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, 49 insertions, 52 deletions

diff --git a/gdb/dwarf2expr.h b/gdb/dwarf2expr.h
index 7df697d..39bcea3 100644
--- a/gdb/dwarf2expr.h
+++ b/gdb/dwarf2expr.h
@@ -49,6 +49,53 @@ enum dwarf_value_location
   DWARF_VALUE_IMPLICIT_POINTER
 };
 
+/* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece.  */
+struct dwarf_expr_piece
+{
+  enum dwarf_value_location location;
+
+  union
+  {
+    struct
+    {
+      /* This piece's address, for DWARF_VALUE_MEMORY pieces.  */
+      CORE_ADDR addr;
+      /* Non-zero if the piece is known to be in memory and on
+	 the program's stack.  */
+      int in_stack_memory;
+    } mem;
+
+    /* The piece's register number, for DWARF_VALUE_REGISTER pieces.  */
+    int regno;
+
+    /* The piece's literal value, for DWARF_VALUE_STACK pieces.  */
+    struct value *value;
+
+    struct
+    {
+      /* A pointer to the data making up this piece,
+	 for DWARF_VALUE_LITERAL pieces.  */
+      const gdb_byte *data;
+      /* The length of the available data.  */
+      ULONGEST length;
+    } literal;
+
+    /* Used for DWARF_VALUE_IMPLICIT_POINTER.  */
+    struct
+    {
+      /* The referent DIE from DW_OP_implicit_pointer.  */
+      sect_offset die_sect_off;
+      /* The byte offset into the resulting data.  */
+      LONGEST offset;
+    } ptr;
+  } v;
+
+  /* The length of the piece, in bits.  */
+  ULONGEST size;
+  /* The piece offset, in bits.  */
+  ULONGEST offset;
+};
+
 /* The dwarf expression stack.  */
 
 struct dwarf_stack_value
@@ -114,8 +161,7 @@ struct dwarf_expr_context
      initialized; zero otherwise.  */
   int initialized;
 
-  /* An array of pieces.  PIECES points to its first element;
-     NUM_PIECES is its length.
+  /* A vector of pieces.
 
      Each time DW_OP_piece is executed, we add a new element to the
      end of this array, recording the current top of the stack, the
@@ -137,8 +183,7 @@ struct dwarf_expr_context
      no DW_OP_piece operations have no value to place in a piece's
      'size' field; the size comes from the surrounding data.  So the
      two cases need to be handled separately.)  */
-  int num_pieces;
-  struct dwarf_expr_piece *pieces;
+  std::vector<dwarf_expr_piece> pieces;
 
   /* Return the value of register number REGNUM (a DWARF register number),
      read as an address.  */
@@ -213,54 +258,6 @@ private:
   void pop ();
 };
 
-
-/* A piece of an object, as recorded by DW_OP_piece or DW_OP_bit_piece.  */
-struct dwarf_expr_piece
-{
-  enum dwarf_value_location location;
-
-  union
-  {
-    struct
-    {
-      /* This piece's address, for DWARF_VALUE_MEMORY pieces.  */
-      CORE_ADDR addr;
-      /* Non-zero if the piece is known to be in memory and on
-	 the program's stack.  */
-      int in_stack_memory;
-    } mem;
-
-    /* The piece's register number, for DWARF_VALUE_REGISTER pieces.  */
-    int regno;
-
-    /* The piece's literal value, for DWARF_VALUE_STACK pieces.  */
-    struct value *value;
-
-    struct
-    {
-      /* A pointer to the data making up this piece,
-	 for DWARF_VALUE_LITERAL pieces.  */
-      const gdb_byte *data;
-      /* The length of the available data.  */
-      ULONGEST length;
-    } literal;
-
-    /* Used for DWARF_VALUE_IMPLICIT_POINTER.  */
-    struct
-    {
-      /* The referent DIE from DW_OP_implicit_pointer.  */
-      sect_offset die_sect_off;
-      /* The byte offset into the resulting data.  */
-      LONGEST offset;
-    } ptr;
-  } v;
-
-  /* The length of the piece, in bits.  */
-  ULONGEST size;
-  /* The piece offset, in bits.  */
-  ULONGEST offset;
-};
-
 void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *,
 				     const char *);