[compiler-rt] [test] Fix NameError when loading lit.cfg.py for crt

[broadwaylamb]

Summary

The execute_external global variable is defined in [lit.common.cfg.py](https://github.com/llvm/llvm-project/blob/fcfb3170a776f89dde4de8ee105c99e10660f455/compiler-rt/test/lit.common.cfg.py#L18-L27) and used here (on lines 23 and 39). However, this variable is not visible in configs that are loaded independently.

Explicitly assign it to the correct value to avoid NameError.

[compnerd]

compiler-rt/test/crt/lit.cfg.py

12

I don't think that we should try to dig through the test_format type if possible. Why not replicate the check for LIT_USE_INTERNAL_SHELL?

[broadwaylamb]

Copy the logic of setting execute_external from lit.common.cfg.py.

[broadwaylamb]

ping

[broadwaylamb]

ping

[broadwaylamb]

@compnerd can I ask you to take a look?

[phosek]

LGTM

[phosek]

Do you have commit permissions or do you need us to land this for you?

[broadwaylamb]

In D79892#2072039, @phosek wrote:

Do you have commit permissions or do you need us to land this for you?

I’ll commit it, thanks

compiler-rt/test/crt/lit.cfg.py

 # -*- Python -*-
 
 import os
 import subprocess
 
 # Setup config name.
 config.name = 'CRT' + config.name_suffix
 
 # Setup source root.
 config.test_source_root = os.path.dirname(__file__)
 
 
+# Choose between lit's internal shell pipeline runner and a real shell.  If
+# LIT_USE_INTERNAL_SHELL is in the environment, we use that as an override.
+use_lit_shell = os.environ.get("LIT_USE_INTERNAL_SHELL")
+if use_lit_shell:
+    # 0 is external, "" is default, and everything else is internal.
+    execute_external = (use_lit_shell == "0")
+else:
+    # Otherwise we default to internal on Windows and external elsewhere, as
+    # bash on Windows is usually very slow.
+    execute_external = (not sys.platform in ['win32'])
+
 def get_library_path(file):
     cmd = subprocess.Popen([config.clang.strip(),
                             config.target_cflags.strip(),
                             '-print-file-name=%s' % file],
                            stdout=subprocess.PIPE,
                            env=config.environment)
     if not cmd.stdout:
       lit_config.fatal("Couldn't find the library path for '%s'" % file)