From: Tom Tromey <tromey@adacore.com>
Date: Tue, 21 Feb 2023 20:49:17 +0000 (-0700)
Subject: Use entry values for 32-bit PPC struct return
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fbdecfbf285234cd4eba0e7daf480c63b2d65eb3;p=binutils-gdb.git

Use entry values for 32-bit PPC struct return

AdaCore has a local patch for PPC "finish", but last year, Ulrich
Weigand pointed out that this patch was incorrect.  It may work for
simple functions like the one in the internal test, but nothing
guarantees that r3 will be preserved by the callee, so checking r3 on
exit is not always correct.

This patch fixes the problem using the same approach as PPC64: use the
entry value of r3, if available.  Ulrich confirmed this matches the
PPC32 ABI.
---

diff --git a/gdb/ppc-sysv-tdep.c b/gdb/ppc-sysv-tdep.c
index ab859fbe143..66630793e86 100644
--- a/gdb/ppc-sysv-tdep.c
+++ b/gdb/ppc-sysv-tdep.c
@@ -2159,8 +2159,7 @@ ppc64_sysv_abi_return_value (struct gdbarch *gdbarch, struct value *function,
 }
 
 CORE_ADDR
-ppc64_sysv_get_return_buf_addr (struct type *val_type,
-				frame_info_ptr cur_frame)
+ppc_sysv_get_return_buf_addr (struct type *val_type, frame_info_ptr cur_frame)
 {
   /* The PowerPC ABI specifies aggregates that are not returned by value
      are returned in a storage buffer provided by the caller.  The
diff --git a/gdb/ppc-tdep.h b/gdb/ppc-tdep.h
index db4e53205a6..ddeb810f35b 100644
--- a/gdb/ppc-tdep.h
+++ b/gdb/ppc-tdep.h
@@ -175,7 +175,9 @@ extern void ppc_collect_vsxregset (const struct regset *regset,
 				  const struct regcache *regcache,
 				  int regnum, void *vsxregs, size_t len);
 
-extern CORE_ADDR ppc64_sysv_get_return_buf_addr (type*, frame_info_ptr);
+/* Implementation of the gdbarch get_return_buf_addr hook.  */
+
+extern CORE_ADDR ppc_sysv_get_return_buf_addr (type*, frame_info_ptr);
 
 /* Private data that this module attaches to struct gdbarch.  */
 
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index ee18b495d4c..966b75b8baa 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -8273,12 +8273,11 @@ rs6000_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   if (wordsize == 8)
     {
       set_gdbarch_return_value (gdbarch, ppc64_sysv_abi_return_value);
-      set_gdbarch_get_return_buf_addr (gdbarch,
-				       ppc64_sysv_get_return_buf_addr);
       set_gdbarch_update_call_site_pc (gdbarch, ppc64_update_call_site_pc);
     }
   else
     set_gdbarch_return_value (gdbarch, ppc_sysv_abi_return_value);
+  set_gdbarch_get_return_buf_addr (gdbarch, ppc_sysv_get_return_buf_addr);
 
   /* Set lr_frame_offset.  */
   if (wordsize == 8)