[Qemu-devel] [PATCH v3 0/5] tracetool: Python 2.4 compatibility fixes

[Qemu-devel] [PATCH v3 0/5] tracetool: Python 2.4 compatibility fixes

[Stefan Hajnoczi]

The new Python tracetool implementation works great but does not run on older
Python installations.  This series takes us back to the happy days of Python
2.4, which was released in 2004.

As a result tracetool should now work again on Mac OS X v10.5.8, OpenIndiana
oi_151a, Solaris 10 U9, and Red Hat Enterprise Linux 5.

I added a new patch which should make --list-backends work on Python <2.7 now.

Thanks for everyone's help testing on these platforms.

v2:
 * Use nicer version check Python expression [Lluís]
 * Avoid pkgutil.iter_modules() [Andreas]

v3:
 * Fix missing sys.exit() in configure check [Lluís]

Stefan Hajnoczi (5):
  tracetool: use Python 2.4-compatible exception handling syntax
  tracetool: use Python 2.4-compatible __import__() arguments
  tracetool: avoid str.rpartition() Python 2.5 function
  tracetool: avoid pkgutil.iter_modules() Python 2.7 function
  configure: check for supported Python 2.x versions

 configure                             |    7 ++++---
 scripts/tracetool.py                  |    4 ++--
 scripts/tracetool/__init__.py         |   19 +++++++++++--------
 scripts/tracetool/backend/__init__.py |    8 ++++++--
 scripts/tracetool/format/__init__.py  |    8 ++++++--
 5 files changed, 29 insertions(+), 17 deletions(-)

-- 
1.7.10

[Qemu-devel] [PATCH v3 1/5] tracetool: use Python 2.4-compatible exception handling syntax

[Stefan Hajnoczi]

The newer "except <exception-type> as <exception>:" syntax is not
supported by Python 2.4, we need to use "except <exception-type>,
<exception>:".

Tested all trace backends with Python 2.4.

Reported-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool.py |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index cacfd99..c003cf6 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -70,7 +70,7 @@ def main(args):
 
     try:
         opts, args = getopt.getopt(args[1:], "", long_opts)
-    except getopt.GetoptError as err:
+    except getopt.GetoptError, err:
         error_opt(str(err))
 
     check_backend = False
@@ -131,7 +131,7 @@ def main(args):
     try:
         tracetool.generate(sys.stdin, arg_format, arg_backend,
                            binary = binary, probe_prefix = probe_prefix)
-    except tracetool.TracetoolError as e:
+    except tracetool.TracetoolError, e:
         error_opt(str(e))
 
 if __name__ == "__main__":
-- 
1.7.10

[Qemu-devel] [PATCH v3 2/5] tracetool: use Python 2.4-compatible __import__() arguments

[Stefan Hajnoczi]

In Python 2.5 keyword arguments were added to __import__().  Avoid using
them to achieve Python 2.4 compatibility.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool/__init__.py |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index 74fe21b..49858c9 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -204,7 +204,7 @@ def try_import(mod_name, attr_name = None, attr_default = None):
     object or attribute value.
     """
     try:
-        module = __import__(mod_name, fromlist=["__package__"])
+        module = __import__(mod_name, globals(), locals(), ["__package__"])
         if attr_name is None:
             return True, module
         return True, getattr(module, str(attr_name), attr_default)
-- 
1.7.10

[Qemu-devel] [PATCH v3 3/5] tracetool: avoid str.rpartition() Python 2.5 function

[Stefan Hajnoczi]

The str.rpartition() function is related to str.split() and is used for
splitting strings.  It was introduced in Python 2.5 and therefore cannot
be used in tracetool as Python 2.4 compatibility is required.

Replace the code using str.rsplit().

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool/__init__.py |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index 49858c9..175df08 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -64,14 +64,17 @@ class Arguments:
         res = []
         for arg in arg_str.split(","):
             arg = arg.strip()
-            parts = arg.split()
-            head, sep, tail = parts[-1].rpartition("*")
-            parts = parts[:-1]
-            if tail == "void":
-                assert len(parts) == 0 and sep == ""
+            if arg == 'void':
                 continue
-            arg_type = " ".join(parts + [ " ".join([head, sep]).strip() ]).strip()
-            res.append((arg_type, tail))
+
+            if '*' in arg:
+                arg_type, identifier = arg.rsplit('*', 1)
+                arg_type += '*'
+                identifier = identifier.strip()
+            else:
+                arg_type, identifier = arg.rsplit(None, 1)
+
+            res.append((arg_type, identifier))
         return Arguments(res)
 
     def __iter__(self):
-- 
1.7.10

[Qemu-devel] [PATCH v3 4/5] tracetool: avoid pkgutil.iter_modules() Python 2.7 function

[Stefan Hajnoczi]

The pkgutil.iter_modules() function provides a way to enumerate child
modules.  Unfortunately it's missing in Python <2.7 so we must implement
similar behavior ourselves.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool/backend/__init__.py |    8 ++++++--
 scripts/tracetool/format/__init__.py  |    8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/scripts/tracetool/backend/__init__.py b/scripts/tracetool/backend/__init__.py
index 34b7ed8..be43472 100644
--- a/scripts/tracetool/backend/__init__.py
+++ b/scripts/tracetool/backend/__init__.py
@@ -37,7 +37,7 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@linux.vnet.ibm.com"
 
 
-import pkgutil
+import os
 
 import tracetool
 
@@ -45,7 +45,11 @@ import tracetool
 def get_list():
     """Get a list of (name, description) pairs."""
     res = [("nop", "Tracing disabled.")]
-    for _, modname, _ in pkgutil.iter_modules(tracetool.backend.__path__):
+    modnames = []
+    for filename in os.listdir(tracetool.backend.__path__[0]):
+        if filename.endswith('.py') and filename != '__init__.py':
+            modnames.append(filename.rsplit('.', 1)[0])
+    for modname in modnames:
         module = tracetool.try_import("tracetool.backend." + modname)
 
         # just in case; should never fail unless non-module files are put there
diff --git a/scripts/tracetool/format/__init__.py b/scripts/tracetool/format/__init__.py
index 0e4baf0..3c2a0d8 100644
--- a/scripts/tracetool/format/__init__.py
+++ b/scripts/tracetool/format/__init__.py
@@ -41,7 +41,7 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@linux.vnet.ibm.com"
 
 
-import pkgutil
+import os
 
 import tracetool
 
@@ -49,7 +49,11 @@ import tracetool
 def get_list():
     """Get a list of (name, description) pairs."""
     res = []
-    for _, modname, _ in pkgutil.iter_modules(tracetool.format.__path__):
+    modnames = []
+    for filename in os.listdir(tracetool.format.__path__[0]):
+        if filename.endswith('.py') and filename != '__init__.py':
+            modnames.append(filename.rsplit('.', 1)[0])
+    for modname in modnames:
         module = tracetool.try_import("tracetool.format." + modname)
 
         # just in case; should never fail unless non-module files are put there
-- 
1.7.10

[Qemu-devel] [PATCH v3 5/5] configure: check for supported Python 2.x versions

[Stefan Hajnoczi]

The tracetool code requires Python 2.4, which was released in 2004.
Check for a supported Python version so we can give a clear error
message.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 configure |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/configure b/configure
index 25697bb..ccffd87 100755
--- a/configure
+++ b/configure
@@ -1247,9 +1247,10 @@ fi
 
 # Note that if the Python conditional here evaluates True we will exit
 # with status 1 which is a shell 'false' value.
-if ! "$python" -c 'import sys; sys.exit(sys.version_info[0] >= 3)'; then
-  echo "Python 2 required but '$python' is version 3 or better."
-  echo "Use --python=/path/to/python to specify a Python 2."
+if ! "$python" -c 'import sys; sys.exit(sys.version_info < (2,4) or sys.version_info >= (3,))'; then
+  echo "Cannot use '$python', Python 2.4 or later is required."
+  echo "Note that Python 3 or later is not yet supported."
+  echo "Use --python=/path/to/python to specify a supported Python."
   exit 1
 fi
 
-- 
1.7.10

Re: [Qemu-devel] [PATCH v3 5/5] configure: check for supported Python 2.x versions

[Lluís Vilanova]

Stefan Hajnoczi writes:

> The tracetool code requires Python 2.4, which was released in 2004.
> Check for a supported Python version so we can give a clear error
> message.

> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Reviewed-by: Lluís Vilanova <vilanova@ac.upc.edu>

> ---
>  configure |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

> diff --git a/configure b/configure
> index 25697bb..ccffd87 100755
> --- a/configure
> +++ b/configure
> @@ -1247,9 +1247,10 @@ fi
 
>  # Note that if the Python conditional here evaluates True we will exit
>  # with status 1 which is a shell 'false' value.
> -if ! "$python" -c 'import sys; sys.exit(sys.version_info[0] >= 3)'; then
> -  echo "Python 2 required but '$python' is version 3 or better."
> -  echo "Use --python=/path/to/python to specify a Python 2."
> +if ! "$python" -c 'import sys; sys.exit(sys.version_info < (2,4) or sys.version_info >= (3,))'; then
> +  echo "Cannot use '$python', Python 2.4 or later is required."
> +  echo "Note that Python 3 or later is not yet supported."
> +  echo "Use --python=/path/to/python to specify a supported Python."
>    exit 1
>  fi
 
> -- 
> 1.7.10


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 "And it's much the same thing with knowledge, for whenever you learn
 something new, the whole world becomes that much richer."
 -- The Princess of Pure Reason, as told by Norton Juster in The Phantom
 Tollbooth