm/unwind-arm.h	2022-12-24 20:03:41.415095129 -0600
+@@ -72,7 +72,7 @@
+     {
+       return _URC_FAILURE;
+     }
+-#ifndef __FreeBSD__
++#if defined(IN_STAGE1_ADA) || (!defined(__FreeBSD__) && !defined(linux))
+   /* Return the address of the instruction, not the actual IP value.  */
+ #define _Unwind_GetIP(context) \
+   (_Unwind_GetGR (context, 15) & ~(_Unwind_Word)1)
+--- gcc-8.5.0/gcc/ada/raise-gcc.c.old	2021-05-14 03:42:08.000000000 -0500
++++ gcc-8.5.0/gcc/ada/raise-gcc.c	2022-12-24 22:43:03.605084414 -0600
+@@ -91,7 +91,9 @@
+      This is a hack ???, the real fix is to link gnat1/gnatbind with the
+      runtime of the build compiler.  */
+ # ifdef EH_MECHANISM_arm
++#   define IN_STAGE1_ADA  /* even worse hack  */
+ #   include "config/arm/unwind-arm.h"
++#   undef IN_STAGE1_ADA
+ # else
+ #   include "unwind-generic.h"
+ # endif