Merge bitcoin#682: Remove Java Native Interface

642cd06 Remove Java Native Interface (Jonas Nick)

Pull request description:

  This was discussed in bitcoin#508. The main reasons are that the existing Java Native Interface (JNI) bindings would need way more work to remain useful to Java developers but the maintainers and regular contributors of libsecp are not very familiar with Java (and evidently are motivated enough to improve the situation). We don't know who relies on these bindings with the exception of ACINQ who have their own fork at https://github.com/ACINQ/secp256k1/tree/jni-embed/src/java (@sstone). Bitcoinj can optionally use the libsecp bindings.

  Ideally, there would be a separate repository owned by Java developers with just the bindings. Until this exists, Java developers relying on libsecp can use ACINQs fork or an older commit of libsecp.

ACKs for top commit:
  real-or-random:
    ACK 642cd06 I read the diff
  real-or-random:
    ACK 642cd06 I read the diff, and I verified that the diff to 7d9066a66c0f13cabb0c4f71aca30edd3494f0d5, which has been ACKed by sipa, is only the additonal removal of ax_jni_include_dir.m4

Tree-SHA512: 9e573f2b01897bd5f301707062b41de53424517b537ce0834d9049d003cfd73fa1bcc024b543256016e4c9a1126f7c7fef559b84dc4914083b5a2d0ad5e57ea8

.travis.yml

@@ -6,13 +6,9 @@ addons:
 compiler:
   - clang
   - gcc
-cache:
-  directories:
-  - src/java/guava/
 env:
   global:
-    - FIELD=auto  BIGNUM=auto  SCALAR=auto  ENDOMORPHISM=no  STATICPRECOMPUTATION=yes  ECMULTGENPRECISION=auto  ASM=no  BUILD=check  EXTRAFLAGS=  HOST=  ECDH=no  RECOVERY=no  EXPERIMENTAL=no  JNI=no
-    - GUAVA_URL=https://search.maven.org/remotecontent?filepath=com/google/guava/guava/18.0/guava-18.0.jar GUAVA_JAR=src/java/guava/guava-18.0.jar
+    - FIELD=auto  BIGNUM=auto  SCALAR=auto  ENDOMORPHISM=no  STATICPRECOMPUTATION=yes  ECMULTGENPRECISION=auto  ASM=no  BUILD=check  EXTRAFLAGS=  HOST=  ECDH=no  RECOVERY=no  EXPERIMENTAL=no
   matrix:
     - SCALAR=32bit    RECOVERY=yes
     - SCALAR=32bit    FIELD=32bit       ECDH=yes  EXPERIMENTAL=yes
@@ -29,7 +25,6 @@ env:
     - BUILD=distcheck
     - EXTRAFLAGS=CPPFLAGS=-DDETERMINISTIC
     - EXTRAFLAGS=CFLAGS=-O0
-    - BUILD=check-java JNI=yes ECDH=yes EXPERIMENTAL=yes
     - ECMULTGENPRECISION=2
     - ECMULTGENPRECISION=8
 matrix:
@@ -78,14 +73,12 @@ matrix:
           packages:
             - valgrind
 
-before_install: mkdir -p `dirname $GUAVA_JAR`
-install: if [ ! -f $GUAVA_JAR ]; then wget $GUAVA_URL -O $GUAVA_JAR; fi
 before_script: ./autogen.sh
 
 script:
  - if [ -n "$HOST" ]; then export USE_HOST="--host=$HOST"; fi
  - if [ "x$HOST" = "xi686-linux-gnu" ]; then export CC="$CC -m32"; fi
- - ./configure --enable-experimental=$EXPERIMENTAL --enable-endomorphism=$ENDOMORPHISM --with-field=$FIELD --with-bignum=$BIGNUM --with-asm=$ASM --with-scalar=$SCALAR --enable-ecmult-static-precomputation=$STATICPRECOMPUTATION --with-ecmult-gen-precision=$ECMULTGENPRECISION --enable-module-ecdh=$ECDH --enable-module-recovery=$RECOVERY --enable-jni=$JNI $EXTRAFLAGS $USE_HOST
+ - ./configure --enable-experimental=$EXPERIMENTAL --enable-endomorphism=$ENDOMORPHISM --with-field=$FIELD --with-bignum=$BIGNUM --with-asm=$ASM --with-scalar=$SCALAR --enable-ecmult-static-precomputation=$STATICPRECOMPUTATION --with-ecmult-gen-precision=$ECMULTGENPRECISION --enable-module-ecdh=$ECDH --enable-module-recovery=$RECOVERY $EXTRAFLAGS $USE_HOST
  - if [ -n "$BUILD" ]; then make -j2 $BUILD; fi
  - # travis_wait extends the 10 minutes without output allowed (https://docs.travis-ci.com/user/common-build-problems/#build-times-out-because-no-output-was-received)
  - # the `--error-exitcode` is required to make the test fail if valgrind found errors, otherwise it'll return 0 (http://valgrind.org/docs/manual/manual-core.html)

Makefile.am

@@ -1,12 +1,6 @@
 ACLOCAL_AMFLAGS = -I build-aux/m4
 
 lib_LTLIBRARIES = libsecp256k1.la
-if USE_JNI
-JNI_LIB = libsecp256k1_jni.la
-noinst_LTLIBRARIES = $(JNI_LIB)
-else
-JNI_LIB =
-endif
 include_HEADERS = include/secp256k1.h
 include_HEADERS += include/secp256k1_preallocated.h
 noinst_HEADERS =
@@ -40,8 +34,6 @@ noinst_HEADERS += src/field_5x52.h
 noinst_HEADERS += src/field_5x52_impl.h
 noinst_HEADERS += src/field_5x52_int128_impl.h
 noinst_HEADERS += src/field_5x52_asm_impl.h
-noinst_HEADERS += src/java/org_bitcoin_NativeSecp256k1.h
-noinst_HEADERS += src/java/org_bitcoin_Secp256k1Context.h
 noinst_HEADERS += src/util.h
 noinst_HEADERS += src/scratch.h
 noinst_HEADERS += src/scratch_impl.h
@@ -75,10 +67,7 @@ endif
 
 libsecp256k1_la_SOURCES = src/secp256k1.c
 libsecp256k1_la_CPPFLAGS = -DSECP256K1_BUILD -I$(top_srcdir)/include -I$(top_srcdir)/src $(SECP_INCLUDES)
-libsecp256k1_la_LIBADD = $(JNI_LIB) $(SECP_LIBS) $(COMMON_LIB)
-
-libsecp256k1_jni_la_SOURCES  = src/java/org_bitcoin_NativeSecp256k1.c src/java/org_bitcoin_Secp256k1Context.c
-libsecp256k1_jni_la_CPPFLAGS = -DSECP256K1_BUILD $(JNI_INCLUDES)
+libsecp256k1_la_LIBADD = $(SECP_LIBS) $(COMMON_LIB)
 
 noinst_PROGRAMS =
 if USE_BENCHMARK
@@ -120,36 +109,6 @@ exhaustive_tests_LDFLAGS = -static
 TESTS += exhaustive_tests
 endif
 
-JAVAROOT=src/java
-JAVAORG=org/bitcoin
-JAVA_GUAVA=$(srcdir)/$(JAVAROOT)/guava/guava-18.0.jar
-CLASSPATH_ENV=CLASSPATH=$(JAVA_GUAVA)
-JAVA_FILES= \
-  $(JAVAROOT)/$(JAVAORG)/NativeSecp256k1.java \
-  $(JAVAROOT)/$(JAVAORG)/NativeSecp256k1Test.java \
-  $(JAVAROOT)/$(JAVAORG)/NativeSecp256k1Util.java \
-  $(JAVAROOT)/$(JAVAORG)/Secp256k1Context.java
-
-if USE_JNI
-
-$(JAVA_GUAVA):
-	@echo Guava is missing. Fetch it via: \
-	wget https://search.maven.org/remotecontent?filepath=com/google/guava/guava/18.0/guava-18.0.jar -O $(@)
-	@false
-
-.stamp-java: $(JAVA_FILES)
-	@echo   Compiling $^
-	$(AM_V_at)$(CLASSPATH_ENV) javac $^
-	@touch $@
-
-if USE_TESTS
-
-check-java: libsecp256k1.la $(JAVA_GUAVA) .stamp-java
-	$(AM_V_at)java -Djava.library.path="./:./src:./src/.libs:.libs/" -cp "$(JAVA_GUAVA):$(JAVAROOT)" $(JAVAORG)/NativeSecp256k1Test
-
-endif
-endif
-
 if USE_ECMULT_STATIC_PRECOMPUTATION
 CPPFLAGS_FOR_BUILD +=-I$(top_srcdir) -I$(builddir)/src
 
@@ -169,10 +128,10 @@ $(bench_ecmult_OBJECTS): src/ecmult_static_context.h
 src/ecmult_static_context.h: $(gen_context_BIN)
 	./$(gen_context_BIN)
 
-CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h $(JAVAROOT)/$(JAVAORG)/*.class .stamp-java
+CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h
 endif
 
-EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h $(JAVA_FILES)
+EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h
 
 if ENABLE_MODULE_ECDH
 include src/modules/ecdh/Makefile.am.include

configure.ac

@@ -139,11 +139,6 @@ AC_ARG_ENABLE(external_default_callbacks,
     [use_external_default_callbacks=$enableval],
     [use_external_default_callbacks=no])
 
-AC_ARG_ENABLE(jni,
-    AS_HELP_STRING([--enable-jni],[enable libsecp256k1_jni [default=no]]),
-    [use_jni=$enableval],
-    [use_jni=no])
-
 AC_ARG_WITH([field], [AS_HELP_STRING([--with-field=64bit|32bit|auto],
 [finite field implementation to use [default=auto]])],[req_field=$withval], [req_field=auto])
 
@@ -472,29 +467,6 @@ else
   fi
 fi
 
-if test x"$use_jni" != x"no"; then
-  AX_JNI_INCLUDE_DIR
-  have_jni_dependencies=yes
-  if test x"$enable_module_ecdh" = x"no"; then
-    have_jni_dependencies=no
-  fi
-  if test "x$JNI_INCLUDE_DIRS" = "x"; then
-    have_jni_dependencies=no
-  fi
-  if test "x$have_jni_dependencies" = "xno"; then
-    if test x"$use_jni" = x"yes"; then
-      AC_MSG_ERROR([jni support explicitly requested but headers/dependencies were not found. Enable ECDH and try again.])
-    fi
-    AC_MSG_WARN([jni headers/dependencies not found. jni support disabled])
-    use_jni=no
-  else
-    use_jni=yes
-    for JNI_INCLUDE_DIR in $JNI_INCLUDE_DIRS; do
-      JNI_INCLUDES="$JNI_INCLUDES -I$JNI_INCLUDE_DIR"
-    done
-  fi
-fi
-
 if test x"$set_bignum" = x"gmp"; then
   SECP_LIBS="$SECP_LIBS $GMP_LIBS"
   SECP_INCLUDES="$SECP_INCLUDES $GMP_CPPFLAGS"
@@ -543,7 +515,6 @@ fi
 
 AC_CONFIG_HEADERS([src/libsecp256k1-config.h])
 AC_CONFIG_FILES([Makefile libsecp256k1.pc])
-AC_SUBST(JNI_INCLUDES)
 AC_SUBST(SECP_INCLUDES)
 AC_SUBST(SECP_LIBS)
 AC_SUBST(SECP_TEST_LIBS)
@@ -555,7 +526,6 @@ AM_CONDITIONAL([USE_BENCHMARK], [test x"$use_benchmark" = x"yes"])
 AM_CONDITIONAL([USE_ECMULT_STATIC_PRECOMPUTATION], [test x"$set_precomp" = x"yes"])
 AM_CONDITIONAL([ENABLE_MODULE_ECDH], [test x"$enable_module_ecdh" = x"yes"])
 AM_CONDITIONAL([ENABLE_MODULE_RECOVERY], [test x"$enable_module_recovery" = x"yes"])
-AM_CONDITIONAL([USE_JNI], [test x"$use_jni" = x"yes"])
 AM_CONDITIONAL([USE_EXTERNAL_ASM], [test x"$use_external_asm" = x"yes"])
 AM_CONDITIONAL([USE_ASM_ARM], [test x"$set_asm" = x"arm"])
 
@@ -571,7 +541,6 @@ echo "Build Options:"
 echo "  with endomorphism       = $use_endomorphism"
 echo "  with ecmult precomp     = $set_precomp"
 echo "  with external callbacks = $use_external_default_callbacks"
-echo "  with jni                = $use_jni"
 echo "  with benchmarks         = $use_benchmark"
 echo "  with coverage           = $enable_coverage"
 echo "  module ecdh             = $enable_module_ecdh"