[lldb] Inherit host environment when running shell commands

[labath]

Summary

On most hosts we were running shell commands with an empty environment.
The only exception was windows, which was inheriting the host enviroment
mostly by accident.

Running the commands in an empty environment does not sound like a
sensible default, so this patch changes Host::RunShellCommand to inherit
the host environment. This impacts both commands run via
SBPlatform::Run (in case of host platforms), as well as the "platform
shell" CLI command.

[labath]

This stems from D76835 -- when the inherit fallback on windows gets removed some tests fail bacause the can't find ls. This is used in lldbutil.wait_for_file_on_target. The inheritance was not a problem because ls is normally in the hardcoded default path, but that is not the case on windows.

[friss]

I agree host shell command should run with the host environment.

lldb/source/Host/common/Host.cpp

if (run_in_default_shell) {
     launch_info.ConvertArgumentsForLaunchingInShell(
         error, localhost, will_debug, first_arg_is_full_shell_command, 0);
   } else {
     // No shell, just run it
     const bool first_arg_is_executable = true;
     launch_info.SetArguments(args, first_arg_is_executable);
   }
 
+  launch_info.GetEnvironment() = Host::GetEnvironment();
+
   if (working_dir)
     launch_info.SetWorkingDirectory(working_dir);
   llvm::SmallString<64> output_file_path;
 
   if (command_output_ptr) {
     // Create a temporary file to get the stdout/stderr and redirect the output
     // of the command into this file. We will later read this file if all goes
     // well and fill the data into "command_output_ptr"

lldb/test/API/python_api/sbplatform/Makefile

+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/python_api/sbplatform/TestSBPlatform.py

+"""Test the SBPlatform APIs."""
+
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+
+class SBPlatformAPICase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @add_test_categories(['pyapi'])
+    def test_run(self):
+        self.build()
+        plat = lldb.SBPlatform.GetHostPlatform()
+
+        os.environ["MY_TEST_ENV_VAR"]="SBPlatformAPICase.test_run"
+        def cleanup():
+            del os.environ["MY_TEST_ENV_VAR"]
+        self.addTearDownHook(cleanup)
+        cmd = lldb.SBPlatformShellCommand(self.getBuildArtifact("a.out"))
+        self.assertTrue(plat.Run(cmd).Success())
+        self.assertIn("MY_TEST_ENV_VAR=SBPlatformAPICase.test_run", cmd.GetOutput())

lldb/test/API/python_api/sbplatform/main.cpp

+#include <cstdlib>
+#include <cstdio>
+
+int main() {
+  printf("MY_TEST_ENV_VAR=%s\n", getenv("MY_TEST_ENV_VAR"));
+
+  return 0;
+}