Implement a CMake based build system for KLEE.

This is based off intial work by @jirislaby in #481. However it
has been substantially modified.

Notably it includes a separate build sytem to build the runtimes which
is inspired by the old build system. The reason for doing this is
because CMake is not well suited for building the runtime:

* CMake is configured to use the host compiler, not the bitcode
  compiler. These are not the same thing.

* Building the runtime using `add_custom_command()` is flawed
  because we can't automatically get transitive depencies (i.e.
  header file dependencies) unless the CMake generator is makefiles.
  (See `IMPLICIT_DEPENDS` of `add_custom_command()` in CMake).

So for now we have a very simple build system for building the runtimes.
In the future we can replace this with something more sophisticated if
we need it.

Support for all features of the old build system are implemented apart
from recording the git revision and showing it in the output of
`klee --help`.

Another notable change is the CMake build system works much better with
LLVM installs which don't ship with testing tools. The build system
will download the sources for `FileCheck` and `not` tools if the
corresponding binaries aren't available and will build them. However
`lit` (availabe via `pip install lit`) and GTest must already be
installed.

Apart from better support for testing a significant advantage of the
new CMake build system compared to the existing "Autoconf/Makefile"
build system is that it is **not** coupled to LLVM's build system
(unlike the existing build system). This means that LLVM's
autoconf/Makefiles don't need to be installed somewhere on the system.

Currently all tests pass.

Support has been implemented in TravisCI and the Dockerfile for
building with CMake.

The existing "Autoconf/Makefile" build system has been left intact
and so both build systems can coexist for a short while. We should
remove the old build system as soon as possible though because it
creates an unnecessary maintance burden.

4 files changed, 202 insertions, 1 deletions

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
new file mode 100644
index 00000000..6d3ec926
--- /dev/null
+++ b/test/CMakeLists.txt
@@ -0,0 +1,139 @@
+#===------------------------------------------------------------------------===#
+#
+#                     The KLEE Symbolic Virtual Machine
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===------------------------------------------------------------------------===#
+
+set(KLEE_TOOLS_DIR "${CMAKE_BINARY_DIR}/bin")
+set(LLVM_TOOLS_DIR "${LLVM_TOOLS_BINARY_DIR}")
+# FIXME: Do this to avoid changing the template file that
+# is shared by both build systems.
+set(LLVMCC "${LLVMCC} -I${CMAKE_SOURCE_DIR}/include")
+set(LLVMCXX "${LLVMCXX} -I${CMAKE_SOURCE_DIR}/include")
+set(TARGET_TRIPLE "${TARGET_TRIPLE}")
+if (ENABLE_KLEE_UCLIBC)
+  set(ENABLE_UCLIBC 1)
+else()
+  set(ENABLE_UCLIBC 0)
+endif()
+
+# FIXME: Do this to avoid changing the template file that
+# is shared by both build systems.
+if (ENABLE_POSIX_RUNTIME)
+  if (ENABLE_KLEE_UCLIBC)
+    set(ENABLE_POSIX_RUNTIME 1)
+  else()
+    message(AUTHOR_WARNING
+      "Disabling POSIX runtime tests because they depend on klee-uclibc"
+      "\nFIXME!")
+  set(ENABLE_POSIX_RUNTIME 0)
+  endif()
+else()
+  set(ENABLE_POSIX_RUNTIME 0)
+endif()
+
+###############################################################################
+# Find LLVM testing tools
+###############################################################################
+option(DOWNLOAD_LLVM_TESTING_TOOLS "Always download LLVM testing tools sources" OFF)
+mark_as_advanced(DOWNLOAD_LLVM_TESTING_TOOLS)
+
+# Check `FileCheck` and the `not` tools are available.  By default we'll try
+# looking in the LLVM binary directory.  If that fails download the sources.
+# This might be necessary if using a shipped version of LLVM because LLVM
+# unfortunately does not ship its testing tools.
+set(DOWNLOAD_FILECHECK_SOURCE FALSE)
+set(DOWNLOAD_NOT_SOURCE FALSE)
+
+if (DOWNLOAD_LLVM_TESTING_TOOLS)
+  set(DOWNLOAD_FILECHECK_SOURCE TRUE)
+  set(DOWNLOAD_NOT_SOURCE TRUE)
+endif()
+
+if (NOT EXISTS "${LLVM_TOOLS_BINARY_DIR}/FileCheck")
+  message(WARNING "\"${LLVM_TOOLS_BINARY_DIR}/FileCheck\" does not exist. Downloading sources.")
+  set(DOWNLOAD_FILECHECK_SOURCE TRUE)
+endif()
+
+if (NOT EXISTS "${LLVM_TOOLS_BINARY_DIR}/not")
+  message(WARNING "\"${LLVM_TOOLS_BINARY_DIR}/not\" does not exist. Downloading sources.")
+  set(DOWNLOAD_NOT_SOURCE TRUE)
+endif()
+
+if (DOWNLOAD_FILECHECK_SOURCE)
+  set(FILECHECK_SRC_URL "https://raw.githubusercontent.com/llvm-mirror/llvm/release_${LLVM_VERSION_MAJOR}${LLVM_VERSION_MINOR}/utils/FileCheck/FileCheck.cpp")
+  set(FILECHECK_SRC_FILE "${CMAKE_CURRENT_BINARY_DIR}/FileCheck.cpp")
+  if (NOT EXISTS "${FILECHECK_SRC_URL}")
+    message(STATUS "Downloading LLVM FileCheck source")
+    file(DOWNLOAD "${FILECHECK_SRC_URL}" "${FILECHECK_SRC_FILE}" SHOW_PROGRESS)
+  endif()
+  add_executable(FileCheck
+    ${FILECHECK_SRC_FILE}
+  )
+  klee_get_llvm_libs(FILECHECK_NEEDED_LIBS Support)
+  target_include_directories(FileCheck PRIVATE ${KLEE_COMPONENT_EXTRA_INCLUDE_DIRS})
+  target_compile_options(FileCheck PRIVATE ${KLEE_COMPONENT_CXX_FLAGS})
+  target_compile_definitions(FileCheck PRIVATE ${KLEE_COMPONENT_CXX_DEFINES})
+  target_link_libraries(FileCheck PRIVATE ${FILECHECK_NEEDED_LIBS})
+endif()
+
+if (DOWNLOAD_NOT_SOURCE)
+  set(NOT_SRC_URL "https://raw.githubusercontent.com/llvm-mirror/llvm/release_${LLVM_VERSION_MAJOR}${LLVM_VERSION_MINOR}/utils/not/not.cpp")
+  set(NOT_SRC_FILE "${CMAKE_CURRENT_BINARY_DIR}/not.cpp")
+  if (NOT EXISTS "${NOT_SRC_FILE}")
+    message(STATUS "Downloading LLVM not source")
+    file(DOWNLOAD "${NOT_SRC_URL}" "${NOT_SRC_FILE}" SHOW_PROGRESS)
+  endif()
+  add_executable("not"
+    ${NOT_SRC_FILE}
+  )
+  klee_get_llvm_libs(NOT_NEEDED_LIBS Support)
+  target_include_directories("not" PRIVATE ${KLEE_COMPONENT_EXTRA_INCLUDE_DIRS})
+  target_compile_options("not" PRIVATE ${KLEE_COMPONENT_CXX_FLAGS})
+  target_compile_definitions("not" PRIVATE ${KLEE_COMPONENT_CXX_DEFINES})
+  target_link_libraries("not" PRIVATE ${FILECHECK_NEEDED_LIBS})
+endif()
+
+###############################################################################
+# Concrete tests build system
+###############################################################################
+add_subdirectory(Concrete)
+
+###############################################################################
+# Configure lit test suite
+###############################################################################
+configure_file(lit.site.cfg.in
+  ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
+  @ONLY
+)
+
+add_custom_target(integrationtests
+  COMMAND "${LIT_TOOL}" ${LIT_ARGS} "${CMAKE_CURRENT_BINARY_DIR}"
+  DEPENDS klee kleaver
+  COMMENT "Running integration tests"
+  ${ADD_CUSTOM_COMMAND_USES_TERMINAL_ARG}
+)
+
+# Tell CMake to remove lit's output directories when
+# running `make clean`.
+file(GLOB_RECURSE
+  test_contents
+  LIST_DIRECTORIES true
+  RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}"
+  "*"
+)
+set(dirs_to_clean "")
+foreach (f ${test_contents})
+  if (IS_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/${f}")
+    list(APPEND dirs_to_clean "${CMAKE_CURRENT_BINARY_DIR}/${f}/Output")
+  endif()
+endforeach()
+set_property(
+  DIRECTORY
+  APPEND
+  PROPERTY ADDITIONAL_MAKE_CLEAN_FILES
+  ${dirs_to_clean}
+)
diff --git a/test/Concrete/CMakeLists.txt b/test/Concrete/CMakeLists.txt
new file mode 100644
index 00000000..b3e4948f
--- /dev/null
+++ b/test/Concrete/CMakeLists.txt
@@ -0,0 +1,9 @@
+#===------------------------------------------------------------------------===#
+#
+#                     The KLEE Symbolic Virtual Machine
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===------------------------------------------------------------------------===#
+configure_file(Makefile.cmake.test.in Makefile.cmake.test @ONLY)
diff --git a/test/Concrete/ConcreteTest.py b/test/Concrete/ConcreteTest.py
index 754c0fe6..66d18c83 100755
--- a/test/Concrete/ConcreteTest.py
+++ b/test/Concrete/ConcreteTest.py
@@ -8,11 +8,16 @@ import sys
 import shutil
 
 def testFile(name, klee_path, lli_path):
+    print("CWD: \"{}\"".format(os.getcwd()))
     baseName,ext = os.path.splitext(name)
     exeFile = 'Output/linked_%s.bc'%baseName
 
     print('-- building test bitcode --')
-    make_cmd = 'make %s 2>&1' % (exeFile,)
+    if os.path.exists("Makefile.cmake.test"):
+        # Prefer CMake generated make file
+        make_cmd = 'make -f Makefile.cmake.test %s 2>&1' % (exeFile,)
+    else:
+        make_cmd = 'make %s 2>&1' % (exeFile,)
     print("EXECUTING: %s" % (make_cmd,))
     sys.stdout.flush()
     if os.system(make_cmd):
diff --git a/test/Concrete/Makefile.cmake.test.in b/test/Concrete/Makefile.cmake.test.in
new file mode 100644
index 00000000..feb879de
--- /dev/null
+++ b/test/Concrete/Makefile.cmake.test.in
@@ -0,0 +1,48 @@
+#===------------------------------------------------------------------------===#
+#
+#                     The KLEE Symbolic Virtual Machine
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===------------------------------------------------------------------------===#
+#
+# @AUTO_GEN_MSG@
+#
+#===------------------------------------------------------------------------===#
+LLVMCC := @LLVMCC@
+LLVMAS := @LLVM_AS@
+LLVMLINK := @LLVM_LINK@
+LLVMCC.CFlags := -O0 -Wall
+
+# Make sure source files can match the pattern rules
+VPATH := @CMAKE_CURRENT_SOURCE_DIR@
+
+Output/.dir:
+	mkdir -p $@
+
+clean::
+	-rm -rf Output/
+
+Output/%.bc: %.c Output/.dir
+	$(LLVMCC) -emit-llvm -c $(LLVMCC.CFlags) $< -o $@
+
+Output/%.bc: %.ll $(LLVMAS) Output/.dir
+	$(LLVMAS) -f $< -o $@
+
+# We build a separate testingUtils bitcode for each test, to make sure parallel
+# tests don't interact with one another.
+Output/%_testingUtils.bc: _testingUtils.c Output/.dir
+	$(LLVMCC) -emit-llvm -c $(LLVMCC.CFlags) $< -o $@
+
+Output/linked_%.bc: Output/%.bc Output/%_testingUtils.bc
+	$(LLVMLINK) $< Output/$*_testingUtils.bc -o $@
+
+.PRECIOUS: Output/.dir
+
+## Cancel built-in implicit rules that override above rules
+%: %.s
+
+%: %.c
+
+%.o: %.c