Improve the heap limit measure tool (#2092)

Changes:
 * Added support for Python3
 * Suppressed the build output text
 * Code cleanup
 * Fixed pylint warnings

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

tools/heaplimit_measure.py

@@ -13,6 +13,9 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import print_function
+# force // operator to be integer division in Python 2
+from __future__ import division
 
 import argparse
 import json
@@ -20,75 +23,66 @@ import os
 import subprocess
 import sys
 
-from subprocess import Popen, PIPE, STDOUT
+TOOLS_PATH = os.path.dirname(os.path.realpath(__file__))
+BASE_PATH = os.path.join(TOOLS_PATH, '..')
 
-
-BIN_JERRY = os.path.join(os.getcwd(), 'build/bin/jerry')
 FLAG_CLEAN = '--clean'
 FLAG_DEBUG = '--debug'
 FLAG_HEAPLIMIT = '--mem-heap'
-JERRY_BUILDER = os.path.join(os.getcwd(), 'tools/build.py')
-TEST_DIR = os.path.join(os.getcwd(), 'tests')
+JERRY_BUILDER = os.path.join(BASE_PATH, 'tools', 'build.py')
+JERRY_BIN = os.path.join(BASE_PATH, 'build', 'bin', 'jerry')
+TEST_DIR = os.path.join(BASE_PATH, 'tests')
+
 
 def get_args():
     """ Parse input arguments. """
-    parser = argparse.ArgumentParser(description='Finds the smallest possible \
-                    size of JerryHeap without failing to run the given js file')
+    desc = 'Finds the smallest possible JerryHeap size without failing to run the given js file'
+    parser = argparse.ArgumentParser(description=desc)
     parser.add_argument('testfile')
     parser.add_argument('--heapsize', type=int, default=512,
-                         help='Set the limit of the first heapsize')
-
-    parser.add_argument('--buildtype', type=str,
-                        help='debug build, default release build')
+                        help='set the limit of the first heapsize (default: %(default)d)')
+    parser.add_argument('--buildtype', choices=['release', 'debug'], default='release',
+                        help='select build type (default: %(default)s)')
 
     script_args = parser.parse_args()
 
     return script_args
 
 
-def is_exe(fpath):
-    """ Check whether the file is exist. """
-    return os.path.isfile(fpath)
-
-
-def init(opts):
-    if not is_exe(JERRY_BUILDER):
-        sys.exit("Builder script isn't a file!")
-    if not is_exe(opts.testfile):
-        sys.exit("Testfile isn't a file!")
+def check_files(opts):
+    files = [JERRY_BUILDER, opts.testfile]
+    for file in files:
+        if not os.path.isfile(file):
+            sys.exit("File not found: %s" % file)
 
 
 def build_bin(heapsize, opts):
     """ Run tools/build.py script """
-    hsize = str(heapsize)
+    command = [
+        JERRY_BUILDER,
+        FLAG_CLEAN,
+        FLAG_HEAPLIMIT,
+        str(heapsize)
+    ]
+
     if opts.buildtype == 'debug':
-        subprocess.call([JERRY_BUILDER, FLAG_CLEAN, FLAG_HEAPLIMIT, \
-            hsize, FLAG_DEBUG])
-    else:
-        subprocess.call([JERRY_BUILDER, FLAG_CLEAN, FLAG_HEAPLIMIT, hsize])
+        command.append(FLAG_DEBUG)
 
-
-def get_output(cwd, cmd):
-    """ Run the given command and return with the output. """
-    process = Popen(cmd, stdout=PIPE, stderr=STDOUT, cwd=cwd)
-
-    output = process.communicate()[0]
-    exitcode = process.returncode
-
-    return output, exitcode
+    print('Building JerryScript with: %s' % (' '.join(command)))
+    subprocess.check_output(command)
 
 
 def run_test(opts):
-    """ Run the testfile for output and exitcode. """
+    """ Run the testfile to get the exitcode. """
     try:
         testfile = os.path.abspath(opts.testfile)
-        run_cmd = [BIN_JERRY, testfile]
-        output, ret = get_output(TEST_DIR, run_cmd)
+        run_cmd = [JERRY_BIN, testfile]
+        # check output will raise an error if the exit code is not 0
+        subprocess.check_output(run_cmd, cwd=TEST_DIR)
     except subprocess.CalledProcessError as err:
-        output = err.output
-        ret = err.returncode
+        return err.returncode
 
-    return opts.testfile, output, ret
+    return 0
 
 
 def heap_limit(opts):
@@ -99,21 +93,24 @@ def heap_limit(opts):
 
     while lowheap < hiheap:
         build_bin(hiheap, opts)
-        assert is_exe(BIN_JERRY), 'Binary file not exist'
+        assert os.path.isfile(JERRY_BIN), 'Jerry binary file does not exists'
 
-        testfile, output, exitcode = run_test(opts)
+        exitcode = run_test(opts)
         if exitcode != 0:
             lowheap = hiheap
-            hiheap = (lowheap + goodheap) / 2
+            hiheap = (lowheap + goodheap) // 2
         else:
             goodheap = hiheap
-            hiheap = (lowheap + hiheap) / 2
+            hiheap = (lowheap + hiheap) // 2
 
-    return { 'testfile': testfile, 'heaplimit to pass': goodheap }
+    return {
+        'testfile': opts.testfile,
+        'heaplimit to pass': goodheap
+    }
 
 
 def main(options):
-    init(options)
+    check_files(options)
     result = heap_limit(options)
     print(json.dumps(result, indent=4))