From 5ccebfdec189622b0c5b41eabb46fe67f8282443 Mon Sep 17 00:00:00 2001
From: "benjamin.franksen" <benjamin.franksen@helmholtz-berlin.de>
Date: Wed, 2 Oct 2013 01:30:51 +0000
Subject: [PATCH] snc: allow indirect function calls
This simply replaces 'ident ( args )' with 'expr ( args )' in the
syntax. A few more changes in the code generator and we're done.
---
src/snc/gen_ss_code.c | 16 ++++++++++------
src/snc/snl.lem | 38 ++++++++++++++++++--------------------
src/snc/types.h | 7 ++++---
3 files changed, 32 insertions(+), 29 deletions(-)
diff --git a/src/snc/gen_ss_code.c b/src/snc/gen_ss_code.c
index f30e4576..fd54cd25 100644
--- a/src/snc/gen_ss_code.c
+++ b/src/snc/gen_ss_code.c
@@ -445,9 +445,10 @@ static void gen_expr(
gen_code("\"%s\"", ep->value);
break;
case E_FUNC:
- if (gen_builtin_func(context, ep))
+ if (ep->func_expr->type == E_VAR && gen_builtin_func(context, ep))
break;
- gen_code("%s(", ep->value);
+ gen_expr(context, ep->func_expr, 0);
+ gen_code("(");
foreach (cep, ep->func_args)
{
gen_expr(context, cep, 0);
@@ -533,10 +534,13 @@ static int gen_builtin_const(Expr *ep)
/* Generate builtin function call */
static int gen_builtin_func(int context, Expr *ep)
{
- char *func_name = ep->value; /* function name */
+ char *func_name = ep->func_expr->value;
Expr *ap; /* argument expr */
- struct func_symbol *sym = lookup_builtin_func(global_sym_table, func_name);
+ struct func_symbol *sym;
+ if (ep->func_expr->type != E_VAR)
+ return FALSE;
+ sym = lookup_builtin_func(global_sym_table, func_name);
if (!sym)
return FALSE; /* not a special function */
@@ -688,7 +692,7 @@ static void gen_pv_func(
}
#ifdef DEBUG
- report("gen_pv_func: fun=%s, var=%s\n", ep->value, vp->name);
+ report("gen_pv_func: fun=%s, var=%s\n", func_name, vp->name);
#endif
gen_code(", ");
if (vp->assign == M_NONE)
@@ -767,7 +771,7 @@ static void gen_pv_func(
/* Close the parameter list */
gen_code(")");
#ifdef DEBUG
- report("gen_pv_func: done (fun=%s, var=%s)\n", ep->value, vp->name);
+ report("gen_pv_func: done (fun=%s, var=%s)\n", func_name, vp->name);
#endif
}
diff --git a/src/snc/snl.lem b/src/snc/snl.lem
index b5011b81..89b93887 100644
--- a/src/snc/snl.lem
+++ b/src/snc/snl.lem
@@ -44,7 +44,7 @@ in the file LICENSE that is included with this distribution.
%token_type { Token }
%default_type { Expr* }
-/* Standard C operator table
+/* Standard C operator table, highest precedence first.
Primary Expression Operators () [] . -> expr++ expr-- left-to-right
Unary Operators * & + - ! ~ ++expr --expr (typecast) sizeof() right-to-left
Binary Operators * / % left-to-right
@@ -62,8 +62,10 @@ in the file LICENSE that is included with this distribution.
Comma , left-to-right
*/
-// PRE and POST are pseudo tokens, they only for the
-// precedence declaration.
+// PRE and POST are pseudo tokens used for precedence declaration.
+// They are needed for operators that can appear in more than
+// one position (and then have different precedences) because lemon
+// allows only one precedence declaration for each token.
// The comma operator is implemented as an extra production,
// so we need no explicit precedence for it.
@@ -80,10 +82,8 @@ in the file LICENSE that is included with this distribution.
%left LSHIFT RSHIFT.
%left ADD SUB.
%left ASTERISK SLASH MOD.
-%right CAST.
-%right NOT INCR DECR PRE.
-%left LBRACKET RBRACKET POINTER PERIOD POST.
-// LPAREN RPAREN not listed as we do not support indirect calls. */
+%right NOT TILDE INCR DECR PRE. // omitted duplicates: ADD SUB ASTERISK AMPERSAND
+%left LBRACKET LPAREN POINTER PERIOD POST. // omitted duplicates: INCR DECR
program ::=
PROGRAM NAME(n)
@@ -400,19 +400,17 @@ expr(p) ::= FPCON(x). { p = expr(E_CONST, x); }
expr(p) ::= string(x). { p = x; }
expr(p) ::= variable(v). { p = expr(E_VAR, v); }
-// Parenthesized
-expr(p) ::= LPAREN(t) comma_expr(x) RPAREN. { p = expr(E_PAREN, t, x); }
-
// Primary Expression and Unary Postfix Operators
-expr(p) ::= NAME(t) LPAREN args(xs) RPAREN. [POST] { p = expr(E_FUNC, t, xs); }
-expr(p) ::= EXIT(t) LPAREN args(xs) RPAREN. [POST] { p = expr(E_FUNC, t, xs); }
-expr(p) ::= SIZEOF(t) LPAREN expr(x) RPAREN. [POST] { p = expr(E_FUNC, t, x); }
-expr(p) ::= SIZEOF(t) LPAREN type_expr(x) RPAREN.[POST] { p = expr(E_FUNC, t, x); }
-expr(p) ::= expr(x) LBRACKET(t) expr(y) RBRACKET.[POST] { p = expr(E_SUBSCR, t, x, y); }
-expr(p) ::= expr(x) PERIOD(t) member(y). [POST] { p = expr(E_SELECT, t, x, y); }
-expr(p) ::= expr(x) POINTER(t) member(y). [POST] { p = expr(E_SELECT, t, x, y); }
-expr(p) ::= expr(x) INCR(t). [POST] { p = expr(E_POST, t, x); }
-expr(p) ::= expr(x) DECR(t). [POST] { p = expr(E_POST, t, x); }
+expr(p) ::= LPAREN(t) comma_expr(x) RPAREN. { p = expr(E_PAREN, t, x); }
+expr(p) ::= expr(x) LPAREN(t) args(y) RPAREN. { p = expr(E_FUNC, t, x, y); }
+expr(p) ::= EXIT(n) LPAREN(t) args(y) RPAREN. { p = expr(E_FUNC, t, expr(E_VAR, n), y); }
+expr(p) ::= SIZEOF(n) LPAREN(t) expr(y) RPAREN. { p = expr(E_FUNC, t, expr(E_VAR, n), y); }
+expr(p) ::= SIZEOF(n) LPAREN(t) type_expr(y) RPAREN. { p = expr(E_FUNC, t, expr(E_VAR, n), y); }
+expr(p) ::= expr(x) LBRACKET(t) expr(y) RBRACKET. { p = expr(E_SUBSCR, t, x, y); }
+expr(p) ::= expr(x) PERIOD(t) member(y). { p = expr(E_SELECT, t, x, y); }
+expr(p) ::= expr(x) POINTER(t) member(y). { p = expr(E_SELECT, t, x, y); }
+expr(p) ::= expr(x) INCR(t). [POST] { p = expr(E_POST, t, x); }
+expr(p) ::= expr(x) DECR(t). [POST] { p = expr(E_POST, t, x); }
// Unary Prefix Operators
expr(p) ::= ADD(t) expr(x). [PRE] { p = expr(E_PRE, t, x); }
@@ -425,7 +423,7 @@ expr(p) ::= INCR(t) expr(x). [PRE] { p = expr(E_PRE, t, x); }
expr(p) ::= DECR(t) expr(x). [PRE] { p = expr(E_PRE, t, x); }
// Type Cast
-expr(p) ::= LPAREN(t) type_expr(c) RPAREN expr(x). [CAST] { p = expr(E_CAST, t, c, x); }
+expr(p) ::= LPAREN(t) type_expr(c) RPAREN expr(x). [PRE] { p = expr(E_CAST, t, c, x); }
// Binary Operators, left-to-right
expr(p) ::= expr(x) SUB(t) expr(y). { p = expr(E_BINOP, t, x, y); }
diff --git a/src/snc/types.h b/src/snc/types.h
index d940b470..2ee9027a 100644
--- a/src/snc/types.h
+++ b/src/snc/types.h
@@ -286,7 +286,7 @@ enum expr_type /* description [child expressions...] */
E_BINOP, /* binary operator [left,right] */
E_CAST, /* type cast [operand] */
E_CONST, /* numeric (inkl. character) constant [] */
- E_FUNC, /* function call [args] */
+ E_FUNC, /* function call [expr,args] */
E_INIT, /* array or struct initializer [elems] */
E_MEMBER, /* struct or union member [] */
E_PAREN, /* parenthesis around an expression [expr] */
@@ -332,7 +332,8 @@ STATIC_ASSERT(NUM_EXPR_TYPES <= 8*sizeof(TypeMask));
#define for_cond children[1]
#define for_iter children[2]
#define for_stmt children[3]
-#define func_args children[0]
+#define func_expr children[0]
+#define func_args children[1]
#define if_cond children[0]
#define if_then children[1]
#define if_else children[2]
@@ -405,7 +406,7 @@ expr_type_info[]
{ "E_BINOP", 2 },
{ "E_CAST", 2 },
{ "E_CONST", 0 },
- { "E_FUNC", 1 },
+ { "E_FUNC", 2 },
{ "E_INIT", 1 },
{ "E_MEMBER", 0 },
{ "E_PAREN", 1 },
--
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