Re: RFA: Changes to allow extensions to operator set

Paul Hilfinger
2003-09-18T09:20:01Z

Andrew,

Here is a version of the patch I submitted earlier that I believe addresses
your comments from last time. The specific changes from last time that you
wanted were

1. Putting evaluate_exp into the exp_descriptor structure.

2. Modifying the description of the OP_EXTENDED_LAST operator slightly
and including a note indicating the temporary nature of the extension
mechanism and our intention to OOize expression handling in general.

Other parts you previously approved. If these changes were what you
were after, I will commit.

Paul

ChangeLog:

2003-09-18 Paul N. Hilfinger <hilfingr@nile.gnat.com>

* parser-defs.h (struct exp_descriptor): New definition, containing
language-specific info for printing, prefixifying, dumping, and
evaluating expressions.
(exp_descriptor_standard): Declare new variable.
(print_subexp): Make global and declare here (from expprint.c).
(dump_subexp): Ditto.
(dump_subexp_body_standard): Declare.
(operator_length): Declare.
(operator_length_standard): Declare.
(op_name_standard): Declare.
(print_subexp): Declare.
(print_subexp_standard): Declare.

* language.h (struct language_defn): Add la_exp_desc field to hold
pointer to table for language-specific operators.
Remove evaluate_exp field, which is now in struct exp_descriptor.

* parse.c (length_of_subexp): Use operator_length to get
operator lengths and arities for operators.
Move most code to new operator_length_standard function.
(operator_length_standard): New function taking most code from
length_of_subexp.
(prefixify_subexp): Remove large case and use operator_length instead.
(operator_length): New function. Uses language-specific information.
(exp_descriptor_standard): New constant.
(parse_exp_1): Use renamings:
dump_prefix_expression => dump_raw_expression and
dump_postfix_expression => dump_prefix_expression.

* expression.h (enum exp_opcode): Add definitions of OP_EXTENDED0
and OP_EXTENDED_LAST.
(dump_prefix_expression): Rename to ...
(dump_raw_expression): New name.
(dump_postfix_expression): Rename to ...
(dump_prefix_expression): New name.

* expprint.c (print_subexp): Make global, remove static declaration.
Use language-specific print_subexp.
Move most existing code to print_subexp_standard.
(print_subexp_standard): New function, containing code formerly in
print_subexp.
(op_name): Add expression to argument signature.
Use langauge-specific op_name.
Move most code to op_name_standard.
(op_name_standard): New function, containing code formerly in op_name.
(dump_subexp): Make global. Add comment.
Use new version of op_name function.
Use language-specific dump_subexp_body, and move most existing code to
dump_subexp_body_standard.
(dump_subexp_body): New function.
(dump_subexp_body_standard): New function, containing code formerly
in dump_subexp.
(dump_prefix_expression): Rename to dump_raw_expression.
Remove attempt to print the expression via print_expression: it can't
work before the expression is prefixified!
Use new version of op_name.
(dump_raw_expression): Renamed from dump_prefix_expression.
(dump_postfix_expression): Rename to dump_prefix_expression, since
that's what it does!
Remove 'note' parameter, since this routine must be used on
prefixified expression.
(dump_prefix_expression): Renamed from dump_postfix_expression.

* language.c (unknown_language): Add default la_exp_desc field and
remove evaluate_exp field.
(auto_language): Ditto.
(local_language): Ditto.
* f-lang.c (f_language_defn): Ditto.
* c-lang.c (c_language_defn): Ditto.
(cplus_language_defn): Ditto.
(asm_language_defn): Ditto.
(minimal_language_defn): Ditto.
* p-lang.c (pascal_language_defn): Ditto.
* m2-lang.c (m2_language_defn): Ditto.
* objc-lang.c (objc_language_defn): Ditto.

* jv-lang.c (exp_descriptor_java): New variable, containing
Java-specific expression evaluator.
(java_language_defn): Add la_exp_desc field.
* scm-lang.c (exp_descriptor_scm): New variable, containing
Scheme-specific expression evaluator.
(scm_language_defn): Add la_exp_desc field.
* objc-lang.c (print_object_command): Take evaluate_exp from the
la_exp_desc field.

* Makefile.in (eval.o): Add dependency on parser-defs.h.

* eval.c: Include parser-defs.h for the full declaration of
la_exp_desc's type.
(evaluate_subexp): Get evaluate_exp out of la_exp_desc field.

Index: current-public.25/gdb/p-lang.c
--- current-public.25/gdb/p-lang.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/e/26_p-lang.c 1.1.1.2.2.1 644)
+++ submit.16(w)/gdb/p-lang.c Tue, 16 Sep 2003 01:31:55 -0700 hilfingr (GdbPub/e/26_p-lang.c 1.1.1.2.2.3 644)
@@ -451,9 +451,9 @@ const struct language_defn pascal_langua
range_check_on,
type_check_on,
case_sensitive_on,
+ &exp_descriptor_standard,
pascal_parse,
pascal_error,
- evaluate_subexp_standard,
pascal_printchar, /* Print a character constant */
pascal_printstr, /* Function to print string constant */
pascal_emit_char, /* Print a single char */
Index: current-public.25/gdb/Makefile.in
--- current-public.25/gdb/Makefile.in Wed, 17 Sep 2003 23:22:28 -0700 hilfingr (GdbPub/g/6_Makefile.i 1.1.1.8.1.1.1.1.1.1.1.1.1.3.2.1 644)
+++ submit.16(w)/gdb/Makefile.in Wed, 17 Sep 2003 23:35:15 -0700 hilfingr (GdbPub/g/6_Makefile.i 1.1.1.8.1.1.1.1.1.1.1.1.1.3.2.2 644)
@@ -1735,7 +1735,8 @@ elfread.o: elfread.c $(defs_h) $(bfd_h)
environ.o: environ.c $(defs_h) $(environ_h) $(gdb_string_h)
eval.o: eval.c $(defs_h) $(gdb_string_h) $(symtab_h) $(gdbtypes_h) \
$(value_h) $(expression_h) $(target_h) $(frame_h) $(language_h) \
- $(f_lang_h) $(cp_abi_h) $(infcall_h) $(objc_lang_h) $(block_h)
+ $(f_lang_h) $(cp_abi_h) $(infcall_h) $(objc_lang_h) $(block_h) \
+ $(parser_defs_h)
event-loop.o: event-loop.c $(defs_h) $(event_loop_h) $(event_top_h) \
$(gdb_string_h)
event-top.o: event-top.c $(defs_h) $(top_h) $(inferior_h) $(target_h) \
Index: current-public.25/gdb/c-lang.c
--- current-public.25/gdb/c-lang.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/g/28_c-lang.c 1.1.1.3.2.1 644)
+++ submit.16(w)/gdb/c-lang.c Tue, 16 Sep 2003 21:35:59 -0700 hilfingr (GdbPub/g/28_c-lang.c 1.1.1.3.2.3 644)
@@ -543,9 +543,9 @@ const struct language_defn c_language_de
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
c_preprocess_and_parse,
c_error,
- evaluate_subexp_standard,
c_printchar, /* Print a character constant */
c_printstr, /* Function to print string constant */
c_emit_char, /* Print a single char */
@@ -599,9 +599,9 @@ const struct language_defn cplus_languag
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
c_preprocess_and_parse,
c_error,
- evaluate_subexp_standard,
c_printchar, /* Print a character constant */
c_printstr, /* Function to print string constant */
c_emit_char, /* Print a single char */
@@ -632,9 +632,9 @@ const struct language_defn asm_language_
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
c_preprocess_and_parse,
c_error,
- evaluate_subexp_standard,
c_printchar, /* Print a character constant */
c_printstr, /* Function to print string constant */
c_emit_char, /* Print a single char */
@@ -670,9 +670,9 @@ const struct language_defn minimal_langu
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
c_preprocess_and_parse,
c_error,
- evaluate_subexp_standard,
c_printchar, /* Print a character constant */
c_printstr, /* Function to print string constant */
c_emit_char, /* Print a single char */
Index: current-public.25/gdb/eval.c
--- current-public.25/gdb/eval.c Wed, 17 Sep 2003 23:22:28 -0700 hilfingr (GdbPub/h/26_eval.c 1.1.1.3.1.1.3.1 644)
+++ submit.16(w)/gdb/eval.c Wed, 17 Sep 2003 23:37:29 -0700 hilfingr (GdbPub/h/26_eval.c 1.1.1.3.1.1.3.2 644)
@@ -35,6 +35,7 @@
#include "infcall.h"
#include "objc-lang.h"
#include "block.h"
+#include "parser-defs.h"

/* Defined in symtab.c */
extern int hp_som_som_object_present;
@@ -70,7 +71,8 @@ static struct value *
evaluate_subexp (struct type *expect_type, struct expression *exp,
int *pos, enum noside noside)
{
- return (*exp->language_defn->evaluate_exp) (expect_type, exp, pos, noside);
+ return (*exp->language_defn->la_exp_desc->evaluate_exp)
+ (expect_type, exp, pos, noside);
}
\f
/* Parse the string EXP as a C expression, evaluate it,
Index: current-public.25/gdb/expprint.c
--- current-public.25/gdb/expprint.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/h/29_expprint.c 1.1.1.3.3.1 644)
+++ submit.16(w)/gdb/expprint.c Thu, 18 Sep 2003 02:08:41 -0700 hilfingr (GdbPub/h/29_expprint.c 1.1.1.3.3.3 644)
@@ -36,11 +36,6 @@
#include <ctype.h>
#endif

-/* Prototypes for local functions */
-
-static void print_subexp (struct expression *, int *, struct ui_file *,
- enum precedence);
-
void
print_expression (struct expression *exp, struct ui_file *stream)
{
@@ -53,10 +48,19 @@ print_expression (struct expression *exp
if the precedence of the main operator of this subexpression is less,
parentheses are needed here. */

-static void
+void
print_subexp (struct expression *exp, int *pos,
struct ui_file *stream, enum precedence prec)
{
+ exp->language_defn->la_exp_desc->print_subexp (exp, pos, stream, prec);
+}
+
+/* Standard implementation of print_subexp for use in language_defn
+ vectors. */
+void
+print_subexp_standard (struct expression *exp, int *pos,
+ struct ui_file *stream, enum precedence prec)
+{
unsigned tem;
const struct op_print *op_print_tab;
int pc;
@@ -547,10 +551,22 @@ op_string (enum exp_opcode op)
/* Support for dumping the raw data from expressions in a human readable
form. */

-static char *op_name (int opcode);
+static char *op_name (struct expression *, enum exp_opcode);
+static int dump_subexp_body (struct expression *exp, struct ui_file *, int);
+
+/* Name for OPCODE, when it appears in expression EXP. */

static char *
-op_name (int opcode)
+op_name (struct expression *exp, enum exp_opcode opcode)
+{
+ return exp->language_defn->la_exp_desc->op_name (opcode);
+}
+
+/* Default name for the standard operator OPCODE (i.e., one defined in
+ the definition of enum exp_opcode). */
+
+char *
+op_name_standard (enum exp_opcode opcode)
{
switch (opcode)
{
@@ -737,8 +753,8 @@ op_name (int opcode)
}

void
-dump_prefix_expression (struct expression *exp, struct ui_file *stream,
- char *note)
+dump_raw_expression (struct expression *exp, struct ui_file *stream,
+ char *note)
{
int elt;
char *opcode_name;
@@ -747,11 +763,6 @@ dump_prefix_expression (struct expressio

fprintf_filtered (stream, "Dump of expression @ ");
gdb_print_host_address (exp, stream);
- fprintf_filtered (stream, ", %s:\nExpression: `", note);
- if (exp->elts[0].opcode != OP_TYPE)
- print_expression (exp, stream);
- else
- fprintf_filtered (stream, "Type printing not yet supported....");
fprintf_filtered (stream, "'\n\tLanguage %s, %d elements, %ld bytes each.\n",
exp->language_defn->la_name, exp->nelts,
(long) sizeof (union exp_element));
@@ -760,7 +771,7 @@ dump_prefix_expression (struct expressio
for (elt = 0; elt < exp->nelts; elt++)
{
fprintf_filtered (stream, "\t%5d ", elt);
- opcode_name = op_name (exp->elts[elt].opcode);
+ opcode_name = op_name (exp, exp->elts[elt].opcode);

fprintf_filtered (stream, "%20s ", opcode_name);
print_longest (stream, 'd', 0, exp->elts[elt].longconst);
@@ -778,10 +789,11 @@ dump_prefix_expression (struct expressio
}
}

-static int dump_subexp (struct expression *exp, struct ui_file *stream,
- int elt);
+/* Dump the subexpression of prefix expression EXP whose operator is at
+ position ELT onto STREAM. Returns the position of the next
+ subexpression in EXP. */

-static int
+int
dump_subexp (struct expression *exp, struct ui_file *stream, int elt)
{
static int indent = 0;
@@ -794,9 +806,34 @@ dump_subexp (struct expression *exp, str
fprintf_filtered (stream, " ");
indent += 2;

- fprintf_filtered (stream, "%-20s ", op_name (exp->elts[elt].opcode));
+ fprintf_filtered (stream, "%-20s ", op_name (exp, exp->elts[elt].opcode));
+
+ elt = dump_subexp_body (exp, stream, elt);

- switch (exp->elts[elt++].opcode)
+ indent -= 2;
+
+ return elt;
+}
+
+/* Dump the operands of prefix expression EXP whose opcode is at
+ position ELT onto STREAM. Returns the position of the next
+ subexpression in EXP. */
+
+static int
+dump_subexp_body (struct expression *exp, struct ui_file *stream, int elt)
+{
+ return exp->language_defn->la_exp_desc->dump_subexp_body (exp, stream, elt);
+}
+
+/* Default value for subexp_body in exp_descriptor vector. */
+
+int
+dump_subexp_body_standard (struct expression *exp,
+ struct ui_file *stream, int elt)
+{
+ int opcode = exp->elts[elt++].opcode;
+
+ switch (opcode)
{
case TERNOP_COND:
case TERNOP_SLICE:
@@ -914,7 +951,7 @@ dump_subexp (struct expression *exp, str
break;
case OP_FUNCALL:
{
- int nargs;
+ int i, nargs;

nargs = longest_to_int (exp->elts[elt].longconst);

@@ -1006,20 +1043,17 @@ dump_subexp (struct expression *exp, str
fprintf_filtered (stream, "Unknown format");
}

- indent -= 2;
-
return elt;
}

void
-dump_postfix_expression (struct expression *exp, struct ui_file *stream,
- char *note)
+dump_prefix_expression (struct expression *exp, struct ui_file *stream)
{
int elt;

fprintf_filtered (stream, "Dump of expression @ ");
gdb_print_host_address (exp, stream);
- fprintf_filtered (stream, ", %s:\nExpression: `", note);
+ fputs_filtered (", after conversion to prefix form:\nExpression: `", stream);
if (exp->elts[0].opcode != OP_TYPE)
print_expression (exp, stream);
else
Index: current-public.25/gdb/expression.h
--- current-public.25/gdb/expression.h Tue, 17 Jun 2003 02:35:33 -0700 hilfingr (GdbPub/h/30_expression 1.1.1.2 644)
+++ submit.16(w)/gdb/expression.h Thu, 18 Sep 2003 01:44:54 -0700 hilfingr (GdbPub/h/30_expression 1.1.1.6 644)
@@ -322,7 +322,27 @@ enum exp_opcode
OP_EXPRSTRING,

/* An Objective C Foundation Class NSString constant */
- OP_OBJC_NSSTRING
+ OP_OBJC_NSSTRING,
+
+ /* First extension operator. Individual language modules define
+ extra operators they need as constants with values
+ OP_LANGUAGE_SPECIFIC0 + k, for k >= 0, using a separate
+ enumerated type definition:
+ enum foo_extension_operator {
+ BINOP_MOGRIFY = OP_EXTENDED0,
+ BINOP_FROB,
+ ...
+ }; */
+ OP_EXTENDED0,
+
+ /* Last possible extension operator. Defined to provide an
+ explicit and finite number of extended operators. */
+ OP_EXTENDED_LAST = 0xff
+ /* NOTE: Eventually, we expect to convert to an object-oriented
+ formulation for expression operators that does away with the
+ need for these extension operators, and indeed for this
+ entire enumeration type. Therefore, consider the OP_EXTENDED
+ definitions to be a temporary measure. */
};

union exp_element
@@ -393,11 +413,7 @@ extern void print_expression (struct exp

extern char *op_string (enum exp_opcode);

-extern void dump_prefix_expression (struct expression *,
- struct ui_file *,
- char *);
-extern void dump_postfix_expression (struct expression *,
- struct ui_file *,
- char *);
+extern void dump_raw_expression (struct expression *, struct ui_file *, char *);
+extern void dump_prefix_expression (struct expression *, struct ui_file *);

#endif /* !defined (EXPRESSION_H) */
Index: current-public.25/gdb/f-lang.c
--- current-public.25/gdb/f-lang.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/h/32_f-lang.c 1.1.1.2.2.1 644)
+++ submit.16(w)/gdb/f-lang.c Tue, 16 Sep 2003 01:31:54 -0700 hilfingr (GdbPub/h/32_f-lang.c 1.1.1.2.2.3 644)
@@ -462,9 +462,9 @@ const struct language_defn f_language_de
range_check_on,
type_check_on,
case_sensitive_off,
+ &exp_descriptor_standard,
f_parse, /* parser */
f_error, /* parser error function */
- evaluate_subexp_standard,
f_printchar, /* Print character constant */
f_printstr, /* function to print string constant */
f_emit_char, /* Function to print a single character */
Index: current-public.25/gdb/jv-lang.c
--- current-public.25/gdb/jv-lang.c Sat, 13 Sep 2003 23:40:42 -0700 hilfingr (GdbPub/i/30_jv-lang.c 1.1.1.3.3.1.1.1 644)
+++ submit.16(w)/gdb/jv-lang.c Tue, 16 Sep 2003 01:31:54 -0700 hilfingr (GdbPub/i/30_jv-lang.c 1.1.1.3.3.1.1.1.1.1 644)
@@ -1030,6 +1030,15 @@ const struct op_print java_op_print_tab[
{NULL, 0, 0, 0}
};

+const struct exp_descriptor exp_descriptor_java =
+{
+ print_subexp_standard,
+ operator_length_standard,
+ op_name_standard,
+ dump_subexp_body_standard,
+ evaluate_subexp_java
+};
+
const struct language_defn java_language_defn =
{
"java", /* Language name */
@@ -1038,9 +1047,9 @@ const struct language_defn java_language
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_java,
java_parse,
java_error,
- evaluate_subexp_java,
c_printchar, /* Print a character constant */
c_printstr, /* Function to print string constant */
java_emit_char, /* Function to print a single character */
Index: current-public.25/gdb/language.c
--- current-public.25/gdb/language.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/i/34_language.c 1.1.1.3.1.1.3.1 644)
+++ submit.16(w)/gdb/language.c Tue, 16 Sep 2003 01:31:53 -0700 hilfingr (GdbPub/i/34_language.c 1.1.1.3.1.1.3.3 644)
@@ -1267,9 +1267,9 @@ const struct language_defn unknown_langu
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
unk_lang_parser,
unk_lang_error,
- evaluate_subexp_standard,
unk_lang_printchar, /* Print character constant */
unk_lang_printstr,
unk_lang_emit_char,
@@ -1301,9 +1301,9 @@ const struct language_defn auto_language
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
unk_lang_parser,
unk_lang_error,
- evaluate_subexp_standard,
unk_lang_printchar, /* Print character constant */
unk_lang_printstr,
unk_lang_emit_char,
@@ -1334,9 +1334,9 @@ const struct language_defn local_languag
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
unk_lang_parser,
unk_lang_error,
- evaluate_subexp_standard,
unk_lang_printchar, /* Print character constant */
unk_lang_printstr,
unk_lang_emit_char,
Index: current-public.25/gdb/language.h
--- current-public.25/gdb/language.h Fri, 22 Aug 2003 00:46:52 -0700 hilfingr (GdbPub/i/35_language.h 1.1.1.3.1.1 644)
+++ submit.16(w)/gdb/language.h Tue, 16 Sep 2003 01:22:12 -0700 hilfingr (GdbPub/i/35_language.h 1.1.1.3.1.1.1.2 644)
@@ -167,6 +167,11 @@ struct language_defn
/* Default case sensitivity */
enum case_sensitivity la_case_sensitivity;

+ /* Definitions related to expression printing, prefixifying, and
+ dumping */
+
+ const struct exp_descriptor *la_exp_desc;
+
/* Parser function. */

int (*la_parser) (void);
@@ -174,10 +179,6 @@ struct language_defn
/* Parser error function */

void (*la_error) (char *);
-
- /* Evaluate an expression. */
- struct value *(*evaluate_exp) (struct type *, struct expression *,
- int *, enum noside);

void (*la_printchar) (int ch, struct ui_file * stream);

Index: current-public.25/gdb/m2-lang.c
--- current-public.25/gdb/m2-lang.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/i/38_m2-lang.c 1.1.1.2.2.1 644)
+++ submit.16(w)/gdb/m2-lang.c Tue, 16 Sep 2003 01:31:53 -0700 hilfingr (GdbPub/i/38_m2-lang.c 1.1.1.2.2.3 644)
@@ -415,9 +415,9 @@ const struct language_defn m2_language_d
range_check_on,
type_check_on,
case_sensitive_on,
+ &exp_descriptor_standard,
m2_parse, /* parser */
m2_error, /* parser error function */
- evaluate_subexp_standard,
m2_printchar, /* Print character constant */
m2_printstr, /* function to print string constant */
m2_emit_char, /* Function to print a single character */
Index: current-public.25/gdb/parse.c
--- current-public.25/gdb/parse.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/j/29_parse.c 1.1.1.4.3.1 644)
+++ submit.16(w)/gdb/parse.c Thu, 18 Sep 2003 02:08:40 -0700 hilfingr (GdbPub/j/29_parse.c 1.1.1.4.3.4 644)
@@ -50,6 +50,17 @@
#include "gdb_assert.h"
#include "block.h"

+/* Standard set of definitions for printing, dumping, prefixifying,
+ * and evaluating expressions. */
+
+const struct exp_descriptor exp_descriptor_standard =
+ {
+ print_subexp_standard,
+ operator_length_standard,
+ op_name_standard,
+ dump_subexp_body_standard,
+ evaluate_subexp_standard
+ };
\f
/* Symbols which architectures can redefine. */

@@ -771,8 +782,7 @@ copy_name (struct stoken token)
static void
prefixify_expression (struct expression *expr)
{
- int len =
- sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
+ int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
struct expression *temp;
int inpos = expr->nelts, outpos = 0;

@@ -784,18 +794,48 @@ prefixify_expression (struct expression
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. */
+/* Return the number of exp_elements in the postfix subexpression
+ of EXPR whose operator is at index ENDPOS - 1 in EXPR. */

int
length_of_subexp (struct expression *expr, int endpos)
{
+ int oplen, args, i;
+
+ operator_length (expr, endpos, &oplen, &args);
+
+ while (args > 0)
+ {
+ oplen += length_of_subexp (expr, endpos - oplen);
+ args--;
+ }
+
+ return oplen;
+}
+
+/* Sets *OPLENP to the length of the operator whose (last) index is
+ ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
+ operator takes. */
+
+void
+operator_length (struct expression *expr, int endpos, int *oplenp, int *argsp)
+{
+ expr->language_defn->la_exp_desc->operator_length (expr, endpos,
+ oplenp, argsp);
+}
+
+/* Default value for operator_length in exp_descriptor vectors. */
+
+void
+operator_length_standard (struct expression *expr, int endpos,
+ int *oplenp, int *argsp)
+{
int oplen = 1;
int args = 0;
int i;

if (endpos < 1)
- error ("?error in length_of_subexp");
+ error ("?error in operator_length_standard");

i = (int) expr->elts[endpos - 1].opcode;

@@ -916,13 +956,8 @@ length_of_subexp (struct expression *exp
args = 1 + (i < (int) BINOP_END);
}

- while (args > 0)
- {
- oplen += length_of_subexp (expr, endpos - oplen);
- args--;
- }
-
- return oplen;
+ *oplenp = oplen;
+ *argsp = args;
}

/* Copy the subexpression ending just before index INEND in INEXPR
@@ -933,132 +968,13 @@ static void
prefixify_subexp (struct expression *inexpr,
struct expression *outexpr, int inend, int outbeg)
{
- int oplen = 1;
- int args = 0;
+ int oplen;
+ int args;
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 = longest_to_int (inexpr->elts[inend - 2].longconst);
- oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
- break;
-
- case OP_LONG:
- case OP_DOUBLE:
- case OP_VAR_VALUE:
- oplen = 4;
- break;
-
- case OP_TYPE:
- case OP_BOOL:
- case OP_LAST:
- case OP_REGISTER:
- case OP_INTERNALVAR:
- oplen = 3;
- break;
-
- case OP_COMPLEX:
- oplen = 1;
- args = 2;
- break;
-
- case OP_FUNCALL:
- case OP_F77_UNDETERMINED_ARGLIST:
- oplen = 3;
- args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
- break;
-
- case OP_OBJC_MSGCALL: /* Objective C message (method) call */
- oplen = 4;
- args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
- break;
-
- case UNOP_MIN:
- case UNOP_MAX:
- oplen = 3;
- 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:
- case OP_LABELED:
- args = 1;
- /* fall through */
- case OP_M2_STRING:
- case OP_STRING:
- case OP_OBJC_NSSTRING: /* Objective C Foundation Class NSString constant */
- case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op */
- case OP_NAME:
- case OP_EXPRSTRING:
- oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
- oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
- break;
-
- case OP_BITSTRING:
- oplen = longest_to_int (inexpr->elts[inend - 2].longconst);
- oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
- oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
- break;
-
- case OP_ARRAY:
- oplen = 4;
- args = longest_to_int (inexpr->elts[inend - 2].longconst);
- args -= longest_to_int (inexpr->elts[inend - 3].longconst);
- args += 1;
- break;
-
- case TERNOP_COND:
- case TERNOP_SLICE:
- case TERNOP_SLICE_COUNT:
- args = 3;
- break;
-
- case BINOP_ASSIGN_MODIFY:
- oplen = 3;
- args = 2;
- break;
-
- /* Modula-2 */
- case MULTI_SUBSCRIPT:
- oplen = 3;
- args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst);
- break;
-
- /* C++ */
- case OP_THIS:
- case OP_OBJC_SELF:
- oplen = 2;
- break;
-
- default:
- args = 1 + ((int) opcode < (int) BINOP_END);
- }
+ operator_length (inexpr, inend, &oplen, &args);

/* Copy the final operator itself, from the end of the input
to the beginning of the output. */
@@ -1156,14 +1072,13 @@ parse_exp_1 (char **stringptr, struct bl
parser, to a prefix form. */

if (expressiondebug)
- dump_prefix_expression (expout, gdb_stdlog,
- "before conversion to prefix form");
+ dump_raw_expression (expout, gdb_stdlog,
+ "before conversion to prefix form");

prefixify_expression (expout);

if (expressiondebug)
- dump_postfix_expression (expout, gdb_stdlog,
- "after conversion to prefix form");
+ dump_prefix_expression (expout, gdb_stdlog);

*stringptr = lexptr;
return expout;
Index: current-public.25/gdb/parser-defs.h
--- current-public.25/gdb/parser-defs.h Tue, 17 Jun 2003 02:35:33 -0700 hilfingr (GdbPub/j/30_parser-def 1.1.1.2 644)
+++ submit.16(w)/gdb/parser-defs.h Thu, 18 Sep 2003 01:58:16 -0700 hilfingr (GdbPub/j/30_parser-def 1.1.1.2.1.5 644)
@@ -159,6 +159,17 @@ extern int pop_type_int (void);

extern int length_of_subexp (struct expression *, int);

+extern int dump_subexp (struct expression *, struct ui_file *, int);
+
+extern int dump_subexp_body_standard (struct expression *,
+ struct ui_file *, int);
+
+extern void operator_length (struct expression *, int, int *, int *);
+
+extern void operator_length_standard (struct expression *, int, int *, int *);
+
+extern char *op_name_standard (enum exp_opcode);
+
extern struct type *follow_types (struct type *);

/* During parsing of a C expression, the pointer to the next character
@@ -219,6 +230,46 @@ struct op_print
For a unary operator: 1 iff postfix. */
int right_assoc;
};
+
+/* Information needed to print, prefixify, and evaluate expressions for
+ a given language. */
+
+struct exp_descriptor
+ {
+ /* Print subexpression. */
+ void (*print_subexp) (struct expression *, int *, struct ui_file *,
+ enum precedence);
+
+ /* Returns number of exp_elements needed to represent an operator and
+ the number of subexpressions it takes. */
+ void (*operator_length) (struct expression*, int, int*, int *);
+
+ /* Name of this operator for dumping purposes. */
+ char *(*op_name) (enum exp_opcode);
+
+ /* Dump the rest of this (prefix) expression after the operator
+ itself has been printed. See dump_subexp_body_standard in
+ (expprint.c). */
+ int (*dump_subexp_body) (struct expression *, struct ui_file *, int);
+
+ /* Evaluate an expression. */
+ struct value *(*evaluate_exp) (struct type *, struct expression *,
+ int *, enum noside);
+ };
+
+
+/* Default descriptor containing standard definitions of all
+ elements. */
+extern const struct exp_descriptor exp_descriptor_standard;
+
+/* Functions used by language-specific extended operators to (recursively)
+ print/dump subexpressions. */
+
+extern void print_subexp (struct expression *, int *, struct ui_file *,
+ enum precedence);
+
+extern void print_subexp_standard (struct expression *, int *,
+ struct ui_file *, enum precedence);

/* Function used to avoid direct calls to fprintf
in the code generated by the bison parser. */
Index: current-public.25/gdb/scm-lang.c
--- current-public.25/gdb/scm-lang.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/k/14_scm-lang.c 1.1.1.3.2.1 644)
+++ submit.16(w)/gdb/scm-lang.c Tue, 16 Sep 2003 01:31:52 -0700 hilfingr (GdbPub/k/14_scm-lang.c 1.1.1.3.2.3 644)
@@ -233,6 +233,15 @@ nosideret:
return value_from_longest (builtin_type_long, (LONGEST) 1);
}

+const struct exp_descriptor exp_descriptor_scm =
+{
+ print_subexp_standard,
+ operator_length_standard,
+ op_name_standard,
+ dump_subexp_body_standard,
+ evaluate_subexp_scm
+};
+
const struct language_defn scm_language_defn =
{
"scheme", /* Language name */
@@ -241,9 +250,9 @@ const struct language_defn scm_language_
range_check_off,
type_check_off,
case_sensitive_off,
+ &exp_descriptor_scm,
scm_parse,
c_error,
- evaluate_subexp_scm,
scm_printchar, /* Print a character constant */
scm_printstr, /* Function to print string constant */
NULL, /* Function to print a single character */
Index: current-public.25/gdb/objc-lang.c
--- current-public.25/gdb/objc-lang.c Thu, 11 Sep 2003 02:43:43 -0700 hilfingr (GdbPub/C/b/24_objc-lang. 1.4.3.1 644)
+++ submit.16(w)/gdb/objc-lang.c Tue, 16 Sep 2003 01:48:04 -0700 hilfingr (GdbPub/C/b/24_objc-lang. 1.4.3.3 644)
@@ -659,9 +659,9 @@ const struct language_defn objc_language
range_check_off,
type_check_off,
case_sensitive_on,
+ &exp_descriptor_standard,
objc_parse,
objc_error,
- evaluate_subexp_standard,
objc_printchar, /* Print a character constant */
objc_printstr, /* Function to print string constant */
objc_emit_char,
@@ -1537,8 +1537,8 @@ print_object_command (char *args, int fr
make_cleanup (free_current_contents, &expr);
int pc = 0;

- object = expr->language_defn->evaluate_exp (builtin_type_void_data_ptr,
- expr, &pc, EVAL_NORMAL);
+ object = expr->language_defn->la_exp_desc->evaluate_exp
+ (builtin_type_void_data_ptr, expr, &pc, EVAL_NORMAL);
do_cleanups (old_chain);
}