[PATCH 3/3] gdb/arm: Make sp alias for one of the other stack pointers

[Yvan Roux <yvan.roux@foss.st.com>]

For Cortex-M targets, the sp register is never detached from msp or
psp, it always has the same value as one of them. Let GDB treat
ARM_SP_REGNUM as an alias similar to what is done in hardware.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
Signed-off-by: Yvan Roux <yvan.roux@foss.st.com>
---
 gdb/arm-tdep.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index e497dd1b3b8..694fe8a8859 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -385,9 +385,6 @@ static CORE_ADDR
 arm_cache_get_sp_register (struct arm_prologue_cache *cache,
 			   arm_gdbarch_tdep *tdep, int regnum)
 {
-  if (regnum == ARM_SP_REGNUM)
-    return cache->sp;
-
   if (tdep->have_sec_ext)
     {
       if (regnum == tdep->m_profile_msp_s_regnum)
@@ -402,6 +399,8 @@ arm_cache_get_sp_register (struct arm_prologue_cache *cache,
 	return arm_cache_get_sp_register (cache, tdep, cache->active_msp_regnum);
       if (regnum == tdep->m_profile_psp_regnum)
 	return arm_cache_get_sp_register (cache, tdep, cache->active_psp_regnum);
+      if (regnum == ARM_SP_REGNUM)
+	return arm_cache_get_sp_register (cache, tdep, cache->active_sp_regnum);
     }
   else if (tdep->is_m)
     {
@@ -409,7 +408,11 @@ arm_cache_get_sp_register (struct arm_prologue_cache *cache,
 	return cache->msp_s;
       if (regnum == tdep->m_profile_psp_regnum)
 	return cache->psp_s;
+      if (regnum == ARM_SP_REGNUM)
+	return arm_cache_get_sp_register (cache, tdep, cache->active_sp_regnum);
     }
+  else if (regnum == ARM_SP_REGNUM)
+    return cache->sp;
 
   gdb_assert_not_reached ("Invalid SP selection");
 }
@@ -430,12 +433,6 @@ static void
 arm_cache_set_active_sp_value (struct arm_prologue_cache *cache,
 			       arm_gdbarch_tdep *tdep, CORE_ADDR val)
 {
-  if (cache->active_sp_regnum == ARM_SP_REGNUM)
-    {
-      cache->sp = val;
-      return;
-    }
-
   if (tdep->have_sec_ext)
     {
       if (cache->active_sp_regnum == tdep->m_profile_msp_s_regnum)
@@ -458,6 +455,11 @@ arm_cache_set_active_sp_value (struct arm_prologue_cache *cache,
 
       return;
     }
+  else if (cache->active_sp_regnum == ARM_SP_REGNUM)
+    {
+      cache->sp = val;
+      return;
+    }
 
   gdb_assert_not_reached ("Invalid SP selection");
 }
-- 
2.17.1