From c97419f3bacbfb2a50b9fe1b57cf500d1c00018f Mon Sep 17 00:00:00 2001
From: Bernhard Urban <lewurm@gmail.com>
Date: Tue, 30 Mar 2010 14:46:10 +0200
Subject: [PATCH] ag: even more refactored

---
 ag/parser.y   | 20 ++++++++++----------
 ag/symtable.c | 27 +++++++++------------------
 2 files changed, 19 insertions(+), 28 deletions(-)

diff --git a/ag/parser.y b/ag/parser.y
index 3d278fd..7eb49e8 100644
--- a/ag/parser.y
+++ b/ag/parser.y
@@ -18,7 +18,7 @@
 @attributes	{ struct symbol *symbols; } Funcdef Stats Bool Expr Call Lexpr Field Term Plusterm Malterm Bterm Orterm Exprs
 @attributes	{ struct symbol *in_symbols; struct symbol *out_symbols; } Stat
 
-@traversal @postorder t
+@traversal @postorder c
 
 %%
 
@@ -29,12 +29,12 @@ Input:		  Program
 
 Program:	  Funcdef ';' Program
 		@{
-		   @i @Program.fields@ = @Program.1.fields@;
+		   @i @Program.0.fields@ = @Program.1.fields@;
 		@}
 
 		| Structdef ';' Program
 		@{
-		   @i @Program.fields@ = tab_merge(@Structdef.fields@, @Program.1.fields@, 1);
+		   @i @Program.0.fields@ = tab_merge(@Structdef.fields@, @Program.1.fields@, 1);
 		   @i @Program.1.symbols@ = @Program.0.symbols@;
 		@}
 
@@ -58,7 +58,7 @@ Structdef: 	  STRUCT Ids END
 		;  
 
 Ids:		  ID Ids
-		@{ @i @Ids.fields@ = tab_add_symbol(@Ids.1.fields@, @ID.name@, S_FIELD, 1); @}
+		@{ @i @Ids.0.fields@ = tab_add_symbol(@Ids.1.fields@, @ID.name@, S_FIELD, 1); @}
 
 		|
 		@{ @i @Ids.fields@ = new_tab(); @}
@@ -66,7 +66,7 @@ Ids:		  ID Ids
 		;
 
 Pars: 		  Pars ',' ID
-		@{ @i @Pars.pars@ = tab_add_symbol(@Pars.1.pars@, @ID.name@, S_VAR, 0); @}
+		@{ @i @Pars.0.pars@ = tab_add_symbol(@Pars.1.pars@, @ID.name@, S_VAR, 0); @}
 
   		| ID
 		@{ @i @Pars.pars@ = tab_add_symbol(new_tab(), @ID.name@, S_VAR, 0); @}
@@ -75,7 +75,7 @@ Pars: 		  Pars ',' ID
  
 Stats:		  Stat ';' Stats
      		@{
-		   @i @Stat.in_symbols@ = @Stats.symbols@;
+		   @i @Stat.in_symbols@ = @Stats.0.symbols@;
 		   @i @Stats.1.symbols@ = @Stat.out_symbols@;
 		@}
 
@@ -105,7 +105,7 @@ Stat:		  VAR ID ASSIGN Expr
 		| IF Bool THEN Stats ELSE Stats END
 		@{
 		   @i @Bool.symbols@ = @Stat.in_symbols@;
-		   @i @Stats.symbols@ = @Stat.in_symbols@;
+		   @i @Stats.0.symbols@ = @Stat.in_symbols@;
 		   @i @Stats.1.symbols@ = @Stat.in_symbols@;
 		   @i @Stat.out_symbols@ = @Stat.in_symbols@;
 		@}
@@ -132,7 +132,7 @@ Stat:		  VAR ID ASSIGN Expr
 		;
  
 Lexpr:		  ID
-		@{ @t check_variable(@Lexpr.symbols@, @ID.name@); @}
+		@{ @c check_variable(@Lexpr.symbols@, @ID.name@); @}
 
 		| Field
 		;
@@ -153,7 +153,7 @@ Malterm:	  '*' Term Malterm
  
 Term:		  '(' Expr ')'
     		| ID
-		@{ @t check_variable(@Term.symbols@, @ID.name@); @}
+		@{ @c check_variable(@Term.symbols@, @ID.name@); @}
 
 		| NUM
 		| Call
@@ -175,7 +175,7 @@ Bterm:		  Term GREATER Term
 		;
 
 Field:		  Term '.' ID
-		@{ @t check_field(@Field.symbols@, @ID.name@); @}
+		@{ @c check_field(@Field.symbols@, @ID.name@); @}
 
      		;
 
diff --git a/ag/symtable.c b/ag/symtable.c
index 4195720..7242f06 100755
--- a/ag/symtable.c
+++ b/ag/symtable.c
@@ -28,12 +28,13 @@ struct symbol *tab_add_symbol(struct symbol *tab, char *ident, short type, short
 	struct symbol *elm;
 	struct symbol *new_elm;
 
-	if(tab_lookup(tab,ident) != SYMNULL) {
+	if(tab_lookup(tab, ident) != SYMNULL) {
 		if(check) {
 			fprintf(stderr, "Feld doppelt vorhanden: \"%s\"\n", ident);
 			exit(3);
+		} else {
+			tab = tab_remove_symbol(tab, ident);
 		}
-		tab = tab_remove_symbol(tab, ident);
 	}
 	
 	new_elm = (struct symbol *) malloc(sizeof(struct symbol));
@@ -61,17 +62,13 @@ struct symbol *tab_lookup(struct symbol *tab, char *ident)
 	if(tab == SYMNULL) {
 		return SYMNULL;
 	}
-	
-	if(strcmp(elm->ident, ident) == 0) {
-		return elm;
-	}
-	
-	while(elm->next != SYMNULL) {
-		elm = elm->next;
+
+	do {
 		if(strcmp(elm->ident, ident) == 0) {
 			return elm;
 		}
-	}
+		elm = elm->next;
+	} while(elm != SYMNULL);
 
 	return SYMNULL;
 }
@@ -93,23 +90,17 @@ struct symbol *tab_remove_symbol(struct symbol *tab, char *ident)
 {
 	struct symbol *elm = tab;
 	struct symbol *previous_elm = SYMNULL;
-	struct symbol *new_elm;
-
-	if(tab == SYMNULL) {
-		return SYMNULL;
-	}
 
 	while(elm != SYMNULL) {
 		if(strcmp(elm->ident, ident) == 0) {
 			if(previous_elm == SYMNULL) {
-				new_elm = elm->next;
+				tab = elm->next;
 			} else {
 				previous_elm->next = elm->next;
-				new_elm = tab;
 			}
 			(void)free(elm->ident);
 			(void)free(elm);
-			return new_elm;
+			break;
 		}
 		previous_elm = elm;
 		elm = elm->next;
-- 
2.25.1