Handle variable names (things strating with $ or @) in yylex() this way

the error handling of strange variable names can be better controlled.
With and OK dv@

diff --git a/usr.sbin/btrace/bt_parse.y b/usr.sbin/btrace/bt_parse.y
index 1eb5280..b378b89 100644 (file)
--- a/usr.sbin/btrace/bt_parse.y
+++ b/usr.sbin/btrace/bt_parse.y
@@ -1,4 +1,4 @@
-/*     $OpenBSD: bt_parse.y,v 1.56 2023/12/20 14:00:17 dv Exp $        */
+/*     $OpenBSD: bt_parse.y,v 1.57 2024/01/16 14:35:56 claudio Exp $   */
 
 /*
  * Copyright (c) 2019-2023 Martin Pieuchot <mpi@openbsd.org>
@@ -123,15 +123,15 @@ static int         beflag = 0;            /* BEGIN/END parsing context flag */
 /* Functions and Map operators */
 %token  <v.i>          F_DELETE F_PRINT
 %token <v.i>           MFUNC FUNC0 FUNC1 FUNCN OP1 OP2 OP4 MOP0 MOP1
-%token <v.string>      STRING CSTRING
+%token <v.string>      STRING CSTRING GVAR LVAR
+%token <v.arg>         PVAR PNUM
 %token <v.number>      NUMBER
 
-%type  <v.string>      gvar lvar
 %type  <v.i>           beginend
 %type  <v.probe>       plist probe pname
 %type  <v.filter>      filter
 %type  <v.stmt>        action stmt stmtblck stmtlist block
-%type  <v.arg>         vargs mentry mpat pargs staticv
+%type  <v.arg>         vargs mentry mpat pargs
 %type  <v.arg>         expr term fterm variable factor func
 %%
 
@@ -158,18 +158,7 @@ pname      : STRING ':' STRING ':' STRING  { $$ = bp_new($1, $3, $5, 0); }
        | STRING ':' HZ ':' NUMBER      { $$ = bp_new($1, "hz", NULL, $5); }
        ;
 
-staticv        : '$' NUMBER                    { $$ = get_varg($2); }
-       | '$' '#'                       { $$ = get_nargs(); }
-       ;
-
-gvar   : '@' STRING                    { $$ = $2; }
-       | '@'                           { $$ = UNNAMED_MAP; }
-       ;
-
-lvar   : '$' STRING                    { $$ = $2; }
-       ;
-
-mentry : gvar '[' vargs ']'            { $$ = bm_find($1, $3); }
+mentry : GVAR '[' vargs ']'            { $$ = bm_find($1, $3); }
        ;
 
 mpat   : MOP0 '(' ')'                  { $$ = ba_new(NULL, $1); }
@@ -212,8 +201,8 @@ fterm       : fterm '*' factor      { $$ = ba_op(B_AT_OP_MULT, $1, $3); }
        | factor
        ;
 
-variable: lvar                 { $$ = bl_find($1); }
-       | gvar                  { $$ = bg_find($1); }
+variable: LVAR                 { $$ = bl_find($1); }
+       | GVAR                  { $$ = bg_find($1); }
        | variable '.' NUMBER   { $$ = bi_find($1, $3); }
        ;
 
@@ -222,14 +211,15 @@ factor : '(' expr ')'             { $$ = $2; }
        | NUMBER                { $$ = ba_new($1, B_AT_LONG); }
        | BUILTIN               { $$ = ba_new(NULL, $1); }
        | CSTRING               { $$ = ba_new($1, B_AT_STR); }
-       | staticv
+       | PVAR
+       | PNUM
        | variable
        | mentry
        | func
        ;
 
-func   : STR '(' staticv ')'           { $$ = ba_new($3, B_AT_FN_STR); }
-       | STR '(' staticv ',' expr ')'  { $$ = ba_op(B_AT_FN_STR, $3, $5); }
+func   : STR '(' PVAR ')'              { $$ = ba_new($3, B_AT_FN_STR); }
+       | STR '(' PVAR ',' expr ')'     { $$ = ba_op(B_AT_FN_STR, $3, $5); }
        ;
 
 vargs  : expr
@@ -237,7 +227,7 @@ vargs       : expr
        ;
 
 pargs  : expr
-       | gvar ',' expr                 { $$ = ba_append(bg_find($1), $3); }
+       | GVAR ',' expr                 { $$ = ba_append(bg_find($1), $3); }
        ;
 
 NL     : /* empty */
@@ -245,17 +235,17 @@ NL        : /* empty */
        ;
 
 stmt   : ';' NL                        { $$ = NULL; }
-       | gvar '=' expr                 { $$ = bg_store($1, $3); }
-       | lvar '=' expr                 { $$ = bl_store($1, $3); }
-       | gvar '[' vargs ']' '=' mpat   { $$ = bm_insert($1, $3, $6); }
+       | GVAR '=' expr                 { $$ = bg_store($1, $3); }
+       | LVAR '=' expr                 { $$ = bl_store($1, $3); }
+       | GVAR '[' vargs ']' '=' mpat   { $$ = bm_insert($1, $3, $6); }
        | FUNCN '(' vargs ')'           { $$ = bs_new($1, $3, NULL); }
        | FUNC1 '(' expr ')'            { $$ = bs_new($1, $3, NULL); }
        | MFUNC '(' variable ')'        { $$ = bs_new($1, $3, NULL); }
        | FUNC0 '(' ')'                 { $$ = bs_new($1, NULL, NULL); }
        | F_DELETE '(' mentry ')'       { $$ = bm_op($1, $3, NULL); }
        | F_PRINT '(' pargs ')'         { $$ = bs_new($1, $3, NULL); }
-       | gvar '=' OP1 '(' expr ')'     { $$ = bh_inc($1, $5, NULL); }
-       | gvar '=' OP4 '(' expr ',' vargs ')'   { $$ = bh_inc($1, $5, $7); }
+       | GVAR '=' OP1 '(' expr ')'     { $$ = bh_inc($1, $5, NULL); }
+       | GVAR '=' OP4 '(' expr ',' vargs ')'   { $$ = bh_inc($1, $5, $7); }
        ;
 
 stmtblck: IF '(' expr ')' block                        { $$ = bt_new($3, $5); }
@@ -285,7 +275,7 @@ get_varg(int index)
        const char *errstr = NULL;
        long val;
 
-       if (0 < index && index <= nargs) {
+       if (1 <= index && index <= nargs) {
                val = (long)strtonum(vargs[index-1], LONG_MIN, LONG_MAX,
                    &errstr);
                if (errstr == NULL)
@@ -777,6 +767,19 @@ lungetc(void)
        }
 }
 
+static inline int
+allowed_to_end_number(int x)
+{
+       return (isspace(x) || x == ')' || x == '/' || x == '{' || x == ';' ||
+           x == ']' || x == ',' || x == '=');
+}
+
+static inline int
+allowed_in_string(int x)
+{
+       return (isalnum(x) || x == '_');
+}
+
 int
 yylex(void)
 {
@@ -872,6 +875,76 @@ again:
        case ':':
        case ';':
                return c;
+       case '$':
+               c = lgetc();
+               if (c == '#') {
+                       yylval.v.arg = get_nargs();
+                       return PNUM;
+               } else if (isdigit(c)) {
+                       do {
+                               *p++ = c;
+                               if (p == ebuf) {
+                                       yyerror("line too long");
+                                       return ERROR;
+                               }
+                       } while ((c = lgetc()) != EOF && isdigit(c));
+                       lungetc();
+                       *p = '\0';
+                       if (c == EOF || allowed_to_end_number(c)) {
+                               const char *errstr = NULL;
+                               int num;
+
+                               num = strtonum(buf, 1, INT_MAX, &errstr);
+                               if (errstr) {
+                                       yyerror("'$%s' is %s", buf, errstr);
+                                       return ERROR;
+                               }
+
+                               yylval.v.arg = get_varg(num);
+                               return PVAR;
+                       }
+               } else if (isalpha(c)) {
+                       do {
+                               *p++ = c;
+                               if (p == ebuf) {
+                                       yyerror("line too long");
+                                       return ERROR;
+                               }
+                       } while ((c = lgetc()) != EOF && allowed_in_string(c));
+                       lungetc();
+                       *p = '\0';
+                       if ((yylval.v.string = strdup(buf)) == NULL)
+                               err(1, "%s", __func__);
+                       return LVAR;
+               }
+               yyerror("'$%s%c' is an invalid variable name", buf, c);
+               return ERROR;
+               break;
+       case '@':
+               c = lgetc();
+               /* check for unnamed map '@' */
+               if (isalpha(c)) {
+                       do {
+                               *p++ = c;
+                               if (p == ebuf) {
+                                       yyerror("line too long");
+                                       return ERROR;
+                               }
+                       } while ((c = lgetc()) != EOF && allowed_in_string(c));
+                       lungetc();
+                       *p = '\0';
+                       if ((yylval.v.string = strdup(buf)) == NULL)
+                               err(1, "%s", __func__);
+                       return GVAR;
+               } else if (allowed_to_end_number(c) || c == '[') {
+                       lungetc();
+                       *p = '\0';
+                       yylval.v.string = UNNAMED_MAP;
+                       return GVAR;
+               }
+               yyerror("'@%s%c' is an invalid variable name", buf, c);
+               return ERROR;
+               break;
        case EOF:
                return 0;
        case '"':
@@ -915,9 +988,6 @@ again:
                break;
        }
 
-#define allowed_to_end_number(x) \
-    (isspace(x) || x == ')' || x == '/' || x == '{' || x == ';' || x == ']' || x == ',')
-
        /* parsing number */
        if (isdigit(c)) {
                do {
@@ -952,8 +1022,6 @@ again:
                }
        }
 
-#define allowed_in_string(x) (isalnum(c) || c == '_')
-
        /* parsing next word */
        if (allowed_in_string(c)) {
                struct keyword *kwp;