diff mbox

[2/3] gdb/arm: Use type_align instead of arm_type_align

Message ID dc5518dbbe014bf6b4b594246c01a8fe7ede14fa.1555111225.git.andrew.burgess@embecosm.com
State New
Headers show

Commit Message

Andrew Burgess April 12, 2019, 11:25 p.m. UTC
Replaces use of arm_type_align with common type_align function.

Doing this fixes a bug in arm_type_align where static fields are
considered as part of the alignment calculation of a struct, which
results in arguments passed on the stack being misaligned, this bug
was causing a failure in gdb.cp/many-args.exp.

Part of the old arm_type_align is retained and used as the gdbarch
type align callback in order to correctly align vectors.

gdb/ChangeLog:

	* arm-tdep.c (arm_type_align): Only handle vector override case.
	(arm_push_dummy_call): Use type_align.
	(arm_gdbarch_init): Register arm_type_align gdbarch function.
---
 gdb/ChangeLog  |  6 ++++++
 gdb/arm-tdep.c | 68 +++++++++++++++-------------------------------------------
 2 files changed, 23 insertions(+), 51 deletions(-)

Comments

Kevin Buettner April 14, 2019, 6:56 p.m. UTC | #1
On Sat, 13 Apr 2019 00:25:33 +0100
Andrew Burgess <andrew.burgess@embecosm.com> wrote:

> Replaces use of arm_type_align with common type_align function.
> 
> Doing this fixes a bug in arm_type_align where static fields are
> considered as part of the alignment calculation of a struct, which
> results in arguments passed on the stack being misaligned, this bug
> was causing a failure in gdb.cp/many-args.exp.
> 
> Part of the old arm_type_align is retained and used as the gdbarch
> type align callback in order to correctly align vectors.
> 
> gdb/ChangeLog:
> 
> 	* arm-tdep.c (arm_type_align): Only handle vector override case.
> 	(arm_push_dummy_call): Use type_align.
> 	(arm_gdbarch_init): Register arm_type_align gdbarch function.

LGTM.

Kevin
diff mbox

Patch

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 599f785b349..742bfa57069 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -3314,62 +3314,25 @@  pop_stack_item (struct stack_item *si)
   return si;
 }
 
+/* Implement the gdbarch type alignment method, overrides the generic
+   alignment algorithm for anything that is arm specific.  */
 
-/* Return the alignment (in bytes) of the given type.  */
-
-static int
-arm_type_align (struct type *t)
+static ULONGEST
+arm_type_align (gdbarch *gdbarch, struct type *t)
 {
-  int n;
-  int align;
-  int falign;
-
   t = check_typedef (t);
-  switch (TYPE_CODE (t))
+  if (TYPE_CODE (t) == TYPE_CODE_ARRAY && TYPE_VECTOR (t))
     {
-    default:
-      /* Should never happen.  */
-      internal_error (__FILE__, __LINE__, _("unknown type alignment"));
-      return 4;
-
-    case TYPE_CODE_PTR:
-    case TYPE_CODE_ENUM:
-    case TYPE_CODE_INT:
-    case TYPE_CODE_FLT:
-    case TYPE_CODE_SET:
-    case TYPE_CODE_RANGE:
-    case TYPE_CODE_REF:
-    case TYPE_CODE_RVALUE_REF:
-    case TYPE_CODE_CHAR:
-    case TYPE_CODE_BOOL:
-      return TYPE_LENGTH (t);
-
-    case TYPE_CODE_ARRAY:
-      if (TYPE_VECTOR (t))
-	{
-	  /* Use the natural alignment for vector types (the same for
-	     scalar type), but the maximum alignment is 64-bit.  */
-	  if (TYPE_LENGTH (t) > 8)
-	    return 8;
-	  else
-	    return TYPE_LENGTH (t);
-	}
+      /* Use the natural alignment for vector types (the same for
+	 scalar type), but the maximum alignment is 64-bit.  */
+      if (TYPE_LENGTH (t) > 8)
+	return 8;
       else
-	return arm_type_align (TYPE_TARGET_TYPE (t));
-    case TYPE_CODE_COMPLEX:
-      return arm_type_align (TYPE_TARGET_TYPE (t));
-
-    case TYPE_CODE_STRUCT:
-    case TYPE_CODE_UNION:
-      align = 1;
-      for (n = 0; n < TYPE_NFIELDS (t); n++)
-	{
-	  falign = arm_type_align (TYPE_FIELD_TYPE (t, n));
-	  if (falign > align)
-	    align = falign;
-	}
-      return align;
+	return TYPE_LENGTH (t);
     }
+
+  /* Allow the common code to calculate the alignment.  */
+  return 0;
 }
 
 /* Possible base types for a candidate for passing and returning in
@@ -3715,7 +3678,7 @@  arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
       typecode = TYPE_CODE (arg_type);
       val = value_contents (args[argnum]);
 
-      align = arm_type_align (arg_type);
+      align = type_align (arg_type);
       /* Round alignment up to a whole number of words.  */
       align = (align + INT_REGISTER_SIZE - 1) & ~(INT_REGISTER_SIZE - 1);
       /* Different ABIs have different maximum alignments.  */
@@ -9309,6 +9272,9 @@  arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   else
     set_gdbarch_wchar_signed (gdbarch, 1);
 
+  /* Compute type alignment.  */
+  set_gdbarch_type_align (gdbarch, arm_type_align);
+
   /* Note: for displaced stepping, this includes the breakpoint, and one word
      of additional scratch space.  This setting isn't used for anything beside
      displaced stepping at present.  */