rearrange and refactor compiler

part 1/? of making compiler use badthing objects instead of separate ast

1 files changed, 154 insertions, 217 deletions

diff --git a/com.c b/com.c
index 10774c8..38a4196 100644
--- a/com.c
+++ b/com.c
@@ -15,6 +15,11 @@
 
 #define BYTECODE(C) (C->ch->bc)
 
+enum flags {
+	F_toplevel = 1,
+	F_tail = 2,
+};
+
 Chunk chunk_new(State *S) {
 	return (Chunk){ 0 };
 }
@@ -28,10 +33,6 @@ Compiler compiler_new(Compiler *outer, Chunk *ch) {
 	};
 }
 
-static void compile_byte(Compiler *C, uint8_t byte);
-static void compile_opcode(Compiler *C, Op opcode);
-static size_t compile_constant(Compiler *C, Val v);
-
 static int stack_effect_of(Op opcode) {
 	switch (opcode) {
 	case OP_LOADK:
@@ -68,73 +69,65 @@ static int stack_effect_of(Op opcode) {
 	case OP_CALL:
 	case OP_TAILCALL:
 	case OP_ENDSCOPE:
-		return 0;
+		ERROR("stack effect of opcode %d not constant",opcode);
+		break;
 
 	default:
 		ERROR("unknown stack effect of opcode %d",opcode); 
+		break;
 	}
 }
 
-
-// compile that byte directly
-static void compile_byte(Compiler *C, uint8_t byte) {
+// compilation of things
+static void cpl_byte(Compiler *C, uint8_t byte) {
 	Chunk *ch = C->ch;
-	if (ch->bc.len == ch->bc.cap) {
-		size_t newsz = (ch->bc.cap == 0 ? 8 : ch->bc.cap * 2);
-		ch->bc.d = RENEW_ARR(C->S, ch->bc.d, uint8_t, ch->bc.cap, newsz);
-		ch->bc.cap = newsz;
-	}
-	size_t ix = ch->bc.len;
-	ch->bc.d[ix] = byte;
-	ch->bc.len ++;
+	ENSURE_CAP(C->S, ch->bc, uint8_t, ch->bc.len+1);
+	ch->bc.d[ch->bc.len++] = byte;
 }
-// compile an opcode, keeping track of its stack effect
-static void compile_opcode(Compiler *C, Op opcode) {
-	int stack_effect = stack_effect_of(opcode);
+static void cpl_op(Compiler *C, Op op) {
+	int stack_effect = stack_effect_of(op);
 	C->stack_cur += stack_effect;
-	compile_byte(C, opcode);
+	cpl_byte(C, op);
 }
-// add a new constant to the constant table, and return its index
-// (but return the index of any existing identical constant instead of
-//  inserting a duplicate)
-static size_t compile_constant(Compiler *C, Val v) {
+// particular instructions
+static uint8_t cpl_const(Compiler *C, Val v) {
 	Chunk *ch = C->ch;
-	for (int i = 0; i < ch->consts.len; i ++)
-		if (val_equal(v, ch->consts.d[i])) return i;
 
-	if (ch->consts.len == ch->consts.cap) {
-		size_t newsz = (ch->consts.cap == 0 ? 8 : ch->consts.cap *2);
-		ch->consts.d = RENEW_ARR(C->S, ch->consts.d, Val, ch->consts.cap, newsz);
-		ch->consts.cap = newsz;
+	for (int i = 0; i < ch->consts.len; i++) {
+		if (val_equal(v, ch-consts.d[i])) {
+			return i;
+		}
 	}
 
-	size_t ix = ch->consts.len;
-	ch->consts.d[ix] = v;
-	ch->consts.len ++;
+	CHECK(ch->consts.len < 256, "maximum number of constants per function reached");
+
+	ENSURE_CAP(C->S, ch->consts, Val, ch->consts.len+1);
+	uint8_t ix = ch->consts.len;
+	ch->consts.d[ch->consts.len++] = v;
 	return ix;
 }
-
-// len is 1 + number of args
-static void compile_call_instr(Compiler *C, uint8_t len) {
-	compile_opcode(C, OP_CALL);
-	compile_byte(C, len);
+static void cpl_constop(Compiler *C, Op op, Val v) {
+	cpl_op(C, op);
+	cpl_byte(C, cpl_const(C, v));
+}
+static void cpl_call(Compiler *C, uint8_t len) {
+	cpl_byte(C, OP_CALL);
+	cpl_byte(C, len);
 	C->stack_cur -= len - 1;
 }
-
-static void compile_tailcall_instr(Compiler *C, uint8_t len) {
-	compile_opcode(C, OP_TAILCALL);
-	compile_byte(C, len);
+static void cpl_tailcall(Compiler *C, uint8_t len) {
+	cpl_byte(C, OP_TAILCALL);
+	cpl_byte(C, len);
 	C->stack_cur -= len - 1;
 }
-
-static void compile_endscope_instr(Compiler *C, uint8_t nlocals) {
+static void cpl_endscope(Compiler *C, uint8_t nlocals) {
 	if (nlocals > 0) {
-		compile_opcode(C, OP_ENDSCOPE);
-		compile_byte(C, nlocals);
+		cpl_byte(C, OP_ENDSCOPE);
+		cpl_byte(C, nlocals);
 		C->stack_cur -= nlocals;
 	}
 }
-
+// jump offsets and things
 static size_t placeholder(Compiler *C) {
 	size_t old_ix = BYTECODE(C).len;
 	compile_byte(C, 0x00);
@@ -145,20 +138,53 @@ static void patch(Compiler *C, size_t addr, uint16_t val) {
 	BYTECODE(C).d[addr] = val & 0xff;
 	BYTECODE(C).d[addr+1] = (val & 0xff00) >> 8;
 }
+// scopes and locals
+static void begin_scope(Compiler *C) {
+	Scope *sc = malloc(sizeof(Scope));
+	CHECK(sc != NULL, "memory fail");
+	memset(sc, 0, sizeof(Scope));
+	sc->outer = C->scope;
+	C->scope = sc;
+}
+static void end_scope(Compiler *C) {
+	Scope *sc = C->scope;
+	CHECK(sc != NULL, "attempt to end nonexistent scope");
+	C->scope = sc->outer;
+	// printf("ending scope with %d locals, named: \n", sc->nlocals);
+	// for (int i = 0; i < sc->nlocals; i++) {
+	// 	Local loc = sc->locals[i];
+	// 	printf("\t%3d  %s\n",loc.slot, loc.name);
+	// }
 
-// ----
-
-enum flags {
-	F_toplevel = 1,
-	F_tail = 2,
-};
-
-static void compile_node(Compiler *C, AstNode a, int flags);
-static void begin_scope(Compiler *C);
-static void end_scope(Compiler *C);
-
-typedef void (*form_compiler)(Compiler *C, AstVec l, Op op, int flags);
+	compile_endscope_instr(C, sc->nlocals);
+	free(sc);
+}
+// returns slot of declared local
+static uint8_t declare_local(Compiler *C, char *name) {
+	Scope *sc = C->scope;
+	CHECK(sc != NULL, "can't declare local outside of scope");
+	Local *l = &sc->locals[sc->nlocals++];
+	l->name = name;
+	// -1 because local is expected to be already on the stack
+	// ie sitting just below where stack_cur points
+	uint8_t slot = C->stack_cur - 1;
+	l->slot = slot;
+	// printf("declaring local %s at %d, stack_cur is %d\n",l->name, l->slot, C->stack_cur);
+	return slot;
+}
+static Local *locate_local(Compiler *C, char *name) {
+	for (Scope *sc = C->scope; sc != NULL; sc = sc->outer) {
+		for (int i = 0; i < sc->nlocals; i++) {
+			Local *loc = &sc->locals[i];
+			if (0 == strcmp(loc->name, name)) 
+				return loc;
+		}
+	}
+	return NULL;
+}
 
+// compiles a body, ie sequence of "toplevel" expressions in which
+// declarations are allowed
 static void compile_body(Compiler *C, AstVec l, int startat, int flags) {
 	begin_scope(C);
 	for (int i = startat; i < l.len - 1; i++) {
@@ -169,14 +195,11 @@ static void compile_body(Compiler *C, AstVec l, int startat, int flags) {
 	end_scope(C);
 }
 
-void single_form(Compiler *C, AstVec l, Op op) {
-	compile_node(C, l.vals[1], 0);
-	compile_opcode(C, op);
-}
 
-static Local *locate_local(Compiler *C, char *name);
 
-void set_form(Compiler *C, AstVec l, Op _, int flags) {
+
+
+static void set_form(Compiler *C, AstVec l, Op _, int flags) {
 	AstNode target = l.vals[1];
 	if (target.ty == AST_IDENT)  {
 		// set variable, local or global
@@ -205,11 +228,11 @@ void set_form(Compiler *C, AstVec l, Op _, int flags) {
 	}
 }
 
-void do_form(Compiler *C, AstVec l, Op _, int flags) {
+static void do_form(Compiler *C, AstVec l, Op _, int flags) {
 	compile_body(C, l, 1, flags);
 }
 
-void if_form(Compiler *C, AstVec l, Op _, int flags) {
+static void if_form(Compiler *C, AstVec l, Op _, int flags) {
 	// (if cond if-true if-false)
 	// cond
 	// 0branch ->A
@@ -246,7 +269,7 @@ void if_form(Compiler *C, AstVec l, Op _, int flags) {
 	CHECK(stack_cur_a == orig_stack_cur + 1, "this should never happen");
 }
 
-void while_form(Compiler *C, AstVec l, Op _, int flags) {
+static void while_form(Compiler *C, AstVec l, Op _, int flags) {
 	// (while cond body ...)
 	// A:
 	// cond
@@ -272,59 +295,15 @@ void while_form(Compiler *C, AstVec l, Op _, int flags) {
 
 
 
-void arith_form(Compiler *C, AstVec l, Op op, int flags) {
+static void arith_form(Compiler *C, AstVec l, Op op, int flags) {
 	compile_node(C, l.vals[1], 0);
 	compile_node(C, l.vals[2], 0);
 	compile_opcode(C, op);
 }
 
 
-static void begin_scope(Compiler *C) {
-	Scope *sc = malloc(sizeof(Scope));
-	CHECK(sc != NULL, "memory fail");
-	memset(sc, 0, sizeof(Scope));
-	sc->outer = C->scope;
-	C->scope = sc;
-}
-static void end_scope(Compiler *C) {
-	Scope *sc = C->scope;
-	CHECK(sc != NULL, "attempt to end nonexistent scope");
-	C->scope = sc->outer;
-	// printf("ending scope with %d locals, named: \n", sc->nlocals);
-	// for (int i = 0; i < sc->nlocals; i++) {
-	// 	Local loc = sc->locals[i];
-	// 	printf("\t%3d  %s\n",loc.slot, loc.name);
-	// }
 
-	compile_endscope_instr(C, sc->nlocals);
-
-	free(sc);
-}
-// returns slot of declared local
-static uint8_t declare_local(Compiler *C, char *name) {
-	Scope *sc = C->scope;
-	CHECK(sc != NULL, "can't declare local outside of scope");
-	Local *l = &sc->locals[sc->nlocals++];
-	l->name = name;
-	// -1 because local is expected to be already on the stack
-	// ie sitting just below where stack_cur points
-	uint8_t slot = C->stack_cur - 1;
-	l->slot = slot;
-	// printf("declaring local %s at %d, stack_cur is %d\n",l->name, l->slot, C->stack_cur);
-	return slot;
-}
-static Local *locate_local(Compiler *C, char *name) {
-	for (Scope *sc = C->scope; sc != NULL; sc = sc->outer) {
-		for (int i = 0; i < sc->nlocals; i++) {
-			Local *loc = &sc->locals[i];
-			if (0 == strcmp(loc->name, name)) 
-				return loc;
-		}
-	}
-	return NULL;
-}
-
-void let_form(Compiler *C, AstVec l, Op _, int flags) {
+static void let_form(Compiler *C, AstVec l, Op _, int flags) {
 	CHECK(l.vals[1].ty == AST_LIST, "let's first argument must be list");
 	AstVec bindlist = l.vals[1].as.list;
 	CHECK(bindlist.len % 2 == 0, "unmatched binding in let");
@@ -346,7 +325,7 @@ void let_form(Compiler *C, AstVec l, Op _, int flags) {
 	end_scope(C);
 }
 
-void for_form(Compiler *C, AstVec l, Op _, int flags) {
+static void for_form(Compiler *C, AstVec l, Op _, int flags) {
 	// (for (x n) ...)
 	CHECK(l.vals[1].ty == AST_LIST, "for needs binding list");
 	AstVec blist = l.vals[1].as.list;
@@ -402,7 +381,7 @@ void for_form(Compiler *C, AstVec l, Op _, int flags) {
 	end_scope(C);
 }
 
-void each_form(Compiler *C, AstVec l, Op _, int flags) {
+static void each_form(Compiler *C, AstVec l, Op _, int flags) {
 	// (each (x a) ...)
 	// returns nil, for now
 	CHECK(l.vals[1].ty == AST_LIST, "each needs binding list");
@@ -487,7 +466,7 @@ void each_form(Compiler *C, AstVec l, Op _, int flags) {
 }
 
 
-void def_form(Compiler *C, AstVec l, Op _, int flags) {
+static void def_form(Compiler *C, AstVec l, Op _, int flags) {
 	CHECK(l.vals[1].ty == AST_IDENT, "def's first argument must be ident");
 	CHECK(flags & F_toplevel, "def only allowed at top level");
 	compile_node(C, l.vals[2], 0);
@@ -498,7 +477,7 @@ void def_form(Compiler *C, AstVec l, Op _, int flags) {
 	compile_opcode(C, OP_NIL);
 }
 
-void fn_form(Compiler *C, AstVec l, Op _, int flags) {
+static void fn_form(Compiler *C, AstVec l, Op _, int flags) {
 	// (fn (arg arg arg) body ...)
 	CHECK(l.vals[1].ty == AST_LIST, "fn's first argument must be list");
 	AstVec arglist = l.vals[1].as.list;
@@ -530,7 +509,7 @@ void fn_form(Compiler *C, AstVec l, Op _, int flags) {
 	compile_byte(C, compile_constant(C, VAL_OBJ(func)));
 }
 
-void defn_form(Compiler *C, AstVec l, Op _, int flags) {
+static void defn_form(Compiler *C, AstVec l, Op _, int flags) {
 	// todo: reduce redundancy
 	CHECK(l.vals[1].ty == AST_LIST, "defns first arg must be list");
 	AstVec blist = l.vals[1].as.list;
@@ -564,6 +543,7 @@ void defn_form(Compiler *C, AstVec l, Op _, int flags) {
 	compile_opcode(C, OP_NIL);
 }
 
+typedef void (*form_compiler)(Compiler *C, AstVec l, Op op, int flags);
 typedef struct {
 	char *name;
 	int min_params;
@@ -596,110 +576,66 @@ static BuiltinForm builtin_forms[] = {
 	{ 0 },
 };
 
-typedef struct {
-	char *name;
-	Op op;
-} BuiltinIdent;
-static BuiltinIdent builtin_idents[] = {
-	{ "true", OP_TRUE },
-	{ "false", OP_FALSE },
-	{ "nil", OP_NIL },
-	{ 0 },
-};
-
-
+static BuiltinForm *find_builtinform(char *name) {
+	for (BuiltinForm *b = builtin_forms; b->name != NULL; b++)
+		if (0 == strcmp(b->name, name)) return b;
+	return NULL;
+}
 
-static void compile_node(Compiler *C, AstNode a, int flags) {
-	switch (a.ty) {
-	case AST_IDENT:;
-		char *ident = a.as.str;
-		bool found_builtin = false;
-		for (BuiltinIdent *b = builtin_idents; b->name != NULL; b++) {
-			if (0 == strcmp(b->name, ident)) {
-				compile_opcode(C, b->op);
-				found_builtin = true;
-				break;
-			}
-		}
-		if (!found_builtin) {
-			Local *loc = locate_local(C, ident);
-			if (loc != NULL) {
-				compile_opcode(C, OP_GETLOCAL);
-				compile_byte(C, loc->slot);
-			} else {
-				// read global
-				ObjString *o = objstring_copy_cstr(C->S, a.as.str);
-				compile_opcode(C, OP_GETGLOBAL);
-				compile_byte(C, compile_constant(C, VAL_OBJ(o)));
-			}
-		}
-		break;
-	case AST_NUM:
-		compile_opcode(C, OP_LOADK);
-		compile_byte(C, compile_constant(C, VAL_NUM(a.as.num)));
-		break;
-	case AST_STRING: {
-		ObjString *o = objstring_copy_cstr(C->S, a.as.str);
-		compile_opcode(C, OP_LOADK);
-		compile_byte(C, compile_constant(C, VAL_OBJ(o)));
+static void compile_expr(Compiler *C, Val v, int flags) {
+	switch (val_type(v)) {
+	case TY_NUM: case TY_NIL: case TY_BOOL:
+		cpl_constop(C, OP_LOADK, v);
 		break;
-	}
-	case AST_ARR: {
-		compile_opcode(C, OP_ARRNEW);
-		AstVec v = a.as.list;
-		for (int i = 0; i < v.len; i++) {
-			compile_node(C, v.vals[i], 0);
-			compile_opcode(C, OP_ARRAPPEND);
+	case OTY_STRING:;
+		Local *loc = locate_local(C, AS_CSTRING(v));
+		if (loc) {
+			cpl_op(C, OP_GETLOCAL);
+			cpl_byte(C, loc->slot);
+		} else {
+			cpl_constop(C, OP_GETGLOBAL, v);
 		}
 		break;
-	}
-
-	case AST_LIST: {
-		AstVec l = a.as.list;
-
-		CHECK(l.len > 0, "can't handle empty list");
-
+	case OTY_ARR:;
+		ObjArr *a = AS_ARR(v);
+		size_t len = a->len;
+		CHECK(len > 0, "can't handle empty array");
+		Val first = a->d[0];
 		BuiltinForm *form = NULL;
+		if (IS_STRING(first))
+			form = find_builtinform(AS_CSTRING(first));
 
-		if (l.vals[0].ty == AST_IDENT) {
-			char *head = l.vals[0].as.str;
-			for (BuiltinForm *b = builtin_forms; b->name != NULL; b++) {
-				if (0 == strcmp(b->name, head)) {
-					form = b;
-					break;
-				}
-			}
-		}
-
-		if (form != NULL) {
-			size_t nparams = l.len - 1;
-			if (form->ellipsis) 
-				CHECK(nparams >= form->min_params, "%s requires at least %d parameters",
+		if (form) {
+			size_t nargs = len - 1;
+			if (form->ellipsis)
+				CHECK(nargs >= form->min_params, "%s requires at least %d args",
 					form->name, form->min_params);
-			else 
-				CHECK(nparams == form->min_params, "%s requires exactly %d parameters",
+			else
+				CHECK(nargs == form->min_params, "%s requires exactly %d args",
 					form->name, form->min_params);
-
-			form->action(C, l, form->op, flags);
+			form->action(C, a, form->op, flags);
 		} else {
 			// function call
-			// (f a b c )
-			CHECK(l.len < 256, "max 255 args in a function call");
-			for (int i = 0; i < l.len; i++) {
-				compile_node(C, l.vals[i], 0);
-			}
-			if (flags & F_tail) {
-				compile_tailcall_instr(C, l.len);
-			} else {
-				compile_call_instr(C, l.len);
-			}
+			CHECK(len < 256, "max 255 args in a function call");
+			for (int i = 0; i  a->len; i++)
+				compile_expr(C, a->d[i], 0);
+			if (flags & F_tail)
+				cpl_tailcall(C, len);
+			else
+				cpl_call(C, len);
 		}
-
 		break;
 	}
-	}
 }
 
+
+		
+
+
+
+
+static char buf[8193];
+
 int main(int argc, char **argv) {
 	State st = state_new();
 	State *S = &st;
@@ -748,15 +684,16 @@ int main(int argc, char **argv) {
 			exit(1);
 		}
 
-		AstNode an = { 0 };
-		AstNode top = astnode_new_list();
-		pcc_context_t *parser = pcc_create(infile);
-		while (pcc_parse(parser, &an)) {
-			astnode_append(&top, an);
-		}
-		pcc_destroy(parser);
-		compile_body(&com, top.as.list, 0, 0);
-		astnode_free(&top);
+
+		fread(buf, 1, 8192, infile);
+		buf[8192] = '\0';
+		ObjArr *top = read_exprs(S, buf);
+
+		println_val(VAL_OBJ(top));
+
+		// pcc_destroy(parser);
+		// compile_body(&com, top.as.list, 0, 0);
+		// astnode_free(&top);
 	}