Work around spurrious GCC 4.7 warning, and split RPC code into separate library.

c++/Makefile.am

@@ -163,7 +163,7 @@ includecapnp_HEADERS =                                         \
   src/capnp/generated-header-support.h                         \
   src/capnp/rpc.h
 
-lib_LTLIBRARIES = libkj.la libcapnp.la libcapnpc.la
+lib_LTLIBRARIES = libkj.la libcapnp.la libcapnp-rpc.la libcapnpc.la
 
 # -lpthread is here to work around https://bugzilla.redhat.com/show_bug.cgi?id=661333
 libkj_la_LIBADD = $(PTHREAD_LIBS) -lpthread
@@ -206,7 +206,12 @@ libcapnp_la_SOURCES=                                           \
   src/capnp/dynamic.c++                                        \
   src/capnp/stringify.c++                                      \
   src/capnp/serialize.c++                                      \
-  src/capnp/serialize-packed.c++                               \
+  src/capnp/serialize-packed.c++
+
+# -lpthread is here to work around https://bugzilla.redhat.com/show_bug.cgi?id=661333
+libcapnp_rpc_la_LIBADD = libcapnp.la libkj.la $(PTHREAD_LIBS) -lpthread
+libcapnp_rpc_la_LDFLAGS = -release $(VERSION) -no-undefined
+libcapnp_rpc_la_SOURCES=                                       \
   src/capnp/rpc.c++                                            \
   src/capnp/rpc.capnp.c++                                      \
   src/capnp/rpc.capnp.h
@@ -299,7 +304,8 @@ $(test_capnpc_outputs): test_capnpc_middleman
 BUILT_SOURCES = $(test_capnpc_outputs)
 
 check_PROGRAMS = capnp-test capnp-evolution-test
-capnp_test_LDADD = gtest/lib/libgtest.la gtest/lib/libgtest_main.la libcapnpc.la libcapnp.la libkj.la
+capnp_test_LDADD = gtest/lib/libgtest.la gtest/lib/libgtest_main.la \
+                   libcapnpc.la libcapnp-rpc.la libcapnp.la libkj.la
 capnp_test_CPPFLAGS = -Igtest/include -I$(srcdir)/gtest/include
 capnp_test_SOURCES =                                           \
   src/kj/common-test.c++                                       \

c++/src/capnp/rpc.c++

@@ -923,8 +923,11 @@ private:
       exports = kj::Vector<ExportId>(caps.getWithoutLock().size());
 
       for (auto& entry: caps.getWithoutLock()) {
-        KJ_IF_MAYBE(exportId, connectionState.writeDescriptor(
-            entry.second.cap->addRef(), entry.second.builder, tables)) {
+        // If maybeExportId is inlined, GCC 4.7 reports a spurious "may be used uninitialized"
+        // error (GCC 4.8 and Clang do not complain).
+        auto maybeExportId = connectionState.writeDescriptor(
+            entry.second.cap->addRef(), entry.second.builder, tables);
+        KJ_IF_MAYBE(exportId, maybeExportId) {
           exports.add(*exportId);
         }
       }

mega-test-quick.cfg

 linux-gcc-4.7      1564 ./super-test.sh tmpdir capnp-gcc-4.7 quick
-linux-gcc-4.8      1567 ./super-test.sh tmpdir capnp-gcc-4.8 quick gcc-4.8
-linux-clang        1581 ./super-test.sh tmpdir capnp-clang quick clang
-mac                 740 ./super-test.sh remote beat caffeinate quick
-cygwin              745 ./super-test.sh remote Kenton@flashman quick
+linux-gcc-4.8      1601 ./super-test.sh tmpdir capnp-gcc-4.8 quick gcc-4.8
+linux-clang        1615 ./super-test.sh tmpdir capnp-clang quick clang
+mac                 752 ./super-test.sh remote beat caffeinate quick
+cygwin              757 ./super-test.sh remote Kenton@flashman quick