comment usage of contexts

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@23805 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/pbx/ael/ael.flex b/pbx/ael/ael.flex
index b4c785571c0d90076dcaf0a98a624aea3b979831..9f5e2f67f1824255d655939535bd7e26bc7a359c 100644 (file)
--- a/pbx/ael/ael.flex
+++ b/pbx/ael/ael.flex
@@ -224,7 +224,13 @@ includes   { STORE_POS; return KW_INCLUDES;}
 
 
 
-
+       /*
+        * context used for arguments of if_head, random_head, switch_head,
+        * for (last statement), while (XXX why not iftime_head ?).
+        * End with the matching parentheses.
+        * A comma at the top level is valid here, unlike in argg where it
+        * is an argument separator so it must be returned as a token.
+        */
 <paren>{NOPARENS}\)    {
                if ( pbcpop(')') ) {    /* error */
                        STORE_LOC;
@@ -268,6 +274,15 @@ includes   { STORE_POS; return KW_INCLUDES;}
                yymore();
        }
 
+
+       /*
+        * handlers for arguments to a macro or application calls.
+        * We enter this context when we find the initial '(' and
+        * stay here until we close all matching parentheses,
+        * and find the comma (argument separator) or the closing ')'
+        * of the (external) call, which happens when parencount == 0
+        * before the decrement.
+        */
 <argg>{NOARGG}[\(\[\{]   {
                char c = yytext[yyleng-1];
                if (c == '(')
@@ -337,8 +352,11 @@ includes   { STORE_POS; return KW_INCLUDES;}
                yymore();
        }
 
-
-
+       /*
+        * context used to find tokens in the right hand side of assignments,
+        * or in the first and second operand of a 'for'. As above, match
+        * commas and use ';' as a separator (hence return it as a separate token).
+        */
 <semic>{NOSEMIC}[\(\[\{]       {
                char c = yytext[yyleng-1];
                yymore();
@@ -360,6 +378,7 @@ includes    { STORE_POS; return KW_INCLUDES;}
 <semic>{NOSEMIC};      {
                STORE_LOC;
                yylval->str = strdup(yytext);
+               /* XXX maybe the truncation should be unconditional ? */
                if(yyleng > 1)
                        *(yylval->str+yyleng-1)=0;
                unput(';');
@@ -504,7 +523,7 @@ void reset_parencount(yyscan_t yyscanner )
        struct yyguts_t * yyg = (struct yyguts_t*)yyscanner;
        parencount = 0;
        pbcpos = 0;
-       pbcpush('(');
+       pbcpush('(');   /* push '(' so the last pcbpop (parencount= -1) will succeed */
        c_prevword();
        BEGIN(paren);
 }
@@ -524,7 +543,7 @@ void reset_argcount(yyscan_t yyscanner )
        parencount = 0;
        pbcpos = 0;
        commaout = 0;
-       pbcpush('(');
+       pbcpush('(');   /* push '(' so the last pcbpop (parencount= -1) will succeed */
        c_prevword();
        BEGIN(argg);
 }

diff --git a/pbx/ael/ael_lex.c b/pbx/ael/ael_lex.c
index 3a8837964055b91e52cd595d040e4243c290ab8c..5e50cb05a9ba29e5a82a43d56edfae8e572feb95 100644 (file)
--- a/pbx/ael/ael_lex.c
+++ b/pbx/ael/ael_lex.c
@@ -1329,10 +1329,17 @@ YY_RULE_SETUP
                return word;
        }
        YY_BREAK
+/*
+        * context used for arguments of if_head, random_head, switch_head,
+        * for (last statement), while (XXX why not iftime_head ?).
+        * End with the matching parentheses.
+        * A comma at the top level is valid here, unlike in argg where it
+        * is an argument separator so it must be returned as a token.
+        */
 case 44:
 /* rule 44 can match eol */
 YY_RULE_SETUP
-#line 228 "ael.flex"
+#line 234 "ael.flex"
 {
                if ( pbcpop(')') ) {    /* error */
                        STORE_LOC;
@@ -1358,7 +1365,7 @@ YY_RULE_SETUP
 case 45:
 /* rule 45 can match eol */
 YY_RULE_SETUP
-#line 250 "ael.flex"
+#line 256 "ael.flex"
 {
                char c = yytext[yyleng-1];
                if (c == '(')
@@ -1370,7 +1377,7 @@ YY_RULE_SETUP
 case 46:
 /* rule 46 can match eol */
 YY_RULE_SETUP
-#line 258 "ael.flex"
+#line 264 "ael.flex"
 {
                char c = yytext[yyleng-1];
                if ( pbcpop(c))  { /* error */
@@ -1384,10 +1391,18 @@ YY_RULE_SETUP
                yymore();
        }
        YY_BREAK
+/*
+        * handlers for arguments to a macro or application calls.
+        * We enter this context when we find the initial '(' and
+        * stay here until we close all matching parentheses,
+        * and find the comma (argument separator) or the closing ')'
+        * of the (external) call, which happens when parencount == 0
+        * before the decrement.
+        */
 case 47:
 /* rule 47 can match eol */
 YY_RULE_SETUP
-#line 271 "ael.flex"
+#line 286 "ael.flex"
 {
                char c = yytext[yyleng-1];
                if (c == '(')
@@ -1399,7 +1414,7 @@ YY_RULE_SETUP
 case 48:
 /* rule 48 can match eol */
 YY_RULE_SETUP
-#line 279 "ael.flex"
+#line 294 "ael.flex"
 {
                if ( pbcpop(')') ) { /* error */
                        STORE_LOC;
@@ -1427,7 +1442,7 @@ YY_RULE_SETUP
 case 49:
 /* rule 49 can match eol */
 YY_RULE_SETUP
-#line 303 "ael.flex"
+#line 318 "ael.flex"
 {
                if( parencount != 0) { /* printf("Folding in a comma!\n"); */
                        yymore();
@@ -1456,7 +1471,7 @@ YY_RULE_SETUP
 case 50:
 /* rule 50 can match eol */
 YY_RULE_SETUP
-#line 328 "ael.flex"
+#line 343 "ael.flex"
 {
                char c = yytext[yyleng-1];
                if ( pbcpop(c) ) { /* error */
@@ -1469,10 +1484,15 @@ YY_RULE_SETUP
                yymore();
        }
        YY_BREAK
+/*
+        * context used to find tokens in the right hand side of assignments,
+        * or in the first and second operand of a 'for'. As above, match
+        * commas and use ';' as a separator (hence return it as a separate token).
+        */
 case 51:
 /* rule 51 can match eol */
 YY_RULE_SETUP
-#line 342 "ael.flex"
+#line 360 "ael.flex"
 {
                char c = yytext[yyleng-1];
                yymore();
@@ -1482,7 +1502,7 @@ YY_RULE_SETUP
 case 52:
 /* rule 52 can match eol */
 YY_RULE_SETUP
-#line 348 "ael.flex"
+#line 366 "ael.flex"
 {
                char c = yytext[yyleng-1];
                if ( pbcpop(c) ) { /* error */
@@ -1498,10 +1518,11 @@ YY_RULE_SETUP
 case 53:
 /* rule 53 can match eol */
 YY_RULE_SETUP
-#line 360 "ael.flex"
+#line 378 "ael.flex"
 {
                STORE_LOC;
                yylval->str = strdup(yytext);
+               /* XXX maybe the truncation should be unconditional ? */
                if(yyleng > 1)
                        *(yylval->str+yyleng-1)=0;
                unput(';');
@@ -1512,7 +1533,7 @@ YY_RULE_SETUP
 case 54:
 /* rule 54 can match eol */
 YY_RULE_SETUP
-#line 370 "ael.flex"
+#line 389 "ael.flex"
 {
                FILE *in1;
                char fnamebuf[1024],*p1,*p2;
@@ -1579,7 +1600,7 @@ case YY_STATE_EOF(INITIAL):
 case YY_STATE_EOF(paren):
 case YY_STATE_EOF(semic):
 case YY_STATE_EOF(argg):
-#line 432 "ael.flex"
+#line 451 "ael.flex"
 {
                if ( --include_stack_index < 0 ) {
                        yyterminate();
@@ -1595,10 +1616,10 @@ case YY_STATE_EOF(argg):
        YY_BREAK
 case 55:
 YY_RULE_SETUP
-#line 445 "ael.flex"
+#line 464 "ael.flex"
 ECHO;
        YY_BREAK
-#line 1602 "ael_lex.c"
+#line 1623 "ael_lex.c"
 
        case YY_END_OF_BUFFER:
                {
@@ -2728,7 +2749,7 @@ void ael_yyfree (void * ptr , yyscan_t yyscanner)
 
 #define YYTABLES_NAME "yytables"
 
-#line 445 "ael.flex"
+#line 464 "ael.flex"
 
 
 
@@ -2792,7 +2813,7 @@ void reset_parencount(yyscan_t yyscanner )
        struct yyguts_t * yyg = (struct yyguts_t*)yyscanner;
        parencount = 0;
        pbcpos = 0;
-       pbcpush('(');
+       pbcpush('(');   /* push '(' so the last pcbpop (parencount= -1) will succeed */
        c_prevword();
        BEGIN(paren);
 }
@@ -2812,7 +2833,7 @@ void reset_argcount(yyscan_t yyscanner )
        parencount = 0;
        pbcpos = 0;
        commaout = 0;
-       pbcpush('(');
+       pbcpush('(');   /* push '(' so the last pcbpop (parencount= -1) will succeed */
        c_prevword();
        BEGIN(argg);
 }