Coverage support: build with --enable-coverage to have tests run with gcov

If you pass the --enable-coverage flag on the command line, we build
our testing binaries with appropriate options eo enable coverage
testing.  We also build a "tor-cov" binary that has coverage enabled,
for integration tests.

On recent OSX versions, test coverage only works with clang, not gcc.
So we warn about that.

Also add a contrib/coverage script to actually run gcov with the
appropriate options to generate useful .gcov files.  (Thanks to
automake, the .o files will not have the names that gcov expects to
find.)

Also, remove generated gcda and gcno files on clean.

.gitignore

@@ -152,6 +152,8 @@
 /src/or/or_sha1.i
 /src/or/tor
 /src/or/tor.exe
+/src/or/tor-cov
+/src/or/tor-cov.exe
 /src/or/libtor.a
 /src/or/libtor-testing.a
 /src/or/libtor.lib

Makefile.am

@@ -32,6 +32,12 @@ EXTRA_DIST+= \
 	README						\
 	ReleaseNotes
 
+if COVERAGE_ENABLED
+TEST_CFLAGS=-fno-inline -fprofile-arcs -ftest-coverage
+else
+TEST_CFLAGS=
+endif
+
 #install-data-local:
 #	$(INSTALL) -m 755 -d $(LOCALSTATEDIR)/lib/tor
 
@@ -89,3 +95,5 @@ version:
 	   (cd "$(top_srcdir)" && git rev-parse --short=16 HEAD); \
 	fi
 
+mostlyclean-local:
+	rm -f src/*/*.gc{da,no}

changes/fancy_testing

@@ -10,3 +10,7 @@
       in the unit tests; all functions exposed from a module for
       unit-testing only are now static in production builds.
 
+    - Add an --enable-coverage configuration option to make the unit
+      tests (and a new src/or/tor-cov target) to build with gcov test
+      coverage support.
+

configure.ac

@@ -41,8 +41,13 @@ AC_ARG_ENABLE(curve25519,
    AS_HELP_STRING(--disable-curve25519, Build Tor with no curve25519 elliptic-curve crypto support))
 AC_ARG_ENABLE(unittests,
    AS_HELP_STRING(--disable-unittests, [Don't build unit tests for Tor. Risky!]))
+AC_ARG_ENABLE(coverage,
+   AS_HELP_STRING(--enable-coverage, [Enable coverage support in the unit-test build]))
 
-AM_CONDITIONAL(UNITTESTS_ENABLED, test x$unittests != xno)
+AM_CONDITIONAL(UNITTESTS_ENABLED, test x$enable_unittests != xno)
+AM_CONDITIONAL(COVERAGE_ENABLED, test x$enable_coverage = xyes)
+
+echo "COVERAGE: $enable_coverage"
 
 if test "$enable_static_tor" = "yes"; then
   enable_static_libevent="yes";
@@ -1457,7 +1462,12 @@ if test x$enable_gcc_warnings = xyes || test x$enable_gcc_warnings_advisory = xy
 # CFLAGS="$CFLAGS -Winline"
 fi
 
-
+if test "$enable_coverage" = yes && test "$have_clang" = "no"; then
+   case "$host_os" in
+    darwin*)
+      AC_MSG_WARN([Tried to enable coverage on OSX without using the clang compiler. This might not work! If coverage fails, use CC=clang when configuring with --enable-profiling.])
+   esac
+fi
 
 CPPFLAGS="$CPPFLAGS $TOR_CPPFLAGS_libevent $TOR_CPPFLAGS_openssl $TOR_CPPFLAGS_zlib"
 

contrib/coverage

+#!/bin/sh
+# Copyright 2013  The Tor Project, Inc.
+# See LICENSE for licensing information.
+
+# coverage -- run gcov on the appropriate set of object files to extract
+# coverage information.
+
+for fn in src/{or,common}/*.c; do
+    BN=`basename $fn`
+    DN=`dirname $fn`
+    F=`echo $BN | sed -e 's/\.c$//;'`
+    gcov -o $DN/src_*$F.o $fn
+done

src/common/include.am

@@ -82,6 +82,10 @@ src_common_libor_event_testing_a_SOURCES = $(LIBOR_EVENT_A_SOURCES)
 src_common_libor_testing_a_CPPFLAGS = -DTOR_UNIT_TESTS $(AM_CPPFLAGS)
 src_common_libor_crypto_testing_a_CPPFLAGS = -DTOR_UNIT_TESTS $(AM_CPPFLAGS)
 src_common_libor_event_testing_a_CPPFLAGS = -DTOR_UNIT_TESTS $(AM_CPPFLAGS)
+src_common_libor_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
+src_common_libor_crypto_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
+src_common_libor_event_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
+
 
 COMMONHEADERS = \
   src/common/address.h				\

src/or/include.am

@@ -5,6 +5,9 @@ if UNITTESTS_ENABLED
 noinst_LIBRARIES += \
 	src/or/libtor-testing.a
 endif
+if COVERAGE_ENABLED
+noinst_PROGRAMS+= src/or/tor-cov
+endif
 
 if BUILD_NT_SERVICES
 tor_platform_source=src/or/ntmain.c
@@ -99,6 +102,7 @@ AM_CPPFLAGS += -DSHARE_DATADIR="\"$(datadir)\"" \
         -DBINDIR="\"$(bindir)\""
 
 src_or_libtor_testing_a_CPPFLAGS = -DTOR_UNIT_TESTS $(AM_CPPFLAGS)
+src_or_libtor_testing_a_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
 
 # -L flags need to go in LDFLAGS. -l flags need to go in LDADD.
 # This seems to matter nowhere but on windows, but I assure you that it
@@ -112,6 +116,18 @@ src_or_tor_LDADD = src/or/libtor.a src/common/libor.a \
 	@TOR_ZLIB_LIBS@ @TOR_LIB_MATH@ @TOR_LIBEVENT_LIBS@ @TOR_OPENSSL_LIBS@ \
 	@TOR_LIB_WS32@ @TOR_LIB_GDI@ @CURVE25519_LIBS@
 
+if COVERAGE_ENABLED
+src_or_tor_cov_SOURCES = src/or/tor_main.c
+src_or_tor_cov_CPPFLAGS = -DTOR_UNIT_TESTS $(AM_CPPFLAGS)
+src_or_tor_cov_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
+src_or_tor_cov_LDFLAGS = @TOR_LDFLAGS_zlib@ @TOR_LDFLAGS_openssl@ @TOR_LDFLAGS_libevent@
+src_or_tor_cov_LDADD = src/or/libtor-testing.a src/common/libor-testing.a \
+	src/common/libor-crypto-testing.a $(LIBDONNA) \
+	src/common/libor-event-testing.a \
+	@TOR_ZLIB_LIBS@ @TOR_LIB_MATH@ @TOR_LIBEVENT_LIBS@ @TOR_OPENSSL_LIBS@ \
+	@TOR_LIB_WS32@ @TOR_LIB_GDI@ @CURVE25519_LIBS@
+endif
+
 ORHEADERS = \
 	src/or/addressmap.h				\
 	src/or/buffers.h				\

src/test/include.am

@@ -31,6 +31,8 @@ src_test_test_SOURCES = \
 	src/test/test_config.c \
 	src/ext/tinytest.c
 
+src_test_test_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
+
 src_test_test_CPPFLAGS= $(src_test_AM_CPPFLAGS)
 
 src_test_bench_SOURCES = \