This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
toke.c: Un-special case something
[perl5.git] / perly.y
diff --git a/perly.y b/perly.y
index 489291a..7d57dea 100644 (file)
--- a/perly.y
+++ b/perly.y
@@ -47,7 +47,7 @@
 
 %token <ival> '{' '}' '[' ']' '-' '+' '@' '%' '&' '=' '.'
 
-%token <opval> WORD METHOD FUNCMETH THING PMFUNC PRIVATEREF QWLIST
+%token <opval> BAREWORD METHOD FUNCMETH THING PMFUNC PRIVATEREF QWLIST
 %token <opval> FUNC0OP FUNC0SUB UNIOPSUB LSTOPSUB
 %token <opval> PLUGEXPR PLUGSTMT
 %token <pval> LABEL
 %type <opval> formname subname proto optsubbody cont my_scalar my_var
 %type <opval> refgen_topic formblock
 %type <opval> subattrlist myattrlist myattrterm myterm
-%type <opval> subsignature termbinop termunop anonymous termdo
+%type <opval> termbinop termunop anonymous termdo
+%type <ival>  sigslurpsigil
+%type <opval> sigvarname sigdefault sigscalarelem sigslurpelem
+%type <opval> sigelem siglist siglistornull subsignature 
 %type <opval> formstmtseq formline formarg
 
 %nonassoc <ival> PREC_LOW
@@ -140,7 +143,7 @@ grammar     :       GRAMPROG
                          PL_eval_root = $3;
                          $$ = 0;
                          yyunlex();
-                         parser->yychar = YYEOF;
+                         parser->yychar = yytoken = YYEOF;
                        }
        |       GRAMBARESTMT
                        {
@@ -152,7 +155,7 @@ grammar     :       GRAMPROG
                          PL_eval_root = $3;
                          $$ = 0;
                          yyunlex();
-                         parser->yychar = YYEOF;
+                         parser->yychar = yytoken = YYEOF;
                        }
        |       GRAMFULLSTMT
                        {
@@ -164,7 +167,7 @@ grammar     :       GRAMPROG
                          PL_eval_root = $3;
                          $$ = 0;
                          yyunlex();
-                         parser->yychar = YYEOF;
+                         parser->yychar = yytoken = YYEOF;
                        }
        |       GRAMSTMTSEQ
                        {
@@ -212,7 +215,7 @@ mremember:  /* NULL */      /* start a partial lexical scope */
 
 /* A sequence of statements in the program */
 stmtseq        :       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       stmtseq fullstmt
                        {   $$ = op_append_list(OP_LINESEQ, $1, $2);
                            PL_pad_reset_pending = TRUE;
@@ -223,7 +226,7 @@ stmtseq     :       /* NULL */
 
 /* A sequence of format lines */
 formstmtseq:   /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       formstmtseq formline
                        {   $$ = op_append_list(OP_LINESEQ, $1, $2);
                            PL_pad_reset_pending = TRUE;
@@ -258,7 +261,7 @@ barestmt:   PLUGSTMT
                        {
                          CV *fmtcv = PL_compcv;
                          newFORM($2, $3, $4);
-                         $$ = (OP*)NULL;
+                         $$ = NULL;
                          if (CvOUTSIDE(fmtcv) && !CvEVAL(CvOUTSIDE(fmtcv))) {
                              pad_add_weakref(fmtcv);
                          }
@@ -293,7 +296,7 @@ barestmt:   PLUGSTMT
                              ? newATTRSUB($3, $2, $5, $6, $7)
                              : newMYSUB($3, $2, $5, $6, $7)
                          ;
-                         $$ = (OP*)NULL;
+                         $$ = NULL;
                          intro_my();
                          parser->parsed_sub = 1;
                        }
@@ -332,25 +335,25 @@ barestmt: PLUGSTMT
                              ? newATTRSUB($3, $2, NULL, $7, body)
                              : newMYSUB($3, $2, NULL, $7, body)
                          ;
-                         $$ = (OP*)NULL;
+                         $$ = NULL;
                          intro_my();
                          parser->parsed_sub = 1;
                        }
-       |       PACKAGE WORD WORD ';'
+       |       PACKAGE BAREWORD BAREWORD ';'
                        {
                          package($3);
                          if ($2)
                              package_version($2);
-                         $$ = (OP*)NULL;
+                         $$ = NULL;
                        }
        |       USE startsub
                        { CvSPECIAL_on(PL_compcv); /* It's a BEGIN {} */ }
-               WORD WORD optlistexpr ';'
+               BAREWORD BAREWORD optlistexpr ';'
                        {
                          SvREFCNT_inc_simple_void(PL_compcv);
                          utilize($1, $2, $4, $5, $6);
                          parser->parsed_sub = 1;
-                         $$ = (OP*)NULL;
+                         $$ = NULL;
                        }
        |       IF '(' remember mexpr ')' mblock else
                        {
@@ -376,14 +379,14 @@ barestmt: PLUGSTMT
        |       WHILE '(' remember texpr ')' mintro mblock cont
                        {
                          $$ = block_end($3,
-                                 newWHILEOP(0, 1, (LOOP*)(OP*)NULL,
+                                 newWHILEOP(0, 1, NULL,
                                      $4, $7, $8, $6));
                          parser->copline = (line_t)$1;
                        }
        |       UNTIL '(' remember iexpr ')' mintro mblock cont
                        {
                          $$ = block_end($3,
-                                 newWHILEOP(0, 1, (LOOP*)(OP*)NULL,
+                                 newWHILEOP(0, 1, NULL,
                                      $4, $7, $8, $6));
                          parser->copline = (line_t)$1;
                        }
@@ -395,7 +398,7 @@ barestmt:   PLUGSTMT
                mblock
                        {
                          OP *initop = $4;
-                         OP *forop = newWHILEOP(0, 1, (LOOP*)(OP*)NULL,
+                         OP *forop = newWHILEOP(0, 1, NULL,
                                      scalar($7), $13, $11, $10);
                          if (initop) {
                              forop = op_prepend_elem(OP_LINESEQ, initop,
@@ -444,16 +447,16 @@ barestmt: PLUGSTMT
        |       FOR '(' remember mexpr ')' mblock cont
                        {
                          $$ = block_end($3,
-                                 newFOROP(0, (OP*)NULL, $4, $6, $7));
+                                 newFOROP(0, NULL, $4, $6, $7));
                          parser->copline = (line_t)$1;
                        }
        |       block cont
                        {
                          /* a block is a loop that happens once */
-                         $$ = newWHILEOP(0, 1, (LOOP*)(OP*)NULL,
-                                 (OP*)NULL, $1, $2, 0);
+                         $$ = newWHILEOP(0, 1, NULL,
+                                 NULL, $1, $2, 0);
                        }
-       |       PACKAGE WORD WORD '{' remember
+       |       PACKAGE BAREWORD BAREWORD '{' remember
                        {
                          package($3);
                          if ($2) {
@@ -463,8 +466,8 @@ barestmt:   PLUGSTMT
                stmtseq '}'
                        {
                          /* a block is a loop that happens once */
-                         $$ = newWHILEOP(0, 1, (LOOP*)(OP*)NULL,
-                                 (OP*)NULL, block_end($5, $7), (OP*)NULL, 0);
+                         $$ = newWHILEOP(0, 1, NULL,
+                                 NULL, block_end($5, $7), NULL, 0);
                          if (parser->copline > (line_t)$4)
                              parser->copline = (line_t)$4;
                        }
@@ -474,7 +477,7 @@ barestmt:   PLUGSTMT
                        }
        |       ';'
                        {
-                         $$ = (OP*)NULL;
+                         $$ = NULL;
                          parser->copline = NOLINE;
                        }
        ;
@@ -505,7 +508,7 @@ formarg     :       /* NULL */
 
 /* An expression which may have a side-effect */
 sideff :       error
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       expr
                        { $$ = $1; }
        |       expr IF expr
@@ -517,7 +520,7 @@ sideff      :       error
        |       expr UNTIL iexpr
                        { $$ = newLOOPOP(OPf_PARENS, 1, $3, $1); }
        |       expr FOR expr
-                       { $$ = newFOROP(0, (OP*)NULL, $3, $1, (OP*)NULL);
+                       { $$ = newFOROP(0, NULL, $3, $1, NULL);
                          parser->copline = (line_t)$2; }
        |       expr WHEN expr
                        { $$ = newWHENOP($3, op_scope($1)); }
@@ -525,7 +528,7 @@ sideff      :       error
 
 /* else and elsif blocks */
 else   :       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       ELSE mblock
                        {
                          ($2)->op_flags |= OPf_PARENS;
@@ -542,7 +545,7 @@ else        :       /* NULL */
 
 /* Continue blocks */
 cont   :       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       CONTINUE block
                        { $$ = op_scope($2); }
        ;
@@ -555,7 +558,7 @@ mintro      :       /* NULL */
 
 /* Normal expression */
 nexpr  :       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       sideff
        ;
 
@@ -581,8 +584,8 @@ mnexpr      :       nexpr
                        { $$ = $1; intro_my(); }
        ;
 
-formname:      WORD            { $$ = $1; }
-       |       /* NULL */      { $$ = (OP*)NULL; }
+formname:      BAREWORD        { $$ = $1; }
+       |       /* NULL */      { $$ = NULL; }
        ;
 
 startsub:      /* NULL */      /* start a regular subroutine scope */
@@ -602,54 +605,225 @@ startformsub:    /* NULL */      /* start a format subroutine scope */
        ;
 
 /* Name of a subroutine - must be a bareword, could be special */
-subname        :       WORD
+subname        :       BAREWORD
        |       PRIVATEREF
        ;
 
 /* Subroutine prototype */
 proto  :       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       THING
        ;
 
 /* Optional list of subroutine attributes */
 subattrlist:   /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       COLONATTR THING
                        { $$ = $2; }
        |       COLONATTR
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        ;
 
 /* List of attributes for a "my" variable declaration */
 myattrlist:    COLONATTR THING
                        { $$ = $2; }
        |       COLONATTR
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        ;
 
-/* Subroutine signature */
-subsignature:  '('
-                       {
-                         /* We shouldn't get here otherwise */
-                         assert(FEATURE_SIGNATURES_IS_ENABLED);
 
-                         Perl_ck_warner_d(aTHX_
-                               packWARN(WARN_EXPERIMENTAL__SIGNATURES),
-                               "The signatures feature is experimental");
-                         $<opval>$ = parse_subsignature();
+
+/* --------------------------------------
+ * subroutine signature parsing
+ */
+
+/* the '' or 'foo' part of a '$' or '@foo' etc signature variable  */
+sigvarname:     /* NULL */
+                       { parser->in_my = 0; $$ = NULL; }
+        |       PRIVATEREF
+                        { parser->in_my = 0; $$ = $1; }
+       ;
+
+sigslurpsigil:
+                '@'
+                        { $$ = '@'; }
+        |       '%'
+                        { $$ = '%'; }
+
+/* @, %, @foo, %foo */
+sigslurpelem: sigslurpsigil sigvarname sigdefault/* def only to catch errors */ 
+                        {
+                            I32 sigil   = $1;
+                            OP *var     = $2;
+                            OP *defexpr = $3;
+
+                            if (parser->sig_slurpy)
+                                yyerror("Multiple slurpy parameters not allowed");
+                            parser->sig_slurpy = (char)sigil;
+
+                            if (defexpr)
+                                yyerror("A slurpy parameter may not have "
+                                        "a default value");
+
+                            $$ = var ? newSTATEOP(0, NULL, var) : NULL;
+                        }
+       ;
+
+/* default part of sub signature scalar element: i.e. '= default_expr' */
+sigdefault:    /* NULL */
+                       { $$ = NULL; }
+        |       ASSIGNOP
+                        { $$ = newOP(OP_NULL, 0); }
+        |       ASSIGNOP term
+                        { $$ = $2; }
+
+
+/* subroutine signature scalar element: e.g. '$x', '$=', '$x = $default' */
+sigscalarelem:
+                '$' sigvarname sigdefault
+                        {
+                            OP *var     = $2;
+                            OP *defexpr = $3;
+
+                            if (parser->sig_slurpy)
+                                yyerror("Slurpy parameter not last");
+
+                            parser->sig_elems++;
+
+                            if (defexpr) {
+                                parser->sig_optelems++;
+
+                                if (   defexpr->op_type == OP_NULL
+                                    && !(defexpr->op_flags & OPf_KIDS))
+                                {
+                                    /* handle '$=' special case */
+                                    if (var)
+                                        yyerror("Optional parameter "
+                                                    "lacks default expression");
+                                    op_free(defexpr);
+                                }
+                                else { 
+                                    /* a normal '=default' expression */ 
+                                    OP *defop = (OP*)alloc_LOGOP(OP_ARGDEFELEM,
+                                                        defexpr,
+                                                        LINKLIST(defexpr));
+                                    /* re-purpose op_targ to hold @_ index */
+                                    defop->op_targ =
+                                        (PADOFFSET)(parser->sig_elems - 1);
+
+                                    if (var) {
+                                        var->op_flags |= OPf_STACKED;
+                                        (void)op_sibling_splice(var,
+                                                        NULL, 0, defop);
+                                        scalar(defop);
+                                    }
+                                    else
+                                        var = newUNOP(OP_NULL, 0, defop);
+
+                                    LINKLIST(var);
+                                    /* NB: normally the first child of a
+                                     * logop is executed before the logop,
+                                     * and it pushes a boolean result
+                                     * ready for the logop. For ARGDEFELEM,
+                                     * the op itself does the boolean
+                                     * calculation, so set the first op to
+                                     * it instead.
+                                     */
+                                    var->op_next = defop;
+                                    defexpr->op_next = var;
+                                }
+                            }
+                            else {
+                                if (parser->sig_optelems)
+                                    yyerror("Mandatory parameter "
+                                            "follows optional parameter");
+                            }
+
+                            $$ = var ? newSTATEOP(0, NULL, var) : NULL;
+                        }
+       ;
+
+
+/* subroutine signature element: e.g. '$x = $default' or '%h' */
+sigelem:        sigscalarelem
+                        { parser->in_my = KEY_sigvar; $$ = $1; }
+        |       sigslurpelem
+                        { parser->in_my = KEY_sigvar; $$ = $1; }
+       ;
+
+/* list of subroutine signature elements */
+siglist:
+               siglist ','
+                       { $$ = $1; }
+       |       siglist ',' sigelem
+                       {
+                         $$ = op_append_list(OP_LINESEQ, $1, $3);
                        }
-               ')'
+        |      sigelem  %prec PREC_LOW
+                       { $$ = $1; }
+       ;
+
+/* () or (....) */
+siglistornull:         /* NULL */
+                       { $$ = NULL; }
+       |       siglist
+                       { $$ = $1; }
+
+/* Subroutine signature */
+subsignature:  '('
+                        {
+                            ENTER;
+                            SAVEIV(parser->sig_elems);
+                            SAVEIV(parser->sig_optelems);
+                            SAVEI8(parser->sig_slurpy);
+                            parser->sig_elems    = 0;
+                            parser->sig_optelems = 0;
+                            parser->sig_slurpy   = 0;
+                            parser->in_my        = KEY_sigvar;
+                        }
+                siglistornull
+                ')'
                        {
-                         $$ = op_append_list(OP_LINESEQ, $<opval>2,
-                               newSTATEOP(0, NULL, sawparens(newNULLLIST())));
-                         parser->expect = XATTRBLOCK;
+                            OP            *sigops = $3;
+                            UNOP_AUX_item *aux;
+                            OP            *check;
+
+                            if (!parser->error_count) {
+                                assert(FEATURE_SIGNATURES_IS_ENABLED);
+                            }
+
+                            /* We shouldn't get here otherwise */
+                            Perl_ck_warner_d(aTHX_
+                                packWARN(WARN_EXPERIMENTAL__SIGNATURES),
+                                "The signatures feature is experimental");
+
+                            aux = (UNOP_AUX_item*)PerlMemShared_malloc(
+                                sizeof(UNOP_AUX_item) * 3);
+                            aux[0].iv = parser->sig_elems;
+                            aux[1].iv = parser->sig_optelems;
+                            aux[2].iv = parser->sig_slurpy;
+                            check = newUNOP_AUX(OP_ARGCHECK, 0, NULL, aux);
+                            sigops = op_prepend_elem(OP_LINESEQ, check, sigops);
+                            sigops = op_prepend_elem(OP_LINESEQ,
+                                                newSTATEOP(0, NULL, NULL),
+                                                sigops);
+                            /* a nextstate at the end handles context
+                             * correctly for an empty sub body */
+                            $$ = op_append_elem(OP_LINESEQ,
+                                                sigops,
+                                                newSTATEOP(0, NULL, NULL));
+
+                            parser->in_my = 0;
+                            parser->expect = XATTRBLOCK;
+                            LEAVE;
                        }
        ;
 
+
+
 /* Optional subroutine body, for named subroutine declaration */
 optsubbody:    block
-       |       ';'     { $$ = (OP*)NULL; }
+       |       ';'     { $$ = NULL; }
        ;
 
 /* Ordinary expressions; logical combinations */
@@ -711,7 +885,7 @@ listop      :       LSTOP indirob listexpr /* map {...} @args or print $fh @args */
                        { $$ = op_convert_list($1, 0, $3); }
        |       LSTOPSUB startanonsub block /* sub f(&@);   f { foo } ... */
                        { SvREFCNT_inc_simple_void(PL_compcv);
-                         $<opval>$ = newANONATTRSUB($2, 0, (OP*)NULL, $3); }
+                         $<opval>$ = newANONATTRSUB($2, 0, NULL, $3); }
                    optlistexpr         %prec LSTOP  /* ... @bar */
                        { $$ = newUNOP(OP_ENTERSUB, OPf_STACKED,
                                 op_append_elem(OP_LIST,
@@ -773,7 +947,7 @@ subscripted:    gelem '{' expr ';' '}'        /* *main::{something} */
        |       QWLIST '[' expr ']'            /* list literal slice */
                        { $$ = newSLICEOP(0, $3, $1); }
        |       '(' ')' '[' expr ']'                 /* empty list slice! */
-                       { $$ = newSLICEOP(0, $4, (OP*)NULL); }
+                       { $$ = newSLICEOP(0, $4, NULL); }
     ;
 
 /* Binary operators between terms */
@@ -850,11 +1024,11 @@ termunop : '-' term %prec UMINUS                       /* -$x */
 anonymous:     '[' expr ']'
                        { $$ = newANONLIST($2); }
        |       '[' ']'
-                       { $$ = newANONLIST((OP*)NULL);}
+                       { $$ = newANONLIST(NULL);}
        |       HASHBRACK expr ';' '}'  %prec '(' /* { foo => "Bar" } */
                        { $$ = newANONHASH($2); }
        |       HASHBRACK ';' '}'       %prec '(' /* { } (';' by tokener) */
-                       { $$ = newANONHASH((OP*)NULL); }
+                       { $$ = newANONHASH(NULL); }
        |       ANONSUB startanonsub proto subattrlist block            %prec '('
                        { SvREFCNT_inc_simple_void(PL_compcv);
                          $$ = newANONATTRSUB($2, $3, $4, $5); }
@@ -1028,7 +1202,7 @@ term      :       termbinop
                        }
                    '(' listexpr optrepl ')'
                        { $$ = pmruntime($1, $4, $5, 1, $<ival>2); }
-       |       WORD
+       |       BAREWORD
        |       listop
        |       YADAYADA
                        {
@@ -1063,19 +1237,19 @@ myterm  :       '(' expr ')'
 
 /* Basic list expressions */
 optlistexpr:   /* NULL */ %prec PREC_LOW
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       listexpr    %prec PREC_LOW
                        { $$ = $1; }
        ;
 
 optexpr:       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       expr
                        { $$ = $1; }
        ;
 
 optrepl:       /* NULL */
-                       { $$ = (OP*)NULL; }
+                       { $$ = NULL; }
        |       '/' expr
                        { $$ = $2; }
        ;
@@ -1145,7 +1319,7 @@ gelem     :       star
        ;
 
 /* Indirect objects */
-indirob        :       WORD
+indirob        :       BAREWORD
                        { $$ = scalar($1); }
        |       scalar %prec PREC_LOW
                        { $$ = scalar($1); }