Expose public garbage collector API for C language

You can now do epic things like this:

    puts(_gc(xasprintf("%d", 123)));

The _gc() API is shorthand for _defer() which works like Go's keyword:

    const char *s = xasprintf("%d", 123);
    _defer(free, s);
    puts(s);

Be sure to always use -fno-omit-frame-pointer which makes code fast too.

Enjoy! See also #114

build/config.mk

@@ -282,11 +282,6 @@ endif
 # such as MSVC or XCode. You can run your binary objects through a tool
 # like objconv to convert them to COFF or MachO. Then use ANSI mode to
 # rollup one header file that'll enable linkage with minimal issues.
-#
-# Lastly note that in some cases, such as gc(), there simply isn't any
-# ANSI workaround available. It's only in cases like that when we'll use
-# the __asm__() header workaround, rather than simply removing it. We do
-# however try to do that much less often than mainstream C libraries.
 
 ifeq ($(MODE), ansi)
 

libc/mem/defer.greg.c

@@ -31,23 +31,9 @@ forceinline bool PointerNotOwnedByParentStackFrame(struct StackFrame *frame,
            ((intptr_t)ptr < (intptr_t)parent));
 }
 
-/**
- * Adds destructor to garbage shadow stack.
- *
- * @param frame is passed automatically by wrapper macro
- * @param fn takes one argument
- * @param arg is passed to fn(arg)
- * @return arg
- */
-void __defer(struct StackFrame *frame, void *fn, void *arg) {
+void __deferer(struct StackFrame *frame, void *fn, void *arg) {
   size_t n2;
   struct Garbage *p2;
-  struct StackFrame *f2;
-  if (!arg) return;
-  f2 = __builtin_frame_address(0);
-  assert(__garbage.n);
-  assert(f2->next == frame);
-  assert(PointerNotOwnedByParentStackFrame(f2, frame, arg));
   if (UNLIKELY(__garbage.i == __garbage.n)) {
     n2 = __garbage.n + (__garbage.n >> 1);
     p2 = malloc(n2 * sizeof(*__garbage.p));
@@ -63,3 +49,21 @@ void __defer(struct StackFrame *frame, void *fn, void *arg) {
   __garbage.i++;
   frame->addr = (intptr_t)__gc;
 }
+
+/**
+ * Adds destructor to garbage shadow stack.
+ *
+ * @param frame is passed automatically by wrapper macro
+ * @param fn takes one argument
+ * @param arg is passed to fn(arg)
+ * @return arg
+ */
+void __defer(struct StackFrame *frame, void *fn, void *arg) {
+  struct StackFrame *f2;
+  if (!arg) return;
+  f2 = __builtin_frame_address(0);
+  assert(__garbage.n);
+  assert(f2->next == frame);
+  assert(PointerNotOwnedByParentStackFrame(f2, frame, arg));
+  __deferer(frame, fn, arg);
+}

libc/mem/gc.c

@@ -0,0 +1,66 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/nexgen32e/stackframe.h"
+#include "libc/runtime/gc.h"
+#include "libc/runtime/runtime.h"
+
+/**
+ * Frees memory when function returns.
+ *
+ * This garbage collector overwrites the return address on the stack so
+ * that the RET instruction calls a trampoline which calls free(). It's
+ * loosely analogous to Go's defer keyword rather than a true cycle gc.
+ *
+ *     const char *s = _gc(strdup("hello"));
+ *     puts(s);
+ *
+ * This macro is equivalent to:
+ *
+ *      _defer(free, ptr)
+ *
+ * @warning do not return a gc()'d pointer
+ * @warning do not realloc() with gc()'d pointer
+ * @warning be careful about static keyword due to impact of inlining
+ * @note you should use -fno-omit-frame-pointer
+ */
+void *(_gc)(void *thing) {
+  struct StackFrame *frame;
+  frame = __builtin_frame_address(0);
+  __deferer(frame->next, _weakfree, thing);
+  return thing;
+}
+
+/**
+ * Calls fn(arg) when function returns.
+ *
+ * This garbage collector overwrites the return address on the stack so
+ * that the RET instruction calls a trampoline which calls free(). It's
+ * loosely analogous to Go's defer keyword rather than a true cycle gc.
+ *
+ * @warning do not return a gc()'d pointer
+ * @warning do not realloc() with gc()'d pointer
+ * @warning be careful about static keyword due to impact of inlining
+ * @note you should use -fno-omit-frame-pointer
+ */
+void *(_defer)(void *fn, void *arg) {
+  struct StackFrame *frame;
+  frame = __builtin_frame_address(0);
+  __deferer(frame->next, fn, arg);
+  return arg;
+}

libc/nexgen32e/gclongjmp.S

@@ -29,7 +29,7 @@
 //	@assume	system five nexgen32e abi conformant
 //	@see	examples/ctrlc.c
 //	@noreturn
-gclongjmp:
+_gclongjmp:
 	.leafprologue
 	.profilable
 	.weak	__garbage
@@ -57,5 +57,4 @@ gclongjmp:
 2:	pop	%rsi
 	pop	%rdi
 	jmp	0b
-	.endfn	gclongjmp,globl
-	.source	__FILE__
+	.endfn	_gclongjmp,globl

libc/nexgen32e/loadxmm.S

@@ -23,7 +23,7 @@
 //
 //	@param	%rdi points to &(forcealign(16) uint8_t[256])[128]
 //	@note	modern cpus have out-of-order execution engines
-loadxmm:
+_loadxmm:
 	.leafprologue
 	movaps	-0x80(%rdi),%xmm0
 	movaps	-0x70(%rdi),%xmm1
@@ -42,5 +42,4 @@ loadxmm:
 	movaps	0x60(%rdi),%xmm14
 	movaps	0x70(%rdi),%xmm15
 	.leafepilogue
-	.endfn	loadxmm,globl,hidden
-	.source	__FILE__
+	.endfn	_loadxmm,globl,hidden

libc/nexgen32e/longjmp.S

@@ -26,7 +26,7 @@
 //	@noreturn
 //	@assume	system five nexgen32e abi conformant
 //	@note	code built w/ microsoft abi compiler can't call this
-//	@see	gclongjmp() unwinds gc() destructors
+//	@see	_gclongjmp() unwinds _gc() destructors
 longjmp:mov	%esi,%eax
 	test	%eax,%eax
 	jnz	1f

libc/nexgen32e/nt2sysv.S

@@ -40,14 +40,14 @@ __nt2sysv:
 	pushf
 	ezlea	_base,bx
 	lea	-0x80(%rbp),%rdi
-	call	savexmm
+	call	_savexmm
 	mov	%rcx,%rdi
 	mov	%rdx,%rsi
 	mov	%r8,%rdx
 	mov	%r9,%rcx
 	call	*%rax
 	lea	-0x80(%rbp),%rdi
-	call	loadxmm
+	call	_loadxmm
 	popf
 	pop	%rsi
 	pop	%rdi

libc/nexgen32e/savexmm.S

@@ -23,7 +23,7 @@
 //
 //	@param	%rdi points to &(forcealign(16) uint8_t[256])[128]
 //	@note	modern cpus have out-of-order execution engines
-savexmm:
+_savexmm:
 	.leafprologue
 	movaps	%xmm0,-0x80(%rdi)
 	movaps	%xmm1,-0x70(%rdi)
@@ -42,5 +42,4 @@ savexmm:
 	movaps	%xmm14,0x60(%rdi)
 	movaps	%xmm15,0x70(%rdi)
 	.leafepilogue
-	.endfn	savexmm,globl,hidden
-	.source	__FILE__
+	.endfn	_savexmm,globl,hidden

libc/nexgen32e/setjmp.S

@@ -25,7 +25,7 @@
 //	@returnstwice
 //	@assume	system five nexgen32e abi conformant
 //	@note	code built w/ microsoft abi compiler can't call this
-//	@see	longjmp(), gclongjmp()
+//	@see	longjmp(), _gclongjmp()
 setjmp:	lea	8(%rsp),%rax
 	mov	%rax,(%rdi)
 	mov	%rbx,8(%rdi)

libc/nexgen32e/triplf.S

@@ -1,41 +0,0 @@
-/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
-│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ Permission to use, copy, modify, and/or distribute this software for         │
-│ any purpose with or without fee is hereby granted, provided that the         │
-│ above copyright notice and this permission notice appear in all copies.      │
-│                                                                              │
-│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
-│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
-│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
-│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
-│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
-│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
-│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
-│ PERFORMANCE OF THIS SOFTWARE.                                                │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "ape/macros.internal.h"
-.real
-.source	__FILE__
-.code16 # ∩ .code32 ∩ .code64
-
-//	Hoses interrupt descriptor table and triple-faults the system.
-//
-//	@see	youtu.be/GIKfEAF2Yhw?t=67
-//	@mode	long,legacy,real
-triplf:	ud2
-	push	%bp
-	mov	%sp,%bp
-	sub	$8,%sp
-	movpp	%bp,%si
-	lea	-8(%bp),%di
-	pushpop	8,%cx
-	xor	%ax,%ax
-	rep stosb
-0:	cli
-	lidt	-8(%bp)
-	ud2
-	jmp	0b
-	.endfn	triplf,globl,protected

libc/runtime/free_s.c

@@ -26,5 +26,7 @@ void free_s(void *v) {
   void **pp = (void **)v;
   void *p = NULL;
   lockxchg(pp, &p);
-  if (isheap(p)) weakfree(p);
+  if (_isheap(p)) {
+    _weakfree(p);
+  }
 }

libc/runtime/gc.h

@@ -0,0 +1,30 @@
+#ifndef COSMOPOLITAN_LIBC_RUNTIME_GC_H_
+#define COSMOPOLITAN_LIBC_RUNTIME_GC_H_
+#include "libc/calls/calls.h"
+#include "libc/nexgen32e/stackframe.h"
+#include "libc/runtime/runtime.h"
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+void *_gc(void *) hidden;
+void *_defer(void *, void *) hidden;
+void __defer(struct StackFrame *, void *, void *) hidden;
+void __deferer(struct StackFrame *, void *, void *) hidden;
+void _gclongjmp(jmp_buf, int) nothrow wontreturn;
+
+#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
+#define _gc(THING) _defer((void *)_weakfree, (void *)(THING))
+#define _defer(FN, ARG)                                                \
+  ({                                                                   \
+    autotype(ARG) Arg = (ARG);                                         \
+    /* prevent weird opts like tail call */                            \
+    asm volatile("" : "+g"(Arg) : : "memory");                         \
+    __defer((struct StackFrame *)__builtin_frame_address(0), FN, Arg); \
+    asm volatile("" : "+g"(Arg) : : "memory");                         \
+    Arg;                                                               \
+  })
+#endif /* defined(__GNUC__) && !defined(__STRICT_ANSI__) */
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_RUNTIME_GC_H_ */

libc/runtime/gc.internal.h

@@ -1,49 +1,10 @@
-#ifndef COSMOPOLITAN_LIBC_RUNTIME_GC_H_
-#define COSMOPOLITAN_LIBC_RUNTIME_GC_H_
-#include "libc/calls/calls.h"
-#include "libc/nexgen32e/stackframe.h"
-#include "libc/runtime/runtime.h"
+#ifndef COSMOPOLITAN_LIBC_RUNTIME_GC_INTERNAL_H_
+#define COSMOPOLITAN_LIBC_RUNTIME_GC_INTERNAL_H_
+#include "libc/runtime/gc.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
-COSMOPOLITAN_C_START_
 
-/**
- * @fileoverview Cosmopolitan Return-Oriented Garbage Collector.
- *
- * This is the same thing as {@code std::unique_ptr<>} in C++ or the
- * {@code defer} keyword in Go. We harness the power of ROP for good
- * using very few lines of code.
- */
+#define gc(THING)      _gc(THING)
+#define defer(FN, ARG) _defer(FN, ARG)
 
-/**
- * Releases resource when function returns.
- *
- * @warning do not return a gc()'d pointer
- * @warning do not realloc() with gc()'d pointer
- */
-#define gc(THING) defer((void *)weakfree, (void *)(THING))
-
-/**
- * Same as longjmp() but runs gc() / defer() destructors.
- */
-void gclongjmp(jmp_buf, int) nothrow wontreturn paramsnonnull();
-
-/**
- * Calls FN(ARG) when function returns.
- */
-#ifndef __VSCODE_INTELLISENSE__
-#define defer(FN, ARG)                                                 \
-  ({                                                                   \
-    autotype(ARG) Arg = (ARG);                                         \
-    /* prevent weird opts like tail call */                            \
-    asm volatile("" : "+g"(Arg) : : "memory");                         \
-    __defer((struct StackFrame *)__builtin_frame_address(0), FN, Arg); \
-    asm volatile("" : "+g"(Arg) : : "memory");                         \
-    Arg;                                                               \
-  })
-#endif /* __VSCODE_INTELLISENSE__ */
-
-void __defer(struct StackFrame *, void *, void *) hidden paramsnonnull((1, 2));
-
-COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
-#endif /* COSMOPOLITAN_LIBC_RUNTIME_GC_H_ */
+#endif /* COSMOPOLITAN_LIBC_RUNTIME_GC_INTERNAL_H_ */

libc/runtime/grow.c

@@ -43,8 +43,8 @@ bool __grow(void *pp, size_t *capacity, size_t itemsize, size_t extra) {
   p = (void **)pp;
   assert(itemsize);
   assert((*p && *capacity) || (!*p && !*capacity));
-  assert(!isheap(*p) || ((intptr_t)*p & 15) == 0);
-  p1 = isheap(*p) ? *p : NULL;
+  assert(!_isheap(*p) || ((intptr_t)*p & 15) == 0);
+  p1 = _isheap(*p) ? *p : NULL;
   p2 = NULL;
   n1 = *capacity;
   n2 = (*p ? n1 + (n1 >> 1) : MAX(4, INITIAL_CAPACITY / itemsize)) + extra;

libc/runtime/isheap.c

@@ -26,7 +26,7 @@
  * @assume stack addresses are always greater than heap addresses
  * @assume stack memory isn't stored beneath %rsp (-mno-red-zone)
  */
-bool isheap(void *p) {
+bool _isheap(void *p) {
   int x, i;
   uintptr_t rsp;
   asm("mov\t%%rsp,%0" : "=r"(rsp));

libc/runtime/peekall.S

@@ -18,10 +18,10 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "ape/relocations.h"
 #include "libc/macros.internal.h"
-.source	__FILE__
 
 //	Loads all pages from program image into memory.
-peekall:.leafprologue
+_peekall:
+	.leafprologue
 	ezlea	_base,si
 	ezlea	_end,cx
 0:	mov	(%rsi),%eax
@@ -29,4 +29,4 @@ peekall:.leafprologue
 	cmp	%rcx,%rsi
 	jb	0b
 	.leafepilogue
-	.endfn	peekall,globl
+	.endfn	_peekall,globl

libc/runtime/print.greg.c

@@ -34,10 +34,10 @@ static void __sys_print_nt(const void *data, size_t len) {
   int64_t hand;
   char xmm[256];
   uint32_t wrote;
-  savexmm(xmm + 128);
+  _savexmm(xmm + 128);
   hand = __imp_GetStdHandle(kNtStdErrorHandle);
   __imp_WriteFile(hand, data, len, &wrote, NULL);
-  loadxmm(xmm + 128);
+  _loadxmm(xmm + 128);
 }
 
 /**

libc/runtime/runtime.h

@@ -33,7 +33,6 @@ extern unsigned char *__relo_end[];                 /* αpε */
 extern uint8_t __zip_start[];                       /* αpε */
 extern uint8_t __zip_end[];                         /* αpε */
 
-long missingno();
 void mcount(void);
 unsigned long getauxval(unsigned long);
 void *mapanon(size_t) vallocesque attributeallocsize((1));
@@ -45,34 +44,35 @@ void exit(int) wontreturn;
 void _exit(int) libcesque wontreturn;
 void _Exit(int) libcesque wontreturn;
 void abort(void) wontreturn noinstrument;
-void triplf(void) wontreturn noinstrument privileged;
 int __cxa_atexit(void *, void *, void *) libcesque;
 int atfork(void *, void *) libcesque;
 int atexit(void (*)(void)) libcesque;
-void free_s(void *) paramsnonnull() libcesque;
-int close_s(int *) paramsnonnull() libcesque;
 char *getenv(const char *) paramsnonnull() nosideeffect libcesque;
 int putenv(char *) paramsnonnull();
 int setenv(const char *, const char *, int) paramsnonnull();
 int unsetenv(const char *);
 int clearenv(void);
 void fpreset(void);
-void savexmm(void *);
-void loadxmm(void *);
-void peekall(void);
 int issetugid(void);
-void weakfree(void *) libcesque;
-bool isheap(void *);
 void *mmap(void *, uint64_t, int32_t, int32_t, int32_t, int64_t);
 void *mremap(void *, uint64_t, uint64_t, int32_t, void *);
 int munmap(void *, uint64_t);
 int mprotect(void *, uint64_t, int) privileged;
 int msync(void *, size_t, int);
-void __print(const void *, size_t);
-void __print_string(const char *);
 void *sbrk(intptr_t);
 int brk(void *);
+
+bool _isheap(void *);
 int NtGetVersion(void);
+long missingno();
+void __print(const void *, size_t);
+void __print_string(const char *);
+void _loadxmm(void *);
+void _peekall(void);
+void _savexmm(void *);
+void _weakfree(void *);
+void free_s(void *) paramsnonnull() libcesque;
+int close_s(int *) paramsnonnull() libcesque;
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

libc/runtime/stackchkfail.c

@@ -50,21 +50,22 @@ privileged noasan void __stack_chk_fail(void) {
                  : "=S"(si), "=c"(cx)
                  : "0"(msg), "1"(len), "d"(0x3F8 /* COM1 */)
                  : "memory");
-    triplf();
+    asm("push\t$0\n\t"
+        "push\t$0\n\t"
+        "cli\n\t"
+        "lidt\t(%rsp)");
+    for (;;) asm("ud2");
   }
   if (NtGetVersion() < kNtVersionFuture) {
     do {
-      asm volatile(
-          "syscall"
-          : "=a"(ax), "=c"(cx)
-          : "0"(NtGetVersion() < kNtVersionWindows8
-                    ? 0x0029
-                    : NtGetVersion() < kNtVersionWindows81
-                          ? 0x002a
-                          : NtGetVersion() < kNtVersionWindows10 ? 0x002b
-                                                                 : 0x002c),
-            "1"(pushpop(-1L)), "d"(42)
-          : "r11", "cc", "memory");
+      asm volatile("syscall"
+                   : "=a"(ax), "=c"(cx)
+                   : "0"(NtGetVersion() < kNtVersionWindows8    ? 0x0029
+                         : NtGetVersion() < kNtVersionWindows81 ? 0x002a
+                         : NtGetVersion() < kNtVersionWindows10 ? 0x002b
+                                                                : 0x002c),
+                     "1"(pushpop(-1L)), "d"(42)
+                   : "r11", "cc", "memory");
     } while (!ax);
   }
   for (;;) {

libc/runtime/weakfree.c

@@ -1,7 +1,7 @@
-/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
-│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
 ╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
 │                                                                              │
 │ Permission to use, copy, modify, and/or distribute this software for         │
 │ any purpose with or without fee is hereby granted, provided that the         │
@@ -16,20 +16,15 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/macros.internal.h"
-.source	__FILE__
+#include "libc/bits/weaken.h"
+#include "libc/mem/mem.h"
+#include "libc/runtime/runtime.h"
 
-//	Thunks free() if it's linked, otherwise do nothing.
-//
-//	@see	free_s() which can ignore static/stack and clear refs
-weakfree:
-	push	%rbp
-	mov	%rsp,%rbp
-	.weak	free
-	ezlea	free,ax
-	test	%rax,%rax
-	jz	1f
-	call	free
-1:	pop	%rbp
-	ret
-	.endfn	weakfree,globl
+/**
+ * Thunks free() if it's linked, otherwise do nothing.
+ */
+void _weakfree(void *p) {
+  if (weaken(free)) {
+    weaken(free)(p);
+  }
+}

libc/testlib/benchrunner.c

@@ -51,7 +51,7 @@ void testlib_benchwarmup(void) {
  * @see BENCH()
  */
 void testlib_runallbenchmarks(void) {
-  peekall();
+  _peekall();
   mlockall(MCL_CURRENT);
   nice(-1);
   __log_level = kLogWarn;

test/libc/release/smoke.c

@@ -6,7 +6,7 @@ int main(int argc, char *argv[]) {
   s = strdup(argv[0]);
   s[0] = 'Z';
   f = fopen("/dev/null", "w");
-  fprintf(f, "hello world %d %s\n", argc, s);
+  fputs(_gc(xasprintf("hello world %d %s\n", argc, s)), f);
   fclose(f);
   rc = system("exit 42");
   CHECK_NE(-1, rc);

test/libc/runtime/grow_test.c

@@ -46,9 +46,9 @@ TEST(grow, testStackMemory_convertsToDynamic) {
   int A[] = {1, 2, 3};
   int *p = A;
   size_t capacity = ARRAYLEN(A);
-  if (!isheap(p)) {
+  if (!_isheap(p)) {
     EXPECT_TRUE(__grow(&p, &capacity, sizeof(int), 0));
-    EXPECT_TRUE(isheap(p));
+    EXPECT_TRUE(_isheap(p));
     EXPECT_GT(capacity, ARRAYLEN(A));
     EXPECT_EQ(1, p[0]);
     EXPECT_EQ(2, p[1]);
@@ -86,9 +86,9 @@ TEST(grow, testOverflow_returnsFalseAndDoesNotFree) {
   int A[] = {1, 2, 3};
   int *p = A;
   size_t capacity = ARRAYLEN(A);
-  if (!isheap(p)) {
+  if (!_isheap(p)) {
     EXPECT_FALSE(__grow(&p, &capacity, pushpop(SIZE_MAX), 0));
-    EXPECT_FALSE(isheap(p));
+    EXPECT_FALSE(_isheap(p));
     EXPECT_EQ(capacity, ARRAYLEN(A));
     EXPECT_EQ(1, p[0]);
     EXPECT_EQ(2, p[1]);

test/libc/runtime/mmap_test.c

@@ -137,18 +137,18 @@ TEST(mmap, mapPrivate_writesDontChangeFile) {
 }
 
 TEST(isheap, nullPtr) {
-  ASSERT_FALSE(isheap(NULL));
+  ASSERT_FALSE(_isheap(NULL));
 }
 
 TEST(isheap, malloc) {
-  ASSERT_TRUE(isheap(gc(malloc(1))));
+  ASSERT_TRUE(_isheap(gc(malloc(1))));
 }
 
 TEST(isheap, emptyMalloc) {
-  ASSERT_TRUE(isheap(gc(malloc(0))));
+  ASSERT_TRUE(_isheap(gc(malloc(0))));
 }
 
 TEST(isheap, mallocOffset) {
   char *p = gc(malloc(131072));
-  ASSERT_TRUE(isheap(p + 100000));
+  ASSERT_TRUE(_isheap(p + 100000));
 }

tool/build/lib/throw.c

@@ -34,7 +34,7 @@ static bool IsHaltingInitialized(struct Machine *m) {
 
 void HaltMachine(struct Machine *m, int code) {
   CHECK(IsHaltingInitialized(m));
-  gclongjmp(m->onhalt, code);
+  _gclongjmp(m->onhalt, code);
 }
 
 void ThrowDivideError(struct Machine *m) {

tool/viz/printvideo.c

@@ -1351,7 +1351,7 @@ static void OnExit(void) {
 }
 
 static void MakeLatencyLittleLessBad(void) {
-  peekall();
+  _peekall();
   LOGIFNEG1(mlockall(MCL_CURRENT));
   LOGIFNEG1(nice(-5));
 }