Merge bitcoin/bitcoin#23282: build: remove build stubs for external leveldb

17ae260 build: remove build stubs for external leveldb (Cory Fields)

Pull request description:

  Presumably these stubs indicate to packagers that external leveldb is meant to be supported in some way. It is not. Remove the stubs to avoid sending any mixed messages.

  For context, this was reported on IRC:

  > \<Talkless> bitcoind fails to start with undefined symbol: _ZTIN7leveldb6LoggerE in Debian Sid after leveldb upgraded from 1.22 to 1.23: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=996486

ACKs for top commit:
  fanquake:
    ACK 17ae260
  hebasto:
    ACK 17ae260. I have reviewed the code and it looks OK, I agree it can be merged.

Tree-SHA512: 2f1ac2cb30dac64791933a245a2b66ce237bde3955e6f4a6b7ec181248f77a9b1b10597d865d3e2c2b6def696af70de40e905ec274e4ae7cccd1daf461473957

Author: fanquake

configure.ac

@@ -1219,14 +1219,6 @@ if test "x$have_any_system" != "xno"; then
   AC_DEFINE(HAVE_SYSTEM, 1, Define to 1 if std::system or ::wsystem is available.)
 fi
 
-LEVELDB_CPPFLAGS=
-LIBLEVELDB=
-LIBMEMENV=
-AM_CONDITIONAL([EMBEDDED_LEVELDB],[true])
-AC_SUBST(LEVELDB_CPPFLAGS)
-AC_SUBST(LIBLEVELDB)
-AC_SUBST(LIBMEMENV)
-
 dnl SUPPRESSED_CPPFLAGS=SUPPRESS_WARNINGS([$SOME_CPPFLAGS])
 dnl Replace -I with -isystem in $SOME_CPPFLAGS to suppress warnings from
 dnl headers from its include directories and return the result.

src/Makefile.am

@@ -841,11 +841,8 @@ nodist_libbitcoin_ipc_a_SOURCES = $(libbitcoin_ipc_mpgen_output)
 CLEANFILES += $(libbitcoin_ipc_mpgen_output)
 endif
 
-if EMBEDDED_LEVELDB
 include Makefile.crc32c.include
 include Makefile.leveldb.include
-endif
-
 include Makefile.test_util.include
 include Makefile.test_fuzz.include
 

src/Makefile.leveldb.include

@@ -8,9 +8,10 @@ LIBMEMENV_INT  = leveldb/libmemenv.a
 EXTRA_LIBRARIES += $(LIBLEVELDB_INT)
 EXTRA_LIBRARIES += $(LIBMEMENV_INT)
 
-LIBLEVELDB += $(LIBLEVELDB_INT) $(LIBCRC32C)
-LIBMEMENV += $(LIBMEMENV_INT)
+LIBLEVELDB = $(LIBLEVELDB_INT) $(LIBCRC32C)
+LIBMEMENV = $(LIBMEMENV_INT)
 
+LEVELDB_CPPFLAGS =
 LEVELDB_CPPFLAGS += -I$(srcdir)/leveldb/include
 LEVELDB_CPPFLAGS += -I$(srcdir)/leveldb/helpers/memenv