Remove union exp_element

This removes union exp_element functions that either create such
elements or walk them.  struct expression no longer holds
exp_elements.  A couple of language_defn methods are also removed, as
they are obsolete.

Note that this patch also removes the print_expression code.  The only
in-tree caller of this was from dump_prefix_expression, which is only
called when expression debugging is enabled.  Implementing this would
involve a fair amount of code, and it seems to me that prefix dumping
is preferable anyway, as it is unambiguous.  So, I have not
reimplemented this feature.

gdb/ChangeLog
2021-03-08  Tom Tromey  <tom@tromey.com>

	* value.h (evaluate_subexp_with_coercion): Don't declare.
	* parse.c (exp_descriptor_standard): Remove.
	(expr_builder::expr_builder, expr_builder::release): Update.
	(expression::expression): Remove size_t parameter.
	(expression::~expression): Simplify.
	(expression::resize): Remove.
	(write_exp_elt, write_exp_elt_opcode, write_exp_elt_sym)
	(write_exp_elt_msym, write_exp_elt_block, write_exp_elt_objfile)
	(write_exp_elt_longcst, write_exp_elt_floatcst)
	(write_exp_elt_type, write_exp_elt_intern, write_exp_string)
	(write_exp_string_vector, write_exp_bitstring): Remove.
	* p-lang.h (class pascal_language) <opcode_print_table,
	op_print_tab>: Remove.
	* p-lang.c (pascal_language::op_print_tab): Remove.
	* opencl-lang.c (class opencl_language) <opcode_print_table>:
	Remove.
	* objc-lang.c (objc_op_print_tab): Remove.
	(class objc_language) <opcode_print_table>: Remove.
	* m2-lang.h (class m2_language) <opcode_print_table,
	op_print_tab>: Remove.
	* m2-lang.c (m2_language::op_print_tab): Remove.
	* language.h (struct language_defn) <post_parser, expression_ops,
	opcode_print_table>: Remove.
	* language.c (language_defn::expression_ops)
	(auto_or_unknown_language::opcode_print_table): Remove.
	* go-lang.h (class go_language) <opcode_print_table,
	op_print_tab>: Remove.
	* go-lang.c (go_language::op_print_tab): Remove.
	* f-lang.h (class f_language) <opcode_print_table>: Remove
	<op_print_tab>: Remove.
	* f-lang.c (f_language::op_print_tab): Remove.
	* expression.h (union exp_element): Remove.
	(struct expression): Remove size_t parameter from constructor.
	<resize>: Remove.
	<first_opcode>: Update.
	<nelts, elts>: Remove.
	(EXP_ELEM_TO_BYTES, BYTES_TO_EXP_ELEM): Remove.
	(evaluate_subexp_standard, print_expression, op_string)
	(dump_raw_expression): Don't declare.
	* expprint.c (print_expression, print_subexp)
	(print_subexp_funcall, print_subexp_standard, op_string)
	(dump_raw_expression, dump_subexp, dump_subexp_body)
	(dump_subexp_body_funcall, dump_subexp_body_standard): Remove.
	(dump_prefix_expression): Update.
	* eval.c (evaluate_subexp): Remove.
	(evaluate_expression, evaluate_type): Update.
	(evaluate_subexpression_type): Remove.
	(fetch_subexp_value): Remove "pc" parameter.  Update.
	(extract_field_op, evaluate_struct_tuple, evaluate_funcall)
	(evaluate_subexp_standard, evaluate_subexp_for_address)
	(evaluate_subexp_with_coercion, evaluate_subexp_for_sizeof)
	(evaluate_subexp_for_cast): Remove.
	(parse_and_eval_type): Update.
	* dtrace-probe.c (dtrace_probe::compile_to_ax): Update.
	* d-lang.c (d_op_print_tab): Remove.
	(class d_language) <opcode_print_table>: Remove.
	* c-lang.h (c_op_print_tab): Don't declare.
	* c-lang.c (c_op_print_tab): Remove.
	(class c_language, class cplus_language, class asm_language, class
	minimal_language) <opcode_print_table>: Remove.
	* breakpoint.c (update_watchpoint, watchpoint_check)
	(watchpoint_exp_is_const, watch_command_1): Update.
	* ax-gdb.h (union exp_element): Don't declare.
	* ax-gdb.c (const_var_ref, const_expr, maybe_const_expr)
	(gen_repeat, gen_sizeof, gen_expr_for_cast, gen_expr)
	(gen_expr_binop_rest): Remove.
	(gen_trace_for_expr, gen_eval_for_expr, gen_printf): Update.
	* ada-lang.c (ada_op_print_tab): Remove.
	(class ada_language) <post_parser, opcode_print_table>: Remove.

1 files changed, 2 insertions, 56 deletions

diff --git a/gdb/expression.h b/gdb/expression.h
index 3abaf6e..31482be 100644
--- a/gdb/expression.h
+++ b/gdb/expression.h
@@ -40,21 +40,6 @@ enum innermost_block_tracker_type
 DEF_ENUM_FLAGS_TYPE (enum innermost_block_tracker_type,
 		     innermost_block_tracker_types);
 
-/* Definitions for saved C expressions.  */
-
-/* An expression is represented as a vector of union exp_element's.
-   Each exp_element is an opcode, except that some opcodes cause
-   the following exp_element to be treated as a long or double constant
-   or as a variable.  The opcodes are obeyed, using a stack for temporaries.
-   The value is left on the temporary stack at the end.  */
-
-/* When it is necessary to include a string,
-   it can occupy as many exp_elements as it needs.
-   We find the length of the string using strlen,
-   divide to find out how many exp_elements are used up,
-   and skip that many.  Strings, like numbers, are indicated
-   by the preceding opcode.  */
-
 enum exp_opcode : uint8_t
   {
 #define OP(name) name ,
@@ -212,37 +197,17 @@ make_operation (Arg... args)
 
 }
 
-union exp_element
-  {
-    enum exp_opcode opcode;
-    struct symbol *symbol;
-    struct minimal_symbol *msymbol;
-    LONGEST longconst;
-    gdb_byte floatconst[16];
-    /* Really sizeof (union exp_element) characters (or less for the last
-       element of a string).  */
-    char string;
-    struct type *type;
-    struct internalvar *internalvar;
-    const struct block *block;
-    struct objfile *objfile;
-  };
-
 struct expression
 {
-  expression (const struct language_defn *, struct gdbarch *, size_t);
+  expression (const struct language_defn *, struct gdbarch *);
   ~expression ();
   DISABLE_COPY_AND_ASSIGN (expression);
 
-  void resize (size_t);
-
   /* Return the opcode for the outermost sub-expression of this
      expression.  */
   enum exp_opcode first_opcode () const
   {
-    if (op != nullptr)
-      return op->opcode ();
-    return elts[0].opcode;
+    return op->opcode ();
   }
 
   /* Evaluate the expression.  EXPECT_TYPE is the context type of the
@@ -255,20 +220,10 @@ struct expression
   /* Architecture it was parsed in.  */
   struct gdbarch *gdbarch;
   expr::operation_up op;
-  int nelts = 0;
-  union exp_element *elts;
 };
 
 typedef std::unique_ptr<expression> expression_up;
 
-/* Macros for converting between number of expression elements and bytes
-   to store that many expression elements.  */
-
-#define EXP_ELEM_TO_BYTES(elements) \
-    ((elements) * sizeof (union exp_element))
-#define BYTES_TO_EXP_ELEM(bytes) \
-    (((bytes) + sizeof (union exp_element) - 1) / sizeof (union exp_element))
-
 /* From parse.c */
 
 class innermost_block_tracker;
@@ -289,9 +244,6 @@ extern expression_up parse_exp_1 (const char **, CORE_ADDR pc,
 
 /* From eval.c */
 
-extern struct value *evaluate_subexp_standard
-  (struct type *, struct expression *, int *, enum noside);
-
 /* Evaluate a function call.  The function to be called is in CALLEE and
    the arguments passed to the function are in ARGVEC.
    FUNCTION_NAME is the name of the function, if known.
@@ -307,14 +259,8 @@ extern struct value *evaluate_subexp_do_call (expression *exp,
 
 /* From expprint.c */
 
-extern void print_expression (struct expression *, struct ui_file *);
-
 extern const char *op_name (enum exp_opcode opcode);
 
-extern const char *op_string (enum exp_opcode);
-
-extern void dump_raw_expression (struct expression *,
-				 struct ui_file *, const char *);
 extern void dump_prefix_expression (struct expression *, struct ui_file *);
 
 /* In an OP_RANGE expression, either bound could be empty, indicating