utils: Introduce CHECK and DCHECK debugging features

CHECK is same as assert, but dumps stacktrace before stopped.

However, DCHECK is only compiled when DEBUG=1 is on in debug mode build.
Otherwise, it's simply ignored and doesn't make any overhead.

It would be better if we add more assertion like statements with CHECK
and DCHECK.

Here is the example output.

  /home/honggyu/work/uftrace/cmds/report.c:98: add_remaining_fstack: CHECK `root' failed.
  Stack trace:
    #0 uftrace() [0x40ffed]
    #1 uftrace() [0x410542]
    #2 uftrace() [0x410827]
    #3 uftrace(command_report+0x374) [0x4118d5]
    #4 uftrace(main+0x4f7) [0x40c7c5]
    #5 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7f1552007830]
    #6 uftrace(_start+0x29) [0x40a0d9]

  Please report this uftrace internal bug to https://github.com/namhyung/uftrace/issues
  Aborted (core dumped)

Signed-off-by: Honggyu Kim <[email protected]>

Makefile

@@ -85,9 +85,9 @@ LIB_LDFLAGS        = $(COMMON_LDFLAGS) $(LDFLAGS_$@) $(LDFLAGS_lib) -Wl,--no-und
 TEST_LDFLAGS       = $(COMMON_LDFLAGS) -L$(objdir)/libtraceevent -ltraceevent
 
 ifeq ($(DEBUG), 1)
-  COMMON_CFLAGS += -O0 -g -rdynamic
+  COMMON_CFLAGS += -O0 -g -DDEBUG_MODE=1 -rdynamic
 else
-  COMMON_CFLAGS += -O2 -g
+  COMMON_CFLAGS += -O2 -g -DDEBUG_MODE=0
 endif
 
 ifeq ($(TRACE), 1)

utils/utils.h

@@ -376,4 +376,24 @@ void dump_stacktrace(void **buffer, int nptrs);
 		dump_stacktrace(buffer, nptrs);				\
 	} while (0)
 
+#define CHECK(cond) 							\
+	if (unlikely(!(cond))) { 					\
+		pr_red("%s:%d: %s: CHECK `%s' failed.\n",		\
+			__FILE__, __LINE__, __func__, #cond);		\
+		stacktrace();						\
+		pr_red("Please report this uftrace internal bug to " 	\
+		       "https://github.com/namhyung/uftrace/issues");	\
+		abort();						\
+	}
+
+#define DCHECK(cond) 							\
+	if (DEBUG_MODE && unlikely(!(cond))) { 				\
+		pr_red("%s:%d: %s: DCHECK `%s' failed.\n",		\
+			__FILE__, __LINE__, __func__, #cond);		\
+		stacktrace();						\
+		pr_red("Please report this uftrace internal bug to " 	\
+		       "https://github.com/namhyung/uftrace/issues");	\
+		abort();						\
+	}
+
 #endif /* UFTRACE_UTILS_H */