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, 5 insertions, 113 deletions

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index aa2abce..de1e79b 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1898,12 +1898,11 @@ update_watchpoint (struct watchpoint *b, int reparse)
     }
   else if (within_current_scope && b->exp)
     {
-      int pc = 0;
       std::vector<value_ref_ptr> val_chain;
       struct value *v, *result;
       struct program_space *frame_pspace;
 
-      fetch_subexp_value (b->exp.get (), &pc, b->exp->op.get (), &v, &result,
+      fetch_subexp_value (b->exp.get (), b->exp->op.get (), &v, &result,
 			  &val_chain, false);
 
       /* Avoid setting b->val if it's already set.  The meaning of
@@ -5012,7 +5011,6 @@ watchpoint_check (bpstat bs)
 	 free_all_values.  We can't call free_all_values because we
 	 might be in the middle of evaluating a function call.  */
 
-      int pc = 0;
       struct value *mark;
       struct value *new_val;
 
@@ -5023,7 +5021,7 @@ watchpoint_check (bpstat bs)
 	return WP_VALUE_CHANGED;
 
       mark = value_mark ();
-      fetch_subexp_value (b->exp.get (), &pc, b->exp->op.get (), &new_val,
+      fetch_subexp_value (b->exp.get (), b->exp->op.get (), &new_val,
 			  NULL, NULL, false);
 
       if (b->val_bitsize != 0)
@@ -10124,112 +10122,7 @@ break_range_command (const char *arg, int from_tty)
 static bool
 watchpoint_exp_is_const (const struct expression *exp)
 {
-  if (exp->op != nullptr)
-    return exp->op->constant_p ();
-
-  int i = exp->nelts;
-
-  while (i > 0)
-    {
-      int oplenp, argsp;
-
-      /* We are only interested in the descriptor of each element.  */
-      operator_length (exp, i, &oplenp, &argsp);
-      i -= oplenp;
-
-      switch (exp->elts[i].opcode)
-	{
-	case BINOP_ADD:
-	case BINOP_SUB:
-	case BINOP_MUL:
-	case BINOP_DIV:
-	case BINOP_REM:
-	case BINOP_MOD:
-	case BINOP_LSH:
-	case BINOP_RSH:
-	case BINOP_LOGICAL_AND:
-	case BINOP_LOGICAL_OR:
-	case BINOP_BITWISE_AND:
-	case BINOP_BITWISE_IOR:
-	case BINOP_BITWISE_XOR:
-	case BINOP_EQUAL:
-	case BINOP_NOTEQUAL:
-	case BINOP_LESS:
-	case BINOP_GTR:
-	case BINOP_LEQ:
-	case BINOP_GEQ:
-	case BINOP_REPEAT:
-	case BINOP_COMMA:
-	case BINOP_EXP:
-	case BINOP_MIN:
-	case BINOP_MAX:
-	case BINOP_INTDIV:
-	case BINOP_CONCAT:
-	case TERNOP_COND:
-	case TERNOP_SLICE:
-
-	case OP_LONG:
-	case OP_FLOAT:
-	case OP_LAST:
-	case OP_COMPLEX:
-	case OP_STRING:
-	case OP_ARRAY:
-	case OP_TYPE:
-	case OP_TYPEOF:
-	case OP_DECLTYPE:
-	case OP_TYPEID:
-	case OP_NAME:
-	case OP_OBJC_NSSTRING:
-
-	case UNOP_NEG:
-	case UNOP_LOGICAL_NOT:
-	case UNOP_COMPLEMENT:
-	case UNOP_ADDR:
-	case UNOP_HIGH:
-	case UNOP_CAST:
-
-	case UNOP_CAST_TYPE:
-	case UNOP_REINTERPRET_CAST:
-	case UNOP_DYNAMIC_CAST:
-	  /* Unary, binary and ternary operators: We have to check
-	     their operands.  If they are constant, then so is the
-	     result of that operation.  For instance, if A and B are
-	     determined to be constants, then so is "A + B".
-
-	     UNOP_IND is one exception to the rule above, because the
-	     value of *ADDR is not necessarily a constant, even when
-	     ADDR is.  */
-	  break;
-
-	case OP_VAR_VALUE:
-	  /* Check whether the associated symbol is a constant.
-
-	     We use SYMBOL_CLASS rather than TYPE_CONST because it's
-	     possible that a buggy compiler could mark a variable as
-	     constant even when it is not, and TYPE_CONST would return
-	     true in this case, while SYMBOL_CLASS wouldn't.
-
-	     We also have to check for function symbols because they
-	     are always constant.  */
-	  {
-	    struct symbol *s = exp->elts[i + 2].symbol;
-
-	    if (SYMBOL_CLASS (s) != LOC_BLOCK
-		&& SYMBOL_CLASS (s) != LOC_CONST
-		&& SYMBOL_CLASS (s) != LOC_CONST_BYTES)
-	      return false;
-	    break;
-	  }
-
-	/* The default action is to return 0 because we are using
-	   the optimistic approach here: If we don't know something,
-	   then it is not a constant.  */
-	default:
-	  return false;
-	}
-    }
-
-  return true;
+  return exp->op->constant_p ();
 }
 
 /* Watchpoint destructor.  */
@@ -10730,7 +10623,6 @@ watch_command_1 (const char *arg, int accessflag, int from_tty,
   const char *cond_end = NULL;
   enum bptype bp_type;
   int thread = -1;
-  int pc = 0;
   /* Flag to indicate whether we are going to use masks for
      the hardware watchpoint.  */
   bool use_mask = false;
@@ -10847,8 +10739,8 @@ watch_command_1 (const char *arg, int accessflag, int from_tty,
   exp_valid_block = tracker.block ();
   struct value *mark = value_mark ();
   struct value *val_as_value = nullptr;
-  fetch_subexp_value (exp.get (), &pc, exp->op.get (), &val_as_value, &result,
-		      NULL, just_location);
+  fetch_subexp_value (exp.get (), exp->op.get (), &val_as_value, &result, NULL,
+		      just_location);
 
   if (val_as_value != NULL && just_location)
     {