From 9696ee0742adc799b6c3cc949f2e3301751a4cf4 Mon Sep 17 00:00:00 2001
From: Douglas Raillard <douglas.raillard@arm.com>
Date: Tue, 4 Oct 2022 15:15:42 +0100
Subject: [PATCH 1/2] lisa._assets: Make HOST_PATH depend on
 LISA_USE_SYSTEM_BIN

FEATURE

If env var LISA_USE_SYSTEM_BIN=1, HOST_PATH will give priority to
existing PATH, otherwise it will give priority to LISA's PATH containing
the shipped binaries.

Also add get_bin() function that allows getting the path to a binary.
---
 lisa/_assets/__init__.py | 47 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 42 insertions(+), 5 deletions(-)

diff --git a/lisa/_assets/__init__.py b/lisa/_assets/__init__.py
index a66bdbb6f..69deff6da 100644
--- a/lisa/_assets/__init__.py
+++ b/lisa/_assets/__init__.py
@@ -18,6 +18,8 @@
 import os
 import stat
 import platform
+import shutil
+from pathlib import Path
 
 def _get_abi():
     machine = platform.machine()
@@ -58,14 +60,49 @@ del _get_abi_bin
 
 HOST_BINARIES = ABI_BINARIES[HOST_ABI]
 
-HOST_PATH = ':'.join((
-    os.path.join(ASSETS_PATH, 'binaries', HOST_ABI),
-    os.path.join(ASSETS_PATH, 'scripts'),
-    os.environ['PATH']
-))
+def _make_path(abi=None):
+    abi = abi or HOST_ABI
+
+    compos = [
+        os.path.join(ASSETS_PATH, 'binaries', abi),
+        os.path.join(ASSETS_PATH, 'scripts'),
+    ]
+
+    if abi == HOST_ABI:
+        path = os.environ['PATH']
+        use_system = bool(int(os.environ.get('LISA_USE_SYSTEM_BIN', 0)))
+        if use_system:
+            compos = [path] + compos
+        else:
+            compos = compos + [path]
+
+    return ':'.join(compos)
+
+HOST_PATH = _make_path(HOST_ABI)
 """
 Value to be used as the ``PATH`` env var on the host.
 """
 
+def get_bin(name, abi=None):
+    """
+    Return the path to a tool bundled in LISA.
+
+    :param abi: ABI of the binary. If ``abi`` is not the host ABI,
+        ``LISA_USE_SYSTEM_BIN`` is ignored.
+    :type abi: str or None
+
+    The result is influenced by the ``LISA_USE_SYSTEM_BIN`` environment
+    variable:
+
+        * If it is set to ``0`` or unset, it will give priority to the binaries
+          bundled inside the :mod:`lisa` package.
+        * If it is set to ``1``, it will use the bundled binaries as a fallback
+          only.
+    """
+    path = shutil.which(name, path=_make_path(abi))
+    if path:
+        return Path(path).resolve()
+    else:
+        raise FileNotFoundError(f'Could not locate the tool: {name}')
 
 # vim :set tabstop=4 shiftwidth=4 textwidth=80 expandtab
-- 
GitLab


From 962cae4440e7e1b53ecc1ebdb24afc6cf6949843 Mon Sep 17 00:00:00 2001
From: Douglas Raillard <douglas.raillard@arm.com>
Date: Tue, 4 Oct 2022 15:16:51 +0100
Subject: [PATCH 2/2] lisa.trace: Use lisa._assets.get_bin() for trace-cmd

FEATURE

Use the trace-cmd binary shipped by LISA to improve reproducibility and
for when lisa is installed from PyPI.

It is still possible to make LISA prefer the system binary by setting
LISA_USE_SYSTEM_BIN=1 environment variable.
---
 lisa/trace.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/lisa/trace.py b/lisa/trace.py
index 64b27e5b3..e27c9333e 100644
--- a/lisa/trace.py
+++ b/lisa/trace.py
@@ -60,6 +60,7 @@ from lisa.datautils import SignalDesc, df_add_delta, df_deduplicate, df_window,
 from lisa.version import VERSION_TOKEN
 from lisa._typeclass import FromString, IntListFromStringInstance
 from lisa._kmod import LISAFtraceDynamicKmod
+from lisa._assets import get_bin
 
 
 class TaskID(namedtuple('TaskID', ('pid', 'comm'))):
@@ -1567,6 +1568,8 @@ class TxtTraceParser(TxtTraceParserBase):
             be reused in another context (cached on disk), and the set of
             events in a :class:`Trace` object can be expanded dynamically.
         """
+        bin_ = get_bin('trace-cmd')
+
         if not os.path.exists(path):
             raise FileNotFoundError(f'Unable to locate specified trace file: {path}')
 
@@ -1595,7 +1598,7 @@ class TxtTraceParser(TxtTraceParserBase):
         kernel_events = {
             event.split(':', 1)[1]
             for event in subprocess.check_output(
-                ['trace-cmd', 'report', '-N', '-E', '--', path],
+                [bin_, 'report', '-N', '-E', '--', path],
                 stderr=subprocess.DEVNULL,
                 universal_newlines=True,
             ).splitlines()
@@ -1615,7 +1618,7 @@ class TxtTraceParser(TxtTraceParserBase):
             symbols_address = dict(
                 parse(line)
                 for line in subprocess.check_output(
-                    ['trace-cmd', 'report', '-N', '-f', '--', path],
+                    [bin_, 'report', '-N', '-f', '--', path],
                     stderr=subprocess.DEVNULL,
                     universal_newlines=True,
                 ).splitlines()
@@ -1629,7 +1632,7 @@ class TxtTraceParser(TxtTraceParserBase):
         if 'cpus-count' in needed_metadata:
             regex = re.compile(rb'cpus=(?P<cpus>\d+)')
             with subprocess.Popen(
-                ['trace-cmd', 'report', '-N', '--', path],
+                [bin_, 'report', '-N', '--', path],
                 stdout=subprocess.PIPE,
                 stderr=subprocess.DEVNULL,
             ) as p:
@@ -1648,7 +1651,7 @@ class TxtTraceParser(TxtTraceParserBase):
             pre_filled_metadata=pre_filled_metadata,
         )
         cmd = [
-            'trace-cmd',
+            bin_,
             'report',
             # Do not load any plugin, so that we get fully reproducible results
             '-N',
-- 
GitLab