From 985d7177e8aaedcabe48dd911077ddcc8f74891f Mon Sep 17 00:00:00 2001 From: Akim Demaille Date: Thu, 18 Apr 2013 16:36:54 +0200 Subject: [PATCH] parser: no longer use the "braceless" non-terminal The purpose of this symbol was only to factor function calls. As a result the actions were indeed simpler, but the grammar was somewhat uselessly obfuscated. Get rid of this symbol, but introduce functions to simplify dependencies. There is no (intended) changes of behavior here. * src/parse-gram.y (strip_braces, translate_code( (translate_code_braceless): New. (braceless): Remove, use "{...}" instead, and one of the previous functions depending on the context. (STRING, "%{...%}", EPILOGUE): Declare as , instead of , the difference between both is useless (well, I couldn't make sense of it, even after having read the initial commit that introduced them). (%union): Remove the now useless "chars" type. Adjust the printers. * src/scan-gram.l: Adjust. --- src/parse-gram.y | 117 +++++++++++++++++++++++++---------------------- src/scan-gram.l | 6 +-- 2 files changed, 65 insertions(+), 58 deletions(-) diff --git a/src/parse-gram.y b/src/parse-gram.y index 8b57ce80..4c87c909 100644 --- a/src/parse-gram.y +++ b/src/parse-gram.y @@ -60,6 +60,22 @@ #define YY_LOCATION_PRINT(File, Loc) \ location_print (Loc, File) + /* Strip initial '{' and final '}' (must be first and last characters). + Return the result. */ + static char *strip_braces (char *code); + + /* Convert CODE by calling code_props_plain_init if PLAIN, otherwise + code_props_symbol_action_init. Call + gram_scanner_last_string_free to release the latest string from + the scanner (should be CODE). */ + static char const *translate_code (char *code, location loc, bool plain); + + /* Convert CODE by calling code_props_plain_init after having + stripped the first and last characters (expected to be '{', and + '}'). Call gram_scanner_last_string_free to release the latest + string from the scanner (should be CODE). */ + static char const *translate_code_braceless (char *code, location loc); + static void version_check (location const *loc, char const *version); static void gram_error (location const *, char const *); @@ -162,19 +178,10 @@ %type CHAR %printer { fputs (char_name ($$), yyo); } CHAR -/* braceless is not to be used for rule or symbol actions, as it - calls code_props_plain_init. */ -%union -{ - char *code; - char const *chars; -}; -%type STRING "%{...%}" EPILOGUE braceless -%type "{...}" "%?{...}" -%printer { fputs (quotearg_style (c_quoting_style, $$), yyo); } - STRING -%printer { fprintf (yyo, "{\n%s\n}", $$); } - braceless "{...}" "%{...%}" EPILOGUE +%union {char *code;}; +%type "{...}" "%?{...}" "%{...%}" EPILOGUE STRING +%printer { fputs (quotearg_style (c_quoting_style, $$), yyo); } STRING +%printer { fprintf (yyo, "{\n%s\n}", $$); } %union {uniqstr uniqstr;} %type BRACKETED_ID ID ID_COLON PERCENT_FLAG TAG tag variable @@ -266,12 +273,8 @@ prologue_declaration: grammar_declaration | "%{...%}" { - code_props plain_code; - code_props_plain_init (&plain_code, $1, @1); - code_props_translate_code (&plain_code); - gram_scanner_last_string_free (); muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue", - plain_code.code, @1); + translate_code ($1, @1, true), @1); code_scanner_last_string_free (); } | "%" @@ -305,11 +308,7 @@ prologue_declaration: } | "%initial-action" "{...}" { - code_props action; - code_props_symbol_action_init (&action, $2, @2); - code_props_translate_code (&action); - gram_scanner_last_string_free (); - muscle_code_grow ("initial_action", action.code, @2); + muscle_code_grow ("initial_action", translate_code ($2, @2, false), @2); code_scanner_last_string_free (); } | "%language" STRING { language_argmatch ($2, grammar_prio, @1); } @@ -386,16 +385,17 @@ grammar_declaration: { default_prec = false; } -| "%code" braceless +| "%code" "{...}" { /* Do not invoke muscle_percent_code_grow here since it invokes muscle_user_name_list_grow. */ - muscle_code_grow ("percent_code()", $2, @2); + muscle_code_grow ("percent_code()", + translate_code_braceless ($2, @2), @2); code_scanner_last_string_free (); } -| "%code" ID braceless +| "%code" ID "{...}" { - muscle_percent_code_grow ($2, @2, $3, @3); + muscle_percent_code_grow ($2, @2, translate_code_braceless ($3, @3), @3); code_scanner_last_string_free (); } ; @@ -420,10 +420,10 @@ union_name: ; grammar_declaration: - "%union" union_name braceless + "%union" union_name "{...}" { union_seen = true; - muscle_code_grow ("union_members", $3, @3); + muscle_code_grow ("union_members", translate_code_braceless ($3, @3), @3); code_scanner_last_string_free (); } ; @@ -658,27 +658,11 @@ variable: } ; value: - %empty { $$.kind = muscle_keyword; $$.chars = ""; } -| ID { $$.kind = muscle_keyword; $$.chars = $1; } -| STRING { $$.kind = muscle_string; $$.chars = $1; } -| braceless { $$.kind = muscle_code; $$.chars = $1; } -; - - -/*------------. -| braceless. | -`------------*/ - -braceless: - "{...}" - { - code_props plain_code; - $1[strlen ($1) - 1] = '\0'; - code_props_plain_init (&plain_code, $1+1, @1); - code_props_translate_code (&plain_code); - gram_scanner_last_string_free (); - $$ = plain_code.code; - } + %empty { $$.kind = muscle_keyword; $$.chars = ""; } +| ID { $$.kind = muscle_keyword; $$.chars = $1; } +| STRING { $$.kind = muscle_string; $$.chars = $1; } +| "{...}" { $$.kind = muscle_code; + $$.chars = translate_code_braceless ($1, @1); } ; @@ -723,11 +707,7 @@ epilogue.opt: %empty | "%%" EPILOGUE { - code_props plain_code; - code_props_plain_init (&plain_code, $2, @2); - code_props_translate_code (&plain_code); - gram_scanner_last_string_free (); - muscle_code_grow ("epilogue", plain_code.code, @2); + muscle_code_grow ("epilogue", translate_code ($2, @2, true), @2); code_scanner_last_string_free (); } ; @@ -763,6 +743,33 @@ lloc_default (YYLTYPE const *rhs, int n) return loc; } +static +char *strip_braces (char *code) +{ + code[strlen(code) - 1] = 0; + return code + 1; +} + +static +char const * +translate_code (char *code, location loc, bool plain) +{ + code_props plain_code; + if (plain) + code_props_plain_init (&plain_code, code, loc); + else + code_props_symbol_action_init (&plain_code, code, loc); + code_props_translate_code (&plain_code); + gram_scanner_last_string_free (); + return plain_code.code; +} + +static +char const * +translate_code_braceless (char *code, location loc) +{ + return translate_code (strip_braces (code), loc, true); +} static void add_param (param_type type, char *decl, location loc) diff --git a/src/scan-gram.l b/src/scan-gram.l index cf8b220d..665e80de 100644 --- a/src/scan-gram.l +++ b/src/scan-gram.l @@ -512,7 +512,7 @@ eqopt ([[:space:]]*=)? "\"" { STRING_FINISH; loc->start = token_start; - val->chars = last_string; + val->code = last_string; BEGIN INITIAL; return STRING; } @@ -751,7 +751,7 @@ eqopt ([[:space:]]*=)? "%}" { STRING_FINISH; loc->start = code_start; - val->chars = last_string; + val->code = last_string; BEGIN INITIAL; return PROLOGUE; } @@ -770,7 +770,7 @@ eqopt ([[:space:]]*=)? <> { STRING_FINISH; loc->start = code_start; - val->chars = last_string; + val->code = last_string; BEGIN INITIAL; return EPILOGUE; } -- 2.45.2