cmd/gc: simplify code for c2go

- Change forward reference to struct Node* to void* in liblink.
- Use explicit (Node*) casts in cmd/gc to get at that field.
- Define struct Array in go.h instead of hiding it in array.c.
- Remove some sizeof(uint32), sizeof(uint64) uses.
- Remove some ? : expressions.
- Rewrite some problematic mid-expression assignments.

Change-Id: I308c70140238a0cfffd90e133f86f442cd0e17d4
Reviewed-on: https://go-review.googlesource.com/3276Reviewed-by: Rob Pike <r@golang.org>

include/link.h

@@ -67,7 +67,7 @@ struct	Addr
 	int8	class;	// for 5l, 9l
 	uint8	etype; // for 5g, 6g, 8g
 	int32	offset2;	// for 5l, 8l
-	struct Node*	node; // for 5g, 6g, 8g
+	void*	node; // for 5g, 6g, 8g
 	int64	width; // for 5g, 6g, 8g
 };
 

src/cmd/5g/ggen.c

@@ -128,10 +128,10 @@ markautoused(Prog* p)
 			continue;
 
 		if (p->from.node)
-			p->from.node->used = 1;
+			((Node*)(p->from.node))->used = 1;
 
 		if (p->to.node)
-			p->to.node->used = 1;
+			((Node*)(p->to.node))->used = 1;
 	}
 }
 
@@ -142,11 +142,11 @@ fixautoused(Prog* p)
 	Prog **lp;
 
 	for (lp=&p; (p=*lp) != P; ) {
-		if (p->as == ATYPE && p->from.node && p->from.name == D_AUTO && !p->from.node->used) {
+		if (p->as == ATYPE && p->from.node && p->from.name == D_AUTO && !((Node*)(p->from.node))->used) {
 			*lp = p->link;
 			continue;
 		}
-		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !p->to.node->used) {
+		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !((Node*)(p->to.node))->used) {
 			// Cannot remove VARDEF instruction, because - unlike TYPE handled above -
 			// VARDEFs are interspersed with other code, and a jump might be using the
 			// VARDEF as a target. Replace with a no-op instead. A later pass will remove
@@ -158,10 +158,10 @@ fixautoused(Prog* p)
 		}
 
 		if (p->from.name == D_AUTO && p->from.node)
-			p->from.offset += p->from.node->stkdelta;
+			p->from.offset += ((Node*)(p->from.node))->stkdelta;
 
 		if (p->to.name == D_AUTO && p->to.node)
-			p->to.offset += p->to.node->stkdelta;
+			p->to.offset += ((Node*)(p->to.node))->stkdelta;
 
 		lp = &p->link;
 	}

src/cmd/5g/reg.c

@@ -274,7 +274,7 @@ regopt(Prog *firstp)
 	}
 	for(r = firstr; r != R; r = (Reg*)r->f.link) {
 		p = r->f.prog;
-		if(p->as == AVARDEF && isfat(p->to.node->type) && p->to.node->opt != nil) {
+		if(p->as == AVARDEF && isfat(((Node*)(p->to.node))->type) && ((Node*)(p->to.node))->opt != nil) {
 			active++;
 			walkvardef(p->to.node, r, active);
 		}

src/cmd/6g/ggen.c

@@ -124,10 +124,10 @@ markautoused(Prog* p)
 			continue;
 
 		if (p->from.node)
-			p->from.node->used = 1;
+			((Node*)(p->from.node))->used = 1;
 
 		if (p->to.node)
-			p->to.node->used = 1;
+			((Node*)(p->to.node))->used = 1;
 	}
 }
 
@@ -138,11 +138,11 @@ fixautoused(Prog *p)
 	Prog **lp;
 
 	for (lp=&p; (p=*lp) != P; ) {
-		if (p->as == ATYPE && p->from.node && p->from.type == D_AUTO && !p->from.node->used) {
+		if (p->as == ATYPE && p->from.node && p->from.type == D_AUTO && !((Node*)(p->from.node))->used) {
 			*lp = p->link;
 			continue;
 		}
-		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !p->to.node->used) {
+		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !((Node*)(p->to.node))->used) {
 			// Cannot remove VARDEF instruction, because - unlike TYPE handled above -
 			// VARDEFs are interspersed with other code, and a jump might be using the
 			// VARDEF as a target. Replace with a no-op instead. A later pass will remove
@@ -153,10 +153,10 @@ fixautoused(Prog *p)
 			continue;
 		}
 		if (p->from.type == D_AUTO && p->from.node)
-			p->from.offset += p->from.node->stkdelta;
+			p->from.offset += ((Node*)(p->from.node))->stkdelta;
 
 		if (p->to.type == D_AUTO && p->to.node)
-			p->to.offset += p->to.node->stkdelta;
+			p->to.offset += ((Node*)(p->to.node))->stkdelta;
 
 		lp = &p->link;
 	}

src/cmd/6g/reg.c

@@ -255,7 +255,7 @@ regopt(Prog *firstp)
 	}
 	for(r = firstr; r != R; r = (Reg*)r->f.link) {
 		p = r->f.prog;
-		if(p->as == AVARDEF && isfat(p->to.node->type) && p->to.node->opt != nil) {
+		if(p->as == AVARDEF && isfat(((Node*)(p->to.node))->type) && ((Node*)(p->to.node))->opt != nil) {
 			active++;
 			walkvardef(p->to.node, r, active);
 		}

src/cmd/8g/ggen.c

@@ -114,10 +114,10 @@ markautoused(Prog* p)
 			continue;
 
 		if (p->from.node)
-			p->from.node->used = 1;
+			((Node*)(p->from.node))->used = 1;
 
 		if (p->to.node)
-			p->to.node->used = 1;
+			((Node*)(p->to.node))->used = 1;
 	}
 }
 
@@ -128,11 +128,11 @@ fixautoused(Prog* p)
 	Prog **lp;
 
 	for (lp=&p; (p=*lp) != P; ) {
-		if (p->as == ATYPE && p->from.node && p->from.type == D_AUTO && !p->from.node->used) {
+		if (p->as == ATYPE && p->from.node && p->from.type == D_AUTO && !((Node*)(p->from.node))->used) {
 			*lp = p->link;
 			continue;
 		}
-		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !p->to.node->used) {
+		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !((Node*)(p->to.node))->used) {
 			// Cannot remove VARDEF instruction, because - unlike TYPE handled above -
 			// VARDEFs are interspersed with other code, and a jump might be using the
 			// VARDEF as a target. Replace with a no-op instead. A later pass will remove
@@ -144,10 +144,10 @@ fixautoused(Prog* p)
 		}
 
 		if (p->from.type == D_AUTO && p->from.node)
-			p->from.offset += p->from.node->stkdelta;
+			p->from.offset += ((Node*)(p->from.node))->stkdelta;
 
 		if (p->to.type == D_AUTO && p->to.node)
-			p->to.offset += p->to.node->stkdelta;
+			p->to.offset += ((Node*)(p->to.node))->stkdelta;
 
 		lp = &p->link;
 	}

src/cmd/8g/reg.c

@@ -227,7 +227,7 @@ regopt(Prog *firstp)
 	}
 	for(r = firstr; r != R; r = (Reg*)r->f.link) {
 		p = r->f.prog;
-		if(p->as == AVARDEF && isfat(p->to.node->type) && p->to.node->opt != nil) {
+		if(p->as == AVARDEF && isfat(((Node*)(p->to.node))->type) && ((Node*)(p->to.node))->opt != nil) {
 			active++;
 			walkvardef(p->to.node, r, active);
 		}

src/cmd/9g/ggen.c

@@ -124,10 +124,10 @@ markautoused(Prog *p)
 			continue;
 
 		if (p->from.node)
-			p->from.node->used = 1;
+			((Node*)(p->from.node))->used = 1;
 
 		if (p->to.node)
-			p->to.node->used = 1;
+			((Node*)(p->to.node))->used = 1;
 	}
 }
 
@@ -138,11 +138,11 @@ fixautoused(Prog *p)
 	Prog **lp;
 
 	for (lp=&p; (p=*lp) != P; ) {
-		if (p->as == ATYPE && p->from.node && p->from.name == D_AUTO && !p->from.node->used) {
+		if (p->as == ATYPE && p->from.node && p->from.name == D_AUTO && !((Node*)(p->from.node))->used) {
 			*lp = p->link;
 			continue;
 		}
-		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !p->to.node->used) {
+		if ((p->as == AVARDEF || p->as == AVARKILL) && p->to.node && !((Node*)(p->to.node))->used) {
 			// Cannot remove VARDEF instruction, because - unlike TYPE handled above -
 			// VARDEFs are interspersed with other code, and a jump might be using the
 			// VARDEF as a target. Replace with a no-op instead. A later pass will remove
@@ -153,10 +153,10 @@ fixautoused(Prog *p)
 			continue;
 		}
 		if (p->from.name == D_AUTO && p->from.node)
-			p->from.offset += p->from.node->stkdelta;
+			p->from.offset += ((Node*)(p->from.node))->stkdelta;
 
 		if (p->to.name == D_AUTO && p->to.node)
-			p->to.offset += p->to.node->stkdelta;
+			p->to.offset += ((Node*)(p->to.node))->stkdelta;
 
 		lp = &p->link;
 	}

src/cmd/9g/reg.c

@@ -296,7 +296,7 @@ regopt(Prog *firstp)
 	}
 	for(r = firstr; r != R; r = (Reg*)r->f.link) {
 		p = r->f.prog;
-		if(p->as == AVARDEF && isfat(p->to.node->type) && p->to.node->opt != nil) {
+		if(p->as == AVARDEF && isfat(((Node*)(p->to.node))->type) && ((Node*)(p->to.node))->opt != nil) {
 			active++;
 			walkvardef(p->to.node, r, active);
 		}

src/cmd/gc/array.c

@@ -10,14 +10,6 @@ enum {
 	DEFAULTCAPACITY = 16,
 };
 
-struct Array
-{
-	int32	length;  // number of elements
-	int32	size;  // element size
-	int32	capacity;  // size of data in elements
-	char	*data;  // element storage
-};
-
 Array*
 arraynew(int32 capacity, int32 size)
 {

src/cmd/gc/bv.c

@@ -7,7 +7,7 @@
 #include "go.h"
 
 enum {
-	WORDSIZE = sizeof(uint32),
+	WORDSIZE = 4,
 	WORDBITS = 32,
 	WORDMASK = WORDBITS - 1,
 	WORDSHIFT = 5,

src/cmd/gc/cplx.c

@@ -14,6 +14,14 @@ static	void	minus(Node *nl, Node *res);
 
 #define	CASE(a,b)	(((a)<<16)|((b)<<0))
 
+/*c2go
+static int
+CASE(int a, int b)
+{
+	return a<<16 | b;
+}
+*/
+
 static int
 overlap(Node *f, Node *t)
 {
@@ -308,13 +316,13 @@ complexbool(int op, Node *nl, Node *nr, int true, int likely, Prog *to)
 	na.right = &nc;
 	na.type = types[TBOOL];
 
-	memset(&nb, 0, sizeof(na));
+	memset(&nb, 0, sizeof(nb));
 	nb.op = OEQ;
 	nb.left = &n1;
 	nb.right = &n3;
 	nb.type = types[TBOOL];
 
-	memset(&nc, 0, sizeof(na));
+	memset(&nc, 0, sizeof(nc));
 	nc.op = OEQ;
 	nc.left = &n2;
 	nc.right = &n4;
@@ -442,13 +450,13 @@ complexmul(Node *nl, Node *nr, Node *res)
 	tempname(&tmp, n5.type);
 
 	// real part -> tmp
-	memset(&rm1, 0, sizeof(ra));
+	memset(&rm1, 0, sizeof(rm1));
 	rm1.op = OMUL;
 	rm1.left = &n1;
 	rm1.right = &n3;
 	rm1.type = n1.type;
 
-	memset(&rm2, 0, sizeof(ra));
+	memset(&rm2, 0, sizeof(rm2));
 	rm2.op = OMUL;
 	rm2.left = &n2;
 	rm2.right = &n4;
@@ -462,13 +470,13 @@ complexmul(Node *nl, Node *nr, Node *res)
 	cgen(&ra, &tmp);
 
 	// imag part
-	memset(&rm1, 0, sizeof(ra));
+	memset(&rm1, 0, sizeof(rm1));
 	rm1.op = OMUL;
 	rm1.left = &n1;
 	rm1.right = &n4;
 	rm1.type = n1.type;
 
-	memset(&rm2, 0, sizeof(ra));
+	memset(&rm2, 0, sizeof(rm2));
 	rm2.op = OMUL;
 	rm2.left = &n2;
 	rm2.right = &n3;

src/cmd/gc/export.c

@@ -256,7 +256,7 @@ dumpexportvar(Sym *s)
 }
 
 static int
-methcmp(const void *va, const void *vb)
+methodbyname(const void *va, const void *vb)
 {
 	Type *a, *b;
 	
@@ -297,7 +297,7 @@ dumpexporttype(Type *t)
 	i = 0;
 	for(f=t->method; f!=T; f=f->down)
 		m[i++] = f;
-	qsort(m, n, sizeof m[0], methcmp);
+	qsort(m, n, sizeof m[0], methodbyname);
 
 	Bprint(bout, "\ttype %#S %#lT\n", t->sym, t);
 	for(i=0; i<n; i++) {

src/cmd/gc/go.h

@@ -128,10 +128,6 @@ struct	Val
 		Strlit*	sval;		// string CTSTR
 	} u;
 };
-
-// prevent incompatible type signatures between libgc and 8g on Plan 9
-#pragma incomplete struct Array
-
 typedef	struct	Array	Array;
 typedef	struct	Bvec	Bvec;
 typedef	struct	Pkg Pkg;
@@ -141,6 +137,14 @@ typedef	struct	NodeList	NodeList;
 typedef	struct	Type	Type;
 typedef	struct	Label	Label;
 
+struct	Array
+{
+	int32	length;  // number of elements
+	int32	size;  // element size
+	int32	capacity;  // size of data in elements
+	char	*data;  // element storage
+};
+
 struct	Type
 {
 	uchar	etype;
@@ -708,8 +712,10 @@ enum
 	Ecomplit = 1<<11,	// type in composite literal
 };
 
-#define	BITS	3
-#define	NVAR	(BITS*sizeof(uint64)*8)
+enum {
+	BITS = 3,
+	NVAR = 	(BITS*64)
+};
 
 typedef	struct	Bits	Bits;
 struct	Bits

src/cmd/gc/plive.c

@@ -735,23 +735,23 @@ progeffects(Prog *prog, Array *vars, Bvec *uevar, Bvec *varkill, Bvec *avarinit)
 	}
 	if(info.flags & (LeftRead | LeftWrite | LeftAddr)) {
 		from = &prog->from;
-		if (from->node != nil && from->sym != nil && from->node->curfn == curfn) {
-			switch(from->node->class & ~PHEAP) {
+		if (from->node != nil && from->sym != nil && ((Node*)(from->node))->curfn == curfn) {
+			switch(((Node*)(from->node))->class & ~PHEAP) {
 			case PAUTO:
 			case PPARAM:
 			case PPARAMOUT:
-				pos = (int)(uintptr)from->node->opt - 1; // index in vars
+				pos = (int)(uintptr)((Node*)(from->node))->opt - 1; // index in vars
 				if(pos == -1)
 					goto Next;
 				if(pos >= arraylength(vars) || *(Node**)arrayget(vars, pos) != from->node)
 					fatal("bad bookkeeping in liveness %N %d", from->node, pos);
-				if(from->node->addrtaken) {
+				if(((Node*)(from->node))->addrtaken) {
 					bvset(avarinit, pos);
 				} else {
 					if(info.flags & (LeftRead | LeftAddr))
 						bvset(uevar, pos);
 					if(info.flags & LeftWrite)
-						if(from->node != nil && !isfat(from->node->type))
+						if(from->node != nil && !isfat(((Node*)(from->node))->type))
 							bvset(varkill, pos);
 				}
 			}
@@ -760,17 +760,17 @@ progeffects(Prog *prog, Array *vars, Bvec *uevar, Bvec *varkill, Bvec *avarinit)
 Next:
 	if(info.flags & (RightRead | RightWrite | RightAddr)) {
 		to = &prog->to;
-		if (to->node != nil && to->sym != nil && to->node->curfn == curfn) {
-			switch(to->node->class & ~PHEAP) {
+		if (to->node != nil && to->sym != nil && ((Node*)(to->node))->curfn == curfn) {
+			switch(((Node*)(to->node))->class & ~PHEAP) {
 			case PAUTO:
 			case PPARAM:
 			case PPARAMOUT:
-				pos = (int)(uintptr)to->node->opt - 1; // index in vars
+				pos = (int)(uintptr)((Node*)(to->node))->opt - 1; // index in vars
 				if(pos == -1)
 					goto Next1;
 				if(pos >= arraylength(vars) || *(Node**)arrayget(vars, pos) != to->node)
 					fatal("bad bookkeeping in liveness %N %d", to->node, pos);
-				if(to->node->addrtaken) {
+				if(((Node*)(to->node))->addrtaken) {
 					if(prog->as != AVARKILL)
 						bvset(avarinit, pos);
 					if(prog->as == AVARDEF || prog->as == AVARKILL)
@@ -787,7 +787,7 @@ Next:
 					if((info.flags & RightRead) || (info.flags & (RightAddr|RightWrite)) == RightAddr)
 						bvset(uevar, pos);
 					if(info.flags & RightWrite)
-						if(to->node != nil && (!isfat(to->node->type) || prog->as == AVARDEF))
+						if(to->node != nil && (!isfat(((Node*)(to->node))->type) || prog->as == AVARDEF))
 							bvset(varkill, pos);
 				}
 			}
@@ -898,8 +898,12 @@ printnode(Node *node)
 	char *p;
 	char *a;
 
-	p = haspointers(node->type) ? "^" : "";
-	a = node->addrtaken ? "@" : "";
+	p = "";
+	if(haspointers(node->type))
+		p = "^";
+	a = "";
+	if(node->addrtaken)
+		a = "@";
 	print(" %N%s%s", node, p, a);
 }
 
@@ -1604,11 +1608,11 @@ livenessepilogue(Liveness *lv)
 					fmtstrinit(&fmt);
 					fmtprint(&fmt, "%L: live at ", p->lineno);
 					if(p->as == ACALL && p->to.node)
-						fmtprint(&fmt, "call to %s:", p->to.node->sym->name);
+						fmtprint(&fmt, "call to %s:", ((Node*)(p->to.node))->sym->name);
 					else if(p->as == ACALL)
 						fmtprint(&fmt, "indirect call:");
 					else
-						fmtprint(&fmt, "entry to %s:", p->from.node->sym->name);
+						fmtprint(&fmt, "entry to %s:", ((Node*)(p->from.node))->sym->name);
 					numlive = 0;
 					for(j = 0; j < arraylength(lv->vars); j++) {
 						n = *(Node**)arrayget(lv->vars, j);

src/cmd/gc/popt.c

@@ -58,7 +58,7 @@ noreturn(Prog *p)
 
 	if(p->to.node == nil)
 		return 0;
-	s = p->to.node->sym;
+	s = ((Node*)(p->to.node))->sym;
 	if(s == S)
 		return 0;
 	for(i=0; symlist[i]!=S; i++)
@@ -586,10 +586,14 @@ mergetemp(Prog *firstp)
 		p = r->f.prog;
 		proginfo(&info, p);
 
-		if(p->from.node != N && p->from.node->opt && p->to.node != N && p->to.node->opt)
+		if(p->from.node != N && ((Node*)(p->from.node))->opt && p->to.node != N && ((Node*)(p->to.node))->opt)
 			fatal("double node %P", p);
-		if((n = p->from.node) != N && (v = n->opt) != nil ||
-		   (n = p->to.node) != N && (v = n->opt) != nil) {
+		v = nil;
+		if((n = p->from.node) != N)
+			v = n->opt;
+		if(v == nil && (n = p->to.node) != N)
+			v = n->opt;
+		if(v != nil) {
 		   	if(v->def == nil)
 		   		v->def = r;
 			r->uselink = v->use;

src/cmd/gc/subr.c

@@ -708,7 +708,7 @@ static int
 methcmp(const void *va, const void *vb)
 {
 	Type *a, *b;
-	int i;
+	int k;
 	
 	a = *(Type**)va;
 	b = *(Type**)vb;
@@ -718,13 +718,13 @@ methcmp(const void *va, const void *vb)
 		return -1;
 	if(b->sym == S)
 		return 1;
-	i = strcmp(a->sym->name, b->sym->name);
-	if(i != 0)
-		return i;
+	k = strcmp(a->sym->name, b->sym->name);
+	if(k != 0)
+		return k;
 	if(!exportname(a->sym->name)) {
-		i = strcmp(a->sym->pkg->path->s, b->sym->pkg->path->s);
-		if(i != 0)
-			return i;
+		k = strcmp(a->sym->pkg->path->s, b->sym->pkg->path->s);
+		if(k != 0)
+			return k;
 	}
 	return 0;
 }

src/cmd/gc/typecheck.c

@@ -586,7 +586,9 @@ reswitch:
 				l->typecheck = 1;
 				n->left = l;
 				t = l->type;
-			} else if(l->type->etype != TBLANK && (aop = assignop(r->type, l->type, nil)) != 0) {
+				goto converted;
+			}
+			if(l->type->etype != TBLANK && (aop = assignop(r->type, l->type, nil)) != 0) {
 				if(isinter(l->type) && !isinter(r->type) && algtype1(r->type, nil) == ANOEQ) {
 					yyerror("invalid operation: %N (operator %O not defined on %s)", n, op, typekind(r->type));
 					goto error;
@@ -597,6 +599,7 @@ reswitch:
 				n->right = r;
 				t = r->type;
 			}
+		converted:
 			et = t->etype;
 		}
 		if(t->etype != TIDEAL && !eqtype(l->type, r->type)) {

src/cmd/gc/unsafe.c

@@ -27,7 +27,9 @@ unsafenmagic(Node *nn)
 	fn = nn->left;
 	args = nn->list;
 
-	if(safemode || fn == N || fn->op != ONAME || (s = fn->sym) == S)
+	if(safemode || fn == N || fn->op != ONAME)
+		goto no;
+	if((s = fn->sym) == S)
 		goto no;
 	if(s->pkg != unsafepkg)
 		goto no;