Make dwarf_expr_piece::pieces an std::vector

Change the manually managed array dwarf_expr_piece::piece with an
std::vector.  After passing the pieces array to allocate_piece_closure,
dwarf2_evaluate_loc_desc_full doesn't need that data anymore.  We can
therefore move the content of the vector to avoid copying it.

Reg-tested on the buildbot.

gdb/ChangeLog:

	* dwarf2expr.h (struct dwarf_expr_piece): Move up.
	(struct dwarf_expr_context) <n_pieces>: Remove.
	<pieces>: Change type to std::vector.
	* dwarf2expr.c (dwarf_expr_context::dwarf_expr_context): Adjust.
	(dwarf_expr_context::~dwarf_expr_context): Don't manually free
	pieces.
	(dwarf_expr_context::add_piece): Adjust.
	* dwarf2loc.c (struct piece_closure): Initialize fields.
	<n_pieces>: Remove.
	<pieces>: Change type to std::vector.
	(allocate_piece_closure): Adjust, change parameter to
	std::vector rvalue and std::move it to piece_closure.
	(rw_pieced_value): Adjust.
	(check_pieced_synthetic_pointer): Adjust.
	(indirect_synthetic_pointer): Adjust.
	(coerce_pieced_ref): Adjust.
	(free_pieced_value_closure):  Adjust.  Use delete to free
	piece_closure.
	(dwarf2_evaluate_loc_desc_full): Adjust.  std::move ctx.pieces
	to allocate_piece_closure.
	(dwarf2_loc_desc_get_symbol_read_needs): Adjust.

1 files changed, 19 insertions, 27 deletions

diff --git a/gdb/dwarf2expr.c b/gdb/dwarf2expr.c
index e2724da..61a1e9e 100644
--- a/gdb/dwarf2expr.c
+++ b/gdb/dwarf2expr.c
@@ -100,9 +100,7 @@ dwarf_expr_context::dwarf_expr_context ()
   location (DWARF_VALUE_MEMORY),
   len (0),
   data (NULL),
-  initialized (0),
-  num_pieces (0),
-  pieces (NULL)
+  initialized (0)
 {
   this->stack = XNEWVEC (struct dwarf_stack_value, this->stack_allocated);
 }
@@ -112,7 +110,6 @@ dwarf_expr_context::dwarf_expr_context ()
 dwarf_expr_context::~dwarf_expr_context ()
 {
   xfree (this->stack);
-  xfree (this->pieces);
 }
 
 /* Expand the memory allocated stack to contain at least
@@ -285,47 +282,42 @@ dwarf_expr_context::stack_empty_p () const
 void
 dwarf_expr_context::add_piece (ULONGEST size, ULONGEST offset)
 {
-  struct dwarf_expr_piece *p;
+  this->pieces.emplace_back ();
+  dwarf_expr_piece &p = this->pieces.back ();
 
-  this->num_pieces++;
+  p.location = this->location;
+  p.size = size;
+  p.offset = offset;
 
-  this->pieces
-    = XRESIZEVEC (struct dwarf_expr_piece, this->pieces, this->num_pieces);
-
-  p = &this->pieces[this->num_pieces - 1];
-  p->location = this->location;
-  p->size = size;
-  p->offset = offset;
-
-  if (p->location == DWARF_VALUE_LITERAL)
+  if (p.location == DWARF_VALUE_LITERAL)
     {
-      p->v.literal.data = this->data;
-      p->v.literal.length = this->len;
+      p.v.literal.data = this->data;
+      p.v.literal.length = this->len;
     }
   else if (stack_empty_p ())
     {
-      p->location = DWARF_VALUE_OPTIMIZED_OUT;
+      p.location = DWARF_VALUE_OPTIMIZED_OUT;
       /* Also reset the context's location, for our callers.  This is
 	 a somewhat strange approach, but this lets us avoid setting
 	 the location to DWARF_VALUE_MEMORY in all the individual
 	 cases in the evaluator.  */
       this->location = DWARF_VALUE_OPTIMIZED_OUT;
     }
-  else if (p->location == DWARF_VALUE_MEMORY)
+  else if (p.location == DWARF_VALUE_MEMORY)
     {
-      p->v.mem.addr = fetch_address (0);
-      p->v.mem.in_stack_memory = fetch_in_stack_memory (0);
+      p.v.mem.addr = fetch_address (0);
+      p.v.mem.in_stack_memory = fetch_in_stack_memory (0);
     }
-  else if (p->location == DWARF_VALUE_IMPLICIT_POINTER)
+  else if (p.location == DWARF_VALUE_IMPLICIT_POINTER)
     {
-      p->v.ptr.die_sect_off = (sect_offset) this->len;
-      p->v.ptr.offset = value_as_long (fetch (0));
+      p.v.ptr.die_sect_off = (sect_offset) this->len;
+      p.v.ptr.offset = value_as_long (fetch (0));
     }
-  else if (p->location == DWARF_VALUE_REGISTER)
-    p->v.regno = value_as_long (fetch (0));
+  else if (p.location == DWARF_VALUE_REGISTER)
+    p.v.regno = value_as_long (fetch (0));
   else
     {
-      p->v.value = fetch (0);
+      p.v.value = fetch (0);
     }
 }