Refactor travis build to use clang's sanitizers

- Valgrind configuration removed
- Fix errors reported by the undefined behavior sanitizer
- Travis will now run two build steps:
  - A normal build of a shared library for unit testing(in parallel with gcc)
  - A clang build with some sanitizers enabled for integration testing.

After these changes travis will run much faster, while providing valgrind-like
error detection.

9 files changed, 122 insertions, 51 deletions

diff --git a/.gitignore b/.gitignore
index 03ced918a5..e33b0ba01e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,8 @@
 # Build/deps dir
 /build/
+/dist/
 /.deps/
+/tmp/
 
 *.rej
 *.orig
diff --git a/.travis.yml b/.travis.yml
index 2346f865e1..99de0aeaf4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,8 @@
 language: c
-script: ./scripts/travis.sh
-before_install:
-  - sudo apt-get install valgrind
 compiler:
   - clang
   - gcc
+before_install:
+  - sudo ./scripts/travis-setup.sh 
+script:
+  - ./scripts/travis.sh
diff --git a/.valgrind.supp b/.valgrind.supp
deleted file mode 100644
index a0a96518ba..0000000000
--- a/.valgrind.supp
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-   nss_parse_service_list
-   Memcheck:Leak
-   fun:malloc
-   fun:nss_parse_service_list
-   fun:__nss_database_lookup
-}
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c2a2b71915..c5b59ce403 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,12 +10,7 @@ set(NEOVIM_VERSION_PATCH 0)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
-# If the C compiler is some GNU-alike, use the gnu99 standard and enable all warnings.
-if(CMAKE_COMPILER_IS_GNUCC)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror -Wall -Wextra -pedantic -Wno-unused-parameter -std=gnu99")
-elseif(CMAKE_C_COMPILER_ID MATCHES "Clang")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror -Wall -Wextra -pedantic -Wno-unused-parameter -std=gnu99")
-endif(CMAKE_COMPILER_IS_GNUCC)
+add_definitions(-Werror -Wall -Wextra -pedantic -Wno-unused-parameter -std=gnu99)
 
 add_definitions(-DHAVE_CONFIG_H)
 if(CMAKE_BUILD_TYPE MATCHES Debug)
@@ -25,11 +20,6 @@ else()
   set(DEBUG 0)
 endif()
 
-if(DEFINED ENV{VALGRIND_CHECK})
-  message(STATUS "Defining EXITFREE for valgrind checks")
-  add_definitions(-DEXITFREE)
-endif()
-
 # Modules used by platform auto-detection
 include(CheckLibraryExists)
 
diff --git a/scripts/travis-setup.sh b/scripts/travis-setup.sh
new file mode 100755
index 0000000000..437659dd77
--- /dev/null
+++ b/scripts/travis-setup.sh
@@ -0,0 +1,19 @@
+#!/bin/sh -e
+
+# [ "$CC" != "clang" ] && exit
+
+add-apt-repository -y ppa:ubuntu-toolchain-r/ppa
+wget -O - http://llvm.org/apt/llvm-snapshot.gpg.key | apt-key add -
+
+cat > /etc/apt/sources.list.d/clang.list << "EOF"
+deb http://llvm.org/apt/precise/ llvm-toolchain-precise main
+deb-src http://llvm.org/apt/precise/ llvm-toolchain-precise main
+# 3.4
+deb http://llvm.org/apt/precise/ llvm-toolchain-precise-3.4 main
+deb-src http://llvm.org/apt/precise/ llvm-toolchain-precise-3.4 main
+# Common
+deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu precise main
+EOF
+
+apt-get -qq update
+apt-get -qq -y --no-install-recommends install clang-3.4 lldb-3.4
diff --git a/scripts/travis.sh b/scripts/travis.sh
index 7292953710..fb5a770863 100755
--- a/scripts/travis.sh
+++ b/scripts/travis.sh
@@ -1,21 +1,49 @@
 #!/bin/sh -e
 
-export VALGRIND_CHECK=1
-export BUSTED_OUTPUT_TYPE="TAP"
-make cmake CMAKE_EXTRA_FLAGS="-DCMAKE_INSTALL_PREFIX=$PWD/dist"
-make
-make unittest
-echo "Running tests with valgrind..."
-if ! make test; then
-	if ls src/testdir/valgrind.* > /dev/null 2>&1; then
-		echo "Memory leak detected" >&2 
-		cat src/testdir/valgrind.*
-	else
-		echo "Failed tests:" >&2 
-		for t in src/testdir/*.failed; do
-			echo ${t%%.*}
-		done	
+check_and_report() {
+	reset
+	(
+	cd $tmpdir
+	if [ -f asan.* ] || [ -f tsan.* ] || [ -f ubsan.* ]; then
+		cat $tmpdir/asan.* 2> /dev/null || true
+	 	cat $tmpdir/tsan.* 2> /dev/null || true
+	 	cat $tmpdir/ubsan.* 2> /dev/null || true
+		exit 1
 	fi
-	exit 1
+	)
+}
+
+if [ "$CC" = "clang" ]; then
+	# force using the version installed by 'travis-setup.sh'
+	export CC=/usr/bin/clang
+
+	install_dir="$(pwd)/dist"
+	# temporary directory for writing sanitizer logs
+	tmpdir="$(pwd)/tmp"
+	rm -rf "$tmpdir"
+	mkdir -p "$tmpdir"
+
+	# need the symbolizer path for stack traces with source information
+	symbolizer=/usr/bin/llvm-symbolizer-3.4
+
+	export SKIP_UNITTEST=1
+	export SANITIZE=1
+	export ASAN_SYMBOLIZER_PATH=$symbolizer
+	export ASAN_OPTIONS="detect_leaks=1:log_path=$tmpdir/asan"
+	export TSAN_OPTIONS="external_symbolizer_path=$symbolizer:log_path=$tmpdir/tsan"
+	export UBSAN_OPTIONS="log_path=$tmpdir/ubsan" # not sure if this works
+
+	make cmake CMAKE_EXTRA_FLAGS="-DCMAKE_INSTALL_PREFIX=$install_dir"
+	make
+	if ! make test; then
+		check_and_report
+	fi
+	check_and_report
+	make install
+else
+	export BUSTED_OUTPUT_TYPE="TAP"
+	export SKIP_EXEC=1
+	make cmake
+	make unittest
 fi
-make install
+
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 359a9f5180..fecfea8cdf 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -12,8 +12,25 @@ list(APPEND NEOVIM_SOURCES "${PROJECT_BINARY_DIR}/config/auto/pathdef.c")
 
 file( GLOB OS_SOURCES os/*.c )
 
-add_executable (nvim ${NEOVIM_SOURCES} ${OS_SOURCES})
-add_library (nvim-test MODULE ${NEOVIM_SOURCES} ${OS_SOURCES})
+if(CMAKE_C_COMPILER_ID MATCHES "Clang")
+  if(DEFINED ENV{SANITIZE})
+    message(STATUS "Enabling the sanitizers")
+    add_definitions(-DEXITFREE) # is this necessary for LeakSanitizer?
+    add_definitions(-fno-sanitize-recover -fno-omit-frame-pointer
+      -fno-optimize-sibling-calls -fsanitize=address -fsanitize=undefined)
+    set(CMAKE_EXE_LINKER_FLAGS
+      "-fsanitize=address -fsanitize=undefined ${CMAKE_EXE_LINKER_FLAGS}")
+    set(CMAKE_SHARED_LINKER_FLAGS
+      "-fsanitize=address -fsanitize=undefined ${CMAKE_SHARED_LINKER_FLAGS}")
+  endif()
+endif()
+
+if(NOT DEFINED ENV{SKIP_EXEC})
+  add_executable (nvim ${NEOVIM_SOURCES} ${OS_SOURCES})
+endif()
+if(NOT DEFINED ENV{SKIP_UNITTEST})
+  add_library (nvim-test MODULE ${NEOVIM_SOURCES} ${OS_SOURCES})
+endif()
 
 # The libraries we link against for nvim
 set(NVIM_LINK_LIBRARIES m ${LibUV_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
@@ -28,27 +45,46 @@ if (LibIntl_FOUND)
   list(APPEND NVIM_LINK_LIBRARIES ${LibIntl_LIBRARY})
 endif()
 
-target_link_libraries (nvim ${NVIM_LINK_LIBRARIES})
-target_link_libraries (nvim-test ${NVIM_LINK_LIBRARIES})
+if(NOT DEFINED ENV{SKIP_EXEC})
+  target_link_libraries (nvim ${NVIM_LINK_LIBRARIES})
+endif()
+if(NOT DEFINED ENV{SKIP_UNITTEST})
+  target_link_libraries (nvim-test ${NVIM_LINK_LIBRARIES})
+endif()
 
 include(CheckLibraryExists)
 check_library_exists(termcap tgetent "" HAVE_LIBTERMCAP)
 
 if (HAVE_LIBTERMCAP)
-  target_link_libraries(nvim termcap)
-  target_link_libraries(nvim-test termcap)
+
+  if(NOT DEFINED ENV{SKIP_EXEC})
+    target_link_libraries(nvim termcap)
+  endif()
+  if(NOT DEFINED ENV{SKIP_UNITTEST})
+    target_link_libraries(nvim-test termcap)
+  endif()
 else()
   check_library_exists(curses tgetent "" HAVE_LIBCURSES)
   if (HAVE_LIBCURSES)
-    target_link_libraries(nvim curses)
-    target_link_libraries(nvim-test curses)
+    if(NOT DEFINED ENV{SKIP_EXEC})
+      target_link_libraries(nvim curses)
+    endif()
+    if(NOT DEFINED ENV{SKIP_UNITTEST})
+      target_link_libraries(nvim-test curses)
+    endif()
   else()
     find_package(Curses REQUIRED)
-    target_link_libraries(nvim ${CURSES_LIBRARIES})
-    target_link_libraries(nvim-test ${CURSES_LIBRARIES})
+    if(NOT DEFINED ENV{SKIP_EXEC})
+      target_link_libraries(nvim ${CURSES_LIBRARIES})
+    endif()
+    if(DEFINED ENV{SKIP_UNITTEST})
+      target_link_libraries(nvim-test ${CURSES_LIBRARIES})
+    endif()
   endif()
 endif()
 
 include_directories ("${PROJECT_SOURCE_DIR}/src/proto") 
 
-install(TARGETS nvim RUNTIME DESTINATION bin)
+if(NOT DEFINED ENV{SKIP_EXEC})
+  install(TARGETS nvim RUNTIME DESTINATION bin)
+endif()
diff --git a/src/eval.c b/src/eval.c
index b164912c1c..d5ed1b1e04 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -4275,7 +4275,7 @@ eval6 (
         else if (op == '/') {
           /* We rely on the floating point library to handle divide
            * by zero to result in "inf" and not a crash. */
-          f1 = f1 / f2;
+          f1 = f2 != 0 ? f1 / f2 : INFINITY;
         } else   {
           EMSG(_("E804: Cannot use '%' with Float"));
           return FAIL;
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 68b5727786..c4da8d65e7 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -2834,8 +2834,10 @@ do_ecmd (
            * <VN> We could instead free the synblock
            * and re-attach to buffer, perhaps.
            */
-          if (curwin->w_s == &(curwin->w_buffer->b_s))
+          if (curwin->w_buffer != NULL &&
+              curwin->w_s == &(curwin->w_buffer->b_s))
             curwin->w_s = &(buf->b_s);
+
           curwin->w_buffer = buf;
           curbuf = buf;
           ++curbuf->b_nwindows;