Test a few cmake option combinations before the build.

This takes a few seconds but allows us to cover cases that aren't checked
often.

CMakeLists.txt

@@ -596,11 +596,11 @@ endif()
 #
 ################################################################################
 
-find_program(SH NAMES sh dash bash zsh)
+find_program(SHELL NAMES sh dash bash zsh)
 
-if(SH)
+if(SHELL)
   execute_process(
-    COMMAND ${SH} ${toxcore_SOURCE_DIR}/other/version-sync
+    COMMAND ${SHELL} ${toxcore_SOURCE_DIR}/other/version-sync
       ${toxcore_SOURCE_DIR}
       ${PROJECT_VERSION_MAJOR}
       ${PROJECT_VERSION_MINOR}
@@ -615,7 +615,7 @@ endif()
 
 function(make_version_script header ns lib)
   execute_process(
-    COMMAND ${SH} -c "egrep '^\\w' ${header} | grep '${ns}_[a-z0-9_]*(' | grep -v '^typedef' | grep -o '${ns}_[a-z0-9_]*(' | egrep -o '\\w+' | sort -u"
+    COMMAND ${SHELL} -c "egrep '^\\w' ${header} | grep '${ns}_[a-z0-9_]*(' | grep -v '^typedef' | grep -o '${ns}_[a-z0-9_]*(' | egrep -o '\\w+' | sort -u"
     OUTPUT_VARIABLE ${lib}_SYMS
     OUTPUT_STRIP_TRAILING_WHITESPACE)
   string(REPLACE "\n" ";" ${lib}_SYMS ${${lib}_SYMS})
@@ -641,7 +641,7 @@ if(WIN32 OR APPLE)
   set(STRICT_ABI OFF)
 endif()
 
-if(STRICT_ABI AND SH)
+if(STRICT_ABI AND SHELL AND ENABLE_SHARED)
   if(BUILD_TOXAV)
     make_version_script(${toxcore_SOURCE_DIR}/toxav/toxav.h toxav toxav)
   endif()

cmake/ModulePackage.cmake

@@ -2,6 +2,14 @@ option(ENABLE_SHARED "Build shared (dynamic) libraries for all modules" ON)
 option(ENABLE_STATIC "Build static libraries for all modules" ON)
 option(COMPILE_AS_CXX "Compile all C code as C++ code" OFF)
 
+if(NOT ENABLE_SHARED AND NOT ENABLE_STATIC)
+  message(WARNING
+    "Both static and shared libraries are disabled; "
+    "enabling only shared libraries. Use -DENABLE_SHARED or -DENABLE_STATIC to "
+    "select one manually.")
+  set(ENABLE_SHARED ON)
+endif()
+
 find_package(PkgConfig REQUIRED)
 
 if(COMPILE_AS_CXX)

other/travis/toxcore-script

@@ -3,9 +3,26 @@
 # Enable test coverage recording.
 export CFLAGS="$CFLAGS -fprofile-arcs -ftest-coverage"
 
+set_opt() {
+  opts="$opts -D$1="`expr ON \& \( $i % 2 \) \| OFF`
+  set +e # result can be 0
+  i=`expr $i / 2`
+  set -e
+}
+
+# Try some combinations of cmake options.
+for i in `seq 0 7`; do
+  set +x
+  opts="$CMAKE_EXTRA_FLAGS -DWARNINGS=OFF"
+  set_opt STRICT_ABI
+  set_opt ENABLE_STATIC
+  set_opt ENABLE_SHARED
+  set -x
+  RUN $CMAKE -B$BUILD_DIR -H. $opts
+  rm -rf $BUILD_DIR
+done
+
 # Build toxcore and run tests.
-# TODO(iphydf): Enable ASAN. It currently has some bad interactions with gcov,
-# so it's disabled on Travis.
 RUN $CMAKE                                      \
   -B$BUILD_DIR                                  \
   -H.                                           \