[PATCH 1/3] gdb/aarch64: Use type_align instead of aarch64_type_align

[Andrew Burgess <andrew.burgess@embecosm.com>]

Replaces use of aarch64_type_align with common type_align function.

Doing this fixes a bug in aarch64_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
is exposed in the new test gdb.cp/many-args.exp.

Part of the old aarch64_type_align is retained and used as the gdbarch
type align callback in order to correctly align vectors.

gdb/ChangeLog:

	* aarch64-tdep.c (aarch64_type_align): Only handle vector override
	case.
	(pass_on_stack): Use type_align.
	(aarch64_gdbarch_init): Register aarch64_type_align gdbarch
	function.

gdb/testsuite/ChangeLog:

	* gdb.cp/many-args.cc: New file.
	* gdb.cp/many-args.exp: New file.
---
 gdb/ChangeLog                      |  8 ++++
 gdb/aarch64-tdep.c                 | 66 ++++++++-------------------------
 gdb/testsuite/ChangeLog            |  5 +++
 gdb/testsuite/gdb.cp/many-args.cc  | 76 ++++++++++++++++++++++++++++++++++++++
 gdb/testsuite/gdb.cp/many-args.exp | 37 +++++++++++++++++++
 5 files changed, 141 insertions(+), 51 deletions(-)
 create mode 100644 gdb/testsuite/gdb.cp/many-args.cc
 create mode 100644 gdb/testsuite/gdb.cp/many-args.exp

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 1b3977bfaf2..8e44442c33a 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -1218,62 +1218,25 @@ typedef struct
 
 DEF_VEC_O (stack_item_t);
 
-/* Return the alignment (in bytes) of the given type.  */
+/* Implement the gdbarch type alignment method, overrides the generic
+   alignment algorithm for anything that is aarch64 specific.  */
 
-static int
-aarch64_type_align (struct type *t)
+static ULONGEST
+aarch64_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_BITSTRING:
-    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 128-bit.  */
-	  if (TYPE_LENGTH (t) > 16)
-	    return 16;
-	  else
-	    return TYPE_LENGTH (t);
-	}
+      /* Use the natural alignment for vector types (the same for
+	 scalar type), but the maximum alignment is 128-bit.  */
+      if (TYPE_LENGTH (t) > 16)
+	return 16;
       else
-	return aarch64_type_align (TYPE_TARGET_TYPE (t));
-    case TYPE_CODE_COMPLEX:
-      return aarch64_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 = aarch64_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;
 }
 
 /* Worker function for aapcs_is_vfp_call_or_return_candidate.
@@ -1540,7 +1503,7 @@ pass_on_stack (struct aarch64_call_info *info, struct type *type,
 
   info->argnum++;
 
-  align = aarch64_type_align (type);
+  align = type_align (type);
 
   /* PCS C.17 Stack should be aligned to the larger of 8 bytes or the
      Natural alignment of the argument's type.  */
@@ -3370,6 +3333,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
   set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
   set_gdbarch_long_double_format (gdbarch, floatformats_ia64_quad);
+  set_gdbarch_type_align (gdbarch, aarch64_type_align);
 
   /* Internal <-> external register number maps.  */
   set_gdbarch_dwarf2_reg_to_regnum (gdbarch, aarch64_dwarf_reg_to_regnum);
diff --git a/gdb/testsuite/gdb.cp/many-args.cc b/gdb/testsuite/gdb.cp/many-args.cc
new file mode 100644
index 00000000000..389a69ae32b
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/many-args.cc
@@ -0,0 +1,76 @@
+/* Copyright 2019 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+
+/* Vector type will align on a 16-byte boundary.  */
+typedef int v4si __attribute__ ((vector_size (16)));
+
+struct ss
+{
+  static v4si static_field;
+
+  unsigned char aa;
+
+  bool operator== (const ss &rhs)
+  {
+    return (memcmp (&this->static_field, &rhs.static_field,
+		    sizeof (this->static_field)) == 0
+            && this->aa == rhs.aa);
+  }
+};
+
+v4si ss::static_field = { 1, 2, 3, 4 };
+
+ss ref_val = { 'a' };
+
+bool
+check_val (ss v1, ss v2, ss v3, ss v4, ss v5, ss v6, ss v7, ss v8,
+           ss v9, ss v10, ss v11, ss v12, ss v13, ss v14, ss v15,
+           ss v16, ss v17, ss v18, ss v19, ss v20, ss v21, ss v22,
+           ss v23, ss v24, ss v25, ss v26, ss v27, ss v28, ss v29,
+           ss v30, ss v31, ss v32, ss v33, ss v34, ss v35, ss v36,
+           ss v37, ss v38, ss v39, ss v40)
+{
+  return (v1 == ref_val && v2 == ref_val && v3 == ref_val && v4 == ref_val
+          && v5 == ref_val && v6 == ref_val && v7 == ref_val
+          && v8 == ref_val && v9 == ref_val && v10 == ref_val
+          && v11 == ref_val && v12 == ref_val && v13 == ref_val
+          && v14 == ref_val && v15 == ref_val && v16 == ref_val
+          && v17 == ref_val && v18 == ref_val && v19 == ref_val
+          && v20 == ref_val && v21 == ref_val && v22 == ref_val
+          && v23 == ref_val && v24 == ref_val && v25 == ref_val
+          && v26 == ref_val && v27 == ref_val && v28 == ref_val
+          && v29 == ref_val && v30 == ref_val && v31 == ref_val
+          && v32 == ref_val && v33 == ref_val && v34 == ref_val
+          && v35 == ref_val && v36 == ref_val && v37 == ref_val
+          && v38 == ref_val && v39 == ref_val && v40 == ref_val);
+}
+
+int
+main ()
+{
+  bool flag = check_val (ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val,
+			 ref_val, ref_val, ref_val, ref_val, ref_val);
+  return (flag ? 0 : 1);	/* break-here */
+}
diff --git a/gdb/testsuite/gdb.cp/many-args.exp b/gdb/testsuite/gdb.cp/many-args.exp
new file mode 100644
index 00000000000..57da1748397
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/many-args.exp
@@ -0,0 +1,37 @@
+# Copyright 2019 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the gdb testsuite.
+# It tests various aspects of iostream that have caused problems for gdb.
+
+if { [skip_cplus_tests] } { continue }
+
+standard_testfile .cc
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug c++}]} {
+    return -1
+}
+
+if ![runto_main] {
+    perror "couldn't run to breakpoint"
+    continue
+}
+
+gdb_breakpoint [gdb_get_line_number "break-here"]
+gdb_continue_to_breakpoint "break-here"
+
+gdb_test "p check_val (ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val, ref_val)" \
+    "= true" \
+    "check passing many structures"
-- 
2.14.5