X-Git-Url: https://git.m6w6.name/?p=m6w6%2Fext-psi;a=blobdiff_plain;f=src%2Fparser_proc.y;h=7f38f178585f9d5673c426b3d3b31d36ecd303c7;hp=59477baf28ef2ac830a96c61b32d0ec36b900377;hb=e16c15d5936c3b57b05e49570fb9526920de8188;hpb=22b4a95d8fd6525e4539f843ba5bebb9a56e89f2 diff --git a/src/parser_proc.y b/src/parser_proc.y index 59477ba..7f38f17 100644 --- a/src/parser_proc.y +++ b/src/parser_proc.y @@ -15,20 +15,30 @@ %extra_argument {PSI_Parser *P} /* TOKEN is defined inside syntax_error */ %syntax_error { - PSI_ParserSyntaxError(P, P->fn, P->line, "Unexpected token '%s'", TOKEN->text); + if (TOKEN && TOKEN->type != PSI_T_EOF) { + PSI_ParserSyntaxError(P, P->psi.file.fn, P->line, "Unexpected token '%s'", TOKEN->text); + } else { + PSI_ParserSyntaxError(P, P->psi.file.fn, P->line, "Unexpected end of input"); + } } + +%nonassoc NAME. +%left PLUS MINUS. +%left SLASH ASTERISK. +%fallback NAME TEMP FREE SET LET RETURN LIB INT UNSIGNED. + file ::= blocks. blocks ::= block. blocks ::= blocks block. -block ::= COMMENT. +block ::= EOF. block ::= LIB(T) QUOTED_STRING(libname) EOS. { - if (P->lib) { - PSI_ParserSyntaxError(P, P->fn, T->line, "Extra 'lib %s' statement has no effect", libname->text); + if (P->psi.file.ln) { + PSI_ParserSyntaxError(P, P->psi.file.ln, T->line, "Extra 'lib %s' statement has no effect", libname->text); } else { - P->lib = strndup(libname->text + 1, libname->size - 2); + P->psi.file.ln = strndup(libname->text + 1, libname->size - 2); } free(libname); free(T); @@ -54,82 +64,107 @@ block ::= decl_struct(strct). { } %type decl_struct {decl_struct*} -decl_struct(strct) ::= STRUCT NAME(N) LBRACE struct_args(args) RBRACE. { +%destructor decl_struct {free_decl_struct($$);} +decl_struct(strct) ::= STRUCT NAME(N) struct_size(size_) LBRACE struct_args(args) RBRACE. { strct = init_decl_struct(N->text, args); + strct->size = size_; + free(N); } -%type const_type {const_type*} -const_type(type_) ::= BOOL(T). { - type_ = init_const_type(T->type, T->text); - free(T); -} -const_type(type_) ::= INT(T). { - type_ = init_const_type(T->type, T->text); - free(T); +%type struct_size {size_t} +struct_size(size) ::= . { + size = 0; } -const_type(type_) ::= FLOAT(T). { - type_ = init_const_type(T->type, T->text); - free(T); +struct_size(size) ::= COLON COLON LPAREN NUMBER(SIZ) RPAREN. { + size = atol(SIZ->text); + free(SIZ); } -const_type(type_) ::= STRING(T). { + +%token_class const_type_token BOOL INT FLOAT STRING. +%type const_type {const_type*} +%destructor const_type {free_const_type($$);} +const_type(type_) ::= const_type_token(T). { type_ = init_const_type(T->type, T->text); free(T); } %type constant {constant*} +%destructor constant {free_constant($$);} constant(constant) ::= CONST const_type(type) NSNAME(T) EQUALS impl_def_val(val) EOS. { constant = init_constant(type, T->text, val); free(T); } %type decl_typedef {decl_typedef*} +%destructor decl_typedef {free_decl_typedef($$);} decl_typedef(def) ::= TYPEDEF decl_type(type) NAME(ALIAS) EOS. { def = init_decl_typedef(ALIAS->text, type); free(ALIAS); } +/* support opaque types */ +decl_typedef(def) ::= TYPEDEF VOID(V) NAME(ALIAS) EOS. { + def = init_decl_typedef(ALIAS->text, init_decl_type(V->type, V->text)); + def->type->token = V; + //free(V); + free(ALIAS); +} decl_typedef(def) ::= TYPEDEF STRUCT(S) NAME(N) NAME(ALIAS) EOS. { def = init_decl_typedef(ALIAS->text, init_decl_type(S->type, N->text)); + def->type->token = N; free(ALIAS); free(S); - free(N); + //free(N); } decl_typedef(def) ::= TYPEDEF decl_struct(s) NAME(ALIAS) EOS. { def = init_decl_typedef(ALIAS->text, init_decl_type(PSI_T_STRUCT, s->name)); + def->type->token = ALIAS; def->type->strct = s; - free(ALIAS); + //free(ALIAS); } %type decl {decl*} -decl(decl) ::= decl_abi(abi) decl_arg(func) LPAREN decl_args(args) RPAREN EOS. { +%destructor decl {free_decl($$);} +decl(decl) ::= decl_abi(abi) decl_func(func) LPAREN decl_args(args) RPAREN EOS. { decl = init_decl(abi, func, args); + +} + +%type decl_func {decl_arg*} +%destructor decl_func {free_decl_arg($$);} +decl_func(func) ::= decl_arg(arg). { + func = arg; +} +/* special case for void functions */ +decl_func(func) ::= VOID(T) NAME(N). { + func = init_decl_arg( + init_decl_type(T->type, T->text), + init_decl_var(N->text, 0, 0) + ); + func->type->token = T; + //free(T); + free(N); } %type decl_abi {decl_abi*} +%destructor decl_abi {free_decl_abi($$);} decl_abi(abi) ::= NAME(T). { abi = init_decl_abi(T->text); free(T); } %type decl_var {decl_var*} -decl_var(var) ::= NAME(T). { - var = init_decl_var(T->text, 0, 0); - free(T); -} -decl_var(var) ::= pointers(p) NAME(T). { +%destructor decl_var {free_decl_var($$);} +decl_var(var) ::= indirection(p) NAME(T). { var = init_decl_var(T->text, p, 0); free(T); } -decl_var(var) ::= NAME(T) LBRACKET NUMBER(D) RBRACKET. { - var = init_decl_var(T->text, 1, atol(D->text)); - free(T); - free(D); -} -decl_var(var) ::= pointers(p) NAME(T) LBRACKET NUMBER(D) RBRACKET. { +decl_var(var) ::= indirection(p) NAME(T) LBRACKET NUMBER(D) RBRACKET. { var = init_decl_var(T->text, p+1, atol(D->text)); free(T); free(D); } %type decl_vars {decl_vars*} +%destructor decl_vars {free_decl_vars($$);} decl_vars(vars) ::= decl_var(var). { vars = init_decl_vars(var); } @@ -138,11 +173,33 @@ decl_vars(vars) ::= decl_vars(vars_) COMMA decl_var(var). { } %type decl_arg {decl_arg*} -decl_arg(arg) ::= decl_type(type) decl_var(var). { - arg = init_decl_arg(type, var); +%destructor decl_arg {free_decl_arg($$);} +decl_arg(arg_) ::= const_decl_type(type) decl_var(var). { + arg_ = init_decl_arg(type, var); +} +/* void pointers need a specific rule */ +decl_arg(arg_) ::= VOID(T) pointers(p) NAME(N). { + arg_ = init_decl_arg( + init_decl_type(T->type, T->text), + init_decl_var(N->text, p, 0) + ); + arg_->type->token = T; + //free(T); + free(N); +} +decl_arg(arg_) ::= CONST VOID(T) pointers(p) NAME(N). { + arg_ = init_decl_arg( + init_decl_type(T->type, T->text), + init_decl_var(N->text, p, 0) + ); + arg_->type->token = T; + //free(T); + free(N); } %type decl_args {decl_args*} +%destructor decl_args {free_decl_args($$);} +decl_args ::= . decl_args ::= VOID. decl_args(args) ::= decl_arg(arg). { args = init_decl_args(arg); @@ -150,82 +207,76 @@ decl_args(args) ::= decl_arg(arg). { decl_args(args) ::= decl_args(args_) COMMA decl_arg(arg). { args = add_decl_arg(args_, arg); } +decl_args(args) ::= decl_args(args_) COMMA ELLIPSIS. { + args = args_; + args->varargs = 1; +} %type struct_args {decl_args*} -struct_args(args) ::= decl_arg(arg) EOS. { +%destructor struct_args {free_decl_args($$);} +struct_args(args) ::= struct_arg(arg). { args = init_decl_args(arg); } -struct_args(args) ::= struct_args(args_) decl_arg(arg) EOS. { +struct_args(args) ::= struct_args(args_) struct_arg(arg). { args = add_decl_arg(args_, arg); } - -%type decl_type {decl_type*} -decl_type(type_) ::= VOID(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= CHAR(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= SHORT(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= INT(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= LONG(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= FLOAT(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= DOUBLE(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= SIZE_T(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= SINT8(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= UINT8(T). { - type_ = init_decl_type(T->type, T->text); - free(T); -} -decl_type(type_) ::= SINT16(T). { - type_ = init_decl_type(T->type, T->text); - free(T); +%type struct_arg {decl_arg*} +%destructor struct_arg {free_decl_arg($$);} +struct_arg(arg) ::= decl_arg(arg_) struct_layout(layout_) EOS. { + arg_->layout = layout_; + arg = arg_; } -decl_type(type_) ::= UINT16(T). { - type_ = init_decl_type(T->type, T->text); - free(T); + +%type struct_layout {decl_struct_layout*} +%destructor struct_layout {free_decl_struct_layout($$);} +struct_layout(layout) ::= . { + layout = NULL; } -decl_type(type_) ::= SINT32(T). { - type_ = init_decl_type(T->type, T->text); - free(T); +struct_layout(layout) ::= COLON COLON LPAREN NUMBER(POS) COMMA NUMBER(SIZ) RPAREN. { + layout = init_decl_struct_layout(atol(POS->text), atol(SIZ->text)); + free(POS); + free(SIZ); } -decl_type(type_) ::= UINT32(T). { + +%token_class decl_type_token FLOAT DOUBLE INT8 UINT8 INT16 UINT16 INT32 UINT32 INT64 UINT64 NAME. +%type decl_type {decl_type*} +%destructor decl_type {free_decl_type($$);} +decl_type(type_) ::= decl_type_token(T). { type_ = init_decl_type(T->type, T->text); - free(T); + type_->token = T; + //free(T); } -decl_type(type_) ::= SINT64(T). { +/* unsigned, urgh */ +decl_type(type_) ::= UNSIGNED NAME(T). { type_ = init_decl_type(T->type, T->text); - free(T); + type_->token = T; + type_->name = realloc(type_->name, T->size + sizeof("unsigned")); + memmove(type_->name + sizeof("unsigned"), type_->name, T->size); + memcpy(type_->name, "unsigned", sizeof("unsigned")-1); + type_->name[sizeof("unsigned")] = ' '; + type_->name[T->size + sizeof("unsigned")] = 0; + //free(T); +} +/* we have to support plain int here because we have it in our lexer rules */ +decl_type(type_) ::= INT(T). { + type_ = init_decl_type(PSI_T_NAME, T->text); + type_->token = T; + //free(T); +} +/* structs ! */ +decl_type(type_) ::= STRUCT(S) NAME(T). { + type_ = init_decl_type(S->type, T->text); + type_->token = T; + free(S); + //free(T); } -decl_type(type_) ::= UINT64(T). { - type_ = init_decl_type(T->type, T->text); - free(T); + +%type const_decl_type {decl_type*} +%destructor const_decl_type {free_decl_type($$);} +const_decl_type(type) ::= decl_type(type_). { + type = type_; } -decl_type(type_) ::= NAME(T). { - type_ = init_decl_type(T->type, T->text); - free(T); +const_decl_type(type) ::= CONST decl_type(type_). { + type = type_; } %type impl {impl*} @@ -235,48 +286,29 @@ impl(impl) ::= impl_func(func) LBRACE impl_stmts(stmts) RBRACE. { } %type impl_func {impl_func*} -impl_func(func) ::= FUNCTION NSNAME(NAME) impl_args(args) COLON impl_type(type). { - func = init_impl_func(NAME->text, args, type, 0); - free(NAME); -} -impl_func(func) ::= FUNCTION REFERENCE NSNAME(NAME) impl_args(args) COLON impl_type(type). { - func = init_impl_func(NAME->text, args, type, 1); +%destructor impl_func {free_impl_func($$);} +impl_func(func) ::= FUNCTION reference(r) NSNAME(NAME) impl_args(args) COLON impl_type(type). { + func = init_impl_func(NAME->text, args, type, r); free(NAME); } +%token_class impl_def_val_token NULL NUMBER TRUE FALSE QUOTED_STRING. %type impl_def_val {impl_def_val*} -impl_def_val(def) ::= NULL(T). { - def = init_impl_def_val(T); - free(T); -} -impl_def_val(def) ::= NUMBER(T). { - def = init_impl_def_val(T); - free(T); -} -impl_def_val(def) ::= TRUE(T). { - def = init_impl_def_val(T); - free(T); -} -impl_def_val(def) ::= FALSE(T). { - def = init_impl_def_val(T); - free(T); -} -impl_def_val(def) ::= QUOTED_STRING(T). { - def = init_impl_def_val(T); +%destructor impl_def_val {free_impl_def_val($$);} +impl_def_val(def) ::= impl_def_val_token(T). { + def = init_impl_def_val(T->type, T->text); free(T); } %type impl_var {impl_var*} -impl_var(var) ::= DOLLAR NAME(T). { - var = init_impl_var(T->text, 0); - free(T); -} -impl_var(var) ::= REFERENCE DOLLAR NAME(T). { - var = init_impl_var(T->text, 1); +%destructor impl_var {free_impl_var($$);} +impl_var(var) ::= reference(r) DOLLAR NAME(T). { + var = init_impl_var(T->text, r); free(T); } %type impl_arg {impl_arg*} +%destructor impl_arg {free_impl_arg($$);} impl_arg(arg) ::= impl_type(type) impl_var(var). { arg = init_impl_arg(type, var, NULL); } @@ -285,13 +317,26 @@ impl_arg(arg) ::= impl_type(type) impl_var(var) EQUALS impl_def_val(def). { } %type impl_args {impl_args*} +%destructor impl_args {free_impl_args($$);} impl_args(args) ::= LPAREN RPAREN. { args = NULL; } impl_args(args) ::= LPAREN impl_arg_list(args_) RPAREN. { args = args_; } +impl_args(args) ::= LPAREN impl_arg_list(args_) COMMA impl_vararg(va) RPAREN. { + args = args_; + args->vararg = va; +} + +%type impl_vararg {impl_arg*} +%destructor impl_vararg {free_impl_arg($$);} +impl_vararg(va) ::= impl_type(type) reference(r) ELLIPSIS DOLLAR NAME(T). { + va = init_impl_arg(type, init_impl_var(T->text, r), NULL); +} + %type impl_arg_list {impl_args*} +%destructor impl_arg_list {free_impl_args($$);} impl_arg_list(args) ::= impl_arg(arg). { args = init_impl_args(arg); } @@ -323,136 +368,153 @@ impl_stmt(stmt) ::= free_stmt(free). { stmt = init_impl_stmt(PSI_T_FREE, free); } +%token_class num_exp_token NUMBER NSNAME. +%token_class num_exp_op_token PLUS MINUS ASTERISK SLASH. +%type num_exp {num_exp*} +%destructor num_exp {free_num_exp($$);} +num_exp(exp) ::= num_exp_token(tok). { + exp = init_num_exp(tok->type, tok->text); + free(tok); +} +num_exp(exp) ::= decl_var(var). { + exp = init_num_exp(PSI_T_NAME, var); +} +num_exp(exp) ::= num_exp(exp_) num_exp_op_token(operator_) num_exp(operand_). { + exp_->operator = operator_->type; + exp_->operand = operand_; + exp = exp_; + free(operator_); +} + %type let_stmt {let_stmt*} +%destructor let_stmt {free_let_stmt($$);} let_stmt(let) ::= LET decl_var(var) EOS. { - let = init_let_stmt(var, NULL); + let = init_let_stmt(var, init_let_val(PSI_LET_NULL, NULL)); } -let_stmt(let) ::= LET decl_var(var) EQUALS let_value(val) EOS. { +let_stmt(let) ::= LET decl_var(var) EQUALS reference(r) let_val(val) EOS. { + val->flags.one.is_reference = r ? 1 : 0; let = init_let_stmt(var, val); } - -%type let_value {let_value*} -let_value(val) ::= CALLOC(F) LPAREN NUMBER(N) COMMA decl_type(t) RPAREN. { - val = init_let_value( - init_let_func(F->type, F->text, - atol(N->text) * psi_t_size(real_decl_type(t)->type) - ), NULL, 0 - ); - free_decl_type(t); - free(F); - free(N); +let_stmt(let) ::= TEMP decl_var(var) EQUALS decl_var(val) EOS. { + let = init_let_stmt(var, init_let_val(PSI_LET_TMP, val)); } -let_value(val) ::= let_func(func) LPAREN impl_var(var) RPAREN. { - val = init_let_value(func, var, 0); + +%type let_val {let_val*} +%destructor let_val {free_let_val($$);} +let_val(val) ::= NULL. { + val = init_let_val(PSI_LET_NULL, NULL); } -let_value(val) ::= REFERENCE let_func(func) LPAREN impl_var(var) RPAREN. { - val = init_let_value(func, var, 1); +let_val(val) ::= num_exp(exp). { + val = init_let_val(PSI_LET_NUMEXP, exp); } -let_value(val) ::= REFERENCE NULL. { - val = init_let_value(NULL, NULL, 1); +let_val(val) ::= CALLOC LPAREN let_calloc(alloc) RPAREN. { + val = init_let_val(PSI_LET_CALLOC, alloc); } -let_value(val) ::= NULL. { - val = init_let_value(NULL, NULL, 0); +let_val(val) ::= let_func(func). { + val = init_let_val(PSI_LET_FUNC, func); } -%type let_func {let_func*} -let_func(func) ::= STRLEN(T). { - func = init_let_func(T->type, T->text, 0); - free(T); -} -let_func(func) ::= STRVAL(T). { - func = init_let_func(T->type, T->text, 0); - free(T); -} -let_func(func) ::= INTVAL(T). { - func = init_let_func(T->type, T->text, 0); - free(T); +%type let_calloc {let_calloc*} +%destructor let_calloc {free_let_calloc($$);} +let_calloc(alloc) ::= num_exp(nmemb) COMMA num_exp(size). { + alloc = init_let_calloc(nmemb, size); } -let_func(func) ::= FLOATVAL(T). { - func = init_let_func(T->type, T->text, 0); - free(T); -} -let_func(func) ::= BOOLVAL(T). { - func = init_let_func(T->type, T->text, 0); +%token_class let_func_token OBJVAL ARRVAL PATHVAL STRLEN STRVAL FLOATVAL INTVAL BOOLVAL. +%type let_func {let_func*} +%destructor let_func {free_let_func($$);} +let_func(func) ::= let_func_token(T) LPAREN impl_var(var) RPAREN. { + func = init_let_func(T->type, T->text, var); free(T); } + %type set_stmt {set_stmt*} +%destructor set_stmt {free_set_stmt($$);} set_stmt(set) ::= SET impl_var(var) EQUALS set_value(val) EOS. { set = init_set_stmt(var, val); } %type set_value {set_value*} -set_value(val) ::= set_func(func) LPAREN decl_vars(vars) RPAREN. { - val = init_set_value(func, vars); +%destructor set_value {free_set_value($$);} +set_value(val) ::= set_func(func) LPAREN decl_var(var) RPAREN. { + val = init_set_value(func, init_decl_vars(var)); } - -%type set_func {set_func*} -set_func(func) ::= TO_ARRAY(T). { - func = init_set_func(T->type, T->text); - free(T); +set_value(val) ::= set_func(func) LPAREN decl_var(var) COMMA num_exp(num_) RPAREN. { + val = init_set_value(func, init_decl_vars(var)); + val->num = num_; } -set_func(func) ::= TO_STRING(T). { - func = init_set_func(T->type, T->text); - free(T); +set_value(val) ::= set_func(func_) LPAREN decl_var(var) COMMA set_vals(vals) RPAREN. { + val = vals; + val->func = func_; + val->vars = init_decl_vars(var); } -set_func(func) ::= TO_INT(T). { - func = init_set_func(T->type, T->text); - free(T); +set_value(val) ::= set_func(func_) LPAREN decl_var(var) COMMA num_exp(num_) COMMA set_vals(vals) RPAREN. { + val = vals; + val->func = func_; + val->num = num_; + val->vars = init_decl_vars(var); } -set_func(func) ::= TO_FLOAT(T). { - func = init_set_func(T->type, T->text); - free(T); +%type set_vals {set_value*} +%destructor set_vals {free_set_value($$);} +set_vals(vals) ::= set_value(val). { + vals = add_inner_set_value(init_set_value(NULL, NULL), val); } -set_func(func) ::= TO_BOOL(T). { - func = init_set_func(T->type, T->text); - free(T); +set_vals(vals) ::= set_vals(vals_) COMMA set_value(val). { + vals = add_inner_set_value(vals_, val); } -set_func(func) ::= VOID(T). { + +%token_class set_func_token TO_OBJECT TO_ARRAY TO_STRING TO_INT TO_FLOAT TO_BOOL VOID. +%type set_func {set_func*} +%destructor set_func {free_set_func($$);} +set_func(func) ::= set_func_token(T). { func = init_set_func(T->type, T->text); free(T); } %type return_stmt {return_stmt*} -return_stmt(ret) ::= RETURN set_func(func) LPAREN decl_var(var) RPAREN EOS. { - ret = init_return_stmt(func, var); +%destructor return_stmt {free_return_stmt($$);} +return_stmt(ret) ::= RETURN set_value(val) EOS. { + ret = init_return_stmt(val); } %type free_stmt {free_stmt*} -free_stmt(free) ::= FREE decl_vars(vars) EOS. { - free = init_free_stmt(vars); +%destructor free_stmt {free_free_stmt($$);} +free_stmt(free) ::= FREE free_calls(calls) EOS. { + free = init_free_stmt(calls); } -%type impl_type {impl_type*} -impl_type(type_) ::= VOID(T). { - type_ = init_impl_type(T->type, T->text); - free(T); -} -impl_type(type_) ::= MIXED(T). { - type_ = init_impl_type(T->type, T->text); - free(T); -} -impl_type(type_) ::= BOOL(T). { - type_ = init_impl_type(T->type, T->text); - free(T); -} -impl_type(type_) ::= INT(T). { - type_ = init_impl_type(T->type, T->text); - free(T); +%type free_calls {free_calls*} +%destructor free_calls {free_free_calls($$);} +free_calls(calls) ::= free_call(call). { + calls = init_free_calls(call); } -impl_type(type_) ::= FLOAT(T). { - type_ = init_impl_type(T->type, T->text); - free(T); +free_calls(calls) ::= free_calls(calls_) COMMA free_call(call). { + calls = add_free_call(calls_, call); } -impl_type(type_) ::= STRING(T). { - type_ = init_impl_type(T->type, T->text); - free(T); + +%type free_call {free_call*} +%destructor free_call {free_free_call($$);} +free_call(call) ::= NAME(F) LPAREN decl_vars(vars) RPAREN. { + call = init_free_call(F->text, vars); + free(F); } -impl_type(type_) ::= ARRAY(T). { + +%token_class impl_type_token VOID MIXED BOOL INT FLOAT STRING ARRAY OBJECT. +%type impl_type {impl_type*} +%destructor impl_type {free_impl_type($$);} +impl_type(type_) ::= impl_type_token(T). { type_ = init_impl_type(T->type, T->text); free(T); } +%type reference {char} +reference(r) ::= . {r = 0;} +reference(r) ::= AMPERSAND. {r = 1;} + +%type indirection {unsigned} +indirection(i) ::= . {i = 0;} +indirection(i) ::= pointers(p). {i = p;} + %type pointers {unsigned} -pointers(p) ::= POINTER. {++p;} -pointers(p) ::= pointers(P) POINTER. {p = P+1;} +pointers(p) ::= ASTERISK. {p = 1;} +pointers(p) ::= pointers(P) ASTERISK. {p = P+1;}