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Miscellaneous code readability improvements.

Browse Source 
* src/reader.c (reader): Move %define front-end variable
defaults and checking into...
(prepare_percent_define_front_end_variables): ... this new
function.

* src/scan-gram.l (INITIAL): For consistency with string
literals, don't store open quote on character literal.  It's
discarded before returning anyway.
(SC_ESCAPED_CHARACTER): Similarly, don't store close quote.
Make length test more readable, and make the character stored
for an empty literal more obvious while consistent with the
previous behavior.

* src/symtab.c, src/symtab.h: Rename USER_NUMBER_ALIAS to
USER_NUMBER_HAS_STRING_ALIAS throughout.
* src/symtab.c (symbol_make_alias): Remove comment from symtab.c
that is repeated in symtab.h.  Improve argument names to make it
clear which side of the symbol-string alias pair is which.
(symbol_check_alias_consistency): Improve local variable names
for the same purpose.
* src/symtab.h (struct symbol): Make comments about aliases
clearer.
(symbol_make_alias): Improve comments and argument name.
* src/output.c (token_definitions_output): Update for rename to
USER_NUMBER_HAS_STRING_ALIAS and improve comments about aliases.
(cherry picked from commit dfaa48602d)

Conflicts:

	src/symtab.c
	src/symtab.h
This commit is contained in:
Joel E. Denny
2009-08-10 21:43:07 -04:00
parent 1a323c2f71
commit 07c0db18b4
6 changed files with 113 additions and 76 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
ChangeLog
View File

@@ -1,3 +1,33 @@
2009-08-10 Joel E. Denny <jdenny@clemson.edu>
Miscellaneous code readability improvements.
* src/reader.c (reader): Move %define front-end variable
defaults and checking into...
(prepare_percent_define_front_end_variables): ... this new
function.
* src/scan-gram.l (INITIAL): For consistency with string
literals, don't store open quote on character literal. It's
discarded before returning anyway.
(SC_ESCAPED_CHARACTER): Similarly, don't store close quote.
Make length test more readable, and make the character stored
for an empty literal more obvious while consistent with the
previous behavior.
* src/symtab.c, src/symtab.h: Rename USER_NUMBER_ALIAS to
USER_NUMBER_HAS_STRING_ALIAS throughout.
* src/symtab.c (symbol_make_alias): Remove comment from symtab.c
that is repeated in symtab.h. Improve argument names to make it
clear which side of the symbol-string alias pair is which.
(symbol_check_alias_consistency): Improve local variable names
for the same purpose.
* src/symtab.h (struct symbol): Make comments about aliases
clearer.
(symbol_make_alias): Improve comments and argument name.
* src/output.c (token_definitions_output): Update for rename to
USER_NUMBER_HAS_STRING_ALIAS and improve comments about aliases.
2009-08-08 Alex Rozenman <rozenman@gmail.com>
Convert "misleading reference" messages to warnings.

8
src/output.c
View File

@@ -343,10 +343,10 @@ token_definitions_output (FILE *out)
symbol *sym = symbols[i];
int number = sym->user_token_number;
/* At this stage, if there are literal aliases, they are part of
SYMBOLS, so we should not find symbols which are the aliases
here. */
aver (number != USER_NUMBER_ALIAS);
/* At this stage, if there are literal string aliases, they are
part of SYMBOLS, so we should not find their aliased symbols
here. */
aver (number != USER_NUMBER_HAS_STRING_ALIAS);
/* Skip error token. */
if (sym == errtoken)

20
src/reader.c
View File

@@ -36,6 +36,7 @@
#include "scan-gram.h"
#include "scan-code.h"
static void prepare_percent_define_front_end_variables (void);
static void check_and_convert_grammar (void);
static symbol_list *grammar = NULL;
@@ -590,8 +591,18 @@ reader (void)
gram_debug = trace_flag & trace_parse;
gram_scanner_initialize ();
gram_parse ();
prepare_percent_define_front_end_variables ();
/* Set front-end %define variable defaults. */
if (! complaint_issued)
check_and_convert_grammar ();
xfclose (gram_in);
}
static void
prepare_percent_define_front_end_variables (void)
{
/* Set %define front-end variable defaults. */
muscle_percent_define_default ("lr.keep-unreachable-states", "false");
{
char *lr_type;
@@ -606,7 +617,7 @@ reader (void)
free (lr_type);
}
/* Check front-end %define variables. */
/* Check %define front-end variables. */
{
static char const * const values[] = {
"lr.type", "LALR", "IELR", "canonical LR", NULL,
@@ -615,11 +626,6 @@ reader (void)
};
muscle_percent_define_check_values (values);
}
if (! complaint_issued)
check_and_convert_grammar ();
xfclose (gram_in);
}

32
src/scan-gram.l
View File

@@ -251,7 +251,7 @@ splice (\\[ \f\t\v]*\n)*
}
/* Characters. */
"'" STRING_GROW; token_start = loc->start; BEGIN SC_ESCAPED_CHARACTER;
"'" token_start = loc->start; BEGIN SC_ESCAPED_CHARACTER;
/* Strings. */
"\"" token_start = loc->start; BEGIN SC_ESCAPED_STRING;
@@ -465,16 +465,18 @@ splice (\\[ \f\t\v]*\n)*
<SC_ESCAPED_CHARACTER>
{
"'"|"\n" {
STRING_GROW;
STRING_FINISH;
loc->start = token_start;
val->character = last_string[1];
val->character = last_string[0];
{
/* FIXME: Eventually, make these errors. */
size_t length = strlen (last_string);
if (length < 3)
warn_at (*loc, _("empty character literal"));
else if (length > 3)
if (last_string[0] == '\0')
{
warn_at (*loc, _("empty character literal"));
/* '\0' seems dangerous even if we are about to complain. */
val->character = '\'';
}
else if (last_string[1] != '\0')
warn_at (*loc, _("extra characters in character literal"));
}
if (yytext[0] == '\n')
@@ -486,17 +488,17 @@ splice (\\[ \f\t\v]*\n)*
<<EOF>> {
STRING_FINISH;
loc->start = token_start;
val->character = last_string[0];
{
size_t length = strlen (last_string);
/* FIXME: Eventually, make these errors. */
if (length < 2)
warn_at (*loc, _("empty character literal"));
else if (length > 2)
if (last_string[0] == '\0')
{
warn_at (*loc, _("empty character literal"));
/* '\0' seems dangerous even if we are about to complain. */
val->character = '\'';
}
else if (last_string[1] != '\0')
warn_at (*loc, _("extra characters in character literal"));
if (length > 1)
val->character = last_string[1];
else
val->character = last_string[0];
}
unexpected_eof (token_start, "'");
STRING_FREE;

78
src/symtab.c
View File

@@ -367,7 +367,7 @@ symbol_user_token_number_set (symbol *sym, int user_token_number, location loc)
{
int *user_token_numberp;
if (sym->user_token_number != USER_NUMBER_ALIAS)
if (sym->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
user_token_numberp = &sym->user_token_number;
else
user_token_numberp = &sym->alias->user_token_number;
@@ -416,29 +416,24 @@ symbol_check_defined_processor (void *sym, void *null ATTRIBUTE_UNUSED)
}
/*------------------------------------------------------------------.
| Declare the new symbol SYM. Make it an alias of SYMVAL, and type |
| SYMVAL with SYM's type. |
`------------------------------------------------------------------*/
void
symbol_make_alias (symbol *sym, symbol *symval, location loc)
symbol_make_alias (symbol *sym, symbol *str, location loc)
{
if (symval->alias)
if (str->alias)
warn_at (loc, _("symbol `%s' used more than once as a literal string"),
symval->tag);
str->tag);
else if (sym->alias)
warn_at (loc, _("symbol `%s' given more than one literal string"),
sym->tag);
else
{
symval->class = token_sym;
symval->user_token_number = sym->user_token_number;
sym->user_token_number = USER_NUMBER_ALIAS;
symval->alias = sym;
sym->alias = symval;
symval->number = sym->number;
symbol_type_set (symval, sym->type_name, loc);
str->class = token_sym;
str->user_token_number = sym->user_token_number;
sym->user_token_number = USER_NUMBER_HAS_STRING_ALIAS;
str->alias = sym;
sym->alias = str;
str->number = sym->number;
symbol_type_set (str, sym->type_name, loc);
}
}
@@ -451,46 +446,47 @@ symbol_make_alias (symbol *sym, symbol *symval, location loc)
static inline void
symbol_check_alias_consistency (symbol *this)
{
symbol *alias = this;
symbol *orig = this->alias;
symbol *sym = this;
symbol *str = this->alias;
/* Check only those that _are_ the aliases. */
if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
/* Check only the symbol in the symbol-string pair. */
if (!(this->alias
&& this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS))
return;
if (orig->type_name != alias->type_name)
if (str->type_name != sym->type_name)
{
if (orig->type_name)
symbol_type_set (alias, orig->type_name, orig->type_location);
if (str->type_name)
symbol_type_set (sym, str->type_name, str->type_location);
else
symbol_type_set (orig, alias->type_name, alias->type_location);
symbol_type_set (str, sym->type_name, sym->type_location);
}
if (orig->destructor.code || alias->destructor.code)
if (str->destructor.code || sym->destructor.code)
{
if (orig->destructor.code)
symbol_destructor_set (alias, &orig->destructor);
if (str->destructor.code)
symbol_destructor_set (sym, &str->destructor);
else
symbol_destructor_set (orig, &alias->destructor);
symbol_destructor_set (str, &sym->destructor);
}
if (orig->printer.code || alias->printer.code)
if (str->printer.code || sym->printer.code)
{
if (orig->printer.code)
symbol_printer_set (alias, &orig->printer);
if (str->printer.code)
symbol_printer_set (sym, &str->printer);
else
symbol_printer_set (orig, &alias->printer);
symbol_printer_set (str, &sym->printer);
}
if (alias->prec || orig->prec)
if (sym->prec || str->prec)
{
if (orig->prec)
symbol_precedence_set (alias, orig->prec, orig->assoc,
orig->prec_location);
if (str->prec)
symbol_precedence_set (sym, str->prec, str->assoc,
str->prec_location);
else
symbol_precedence_set (orig, alias->prec, alias->assoc,
alias->prec_location);
symbol_precedence_set (str, sym->prec, sym->assoc,
sym->prec_location);
}
}
@@ -530,8 +526,8 @@ symbol_pack (symbol *this)
this->number = this->alias->number;
}
}
/* Do not do processing below for USER_NUMBER_ALIASes. */
if (this->user_token_number == USER_NUMBER_ALIAS)
/* Do not do processing below for USER_NUMBER_HAS_STRING_ALIASes. */
if (this->user_token_number == USER_NUMBER_HAS_STRING_ALIAS)
return true;
}
else /* this->class == token_sym */
@@ -578,7 +574,7 @@ symbol_translation (symbol *this)
{
/* Non-terminal? */
if (this->class == token_sym
&& this->user_token_number != USER_NUMBER_ALIAS)
&& this->user_token_number != USER_NUMBER_HAS_STRING_ALIAS)
{
/* A token which translation has already been set? */
if (token_translations[this->user_token_number] != undeftoken->number)

21
src/symtab.h
View File

@@ -85,9 +85,9 @@ struct symbol
assoc assoc;
int user_token_number;
/* Points to the other in the identifier-symbol pair for an alias.
Special value USER_NUMBER_ALIAS in the identifier half of the
identifier-symbol pair for an alias. */
/* Points to the other in the symbol-string pair for an alias.
Special value USER_NUMBER_HAS_STRING_ALIAS in the symbol half of the
symbol-string pair for an alias. */
symbol *alias;
symbol_class class;
bool declared;
@@ -96,11 +96,11 @@ struct symbol
/** Undefined user number. */
#define USER_NUMBER_UNDEFINED -1
/* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
*has* (not is) a string literal alias. For instance, `%token foo
/* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
this symbol has a literal string alias. For instance, `%token foo
"foo"' has `"foo"' numbered regularly, and `foo' numbered as
USER_NUMBER_ALIAS. */
#define USER_NUMBER_ALIAS -9991
USER_NUMBER_HAS_STRING_ALIAS. */
#define USER_NUMBER_HAS_STRING_ALIAS -9991
/* Undefined internal token number. */
#define NUMBER_UNDEFINED (-1)
@@ -122,8 +122,11 @@ symbol *dummy_symbol_get (location loc);
/** Is this a dummy nonterminal? */
bool symbol_is_dummy (const symbol *sym);
/** Declare the new symbol \c sym. Make it an alias of \c symval. */
void symbol_make_alias (symbol *sym, symbol *symval, location loc);
/**
* Make \c str the literal string alias of \c sym. Copy token number,
* symbol number, and type from \c sym to \c str.
*/
void symbol_make_alias (symbol *sym, symbol *str, location loc);
/** Set the \c type_name associated with \c sym.