meson: fix Windows build

The build fails on Windows. Replace calls to Unix programs like ´cat´,
´sed´ and ´true´ with calls to ´python´ and wrap calls to
´os.path.relpath´ in try-except because it can fail when the two paths
are on different drives. Make sure to convert the Windows paths to Unix
paths to prevent warnings in generated files.

Signed-off-by: oltolm <oleg.tolmatcev@gmail.com>
Message-id: 20250612221521.1109-2-oleg.tolmatcev@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

scripts/tracetool/backend/ftrace.py

@@ -12,8 +12,6 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@redhat.com"
 
 
-import os.path
-
 from tracetool import out
 
 
@@ -47,7 +45,7 @@ def generate_h(event, group):
         args=event.args,
         event_id="TRACE_" + event.name.upper(),
         event_lineno=event.lineno,
-        event_filename=os.path.relpath(event.filename),
+        event_filename=event.filename,
         fmt=event.fmt.rstrip("\n"),
         argnames=argnames)
 

scripts/tracetool/backend/log.py

@@ -12,8 +12,6 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@redhat.com"
 
 
-import os.path
-
 from tracetool import out
 
 
@@ -55,7 +53,7 @@ def generate_h(event, group):
         '    }',
         cond=cond,
         event_lineno=event.lineno,
-        event_filename=os.path.relpath(event.filename),
+        event_filename=event.filename,
         name=event.name,
         fmt=event.fmt.rstrip("\n"),
         argnames=argnames)

scripts/tracetool/backend/syslog.py

@@ -12,8 +12,6 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@redhat.com"
 
 
-import os.path
-
 from tracetool import out
 
 
@@ -43,7 +41,7 @@ def generate_h(event, group):
         '    }',
         cond=cond,
         event_lineno=event.lineno,
-        event_filename=os.path.relpath(event.filename),
+        event_filename=event.filename,
         name=event.name,
         fmt=event.fmt.rstrip("\n"),
         argnames=argnames)