diff --git a/sys/src/cmd/1a/a.h b/sys/src/cmd/1a/a.h
index d9abec361..f0e2443a2 100644
--- a/sys/src/cmd/1a/a.h
+++ b/sys/src/cmd/1a/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../2c/2.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Ref	Ref;
@@ -113,14 +110,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
@@ -132,11 +127,9 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
 int	assemble(char*);
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -172,28 +165,7 @@ void	macend(void);
 void	dodefine(char*);
 void	prfile(long);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-enum	/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2,
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/1a/mkfile b/sys/src/cmd/1a/mkfile
index 75546380e..1b807abc4 100644
--- a/sys/src/cmd/1a/mkfile
+++ b/sys/src/cmd/1a/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../2c/2.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/1c/mkfile b/sys/src/cmd/1c/mkfile
index 9cde57437..76d8350f0 100644
--- a/sys/src/cmd/1c/mkfile
+++ b/sys/src/cmd/1c/mkfile
@@ -15,6 +15,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	../2c/2.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/1l/compat.c b/sys/src/cmd/1l/compat.c
index 1d9f89e43..54ac0283e 100644
--- a/sys/src/cmd/1l/compat.c
+++ b/sys/src/cmd/1l/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void *p, ulong n)
-{
-	fprint(2, "realloc(0x%p %ld) called\n", p, n);
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/1l/l.h b/sys/src/cmd/1l/l.h
index 72cedf3bd..75da18506 100644
--- a/sys/src/cmd/1l/l.h
+++ b/sys/src/cmd/1l/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../2c/2.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 #define	P		((Prog*)0)
 #define	S		((Sym*)0)
@@ -178,7 +175,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -187,7 +183,6 @@ EXTERN	long	lcsize;
 EXTERN	long	relocsize;
 EXTERN	long	ndata;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	long	nsymbol;
 EXTERN	char*	noname;
 EXTERN	short*	op;
@@ -200,7 +195,6 @@ EXTERN	Sym*	symlist;
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	Prog	zprg;
 
@@ -240,7 +234,6 @@ void	errorexit(void);
 int	find1(long, int);
 int	find2(long, int);
 void	follow(void);
-void	gethunk(void);
 int	gnuxi(Ieee*, int, int);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
@@ -254,7 +247,6 @@ Sym*	lookup(char*, int);
 void	lput(long);
 void	main(int, char*[]);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	nuxiinit(void);
 void	objfile(char*);
 void	patch(void);
diff --git a/sys/src/cmd/1l/mkfile b/sys/src/cmd/1l/mkfile
index c56fcb5e6..7c280cb7f 100644
--- a/sys/src/cmd/1l/mkfile
+++ b/sys/src/cmd/1l/mkfile
@@ -14,9 +14,12 @@ OFILES=\
 HFILES=\
 	l.h\
 	../2c/2.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
 
 enam.$O:	../2c/enam.c
 	$CC $CFLAGS ../2c/enam.c
+
+compat.$O:	../cc/compat
diff --git a/sys/src/cmd/1l/obj.c b/sys/src/cmd/1l/obj.c
index 9cc82a56e..094e17101 100644
--- a/sys/src/cmd/1l/obj.c
+++ b/sys/src/cmd/1l/obj.c
@@ -1082,28 +1082,6 @@ copyp(Prog *q)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/2a/a.h b/sys/src/cmd/2a/a.h
index 68cd1e8dc..798b2a1d7 100644
--- a/sys/src/cmd/2a/a.h
+++ b/sys/src/cmd/2a/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../2c/2.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Ref	Ref;
@@ -115,14 +112,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
@@ -134,10 +129,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -173,29 +166,7 @@ void	macend(void);
 void	dodefine(char*);
 void	prfile(long);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-enum				/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2
-};
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/2a/mkfile b/sys/src/cmd/2a/mkfile
index f5584a7e5..73ccb3d20 100644
--- a/sys/src/cmd/2a/mkfile
+++ b/sys/src/cmd/2a/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../2c/2.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/2c/mkfile b/sys/src/cmd/2c/mkfile
index 662466050..7009bbf37 100644
--- a/sys/src/cmd/2c/mkfile
+++ b/sys/src/cmd/2c/mkfile
@@ -15,6 +15,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	2.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/2l/compat.c b/sys/src/cmd/2l/compat.c
index 1d9f89e43..54ac0283e 100644
--- a/sys/src/cmd/2l/compat.c
+++ b/sys/src/cmd/2l/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void *p, ulong n)
-{
-	fprint(2, "realloc(0x%p %ld) called\n", p, n);
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/2l/l.h b/sys/src/cmd/2l/l.h
index a0899c0f5..0e4f519d7 100644
--- a/sys/src/cmd/2l/l.h
+++ b/sys/src/cmd/2l/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../2c/2.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 #define	P		((Prog*)0)
 #define	S		((Sym*)0)
@@ -168,7 +165,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -177,7 +173,6 @@ EXTERN	long	lcsize;
 EXTERN	long	ncase;
 EXTERN	long	ndata;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	long	nsymbol;
 EXTERN	char*	noname;
 EXTERN	short*	op;
@@ -190,7 +185,6 @@ EXTERN	Sym*	symlist;
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	Prog	zprg;
 
@@ -238,7 +232,6 @@ void	errorexit(void);
 int	find1(long, int);
 int	find2(long, int);
 void	follow(void);
-void	gethunk(void);
 int	gnuxi(Ieee*, int, int);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
@@ -250,7 +243,6 @@ Sym*	lookup(char*, int);
 void	lput(long);
 void	main(int, char*[]);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	nuxiinit(void);
 void	objfile(char*);
 void	patch(void);
diff --git a/sys/src/cmd/2l/mkfile b/sys/src/cmd/2l/mkfile
index 569cdd482..f1b21f613 100644
--- a/sys/src/cmd/2l/mkfile
+++ b/sys/src/cmd/2l/mkfile
@@ -14,9 +14,12 @@ OFILES=\
 HFILES=\
 	l.h\
 	../2c/2.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
 
 enam.$O:	../2c/enam.c
 	$CC $CFLAGS ../2c/enam.c
+
+compat.$O:	../cc/compat
diff --git a/sys/src/cmd/2l/obj.c b/sys/src/cmd/2l/obj.c
index 411d2a5f5..aa050520b 100644
--- a/sys/src/cmd/2l/obj.c
+++ b/sys/src/cmd/2l/obj.c
@@ -1104,28 +1104,6 @@ appendp(Prog *q)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/5a/a.h b/sys/src/cmd/5a/a.h
index 08ea625a9..0e07a1e10 100644
--- a/sys/src/cmd/5a/a.h
+++ b/sys/src/cmd/5a/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../5c/5.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Gen	Gen;
@@ -96,14 +93,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
@@ -115,11 +110,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	alloc(long);
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -160,20 +152,3 @@ void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-
-enum				/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2,
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-int	myfork(void);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/5a/mkfile b/sys/src/cmd/5a/mkfile
index 1933aae09..cfd14dde9 100644
--- a/sys/src/cmd/5a/mkfile
+++ b/sys/src/cmd/5a/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../5c/5.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
@@ -16,4 +17,4 @@ BIN=/$objtype/bin
 < /sys/src/cmd/mkone
 YFLAGS=-D1 -d
 
-lex.$O:	../cc/macbody ../cc/lexbody
+lex.$O:	../cc/macbody ../cc/lexbody ../cc/compat
diff --git a/sys/src/cmd/5c/mkfile b/sys/src/cmd/5c/mkfile
index 4568da282..0c58b8f8f 100644
--- a/sys/src/cmd/5c/mkfile
+++ b/sys/src/cmd/5c/mkfile
@@ -18,6 +18,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	5.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/5l/compat.c b/sys/src/cmd/5l/compat.c
index 1d9f89e43..54ac0283e 100644
--- a/sys/src/cmd/5l/compat.c
+++ b/sys/src/cmd/5l/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void *p, ulong n)
-{
-	fprint(2, "realloc(0x%p %ld) called\n", p, n);
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/5l/l.h b/sys/src/cmd/5l/l.h
index 8a45a7a7a..32ac95450 100644
--- a/sys/src/cmd/5l/l.h
+++ b/sys/src/cmd/5l/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../5c/5.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 #define	LIBNAMELEN	300
 
@@ -252,7 +249,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -260,7 +256,6 @@ EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	char	literal[32];
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	long	instoffset;
 EXTERN	Opcross	opcross[8];
 EXTERN	Oprang	oprange[ALAST];
@@ -270,7 +265,6 @@ EXTERN	uchar	repop[ALAST];
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	char	xcmp[C_GOK+1][C_GOK+1];
 EXTERN	Prog	zprg;
@@ -349,7 +343,6 @@ int	fileexists(char*);
 int	find1(long, int);
 char*	findlib(char*);
 void	follow(void);
-void	gethunk(void);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
 long	ieeedtof(Ieee*);
@@ -363,7 +356,6 @@ void	cput(int);
 void	lput(long);
 void	lputl(long);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	names(void);
 void	nocache(Prog*);
 void	nuxiinit(void);
diff --git a/sys/src/cmd/5l/mkfile b/sys/src/cmd/5l/mkfile
index 829dd12a2..a360441e9 100644
--- a/sys/src/cmd/5l/mkfile
+++ b/sys/src/cmd/5l/mkfile
@@ -15,6 +15,7 @@ OFILES=\
 HFILES=\
 	l.h\
 	../5c/5.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
@@ -25,5 +26,7 @@ BIN=/$objtype/bin
 enam.$O:	../5c/enam.c
 	$CC $CFLAGS ../5c/enam.c
 
+compat.$O:	../cc/compat
+
 x:V:	$O.out
 	$O.out -la -o/dev/null x.5
diff --git a/sys/src/cmd/5l/obj.c b/sys/src/cmd/5l/obj.c
index c10d4b8dd..9aabb6d7e 100644
--- a/sys/src/cmd/5l/obj.c
+++ b/sys/src/cmd/5l/obj.c
@@ -1135,28 +1135,6 @@ prg(void)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/6a/a.h b/sys/src/cmd/6a/a.h
index 9c9833348..709059056 100644
--- a/sys/src/cmd/6a/a.h
+++ b/sys/src/cmd/6a/a.h
@@ -2,11 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../6c/6.out.h"
-
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Ref	Ref;
@@ -109,14 +105,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
@@ -128,10 +122,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -168,28 +160,7 @@ void	macend(void);
 void	dodefine(char*);
 void	prfile(long);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	Posix.c/Inferno.c/Nt.c
- */
-enum	/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/6a/mkfile b/sys/src/cmd/6a/mkfile
index 77b215cdb..03af77a48 100644
--- a/sys/src/cmd/6a/mkfile
+++ b/sys/src/cmd/6a/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../6c/6.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/6c/mkfile b/sys/src/cmd/6c/mkfile
index fbcdc08e9..c08793107 100644
--- a/sys/src/cmd/6c/mkfile
+++ b/sys/src/cmd/6c/mkfile
@@ -19,6 +19,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	6.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/6l/compat.c b/sys/src/cmd/6l/compat.c
index 2d2a9631b..54ac0283e 100644
--- a/sys/src/cmd/6l/compat.c
+++ b/sys/src/cmd/6l/compat.c
@@ -1,55 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void*, ulong)
-{
-	fprint(2, "realloc called\n");
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void*, uintptr)
-{
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/6l/l.h b/sys/src/cmd/6l/l.h
index 6eaa603c6..ee96b51ea 100644
--- a/sys/src/cmd/6l/l.h
+++ b/sys/src/cmd/6l/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../6c/6.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 #define	P		((Prog*)0)
 #define	S		((Sym*)0)
@@ -279,7 +276,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	uchar	inuxi1[1];
 EXTERN	uchar	inuxi2[2];
 EXTERN	uchar	inuxi4[4];
@@ -293,7 +289,6 @@ EXTERN	int	regrex[D_NONE+1];
 EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	long	nsymbol;
 EXTERN	char*	noname;
 EXTERN	char*	outfile;
@@ -303,7 +298,6 @@ EXTERN	Sym*	symlist;
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	vlong	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	Prog	zprg;
 EXTERN	int	dtype;
@@ -358,7 +352,6 @@ int	find1(long, int);
 int	find1v(vlong, int);
 int	find2(long, int);
 void	follow(void);
-void	gethunk(void);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
 long	ieeedtof(Ieee*);
@@ -371,7 +364,6 @@ void	lput(long);
 void	lputl(long);
 void	main(int, char*[]);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	nuxiinit(void);
 void	objfile(char*);
 int	opsize(Prog*);
diff --git a/sys/src/cmd/6l/mkfile b/sys/src/cmd/6l/mkfile
index 984224472..ed6c756b0 100644
--- a/sys/src/cmd/6l/mkfile
+++ b/sys/src/cmd/6l/mkfile
@@ -29,3 +29,4 @@ UPDATE=\
 enam.$O:	../6c/enam.c
 	$CC $CFLAGS ../6c/enam.c
 
+compat.$O:	../cc/compat
diff --git a/sys/src/cmd/6l/obj.c b/sys/src/cmd/6l/obj.c
index 5483eebae..71824398d 100644
--- a/sys/src/cmd/6l/obj.c
+++ b/sys/src/cmd/6l/obj.c
@@ -1205,28 +1205,6 @@ appendp(Prog *q)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/7a/a.h b/sys/src/cmd/7a/a.h
index 3ef0f1a96..306a3a285 100644
--- a/sys/src/cmd/7a/a.h
+++ b/sys/src/cmd/7a/a.h
@@ -5,13 +5,10 @@
 #include <libc.h>
 #include <bio.h>
 #include "../7c/7.out.h"
+#include "../cc/compat.h"
 
 typedef vlong int64;
 
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
-
 typedef	struct	Sym	Sym;
 typedef	struct	Gen	Gen;
 typedef	struct	Io	Io;
@@ -101,14 +98,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
@@ -120,11 +115,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	alloc(long);
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -161,25 +153,7 @@ void	outhist(void);
 void	dodefine(char*);
 void	prfile(long);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-
-enum				/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2,
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-int	myfork(void);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/7a/mkfile b/sys/src/cmd/7a/mkfile
index e48fbea48..66988b36f 100644
--- a/sys/src/cmd/7a/mkfile
+++ b/sys/src/cmd/7a/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../7c/7.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
@@ -16,4 +17,5 @@ BIN=/$objtype/bin
 < /sys/src/cmd/mkone
 YFLAGS=-D1 -d
 
-lex.$O:	../cc/macbody ../cc/lexbody
+lex.$O:	../cc/macbody ../cc/lexbody ../cc/compat
+
diff --git a/sys/src/cmd/7c/mkfile b/sys/src/cmd/7c/mkfile
index c6ffe8503..98d9d5ff9 100644
--- a/sys/src/cmd/7c/mkfile
+++ b/sys/src/cmd/7c/mkfile
@@ -18,6 +18,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	7.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/7l/compat.c b/sys/src/cmd/7l/compat.c
index 1d9f89e43..54ac0283e 100644
--- a/sys/src/cmd/7l/compat.c
+++ b/sys/src/cmd/7l/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void *p, ulong n)
-{
-	fprint(2, "realloc(0x%p %ld) called\n", p, n);
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/7l/l.h b/sys/src/cmd/7l/l.h
index 5528cc6bd..c72202b8a 100644
--- a/sys/src/cmd/7l/l.h
+++ b/sys/src/cmd/7l/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../7c/7.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 #define	LIBNAMELEN	300
 
@@ -291,7 +288,6 @@ EXTERN	Sym*	hash[NHASH];
 EXTERN	Sym*	histfrog[MAXHIST];
 EXTERN	int	histfrogp;
 EXTERN	int	histgen;
-EXTERN	char*	hunk;
 
 EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
@@ -300,7 +296,6 @@ EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	char	literal[32];
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	char*	noname;
 EXTERN	vlong	instoffset;
 EXTERN	Opcross	opcross[8];
@@ -310,7 +305,6 @@ EXTERN	uchar	repop[ALAST];
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	vlong	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	char	xcmp[C_NCLASS][C_NCLASS];
 EXTERN	int	xrefresolv;
@@ -378,7 +372,6 @@ vlong	entryvalue(void);
 void	errorexit(void);
 void	export(void);
 void	follow(void);
-void	gethunk(void);
 void	histtoauto(void);
 void*	halloc(usize);
 int	isnop(Prog*);
@@ -395,7 +388,6 @@ void	lput(long);
 void	lputl(long);
 void	mkfwd(void);
 int	movcon(vlong);
-void*	mysbrk(ulong);
 void	names(void);
 void	nocache(Prog*);
 void	nuxiinit(void);
diff --git a/sys/src/cmd/7l/mkfile b/sys/src/cmd/7l/mkfile
index 1c1856aa8..46562f0db 100644
--- a/sys/src/cmd/7l/mkfile
+++ b/sys/src/cmd/7l/mkfile
@@ -20,6 +20,7 @@ OFILES=\
 HFILES=\
 	l.h\
 	../7c/7.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
@@ -33,5 +34,7 @@ cnam.c:	l.h mkcname
 enam.$O:	../7c/enam.c
 	$CC $CFLAGS ../7c/enam.c
 
+compat.$O:	../cc/compat
+
 x:V:	$O.out
 	$O.out -la -o/dev/null x.7
diff --git a/sys/src/cmd/7l/obj.c b/sys/src/cmd/7l/obj.c
index 75def5096..444467fa3 100644
--- a/sys/src/cmd/7l/obj.c
+++ b/sys/src/cmd/7l/obj.c
@@ -1161,28 +1161,6 @@ halloc(usize n)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/8a/a.h b/sys/src/cmd/8a/a.h
index 7d4b9366b..868031d80 100644
--- a/sys/src/cmd/8a/a.h
+++ b/sys/src/cmd/8a/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../8c/8.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Ref	Ref;
@@ -109,14 +106,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
 EXTERN	char*	outfile;
@@ -128,10 +123,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -168,28 +161,7 @@ void	macend(void);
 void	dodefine(char*);
 void	prfile(long);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-enum	/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/8a/mkfile b/sys/src/cmd/8a/mkfile
index 7b4cfd774..df2c9f6d4 100644
--- a/sys/src/cmd/8a/mkfile
+++ b/sys/src/cmd/8a/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../8c/8.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/8c/mkfile b/sys/src/cmd/8c/mkfile
index 4c63499ce..0364d27f0 100644
--- a/sys/src/cmd/8c/mkfile
+++ b/sys/src/cmd/8c/mkfile
@@ -20,6 +20,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	8.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/8l/compat.c b/sys/src/cmd/8l/compat.c
index e81bebce8..54ac0283e 100644
--- a/sys/src/cmd/8l/compat.c
+++ b/sys/src/cmd/8l/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void*, ulong)
-{
-	fprint(2, "realloc called\n");
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/8l/l.h b/sys/src/cmd/8l/l.h
index f8968d01d..450d3e2de 100644
--- a/sys/src/cmd/8l/l.h
+++ b/sys/src/cmd/8l/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../8c/8.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 #define	P		((Prog*)0)
 #define	S		((Sym*)0)
@@ -255,7 +252,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -266,7 +262,6 @@ EXTERN	char	reg[D_XNONE];
 EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	long	nsymbol;
 EXTERN	char*	noname;
 EXTERN	char*	outfile;
@@ -276,7 +271,6 @@ EXTERN	Sym*	symlist;
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	Prog	zprg;
 EXTERN	int	dtype;
@@ -328,7 +322,6 @@ void	export(void);
 int	find1(long, int);
 int	find2(long, int);
 void	follow(void);
-void	gethunk(void);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
 long	ieeedtof(Ieee*);
@@ -341,7 +334,6 @@ void	lput(long);
 void	lputl(long);
 void	main(int, char*[]);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	nuxiinit(void);
 void	objfile(char*);
 int	opsize(Prog*);
diff --git a/sys/src/cmd/8l/mkfile b/sys/src/cmd/8l/mkfile
index 8c6401bc3..331bd18e0 100644
--- a/sys/src/cmd/8l/mkfile
+++ b/sys/src/cmd/8l/mkfile
@@ -13,6 +13,7 @@ OFILES=\
 
 HFILES=\
 	l.h\
+	../cc/compat.h\
 	../8c/8.out.h\
 
 BIN=/$objtype/bin
@@ -29,3 +30,4 @@ UPDATE=\
 enam.$O:	../8c/enam.c
 	$CC $CFLAGS ../8c/enam.c
 
+compat.$O:	../cc/compat
diff --git a/sys/src/cmd/8l/obj.c b/sys/src/cmd/8l/obj.c
index efdbd4110..530e6ea3b 100644
--- a/sys/src/cmd/8l/obj.c
+++ b/sys/src/cmd/8l/obj.c
@@ -1179,28 +1179,6 @@ appendp(Prog *q)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/cc/cc.h b/sys/src/cmd/cc/cc.h
index 75ac42d7f..8de3c4e1a 100644
--- a/sys/src/cmd/cc/cc.h
+++ b/sys/src/cmd/cc/cc.h
@@ -5,9 +5,7 @@
 
 #pragma	lib	"../cc/cc.a$O"
 
-#ifndef	EXTERN
-#define EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Node	Node;
 typedef	struct	Sym	Sym;
@@ -184,13 +182,6 @@ enum
 	NALIGN,
 };
 
-enum				/* also in ../{8a,0a}.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2,
-};
-
 enum
 {
 	DMARK,
@@ -437,7 +428,6 @@ EXTERN	Decl*	firstdcl;
 EXTERN	int	fperror;
 EXTERN	Sym*	hash[NHASH];
 EXTERN	int	hasdoubled;
-EXTERN	char*	hunk;
 EXTERN	char*	include[20];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
@@ -451,7 +441,6 @@ EXTERN	long	lineno;
 EXTERN	long	nearln;
 EXTERN	int	nerrors;
 EXTERN	int	newflag;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	Node*	nodproto;
 EXTERN	Node*	nodcast;
@@ -471,7 +460,6 @@ EXTERN	Type*	tufield;
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
 EXTERN	Type*	thisfn;
-EXTERN	uintptr	thunk;
 EXTERN	Type*	types[NTYPE];
 EXTERN	Type*	fntypes[NTYPE];
 EXTERN	Node*	initlist;
@@ -521,21 +509,6 @@ extern	ulong	thash2;
 extern	ulong	thash3;
 extern	ulong	thash[];
 
-/*
- *	compat.c/unix.c/windows.c
- */
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-int	myaccess(char*);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
-
 /*
  *	parser
  */
@@ -545,8 +518,6 @@ int	mpatov(char*, vlong*);
 /*
  *	lex.c
  */
-void*	allocn(void*, long, long);
-void*	alloc(long);
 void	cinit(void);
 int	compile(char*, char**, int);
 void	errorexit(void);
@@ -666,7 +637,6 @@ int	castucom(Node*);
 int	deadheads(Node*);
 Type*	dotsearch(Sym*, Type*, Node*, long*);
 long	dotoffset(Type*, Type*, Node*);
-void	gethunk(void);
 Node*	invert(Node*);
 int	bitno(long);
 void	makedot(Node*, Type*, long);
diff --git a/sys/src/cmd/cc/compat b/sys/src/cmd/cc/compat
index fc0654157..df59f0c98 100644
--- a/sys/src/cmd/cc/compat
+++ b/sys/src/cmd/cc/compat
@@ -1,4 +1,3 @@
-
 int
 myaccess(char *f)
 {
@@ -77,3 +76,117 @@ myfork(void)
 {
 	return fork();
 }
+
+/*
+ * real allocs
+ */
+void
+gethunk(void)
+{
+	char *h;
+	ulong nh;
+
+	nh = NHUNK;
+	if(thunk >= 10L*NHUNK)
+		nh = 10L*NHUNK;
+	h = (char*)mysbrk(nh);
+	if(h == (char*)-1)
+		sysfatal("out of memory");
+	if(nhunk == 0)
+		hunk = h;
+	else
+		nh += (h - hunk) - nhunk;
+	nhunk += nh;
+	thunk += nh;
+}
+
+void*
+alloc(long n)
+{
+	void *p;
+
+	while((uintptr)hunk & 7) {
+		hunk++;
+		nhunk--;
+	}
+	while(nhunk < n)
+		gethunk();
+	p = hunk;
+	nhunk -= n;
+	hunk += n;
+	return p;
+}
+
+void*
+allocn(void *p, long on, long n)
+{
+	void *q;
+
+	q = (uchar*)p + on;
+	if(q != hunk || nhunk < n) {
+		while(nhunk < on+n)
+			gethunk();
+		memmove(hunk, p, on);
+		p = hunk;
+		hunk += on;
+		nhunk -= on;
+	}
+	hunk += n;
+	nhunk -= n;
+	return p;
+}
+
+/*
+ * fake mallocs
+ */
+void*
+malloc(ulong n)
+{
+	return alloc(n);
+}
+
+void*
+calloc(ulong m, ulong n)
+{
+	return alloc(m*n);
+}
+
+void*
+realloc(void *o, ulong n)
+{
+	ulong m;
+	void *a;
+
+	if(n == 0)
+		return nil;
+	if(o == nil)
+		return alloc(n);
+	a = alloc(n);
+	m = (char*)a - (char*)o;
+	if(m < n)
+		n = m;
+	memmove(a, o, n);
+	return a;
+}
+
+void
+free(void*)
+{
+}
+
+/* needed when profiling */
+void*
+mallocz(ulong size, int)
+{
+	return alloc(size);
+}
+
+void
+setmalloctag(void*, uintptr)
+{
+}
+
+void
+setrealloctag(void*, uintptr)
+{
+}
diff --git a/sys/src/cmd/cc/compat.c b/sys/src/cmd/cc/compat.c
index c76ab9968..1724b5b30 100644
--- a/sys/src/cmd/cc/compat.c
+++ b/sys/src/cmd/cc/compat.c
@@ -1,62 +1,2 @@
 #include	"cc.h"
 #include	"compat"
-
-/*
- * fake mallocs
- */
-void*
-malloc(ulong n)
-{
-	return alloc(n);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	return alloc(m*n);
-}
-
-void*
-realloc(void *o, ulong n)
-{
-	ulong m;
-	void *a;
-
-	if(n == 0)
-		return nil;
-	if(o == nil)
-		return alloc(n);
-	a = alloc(n);
-	m = (char*)a - (char*)o;
-	if(m < n)
-		n = m;
-	memmove(a, o, n);
-	return a;
-}
-
-void
-free(void*)
-{
-}
-
-/* needed when profiling */
-void*
-mallocz(ulong size, int clr)
-{
-	void *v;
-
-	v = alloc(size);
-	if(clr && v != nil)
-		memset(v, 0, size);
-	return v;
-}
-
-void
-setmalloctag(void*, uintptr)
-{
-}
-
-void
-setrealloctag(void*, uintptr)
-{
-}
diff --git a/sys/src/cmd/cc/compat.h b/sys/src/cmd/cc/compat.h
new file mode 100644
index 000000000..9f056e36a
--- /dev/null
+++ b/sys/src/cmd/cc/compat.h
@@ -0,0 +1,35 @@
+/*
+ * functions shared by compilers, linkers and assemblers.
+ */
+
+#ifndef	EXTERN
+#define EXTERN	extern
+#endif
+
+enum
+{
+	Plan9	= 1<<0,
+	Unix	= 1<<1,
+	Windows	= 1<<2
+};
+EXTERN	int	systemtype(int);
+EXTERN	int	pathchar(void);
+
+EXTERN	int	myaccess(char *);
+EXTERN	int	mywait(int*);
+EXTERN	int	mycreat(char*, int);
+EXTERN	char*	mygetwd(char*, int);
+EXTERN	int	myexec(char*, char*[]);
+EXTERN	int	mydup(int, int);
+EXTERN	int	myfork(void);
+EXTERN	int	mypipe(int*);
+EXTERN	void*	mysbrk(ulong);
+
+EXTERN	void	gethunk(void);
+
+EXTERN	char*	hunk;
+EXTERN	uintptr	nhunk;
+EXTERN	uintptr	thunk;
+
+EXTERN	void*	alloc(long n);
+EXTERN	void*	allocn(void *p, long on, long n);
diff --git a/sys/src/cmd/cc/lex.c b/sys/src/cmd/cc/lex.c
index 06abc8232..5419f26bf 100644
--- a/sys/src/cmd/cc/lex.c
+++ b/sys/src/cmd/cc/lex.c
@@ -1524,45 +1524,6 @@ VBconv(Fmt *fp)
 	return fmtstrcpy(fp, str);
 }
 
-/*
- * real allocs
- */
-void*
-alloc(long n)
-{
-	void *p;
-
-	while((uintptr)hunk & MAXALIGN) {
-		hunk++;
-		nhunk--;
-	}
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void*
-allocn(void *p, long on, long n)
-{
-	void *q;
-
-	q = (uchar*)p + on;
-	if(q != hunk || nhunk < n) {
-		while(nhunk < on+n)
-			gethunk();
-		memmove(hunk, p, on);
-		p = hunk;
-		hunk += on;
-		nhunk -= on;
-	}
-	hunk += n;
-	nhunk -= n;
-	return p;
-}
-
 void
 setinclude(char *p)
 {
diff --git a/sys/src/cmd/cc/lexbody b/sys/src/cmd/cc/lexbody
index a22c6efba..471041617 100644
--- a/sys/src/cmd/cc/lexbody
+++ b/sys/src/cmd/cc/lexbody
@@ -37,45 +37,6 @@ pragincomplete(void)
 		;
 }
 
-/*
- * real allocs
- */
-void*
-alloc(long n)
-{
-	void *p;
-
-	while((uintptr)hunk & MAXALIGN) {
-		hunk++;
-		nhunk--;
-	}
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void*
-allocn(void *p, long on, long n)
-{
-	void *q;
-
-	q = (uchar*)p + on;
-	if(q != hunk || nhunk < n) {
-		while(nhunk < on+n)
-			gethunk();
-		memmove(hunk, p, on);
-		p = hunk;
-		hunk += on;
-		nhunk -= on;
-	}
-	hunk += n;
-	nhunk -= n;
-	return p;
-}
-
 void
 setinclude(char *p)
 {
diff --git a/sys/src/cmd/cc/mac.c b/sys/src/cmd/cc/mac.c
index 7ec6e3937..e2ec23ace 100644
--- a/sys/src/cmd/cc/mac.c
+++ b/sys/src/cmd/cc/mac.c
@@ -1,3 +1,2 @@
 #include	"cc.h"
-
 #include	"macbody"
diff --git a/sys/src/cmd/cc/macbody b/sys/src/cmd/cc/macbody
index 7d837fb43..0a921cbb8 100644
--- a/sys/src/cmd/cc/macbody
+++ b/sys/src/cmd/cc/macbody
@@ -847,22 +847,3 @@ linehist(char *f, int offset)
 	ehist->link = h;
 	ehist = h;
 }
-
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 10L*NHUNK)
-		nh = 10L*NHUNK;
-	h = (char*)mysbrk(nh);
-	if(h == (char*)-1) {
-		yyerror("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
diff --git a/sys/src/cmd/cc/mkfile b/sys/src/cmd/cc/mkfile
index c7530b3de..91310d62a 100644
--- a/sys/src/cmd/cc/mkfile
+++ b/sys/src/cmd/cc/mkfile
@@ -19,6 +19,7 @@ OFILES=\
 	omachcap.$O\
 
 HFILES=cc.h\
+	compat.h\
 	y.tab.h\
 
 YFILES=cc.y\
@@ -34,7 +35,9 @@ install:V:	$LIB
 $LIB:	$LIBOBJ
 	ar vu $LIB $OFILES
 
-mac.$O:	macbody
+mac.$O: macbody
+
+compat.$O: compat
 
 everything:V:
 	# mk the current compilers
diff --git a/sys/src/cmd/ka/a.h b/sys/src/cmd/ka/a.h
index 9f55ab333..5c15ceb14 100644
--- a/sys/src/cmd/ka/a.h
+++ b/sys/src/cmd/ka/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../kc/k.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Gen	Gen;
@@ -95,14 +92,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	ninclude;
 EXTERN	int	nosched;
 EXTERN	Gen	nullgen;
@@ -115,11 +110,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	alloc(long);
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -154,29 +146,7 @@ void	dodefine(char*);
 void	prfile(long);
 void	outhist(void);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-
-enum				/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/ka/mkfile b/sys/src/cmd/ka/mkfile
index afa5ad506..d7fe9b626 100644
--- a/sys/src/cmd/ka/mkfile
+++ b/sys/src/cmd/ka/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../kc/k.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/kc/mkfile b/sys/src/cmd/kc/mkfile
index 3423c37e2..9031d8a6f 100644
--- a/sys/src/cmd/kc/mkfile
+++ b/sys/src/cmd/kc/mkfile
@@ -17,6 +17,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	k.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/kl/compat.c b/sys/src/cmd/kl/compat.c
index 1d9f89e43..54ac0283e 100644
--- a/sys/src/cmd/kl/compat.c
+++ b/sys/src/cmd/kl/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void *p, ulong n)
-{
-	fprint(2, "realloc(0x%p %ld) called\n", p, n);
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/kl/l.h b/sys/src/cmd/kl/l.h
index e296e4509..0ac5020db 100644
--- a/sys/src/cmd/kl/l.h
+++ b/sys/src/cmd/kl/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../kc/k.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 typedef	struct	Adr	Adr;
 typedef	struct	Sym	Sym;
@@ -224,7 +221,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -232,7 +228,6 @@ EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	char	literal[32];
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	char*	noname;
 EXTERN	long	instoffset;
 EXTERN	char*	outfile;
@@ -241,7 +236,6 @@ EXTERN	long	symsize;
 EXTERN	long	staticgen;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	tothunk;
 EXTERN	char	xcmp[C_NCLASS][C_NCLASS];
 EXTERN	int	version;
 EXTERN	Prog	zprg;
@@ -290,7 +284,6 @@ void	errorexit(void);
 void	exchange(Prog*);
 int	find1(long, int);
 void	follow(void);
-void	gethunk(void);
 double	ieeedtod(Ieee*);
 long	ieeedtof(Ieee*);
 int	isnop(Prog*);
@@ -301,7 +294,6 @@ void	initmuldiv(void);
 Sym*	lookup(char*, int);
 void	lput(long);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	names(void);
 void	nocache(Prog*);
 void	noops(void);
diff --git a/sys/src/cmd/kl/mkfile b/sys/src/cmd/kl/mkfile
index b5befdd38..3c128f703 100644
--- a/sys/src/cmd/kl/mkfile
+++ b/sys/src/cmd/kl/mkfile
@@ -16,9 +16,13 @@ OFILES=\
 HFILES=\
 	l.h\
 	../kc/k.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
 
 enam.$O:	../kc/enam.c
 	$CC $CFLAGS ../kc/enam.c
+
+compat.$O:	../cc/compat
+
diff --git a/sys/src/cmd/kl/obj.c b/sys/src/cmd/kl/obj.c
index b778cfd8d..dd324dfb3 100644
--- a/sys/src/cmd/kl/obj.c
+++ b/sys/src/cmd/kl/obj.c
@@ -194,7 +194,7 @@ main(int argc, char *argv[])
 out:
 	if(debug['v']) {
 		Bprint(&bso, "%5.2f cpu time\n", cputime());
-		Bprint(&bso, "%zud memory used\n", tothunk);
+		Bprint(&bso, "%zud memory used\n", thunk);
 		Bprint(&bso, "%d sizeof adr\n", sizeof(Adr));
 		Bprint(&bso, "%d sizeof prog\n", sizeof(Prog));
 	}
@@ -976,29 +976,6 @@ prg(void)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(tothunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(tothunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char *)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-
-	hunk = h;
-	nhunk = nh;
-	tothunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/qa/a.h b/sys/src/cmd/qa/a.h
index 74f386379..3dbb478b1 100644
--- a/sys/src/cmd/qa/a.h
+++ b/sys/src/cmd/qa/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../qc/q.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Gen	Gen;
@@ -115,14 +112,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	nosched;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
@@ -135,7 +130,6 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
 void	errorexit(void);
@@ -173,28 +167,7 @@ void	dodefine(char*);
 void	prfile(long);
 void	outhist(void);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-enum				/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/qa/mkfile b/sys/src/cmd/qa/mkfile
index 4563f25da..5b10e478b 100644
--- a/sys/src/cmd/qa/mkfile
+++ b/sys/src/cmd/qa/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../qc/q.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/qc/mkfile b/sys/src/cmd/qc/mkfile
index 63cbd5483..fed973694 100644
--- a/sys/src/cmd/qc/mkfile
+++ b/sys/src/cmd/qc/mkfile
@@ -18,6 +18,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	q.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/ql/compat.c b/sys/src/cmd/ql/compat.c
index e81bebce8..54ac0283e 100644
--- a/sys/src/cmd/ql/compat.c
+++ b/sys/src/cmd/ql/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void*, ulong)
-{
-	fprint(2, "realloc called\n");
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/ql/l.h b/sys/src/cmd/ql/l.h
index e7822d01e..063bb9d45 100644
--- a/sys/src/cmd/ql/l.h
+++ b/sys/src/cmd/ql/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../qc/q.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 typedef	struct	Adr	Adr;
 typedef	struct	Sym	Sym;
@@ -216,7 +213,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -224,7 +220,6 @@ EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	char	literal[32];
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	char*	noname;
 EXTERN	long	instoffset;
 EXTERN	char*	outfile;
@@ -234,7 +229,6 @@ EXTERN	long	symsize;
 EXTERN	long	staticgen;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	tothunk;
 EXTERN	char	xcmp[C_NCLASS][C_NCLASS];
 EXTERN	int	version;
 EXTERN	Prog	zprg;
@@ -289,7 +283,6 @@ void	exchange(Prog*);
 void	export(void);
 int	find1(long, int);
 void	follow(void);
-void	gethunk(void);
 double	ieeedtod(Ieee*);
 long	ieeedtof(Ieee*);
 void	import(void);
@@ -301,7 +294,6 @@ void	initmuldiv(void);
 Sym*	lookup(char*, int);
 void	lput(long);
 void	mkfwd(void);
-void*	mysbrk(ulong);
 void	names(void);
 void	nocache(Prog*);
 void	noops(void);
diff --git a/sys/src/cmd/ql/mkfile b/sys/src/cmd/ql/mkfile
index 24dd45c48..681f42ee7 100644
--- a/sys/src/cmd/ql/mkfile
+++ b/sys/src/cmd/ql/mkfile
@@ -18,6 +18,7 @@ OFILES=\
 HFILES=\
 	l.h\
 	../qc/q.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
@@ -26,3 +27,4 @@ enam.$O:	../qc/enam.c
 	$CC $CFLAGS ../qc/enam.c
 cnam.c:	l.h
 	rc mkcname
+compat.$O:	../cc/compat
diff --git a/sys/src/cmd/ql/obj.c b/sys/src/cmd/ql/obj.c
index dba56bd46..cfa8c335f 100644
--- a/sys/src/cmd/ql/obj.c
+++ b/sys/src/cmd/ql/obj.c
@@ -273,7 +273,7 @@ main(int argc, char *argv[])
 out:
 	if(debug['v']) {
 		Bprint(&bso, "%5.2f cpu time\n", cputime());
-		Bprint(&bso, "%zud memory used\n", tothunk);
+		Bprint(&bso, "%zud memory used\n", thunk);
 		Bprint(&bso, "%d sizeof adr\n", sizeof(Adr));
 		Bprint(&bso, "%d sizeof prog\n", sizeof(Prog));
 	}
@@ -1110,29 +1110,6 @@ prg(void)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(tothunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(tothunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char *)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-
-	hunk = h;
-	nhunk = nh;
-	tothunk += nh;
-}
-
 void
 doprof1(void)
 {
diff --git a/sys/src/cmd/va/a.h b/sys/src/cmd/va/a.h
index 7438512f1..4aef20de4 100644
--- a/sys/src/cmd/va/a.h
+++ b/sys/src/cmd/va/a.h
@@ -2,10 +2,7 @@
 #include <libc.h>
 #include <bio.h>
 #include "../vc/v.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include "../cc/compat.h"
 
 typedef	struct	Sym	Sym;
 typedef	struct	Gen	Gen;
@@ -94,14 +91,12 @@ EXTERN	int	nDlist;
 EXTERN	Hist*	ehist;
 EXTERN	int	newflag;
 EXTERN	Hist*	hist;
-EXTERN	char*	hunk;
 EXTERN	char*	include[NINCLUDE];
 EXTERN	Io*	iofree;
 EXTERN	Io*	ionext;
 EXTERN	Io*	iostack;
 EXTERN	long	lineno;
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	int	nosched;
 EXTERN	int	ninclude;
 EXTERN	Gen	nullgen;
@@ -114,11 +109,8 @@ EXTERN	int	sym;
 EXTERN	char	symb[NSYMB];
 EXTERN	int	thechar;
 EXTERN	char*	thestring;
-EXTERN	uintptr	thunk;
 EXTERN	Biobuf	obuf;
 
-void*	alloc(long);
-void*	allocn(void*, long, long);
 void	errorexit(void);
 void	pushio(void);
 void	newio(void);
@@ -154,29 +146,7 @@ void	outhist(void);
 void	dodefine(char*);
 void	prfile(long);
 void	linehist(char*, int);
-void	gethunk(void);
 void	yyerror(char*, ...);
 int	yyparse(void);
 void	setinclude(char*);
 int	assemble(char*);
-
-/*
- *	system-dependent stuff from ../cc/compat.c
- */
-
-enum				/* keep in synch with ../cc/cc.h */
-{
-	Plan9	= 1<<0,
-	Unix	= 1<<1,
-	Windows	= 1<<2
-};
-int	mywait(int*);
-int	mycreat(char*, int);
-int	systemtype(int);
-int	pathchar(void);
-char*	mygetwd(char*, int);
-int	myexec(char*, char*[]);
-int	mydup(int, int);
-int	myfork(void);
-int	mypipe(int*);
-void*	mysbrk(ulong);
diff --git a/sys/src/cmd/va/mkfile b/sys/src/cmd/va/mkfile
index 170c66b89..288562895 100644
--- a/sys/src/cmd/va/mkfile
+++ b/sys/src/cmd/va/mkfile
@@ -7,6 +7,7 @@ OFILES=\
 
 HFILES=\
 	../vc/v.out.h\
+	../cc/compat.h\
 	y.tab.h\
 	a.h\
 
diff --git a/sys/src/cmd/vc/mkfile b/sys/src/cmd/vc/mkfile
index 6446089c1..cad14ebb1 100644
--- a/sys/src/cmd/vc/mkfile
+++ b/sys/src/cmd/vc/mkfile
@@ -17,6 +17,7 @@ OFILES=\
 HFILES=\
 	gc.h\
 	v.out.h\
+	../cc/compat.h\
 	../cc/cc.h\
 
 LIB=../cc/cc.a$O
diff --git a/sys/src/cmd/vl/compat.c b/sys/src/cmd/vl/compat.c
index 1d9f89e43..54ac0283e 100644
--- a/sys/src/cmd/vl/compat.c
+++ b/sys/src/cmd/vl/compat.c
@@ -1,56 +1,2 @@
 #include	"l.h"
-
-/*
- * fake malloc
- */
-void*
-malloc(ulong n)
-{
-	void *p;
-
-	while(n & 7)
-		n++;
-	while(nhunk < n)
-		gethunk();
-	p = hunk;
-	nhunk -= n;
-	hunk += n;
-	return p;
-}
-
-void
-free(void *p)
-{
-	USED(p);
-}
-
-void*
-calloc(ulong m, ulong n)
-{
-	void *p;
-
-	n *= m;
-	p = malloc(n);
-	memset(p, 0, n);
-	return p;
-}
-
-void*
-realloc(void *p, ulong n)
-{
-	fprint(2, "realloc(0x%p %ld) called\n", p, n);
-	abort();
-	return 0;
-}
-
-void*
-mysbrk(ulong size)
-{
-	return sbrk(size);
-}
-
-void
-setmalloctag(void *v, uintptr pc)
-{
-	USED(v, pc);
-}
+#include	"../cc/compat"
diff --git a/sys/src/cmd/vl/l.h b/sys/src/cmd/vl/l.h
index 094da0a50..d605e8f34 100644
--- a/sys/src/cmd/vl/l.h
+++ b/sys/src/cmd/vl/l.h
@@ -2,10 +2,7 @@
 #include	<libc.h>
 #include	<bio.h>
 #include	"../vc/v.out.h"
-
-#ifndef	EXTERN
-#define	EXTERN	extern
-#endif
+#include	"../cc/compat.h"
 
 typedef	struct	Adr	Adr;
 typedef	struct	Sym	Sym;
@@ -215,7 +212,6 @@ EXTERN	char*	library[50];
 EXTERN	char*	libraryobj[50];
 EXTERN	int	libraryp;
 EXTERN	int	xrefresolv;
-EXTERN	char*	hunk;
 EXTERN	char	inuxi1[1];
 EXTERN	char	inuxi2[2];
 EXTERN	char	inuxi4[4];
@@ -223,7 +219,6 @@ EXTERN	Prog*	lastp;
 EXTERN	long	lcsize;
 EXTERN	char	literal[32];
 EXTERN	int	nerrors;
-EXTERN	long	nhunk;
 EXTERN	long	instoffset;
 EXTERN	Opcross	opcross[10];
 EXTERN	Oprang	oprange[ALAST];
@@ -233,7 +228,6 @@ EXTERN	uchar	repop[ALAST];
 EXTERN	long	symsize;
 EXTERN	Prog*	textp;
 EXTERN	long	textsize;
-EXTERN	uintptr	thunk;
 EXTERN	int	version;
 EXTERN	char	xcmp[32][32];
 EXTERN	Prog	zprg;
@@ -292,7 +286,6 @@ void	errorexit(void);
 void	exchange(Prog*);
 int	find1(long, int);
 void	follow(void);
-void	gethunk(void);
 void	histtoauto(void);
 double	ieeedtod(Ieee*);
 long	ieeedtof(Ieee*);
diff --git a/sys/src/cmd/vl/mkfile b/sys/src/cmd/vl/mkfile
index 82b008ee7..96a4d7800 100644
--- a/sys/src/cmd/vl/mkfile
+++ b/sys/src/cmd/vl/mkfile
@@ -16,6 +16,7 @@ OFILES=\
 HFILES=\
 	l.h\
 	../vc/v.out.h\
+	../cc/compat.h\
 
 BIN=/$objtype/bin
 </sys/src/cmd/mkone
@@ -23,6 +24,8 @@ BIN=/$objtype/bin
 enam.$O:	../vc/enam.c
 	$CC $CFLAGS ../vc/enam.c
 
+compat.$O:	../cc/compat
+
 x:V:	$O.out
 	$O.out -la -o/dev/null x.v
 
diff --git a/sys/src/cmd/vl/obj.c b/sys/src/cmd/vl/obj.c
index c20e5c98b..82cff0f22 100644
--- a/sys/src/cmd/vl/obj.c
+++ b/sys/src/cmd/vl/obj.c
@@ -1058,28 +1058,6 @@ prg(void)
 	return p;
 }
 
-void
-gethunk(void)
-{
-	char *h;
-	long nh;
-
-	nh = NHUNK;
-	if(thunk >= 5L*NHUNK) {
-		nh = 5L*NHUNK;
-		if(thunk >= 25L*NHUNK)
-			nh = 25L*NHUNK;
-	}
-	h = mysbrk(nh);
-	if(h == (char*)-1) {
-		diag("out of memory");
-		errorexit();
-	}
-	hunk = h;
-	nhunk = nh;
-	thunk += nh;
-}
-
 void
 doprof1(void)
 {