* parse.c: New file with the common code remains of expread.y.

* expread.y, expread.tab.c:  Remove.
* parser-defs.h:  New file with common declarations from expread.y.
* c-exp.y:  New file with the C parser from expread.y.
* m2-exp.y:  New file with the Modula-2 parser.

1 files changed, 628 insertions, 0 deletions

diff --git a/gdb/parse.c b/gdb/parse.c
new file mode 100644
index 0000000..214df03
--- /dev/null
+++ b/gdb/parse.c
@@ -0,0 +1,628 @@
+/* Parse expressions for GDB.
+   Copyright (C) 1986, 1989, 1990, 1991 Free Software Foundation, Inc.
+   Modified from expread.y by the Department of Computer Science at the
+   State University of New York at Buffalo, 1991.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Parse an expression from text in a string,
+   and return the result as a  struct expression  pointer.
+   That structure contains arithmetic operations in reverse polish,
+   with constants represented by operations that are followed by special data.
+   See expression.h for the details of the format.
+   What is important here is that it can be built up sequentially
+   during the process of parsing; the lower levels of the tree always
+   come first in the result.  */
+   
+#include <stdio.h>
+#include "defs.h"
+#include "param.h"
+#include "symtab.h"
+#include "frame.h"
+#include "expression.h"
+#include "value.h"
+#include "command.h"
+#include "language.h"
+#include "parser-defs.h"
+
+/* Assign machine-independent names to certain registers 
+   (unless overridden by the REGISTER_NAMES table) */
+
+struct std_regs std_regs[] = {
+#ifdef PC_REGNUM
+	{ "pc", PC_REGNUM },
+#endif
+#ifdef FP_REGNUM
+	{ "fp", FP_REGNUM },
+#endif
+#ifdef SP_REGNUM
+	{ "sp", SP_REGNUM },
+#endif
+#ifdef PS_REGNUM
+	{ "ps", PS_REGNUM },
+#endif
+};
+
+unsigned num_std_regs = (sizeof std_regs / sizeof std_regs[0]);
+
+
+/* Begin counting arguments for a function call,
+   saving the data about any containing call.  */
+
+void
+start_arglist ()
+{
+  register struct funcall *new = (struct funcall *) xmalloc (sizeof (struct funcall));
+
+  new->next = funcall_chain;
+  new->arglist_len = arglist_len;
+  arglist_len = 0;
+  funcall_chain = new;
+}
+
+/* Return the number of arguments in a function call just terminated,
+   and restore the data for the containing function call.  */
+
+int
+end_arglist ()
+{
+  register int val = arglist_len;
+  register struct funcall *call = funcall_chain;
+  funcall_chain = call->next;
+  arglist_len = call->arglist_len;
+  free (call);
+  return val;
+}
+
+/* Free everything in the funcall chain.
+   Used when there is an error inside parsing.  */
+
+void
+free_funcalls ()
+{
+  register struct funcall *call, *next;
+
+  for (call = funcall_chain; call; call = next)
+    {
+      next = call->next;
+      free (call);
+    }
+}
+
+/* This page contains the functions for adding data to the  struct expression
+   being constructed.  */
+
+/* Add one element to the end of the expression.  */
+
+/* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
+   a register through here */
+
+void
+write_exp_elt (expelt)
+     union exp_element expelt;
+{
+  if (expout_ptr >= expout_size)
+    {
+      expout_size *= 2;
+      expout = (struct expression *) xrealloc (expout,
+					       sizeof (struct expression)
+					       + expout_size * sizeof (union exp_element));
+    }
+  expout->elts[expout_ptr++] = expelt;
+}
+
+void
+write_exp_elt_opcode (expelt)
+     enum exp_opcode expelt;
+{
+  union exp_element tmp;
+
+  tmp.opcode = expelt;
+
+  write_exp_elt (tmp);
+}
+
+void
+write_exp_elt_sym (expelt)
+     struct symbol *expelt;
+{
+  union exp_element tmp;
+
+  tmp.symbol = expelt;
+
+  write_exp_elt (tmp);
+}
+
+void
+write_exp_elt_longcst (expelt)
+     LONGEST expelt;
+{
+  union exp_element tmp;
+
+  tmp.longconst = expelt;
+
+  write_exp_elt (tmp);
+}
+
+void
+write_exp_elt_dblcst (expelt)
+     double expelt;
+{
+  union exp_element tmp;
+
+  tmp.doubleconst = expelt;
+
+  write_exp_elt (tmp);
+}
+
+void
+write_exp_elt_type (expelt)
+     struct type *expelt;
+{
+  union exp_element tmp;
+
+  tmp.type = expelt;
+
+  write_exp_elt (tmp);
+}
+
+void
+write_exp_elt_intern (expelt)
+     struct internalvar *expelt;
+{
+  union exp_element tmp;
+
+  tmp.internalvar = expelt;
+
+  write_exp_elt (tmp);
+}
+
+/* Add a string constant to the end of the expression.
+   Follow it by its length in bytes, as a separate exp_element.  */
+
+void
+write_exp_string (str)
+     struct stoken str;
+{
+  register int len = str.length;
+  register int lenelt
+    = (len + sizeof (union exp_element)) / sizeof (union exp_element);
+
+  expout_ptr += lenelt;
+
+  if (expout_ptr >= expout_size)
+    {
+      expout_size = max (expout_size * 2, expout_ptr + 10);
+      expout = (struct expression *)
+	xrealloc (expout, (sizeof (struct expression)
+			   + (expout_size * sizeof (union exp_element))));
+    }
+  bcopy (str.ptr, (char *) &expout->elts[expout_ptr - lenelt], len);
+  ((char *) &expout->elts[expout_ptr - lenelt])[len] = 0;
+  write_exp_elt_longcst ((LONGEST) len);
+}
+
+/* Return a null-terminated temporary copy of the name
+   of a string token.  */
+
+char *
+copy_name (token)
+     struct stoken token;
+{
+  bcopy (token.ptr, namecopy, token.length);
+  namecopy[token.length] = 0;
+  return namecopy;
+}
+
+/* Reverse an expression from suffix form (in which it is constructed)
+   to prefix form (in which we can conveniently print or execute it).  */
+
+static void prefixify_subexp ();
+
+void
+prefixify_expression (expr)
+     register struct expression *expr;
+{
+  register int len = sizeof (struct expression) +
+				    expr->nelts * sizeof (union exp_element);
+  register struct expression *temp;
+  register int inpos = expr->nelts, outpos = 0;
+
+  temp = (struct expression *) alloca (len);
+
+  /* Copy the original expression into temp.  */
+  bcopy (expr, temp, len);
+
+  prefixify_subexp (temp, expr, inpos, outpos);
+}
+
+/* Return the number of exp_elements in the subexpression of EXPR
+   whose last exp_element is at index ENDPOS - 1 in EXPR.  */
+
+int
+length_of_subexp (expr, endpos)
+     register struct expression *expr;
+     register int endpos;
+{
+  register int oplen = 1;
+  register int args = 0;
+  register int i;
+
+  if (endpos < 0)
+    error ("?error in length_of_subexp");
+
+  i = (int) expr->elts[endpos - 1].opcode;
+
+  switch (i)
+    {
+      /* C++  */
+    case OP_SCOPE:
+      oplen = 4 + ((expr->elts[endpos - 2].longconst
+		    + sizeof (union exp_element))
+		   / sizeof (union exp_element));
+      break;
+
+    case OP_LONG:
+    case OP_DOUBLE:
+      oplen = 4;
+      break;
+
+    case OP_TYPE:
+    case OP_BOOL:
+    case OP_VAR_VALUE:
+    case OP_LAST:
+    case OP_REGISTER:
+    case OP_INTERNALVAR:
+      oplen = 3;
+      break;
+
+    case OP_FUNCALL:
+      oplen = 3;
+      args = 1 + expr->elts[endpos - 2].longconst;
+      break;
+
+    case UNOP_MAX:
+    case UNOP_MIN:
+      oplen = 3;
+      args = 0;
+      break;
+
+   case BINOP_VAL:
+   case UNOP_CAST:
+   case UNOP_MEMVAL:
+      oplen = 3;
+      args = 1;
+      break;
+
+    case UNOP_ABS:
+    case UNOP_CAP:
+    case UNOP_CHR:
+    case UNOP_FLOAT:
+    case UNOP_HIGH:
+    case UNOP_ODD:
+    case UNOP_ORD:
+    case UNOP_TRUNC:
+      oplen = 1;
+      args = 1;
+      break;
+
+    case STRUCTOP_STRUCT:
+    case STRUCTOP_PTR:
+      args = 1;
+    case OP_M2_STRING:
+    case OP_STRING:
+      oplen = 3 + ((expr->elts[endpos - 2].longconst
+		    + sizeof (union exp_element))
+		   / sizeof (union exp_element));
+      break;
+
+    case TERNOP_COND:
+      args = 3;
+      break;
+
+      /* Modula-2 */
+   case BINOP_MULTI_SUBSCRIPT:
+      oplen=3;
+      args = 1 + expr->elts[endpos- 2].longconst;
+      break;
+
+    case BINOP_ASSIGN_MODIFY:
+      oplen = 3;
+      args = 2;
+      break;
+
+      /* C++ */
+    case OP_THIS:
+      oplen = 2;
+      break;
+
+    default:
+      args = 1 + (i < (int) BINOP_END);
+    }
+
+  while (args > 0)
+    {
+      oplen += length_of_subexp (expr, endpos - oplen);
+      args--;
+    }
+
+  return oplen;
+}
+
+/* Copy the subexpression ending just before index INEND in INEXPR
+   into OUTEXPR, starting at index OUTBEG.
+   In the process, convert it from suffix to prefix form.  */
+
+static void
+prefixify_subexp (inexpr, outexpr, inend, outbeg)
+     register struct expression *inexpr;
+     struct expression *outexpr;
+     register int inend;
+     int outbeg;
+{
+  register int oplen = 1;
+  register int args = 0;
+  register int i;
+  int *arglens;
+  enum exp_opcode opcode;
+
+  /* Compute how long the last operation is (in OPLEN),
+     and also how many preceding subexpressions serve as
+     arguments for it (in ARGS).  */
+
+  opcode = inexpr->elts[inend - 1].opcode;
+  switch (opcode)
+    {
+      /* C++  */
+    case OP_SCOPE:
+      oplen = 4 + ((inexpr->elts[inend - 2].longconst
+		    + sizeof (union exp_element))
+		   / sizeof (union exp_element));
+      break;
+
+    case OP_LONG:
+    case OP_DOUBLE:
+      oplen = 4;
+      break;
+
+    case OP_TYPE:
+    case OP_BOOL:
+    case OP_VAR_VALUE:
+    case OP_LAST:
+    case OP_REGISTER:
+    case OP_INTERNALVAR:
+      oplen = 3;
+      break;
+
+    case OP_FUNCALL:
+      oplen = 3;
+      args = 1 + inexpr->elts[inend - 2].longconst;
+      break;
+
+    case UNOP_MIN:
+    case UNOP_MAX:
+      oplen = 3;
+      args = 0;
+      break;
+
+    case UNOP_CAST:
+    case UNOP_MEMVAL:
+      oplen = 3;
+      args = 1;
+      break;
+
+    case UNOP_ABS:
+    case UNOP_CAP:
+    case UNOP_CHR:
+    case UNOP_FLOAT:
+    case UNOP_HIGH:
+    case UNOP_ODD:
+    case UNOP_ORD:
+    case UNOP_TRUNC:
+      oplen=1;
+      args=1;
+      break;
+
+   case STRUCTOP_STRUCT:
+    case STRUCTOP_PTR:
+      args = 1;
+    case OP_M2_STRING:
+    case OP_STRING:
+      oplen = 3 + ((inexpr->elts[inend - 2].longconst
+		    + sizeof (union exp_element))
+		   / sizeof (union exp_element));
+		   
+      break;
+
+    case TERNOP_COND:
+      args = 3;
+      break;
+
+    case BINOP_ASSIGN_MODIFY:
+      oplen = 3;
+      args = 2;
+      break;
+
+      /* Modula-2 */
+   case BINOP_MULTI_SUBSCRIPT:
+      oplen=3;
+      args = 1 + inexpr->elts[inend - 2].longconst;
+      break;
+
+      /* C++ */
+    case OP_THIS:
+      oplen = 2;
+      break;
+
+    default:
+      args = 1 + ((int) opcode < (int) BINOP_END);
+    }
+
+  /* Copy the final operator itself, from the end of the input
+     to the beginning of the output.  */
+  inend -= oplen;
+  bcopy (&inexpr->elts[inend], &outexpr->elts[outbeg],
+	 oplen * sizeof (union exp_element));
+  outbeg += oplen;
+
+  /* Find the lengths of the arg subexpressions.  */
+  arglens = (int *) alloca (args * sizeof (int));
+  for (i = args - 1; i >= 0; i--)
+    {
+      oplen = length_of_subexp (inexpr, inend);
+      arglens[i] = oplen;
+      inend -= oplen;
+    }
+
+  /* Now copy each subexpression, preserving the order of
+     the subexpressions, but prefixifying each one.
+     In this loop, inend starts at the beginning of
+     the expression this level is working on
+     and marches forward over the arguments.
+     outbeg does similarly in the output.  */
+  for (i = 0; i < args; i++)
+    {
+      oplen = arglens[i];
+      inend += oplen;
+      prefixify_subexp (inexpr, outexpr, inend, outbeg);
+      outbeg += oplen;
+    }
+}
+
+/* This page contains the two entry points to this file.  */
+
+/* Read an expression from the string *STRINGPTR points to,
+   parse it, and return a pointer to a  struct expression  that we malloc.
+   Use block BLOCK as the lexical context for variable names;
+   if BLOCK is zero, use the block of the selected stack frame.
+   Meanwhile, advance *STRINGPTR to point after the expression,
+   at the first nonwhite character that is not part of the expression
+   (possibly a null character).
+
+   If COMMA is nonzero, stop if a comma is reached.  */
+
+struct expression *
+parse_exp_1 (stringptr, block, comma)
+     char **stringptr;
+     struct block *block;
+     int comma;
+{
+  struct cleanup *old_chain;
+
+  lexptr = *stringptr;
+
+  paren_depth = 0;
+  type_stack_depth = 0;
+
+  comma_terminates = comma;
+
+  if (lexptr == 0 || *lexptr == 0)
+    error_no_arg ("expression to compute");
+
+  old_chain = make_cleanup (free_funcalls, 0);
+  funcall_chain = 0;
+
+  expression_context_block = block ? block : get_selected_block ();
+
+  namecopy = (char *) alloca (strlen (lexptr) + 1);
+  expout_size = 10;
+  expout_ptr = 0;
+  expout = (struct expression *)
+    xmalloc (sizeof (struct expression)
+	     + expout_size * sizeof (union exp_element));
+  expout->language_defn = current_language;
+  make_cleanup (free_current_contents, &expout);
+
+  if (current_language->la_parser ())
+    current_language->la_error (NULL);
+
+  discard_cleanups (old_chain);
+  expout->nelts = expout_ptr;
+  expout = (struct expression *)
+    xrealloc (expout,
+	      sizeof (struct expression)
+	      + expout_ptr * sizeof (union exp_element));
+  prefixify_expression (expout);
+  *stringptr = lexptr;
+  return expout;
+}
+
+/* Parse STRING as an expression, and complain if this fails
+   to use up all of the contents of STRING.  */
+
+struct expression *
+parse_expression (string)
+     char *string;
+{
+  register struct expression *exp;
+  exp = parse_exp_1 (&string, 0, 0);
+  if (*string)
+    error ("Junk after end of expression.");
+  return exp;
+}
+
+void 
+push_type (tp)
+     enum type_pieces tp;
+{
+  if (type_stack_depth == type_stack_size)
+    {
+      type_stack_size *= 2;
+      type_stack = (union type_stack_elt *)
+	xrealloc (type_stack, type_stack_size * sizeof (*type_stack));
+    }
+  type_stack[type_stack_depth++].piece = tp;
+}
+
+void
+push_type_int (n)
+     int n;
+{
+  if (type_stack_depth == type_stack_size)
+    {
+      type_stack_size *= 2;
+      type_stack = (union type_stack_elt *)
+	xrealloc (type_stack, type_stack_size * sizeof (*type_stack));
+    }
+  type_stack[type_stack_depth++].int_val = n;
+}
+
+enum type_pieces 
+pop_type ()
+{
+  if (type_stack_depth)
+    return type_stack[--type_stack_depth].piece;
+  return tp_end;
+}
+
+int
+pop_type_int ()
+{
+  if (type_stack_depth)
+    return type_stack[--type_stack_depth].int_val;
+  /* "Can't happen".  */
+  return 0;
+}
+
+void
+_initialize_parse ()
+{
+  type_stack_size = 80;
+  type_stack_depth = 0;
+  type_stack = (union type_stack_elt *)
+    xmalloc (type_stack_size * sizeof (*type_stack));
+}