From 5a85e81685300e2299dabfeb25d513b99df471be Mon Sep 17 00:00:00 2001
From: Paweł Redman <trem.redman@gmail.com>
Date: Fri, 6 Sep 2013 22:40:51 +0200
Subject: Initial commit

---
 src/tools/lcc/src/init.c | 318 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 318 insertions(+)
 create mode 100644 src/tools/lcc/src/init.c

(limited to 'src/tools/lcc/src/init.c')

diff --git a/src/tools/lcc/src/init.c b/src/tools/lcc/src/init.c
new file mode 100644
index 0000000..172d7c0
--- /dev/null
+++ b/src/tools/lcc/src/init.c
@@ -0,0 +1,318 @@
+#include "c.h"
+
+
+static int curseg;		/* current segment */
+
+/* defpointer - initialize a pointer to p or to 0 if p==0 */
+void defpointer(Symbol p) {
+	if (p) {
+		(*IR->defaddress)(p);
+		p->ref++;
+	} else {
+		static Value v;
+		(*IR->defconst)(P, voidptype->size, v);
+	}
+}
+
+/* genconst - generate/check constant expression e; return size */
+static int genconst(Tree e, int def) {
+	for (;;)
+		switch (generic(e->op)) {
+		case ADDRG:
+			if (def)
+				(*IR->defaddress)(e->u.sym);
+			return e->type->size;
+		case CNST:
+			if (e->op == CNST+P && isarray(e->type)) {
+				e = cvtconst(e);
+				continue;
+			}
+			if (def)
+				(*IR->defconst)(e->type->op, e->type->size, e->u.v);
+			return e->type->size;
+		case RIGHT:
+			assert(e->kids[0] || e->kids[1]);
+			if (e->kids[1] && e->kids[0])
+				error("initializer must be constant\n");
+			e = e->kids[1] ? e->kids[1] : e->kids[0];
+			continue;
+		case CVP:
+			if (isarith(e->type))
+				error("cast from `%t' to `%t' is illegal in constant expressions\n",
+					e->kids[0]->type, e->type);
+			/* fall thru */
+		case CVI: case CVU: case CVF:
+			e = e->kids[0];
+			continue;
+		default:
+			error("initializer must be constant\n");
+			if (def)
+				genconst(consttree(0, inttype), def);
+			return inttype->size;
+		}
+}
+
+/* initvalue - evaluate a constant expression for a value of integer type ty */
+static Tree initvalue(Type ty) {
+	Type aty;
+	Tree e;
+
+	needconst++;
+	e = expr1(0);
+	if ((aty = assign(ty, e)) != NULL)
+		e = cast(e, aty);
+	else {
+		error("invalid initialization type; found `%t' expected `%t'\n",
+			e->type,  ty);
+		e = retype(consttree(0, inttype), ty);
+	}
+	needconst--;
+	if (generic(e->op) != CNST) {
+		error("initializer must be constant\n");
+		e = retype(consttree(0, inttype), ty);
+	}
+	return e;
+}
+
+/* initarray - initialize array of ty of <= len bytes; if len == 0, go to } */
+static int initarray(int len, Type ty, int lev) {
+	int n = 0;
+
+	do {
+		initializer(ty, lev);
+		n += ty->size;
+		if ((len > 0 && n >= len) || t != ',')
+			break;
+		t = gettok();
+	} while (t != '}');
+	return n;
+}
+
+/* initchar - initialize array of <= len ty characters; if len == 0, go to } */
+static int initchar(int len, Type ty) {
+	int n = 0;
+	char buf[16], *s = buf;
+
+	do {
+		*s++ = initvalue(ty)->u.v.i;
+		if (++n%inttype->size == 0) {
+			(*IR->defstring)(inttype->size, buf);
+			s = buf;
+		}
+		if ((len > 0 && n >= len) || t != ',')
+			break;
+		t = gettok();
+	} while (t != '}');
+	if (s > buf)
+		(*IR->defstring)(s - buf, buf);
+	return n;
+}
+
+/* initend - finish off an initialization at level lev; accepts trailing comma */
+static void initend(int lev, char follow[]) {
+	if (lev == 0 && t == ',')
+		t = gettok();
+	test('}', follow);
+}
+
+/* initfields - initialize <= an unsigned's worth of bit fields in fields p to q */
+static int initfields(Field p, Field q) {
+	unsigned int bits = 0;
+	int i, n = 0;
+
+	do {
+		i = initvalue(inttype)->u.v.i;
+		if (fieldsize(p) < 8*p->type->size) {
+			if ((p->type == inttype &&
+			   (i < -(int)(fieldmask(p)>>1)-1 || i > (int)(fieldmask(p)>>1)))
+			||  (p->type == unsignedtype && (i&~fieldmask(p)) !=  0))
+				warning("initializer exceeds bit-field width\n");
+			i &= fieldmask(p);
+		}
+		bits |= i<<fieldright(p);
+		if (IR->little_endian) {
+			if (fieldsize(p) + fieldright(p) > n)
+				n = fieldsize(p) + fieldright(p);
+		} else {
+			if (fieldsize(p) + fieldleft(p) > n)
+				n = fieldsize(p) + fieldleft(p);
+		}
+		if (p->link == q)
+			break;
+		p = p->link;
+	} while (t == ',' && (t = gettok()) != 0);
+	n = (n + 7)/8;
+	for (i = 0; i < n; i++) {
+		Value v;
+		if (IR->little_endian) {
+			v.u = (unsigned char)bits;
+			bits >>= 8;
+		} else {	/* a big endian */
+			v.u = (unsigned char)(bits>>(8*(unsignedtype->size - 1)));
+			bits <<= 8;
+		}
+		(*IR->defconst)(U, unsignedchar->size, v);
+	}
+	return n;
+}
+
+/* initstruct - initialize a struct ty of <= len bytes; if len == 0, go to } */
+static int initstruct(int len, Type ty, int lev) {
+	int a, n = 0;
+	Field p = ty->u.sym->u.s.flist;
+
+	do {
+		if (p->offset > n) {
+			(*IR->space)(p->offset - n);
+			n += p->offset - n;
+		}
+		if (p->lsb) {
+			Field q = p;
+			while (q->link && q->link->offset == p->offset)
+				q = q->link;
+			n += initfields(p, q->link);
+			p = q;
+		} else {
+			initializer(p->type, lev);
+			n += p->type->size;
+		}
+		if (p->link) {
+			p = p->link;
+			a = p->type->align;
+		} else
+			a = ty->align;
+		if (a && n%a) {
+			(*IR->space)(a - n%a);
+			n = roundup(n, a);
+		}
+		if ((len > 0 && n >= len) || t != ',')
+			break;
+		t = gettok();
+	} while (t != '}');
+	return n;
+}
+
+/* initializer - constexpr | { constexpr ( , constexpr )* [ , ] } */
+Type initializer(Type ty, int lev) {
+	int n = 0;
+	Tree e;
+	Type aty = NULL;
+	static char follow[] = { IF, CHAR, STATIC, 0 };
+
+	ty = unqual(ty);
+	if (isscalar(ty)) {
+		needconst++;
+		if (t == '{') {
+			t = gettok();
+			e = expr1(0);
+			initend(lev, follow);
+		} else
+			e = expr1(0);
+		e = pointer(e);
+		if ((aty = assign(ty, e)) != NULL)
+			e = cast(e, aty);
+		else
+			error("invalid initialization type; found `%t' expected `%t'\n",
+				e->type, ty);
+		n = genconst(e, 1);
+		deallocate(STMT);
+		needconst--;
+	}
+	if ((isunion(ty) || isstruct(ty)) && ty->size == 0) {
+		static char follow[] = { CHAR, STATIC, 0 };
+		error("cannot initialize undefined `%t'\n", ty);
+		skipto(';', follow);
+		return ty;
+	} else if (isunion(ty)) {
+		if (t == '{') {
+			t = gettok();
+			n = initstruct(ty->u.sym->u.s.flist->type->size, ty, lev + 1);
+			initend(lev, follow);
+		} else {
+			if (lev == 0)
+				error("missing { in initialization of `%t'\n", ty);
+			n = initstruct(ty->u.sym->u.s.flist->type->size, ty, lev + 1);
+		}
+	} else if (isstruct(ty)) {
+		if (t == '{') {
+			t = gettok();
+			n = initstruct(0, ty, lev + 1);
+			test('}', follow);
+		} else if (lev > 0)
+			n = initstruct(ty->size, ty, lev + 1);
+		else {
+			error("missing { in initialization of `%t'\n", ty);
+			n = initstruct(ty->u.sym->u.s.flist->type->size, ty, lev + 1);
+		}
+	}
+	if (isarray(ty))
+		aty = unqual(ty->type);
+	if (isarray(ty) && ischar(aty)) {
+		if (t == SCON) {
+			if (ty->size > 0 && ty->size == tsym->type->size - 1)
+				tsym->type = array(chartype, ty->size, 0);
+			n = tsym->type->size;
+			(*IR->defstring)(tsym->type->size, tsym->u.c.v.p);
+			t = gettok();
+		} else if (t == '{') {
+			t = gettok();
+			if (t == SCON) {
+				ty = initializer(ty, lev + 1);
+				initend(lev, follow);
+				return ty;
+			}
+			n = initchar(0, aty);
+			test('}', follow);
+		} else if (lev > 0 && ty->size > 0)
+			n = initchar(ty->size, aty);
+		else {	/* eg, char c[] = 0; */
+			error("missing { in initialization of `%t'\n", ty);
+			n = initchar(1, aty);
+		}
+	} else if (isarray(ty)) {
+		if (t == SCON && aty == widechar) {
+			int i;
+			unsigned int *s = tsym->u.c.v.p;
+			if (ty->size > 0 && ty->size == tsym->type->size - widechar->size)
+				tsym->type = array(widechar, ty->size/widechar->size, 0);
+			n = tsym->type->size;
+			for (i = 0; i < n; i += widechar->size) {
+				Value v;
+				v.u = *s++;
+				(*IR->defconst)(widechar->op, widechar->size, v);
+			}
+			t = gettok();
+		} else if (t == '{') {
+			t = gettok();
+			if (t == SCON && aty == widechar) {
+				ty = initializer(ty, lev + 1);
+				initend(lev, follow);
+				return ty;
+			}
+			n = initarray(0, aty, lev + 1);
+			test('}', follow);
+		} else if (lev > 0 && ty->size > 0)
+			n = initarray(ty->size, aty, lev + 1);
+		else {
+			error("missing { in initialization of `%t'\n", ty);
+			n = initarray(aty->size, aty, lev + 1);
+		}
+	}	
+	if (ty->size) {
+		if (n > ty->size)
+			error("too many initializers\n");
+		else if (n < ty->size)
+			(*IR->space)(ty->size - n);
+	} else if (isarray(ty) && ty->type->size > 0)
+		ty = array(ty->type, n/ty->type->size, 0);
+	else
+		ty->size = n;
+	return ty;
+}
+
+/* swtoseg - switch to segment seg, if necessary */
+void swtoseg(int seg) {
+	if (curseg != seg)
+		(*IR->segment)(seg);
+	curseg = seg;
+}
-- 
cgit