[tools] Make not tool respect environment variables

The not utility did not capture the parent's environment variables
on POSIX platforms. This has been fixed. Tests have also been added 
for the utility - even for basic functionality.

Author: tarunprabhu

tools/CMakeLists.txt

@@ -41,3 +41,7 @@ else()
 endif()
 
 add_executable(not ${CMAKE_CURRENT_SOURCE_DIR}/not.cpp)
+
+# Always add the test subdirectory. After all, we really should test these
+# tools.
+add_subdirectory(test)

tools/not.cpp

@@ -58,7 +58,8 @@ int main(int argc, char* const* argv) {
 
 #if defined(__unix__) || defined(__APPLE__)
   pid_t pid;
-  if (posix_spawn(&pid, argv[0], NULL, NULL, argv, NULL))
+  extern char** environ;
+  if (posix_spawn(&pid, argv[0], NULL, NULL, argv, environ))
     return EXIT_FAILURE;
   if (waitpid(pid, &result, WUNTRACED | WCONTINUED) == -1)
     return EXIT_FAILURE;

tools/test/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Copy these files to the build directory so that the tests can be run even
+# without the source directory.
+configure_file(test_not.sh test_not.sh
+  @ONLY)
+
+add_executable(ret1 ret1.c)
+llvm_test_run(EXECUTABLE "%b/not" "%b/test/ret1")
+llvm_add_test_for_target(ret1)
+
+add_executable(ret0 ret0.c)
+llvm_test_run(EXECUTABLE "%b/not" "%b/not" "%b/test/ret0")
+llvm_add_test_for_target(ret0)
+
+# Check that expected crashes are handled correctly.
+add_executable(abrt abort.c)
+llvm_test_run(EXECUTABLE "%b/not" "--crash" "%b/test/abrt")
+llvm_add_test_for_target(abrt)
+
+# Check that not passes environment variables to the called executable.
+add_executable(check_env check_env.c)
+llvm_test_run(EXECUTABLE "/bin/bash" "%b/test/test_not.sh %b")
+llvm_add_test(test_not.test test_not.sh)

tools/test/abort.c

@@ -0,0 +1,5 @@
+#include <stdlib.h>
+
+int main(int argc, char* argv[]) {
+  abort();
+}

tools/test/check_env.c

@@ -0,0 +1,11 @@
+#include <stdlib.h>
+
+int main(int argc, char* argv[]) {
+  // SET_IN_PARENT will have been set in by the driver, test_not.sh.
+  // NOT_IN_PARENT will not have been set. Calling getenv with the former will
+  // return non-NULL, the latter will return NULL. If both conditions are true,
+  // this will return non-zero (which is an "error" code). This is intentional
+  // because this will be passed to not which expects an error code.
+
+  return getenv("SET_IN_PARENT") && !getenv("NOT_IN_PARENT");
+}

tools/test/ret0.c

@@ -0,0 +1,3 @@
+int main(int argc, char* argv[]) {
+  return 0;
+}

tools/test/ret1.c

@@ -0,0 +1,3 @@
+int main(int argc, char* argv[]) {
+  return 1;
+}

tools/test/test_not.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env sh
+#
+# USAGE: test_not.sh ${bindir}
+#
+# where bindir is ${CMAKE_BINARY_DIR}/tools
+
+export SET_IN_PARENT="something"
+$1/not $1/test/check_env