Allow tcc to run with bounds checking enabled

tcc failed to run with bounds checking enabled because the functions
rt_wait_sem, rt_post_sem and _rt_error where defined twice.
This is solved by making them weak in tccrun.c

Also a nested lock was present when setting TCC_BOUNDS_PRINT_CALLS=1
This is solved in lib/bt-exe.c by moving lock/unlock code.

Also added a testcase in tests/Makefile to test tcc with bounds
checking enabled.

lib/bt-exe.c

@@ -18,7 +18,6 @@ void __bt_init(rt_context *p, int is_exe)
     __attribute__((weak)) int main();
     __attribute__((weak)) void __bound_init(void*, int);
 
-    WAIT_SEM(&rt_sem);
     //fprintf(stderr, "__bt_init %d %p %p %p\n", is_exe, p, p->stab_sym, p->bounds_start), fflush(stderr);
 
     /* call __bound_init here due to redirection of sigaction */
@@ -27,13 +26,14 @@ void __bt_init(rt_context *p, int is_exe)
 	__bound_init(p->bounds_start, -1);
 
     /* add to chain */
+    WAIT_SEM(&rt_sem);
     p->next = g_rc, g_rc = p;
-    if (is_exe) {
+    if (is_exe)
         /* we are the executable (not a dll) */
         p->top_func = main;
-        set_exception_handler();
-    }
     POST_SEM(&rt_sem);
+    if (is_exe)
+        set_exception_handler();
 }
 
 __declspec(dllexport)
@@ -42,13 +42,13 @@ void __bt_exit(rt_context *p)
     struct rt_context *rc, **pp;
     __attribute__((weak)) void __bound_exit_dll(void*);
 
-    WAIT_SEM(&rt_sem);
     //fprintf(stderr, "__bt_exit %d %p\n", !!p->top_func, p);
 
     if (p->bounds_start)
 	__bound_exit_dll(p->bounds_start);
 
     /* remove from chain */
+    WAIT_SEM(&rt_sem);
     for (pp = &g_rc; rc = *pp, rc; pp = &rc->next)
         if (rc == p) {
             *pp = rc->next;

tccrun.c

@@ -66,9 +66,15 @@ TCC_SEM(static rt_sem);
 static int signal_set;
 static void set_exception_handler(void);
 
-int _rt_error(rt_frame *f, const char *msg, const char *fmt, va_list ap);
+#ifdef _WIN32
-void rt_wait_sem(void) { WAIT_SEM(&rt_sem); }
+#define	ATTR_WEAK
-void rt_post_sem(void) { POST_SEM(&rt_sem); }
+#else
+#define	ATTR_WEAK	__attribute__((weak))
+#endif
+int ATTR_WEAK _rt_error(rt_frame *f, const char *msg, const char *fmt, va_list ap);
+void ATTR_WEAK rt_wait_sem(void) { WAIT_SEM(&rt_sem); }
+void ATTR_WEAK rt_post_sem(void) { POST_SEM(&rt_sem); }
+#undef ATTR_WEAK
 #endif /* def CONFIG_TCC_BACKTRACE */
 
 /* handle exit/atexit for tcc_run() -- thread-unsafe */

tests/Makefile

@@ -28,6 +28,9 @@ TESTS = \
 
 ifneq ($(CONFIG_bcheck),no)
  TESTS += btest test1b
+ ifndef CONFIG_WIN32
+  TESTS += tccb
+ endif
 endif
 ifeq ($(CONFIG_dll),no)
  TESTS := $(filter-out dlltest, $(TESTS))
@@ -198,6 +201,13 @@ btest: boundtest.c
 	done ;\
 	echo Bound test OK
 
+tccb:
+	@echo ------------ $@ ------------
+	$(TCC) -b $(TOPSRC)/tcc.c $(TCCFLAGS) $(NATIVE_DEFINES) -o v1-tcc$(EXESUF)
+	mv v1-tcc$(EXESUF) v2-tcc$(EXESUF)
+	./v2-tcc$(EXESUF) -b $(TOPSRC)/tcc.c $(TCCFLAGS) $(NATIVE_DEFINES) -o v1-tcc$(EXESUF)
+	cmp -s v1-tcc$(EXESUF) v2-tcc$(EXESUF) && echo "Bound-Test tcc OK"
+
 # speed test
 speedtest: ex2 ex3
 	@echo ------------ $@ ------------
@@ -260,7 +270,7 @@ vla_test-run: vla_test$(EXESUF)
 	@echo ------------ $@ ------------
 	./vla_test$(EXESUF)
 
-.PHONY: abitest vla_test
+.PHONY: abitest vla_test tccb
 
 asm-c-connect$(EXESUF): asm-c-connect-1.c asm-c-connect-2.c
 	$(TCC) -o $@ $^