hppa: Implement swapcontext in assembler (bug 28960)

When swapcontext.c is compiled without -g, the following error occurs:
Error: CFI instruction used without previous .cfi_startproc

Fix by converting swapcontext routine to assembler.

(cherry picked from commit 738ee53f0ce5e39b9b7a6777f5d3057afbaac498)

2 files changed, 72 insertions, 83 deletions

diff --git a/sysdeps/unix/sysv/linux/hppa/swapcontext.S b/sysdeps/unix/sysv/linux/hppa/swapcontext.S
new file mode 100644
index 0000000000..94b164dc63
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/swapcontext.S
@@ -0,0 +1,72 @@
+/* Swap to new context.
+   Copyright (C) 2008-2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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.
+
+   The GNU C Library 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include "ucontext_i.h"
+
+	.text
+ENTRY(__swapcontext)
+
+	/* Copy rp to ret0 (r28).  */
+	copy %rp,%ret0
+
+	/* Create a frame.  */
+	ldo 64(%sp),%sp
+	.cfi_def_cfa_offset -64
+
+	/* Save the current machine context to oucp.  */
+	bl __getcontext,%rp
+
+	/* Copy oucp to register ret1 (r29).  __getcontext saves and
+	   restores it on a normal return.  It is restored from oR29
+	   on reactivation.  */
+	copy %r26,%ret1
+
+	/* Pop frame.  */
+	ldo -64(%sp),%sp
+	.cfi_def_cfa_offset 0
+
+	/* Load return pointer from oR28.  */
+	ldw oR28(%ret1),%rp
+
+	/* Return if error.  */
+	or,= %r0,%ret0,%r0
+	bv,n %r0(%rp)
+
+	/* Load sc_sar flag.  */
+	ldb oSAR(%ret1),%r20
+
+	/* Return if oucp context has been reactivated.  */
+	or,= %r0,%r20,%r0
+	bv,n %r0(%rp)
+
+	/* Mark sc_sar flag.  */
+	ldi 1,%r20
+	stb %r20,oSAR(%ret1)
+
+	/* Activate the machine context in ucp.  */
+	bl __setcontext,%rp
+	ldw oR25(%ret1),%r26
+
+	/* Load return pointer.  */
+	ldw oR28(%ret1),%rp
+	bv,n %r0(%rp)
+
+PSEUDO_END(__swapcontext)
+
+weak_alias (__swapcontext, swapcontext)
diff --git a/sysdeps/unix/sysv/linux/hppa/swapcontext.c b/sysdeps/unix/sysv/linux/hppa/swapcontext.c
deleted file mode 100644
index 1664f68c7b..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/swapcontext.c
+++ /dev/null
@@ -1,83 +0,0 @@
-/* Swap to new context.
-   Copyright (C) 2008-2021 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Helge Deller <deller@gmx.de>, 2008.
-
-   The GNU C Library 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.
-
-   The GNU C Library 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <ucontext.h>
-#include "ucontext_i.h"
-
-extern int __getcontext (ucontext_t *ucp);
-extern int __setcontext (const ucontext_t *ucp);
-
-int
-__swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
-{
-  /* Save rp for debugger.  */
-  asm ("stw %rp,-20(%sp)");
-  asm (".cfi_offset 2, -20");
-
-  /* Copy rp to ret0 (r28).  */
-  asm ("copy %rp,%ret0");
-
-  /* Create a frame.  */
-  asm ("ldo 64(%sp),%sp");
-  asm (".cfi_def_cfa_offset -64");
-
-  /* Save the current machine context to oucp.  */
-  asm ("bl __getcontext,%rp");
-
-  /* Copy oucp to register ret1 (r29).  __getcontext saves and restores it
-     on a normal return.  It is restored from oR29 on reactivation.  */
-  asm ("copy %r26,%ret1");
-
-  /* Pop frame.  */
-  asm ("ldo -64(%sp),%sp");
-  asm (".cfi_def_cfa_offset 0");
-
-  /* Load return pointer from oR28.  */
-  asm ("ldw %0(%%ret1),%%rp" : : "i" (oR28));
-
-  /* Return if error.  */
-  asm ("or,= %r0,%ret0,%r0");
-  asm ("bv,n %r0(%rp)");
-
-  /* Load sc_sar flag.  */
-  asm ("ldb %0(%%ret1),%%r20" : : "i" (oSAR));
-
-  /* Return if oucp context has been reactivated.  */
-  asm ("or,= %r0,%r20,%r0");
-  asm ("bv,n %r0(%rp)");
-
-  /* Mark sc_sar flag.  */
-  asm ("1: ldi 1,%r20");
-  asm ("stb %%r20,%0(%%ret1)" : : "i" (oSAR));
-
-  /* Activate the machine context in ucp.  */
-  asm ("bl __setcontext,%rp");
-  asm ("ldw %0(%%ret1),%%r26" : : "i" (oR25));
-
-  /* Load return pointer.  */
-  asm ("ldw %0(%%ret1),%%rp" : : "i" (oR28));
-
-  /* A successful call to setcontext does not return.  */
-  asm ("bv,n %r0(%rp)");
-
-  /* Make gcc happy.  */
-  return 0;
-}
-
-weak_alias (__swapcontext, swapcontext)