gdb/add-dwarf_expr_piece.op.patch

From 89cf6ba4a207f5342db58d9e43178ae516cc220e Mon Sep 17 00:00:00 2001
From: Tom de Vries <tdevries@suse.de>
Date: Wed, 15 Jan 2025 17:02:00 +0100
Subject: [PATCH 23/46] Add dwarf_expr_piece.op

Add a new field "dwarf_location_atom op" to dwarf_expr_piece to keep track of
which dwarf_location_atom caused a dwarf_expr_piece to be added.

This is used in the following patch.

Tested on s390x-linux.

Approved-By: Tom Tromey <tom@tromey.com>
---
 gdb/dwarf2/expr.c | 10 ++++++----
 gdb/dwarf2/expr.h |  6 +++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
index cb80dbf60b1..03107f90575 100644
--- a/gdb/dwarf2/expr.c
+++ b/gdb/dwarf2/expr.c
@@ -1198,13 +1198,15 @@ dwarf_expr_context::stack_empty_p () const
 
 /* Add a new piece to the dwarf_expr_context's piece list.  */
 void
-dwarf_expr_context::add_piece (ULONGEST size, ULONGEST offset)
+dwarf_expr_context::add_piece (ULONGEST size, ULONGEST offset,
+			       enum dwarf_location_atom op)
 {
   dwarf_expr_piece &p = this->m_pieces.emplace_back ();
 
   p.location = this->m_location;
   p.size = size;
   p.offset = offset;
+  p.op = op;
 
   if (p.location == DWARF_VALUE_LITERAL)
     {
@@ -2169,7 +2171,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
 
 	    /* Record the piece.  */
 	    op_ptr = safe_read_uleb128 (op_ptr, op_end, &size);
-	    add_piece (8 * size, 0);
+	    add_piece (8 * size, 0, op);
 
 	    /* Pop off the address/regnum, and reset the location
 	       type.  */
@@ -2187,7 +2189,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
 	    /* Record the piece.  */
 	    op_ptr = safe_read_uleb128 (op_ptr, op_end, &size);
 	    op_ptr = safe_read_uleb128 (op_ptr, op_end, &uleb_offset);
-	    add_piece (size, uleb_offset);
+	    add_piece (size, uleb_offset, op);
 
 	    /* Pop off the address/regnum, and reset the location
 	       type.  */
@@ -2389,7 +2391,7 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
      pointer, then make a pieced value.  This is ok because we can't
      have implicit pointers in contexts where pieces are invalid.  */
   if (this->m_location == DWARF_VALUE_IMPLICIT_POINTER)
-    add_piece (8 * this->m_addr_size, 0);
+    add_piece (8 * this->m_addr_size, 0, DW_OP_implicit_pointer);
 
   this->m_recursion_depth--;
   gdb_assert (this->m_recursion_depth >= 0);
diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h
index b02cc531640..957c58f30c4 100644
--- a/gdb/dwarf2/expr.h
+++ b/gdb/dwarf2/expr.h
@@ -24,6 +24,7 @@
 
 #include "leb128.h"
 #include "dwarf2/call-site.h"
+#include "dwarf2.h"
 
 struct dwarf2_per_objfile;
 
@@ -54,6 +55,9 @@ enum dwarf_value_location
 /* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece.  */
 struct dwarf_expr_piece
 {
+  /* The DWARF operation for which the piece was created.  */
+  enum dwarf_location_atom op;
+
   enum dwarf_value_location location;
 
   union
@@ -208,7 +212,7 @@ struct dwarf_expr_context
   struct type *address_type () const;
   void push (struct value *value, bool in_stack_memory);
   bool stack_empty_p () const;
-  void add_piece (ULONGEST size, ULONGEST offset);
+  void add_piece (ULONGEST size, ULONGEST offset, enum dwarf_location_atom op);
   void execute_stack_op (const gdb_byte *op_ptr, const gdb_byte *op_end);
   void pop ();
   struct value *fetch (int n);
-- 
2.43.0