gdb/

	Fix PR 10640.
	* dwarf2-frame.c (no_dwarf_call): New function.
	(execute_stack_op): Set CTX->DWARF_CALL.
	* dwarf2expr.c (execute_stack_op) <DW_OP_call2, DW_OP_call4>: New.
	* dwarf2expr.h (struct dwarf_expr_context) <dwarf_call>: New.
	(struct dwarf_expr_context) <get_subr>: Remove the #if0-ed field.
	* dwarf2loc.c (per_cu_dwarf_call, dwarf_expr_dwarf_call): New functions.
	(dwarf2_evaluate_loc_desc): Initialize CTX->DWARF_CALL.
	(needs_frame_dwarf_call): New function.
	(dwarf2_loc_desc_needs_frame): Initialize CTX->DWARF_CALL.
	* dwarf2read.c (follow_die_offset): Based on former follow_die_ref.
	Update the comment.  Move variables die, offset and error call to ...
	(follow_die_ref): ... a new function.
	(dwarf2_fetch_die_location_block): New function.
	* dwarf2loc.h (dwarf2_fetch_die_location_block): New prototype.

gdb/testsuite/
	Test PR 10640.
	* gdb.dwarf2/dw2-op-call.exp, gdb.dwarf2/dw2-op-call.S: New.

1 files changed, 39 insertions, 0 deletions

diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index 9864c466a9f..8a9a34616ce 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -232,6 +232,33 @@ dwarf_expr_tls_address (void *baton, CORE_ADDR offset)
   return target_translate_tls_address (objfile, offset);
 }
 
+/* Call DWARF subroutine from DW_AT_location of DIE at DIE_OFFSET in current CU
+   (as is PER_CU).  State of the CTX is not affected by the call and return.  */
+
+static void
+per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset,
+		   struct dwarf2_per_cu_data *per_cu)
+{
+  struct dwarf2_locexpr_baton block;
+
+  block = dwarf2_fetch_die_location_block (die_offset, per_cu);
+
+  /* DW_OP_call_ref is currently not supported.  */
+  gdb_assert (block.per_cu == per_cu);
+
+  dwarf_expr_eval (ctx, block.data, block.size);
+}
+
+/* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc.  */
+
+static void
+dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
+{
+  struct dwarf_expr_baton *debaton = ctx->baton;
+
+  return per_cu_dwarf_call (ctx, die_offset, debaton->per_cu);
+}
+
 struct piece_closure
 {
   /* Reference count.  */
@@ -815,6 +842,7 @@ dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
   ctx->get_frame_base = dwarf_expr_frame_base;
   ctx->get_frame_cfa = dwarf_expr_frame_cfa;
   ctx->get_tls_address = dwarf_expr_tls_address;
+  ctx->dwarf_call = dwarf_expr_dwarf_call;
 
   dwarf_expr_eval (ctx, data, size);
   if (ctx->num_pieces > 0)
@@ -962,6 +990,16 @@ needs_frame_tls_address (void *baton, CORE_ADDR offset)
   return 1;
 }
 
+/* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame.  */
+
+static void
+needs_frame_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
+{
+  struct needs_frame_baton *nf_baton = ctx->baton;
+
+  return per_cu_dwarf_call (ctx, die_offset, nf_baton->per_cu);
+}
+
 /* Return non-zero iff the location expression at DATA (length SIZE)
    requires a frame to evaluate.  */
 
@@ -988,6 +1026,7 @@ dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size,
   ctx->get_frame_base = needs_frame_frame_base;
   ctx->get_frame_cfa = needs_frame_frame_cfa;
   ctx->get_tls_address = needs_frame_tls_address;
+  ctx->dwarf_call = needs_frame_dwarf_call;
 
   dwarf_expr_eval (ctx, data, size);