Allow execution under analysis tools (#207)

Performance analysis and memory debugging tools such as Perf and Valgrind do not currently work with Charm4Py's charmrun.start. This patch enables the use of charmrun.start with these tools.

Author: ZwFink

auto_test.py

@@ -69,6 +69,8 @@ def searchForPython(python_implementations):
             if num_tests >= CHARM_QUIET_AFTER_NUM_TESTS and '++quiet' not in commonArgs:
                 additionalArgs.append('++quiet')
             cmd = ['charmrun/charmrun']
+            if test.get('prefix'):
+                cmd += [test['prefix']]
             if not test.get('interactive', False):
                 cmd += [python] + [test['path']]
             else:

charmrun/start.py

@@ -3,6 +3,29 @@
 import os.path
 
 
+def executable_is_python(args):
+    """
+    Determines whether the first executable passed to args is a
+    Python file. Other valid examples include analysis tools
+    such as Perf that will run the actual Python program.
+
+    Note: Returns true if no executable was found or if an executable
+    was found and that executable is a Python file.
+    """
+    def is_exe(fpath):
+        return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
+
+    def is_pyfile(fpath):
+        return os.path.isfile(fpath) and fpath.endswith(".py")
+    for each in args:
+        if is_pyfile(each):
+            return True
+        if is_exe(each):
+            return False
+    # No executable was found, but we'll let Python tell us
+    return True
+
+
 def nodelist_islocal(filename, regexp):
     if not os.path.exists(filename):
         # it is an error if filename doesn't exist, but I'll let charmrun print
@@ -53,7 +76,11 @@ def start(args=[]):
         args += ['-m', 'charm4py.interactive']
 
     cmd = [os.path.join(os.path.dirname(__file__), 'charmrun')]
-    cmd.append(sys.executable)  # for example: /usr/bin/python3
+    if executable_is_python(args):
+        # Note: sys.executable is the absolute path to the Python interpreter
+        # We only want to invoke the interpreter if the execution target is a
+        # Python file
+        cmd.append(sys.executable)  # for example: /usr/bin/python3
     cmd.extend(args)
     try:
         return subprocess.call(cmd)

test_config.json

@@ -288,6 +288,10 @@
     {
         "path": "examples/simple/hello_world.py"
     },
+    {
+        "prefix": "tests/exec.sh",
+        "path": "examples/simple/hello_world.py"
+    },
     {
         "condition": "numbaInstalled",
         "path": "examples/wave2d/wave2d.py",

tests/exec.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+# Just execute the given command
+"$@"