add comment to static_init_test.cpp for DEBUG=1 and MCL_USE_GMP=1

Makefile

@@ -15,7 +15,10 @@ TEST_SRC+=modp_test.cpp
 TEST_SRC+=ecdsa_test.cpp ecdsa_c_test.cpp
 TEST_SRC+=mul_test.cpp
 TEST_SRC+=bint_test.cpp
-TEST_SRC+=low_func_test.cpp static_init_test.cpp
+TEST_SRC+=low_func_test.cpp
+ifneq ($(MCL_USE_GMP),1)
+  TEST_SRC+=static_init_test.cpp
+endif
 TEST_SRC+=invmod_test.cpp
 LIB_OBJ=$(OBJ_DIR)/fp.o
 ifeq ($(MCL_STATIC_CODE),1)

common.mk

@@ -128,7 +128,7 @@ CFLAGS+=$(CFLAGS_USER)
 ifneq ($(MCL_SIZEOF_UNIT),)
   CFLAGS+=-DMCL_SIZEOF_UNIT=$(MCL_SIZEOF_UNIT)
 endif
-MCL_USE_GMP?=1
+MCL_USE_GMP?=0
 ifeq ($(MCL_USE_GMP),1)
   GMP_LIB=-lgmp -lgmpxx
   ifeq ($(UNAME_S),Darwin)

test/static_init_test.cpp

@@ -1,3 +1,7 @@
+/*
+	If the binary compiled with DEBUG=1 and MCL_USE_GMP=1 calls init in a constructor of a static value,
+	then it will show GMP memory leaks, but this is a rare case.
+*/
 #define CYBOZU_TEST_DISABLE_AUTO_RUN
 #include <cybozu/test.hpp>
 #include <mcl/bn256.hpp>