Merge pull request #35 from keszybz/autogenerate-man-page

Autogenerate man page

Author: bluca

.gitignore

@@ -11,3 +11,4 @@
 !/debian/rules
 !/debian/source/format
 __pycache__/
+/dlopen-notes.1

Makefile

@@ -1,5 +1,13 @@
 all:
 
+dlopen-notes.1: dlopen-notes.py docs/dlopen-description.man Makefile
+	argparse-manpage 	\
+		--output=$@ 	\
+		--pyfile=$< 	\
+		--function=make_parser \
+		--project-name=package-notes \
+		--include=docs/dlopen-description.man
+
 install:
 	install -m 755 -D dlopen-notes.py $(DESTDIR)/usr/bin/dlopen-notes
 

dlopen-notes.py

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: CC0-1.0
 
 """\
-Read .note.dlopen notes from ELF files and report the contents
+Read .note.dlopen notes from ELF files and report the contents.
 """
 
 import argparse
@@ -118,23 +118,43 @@ def group_by_feature(filenames, notes):
 
     return features
 
-def parse_args():
-    p = argparse.ArgumentParser(description=__doc__)
-    p.add_argument('--raw',
+def make_parser():
+    p = argparse.ArgumentParser(
+        description=__doc__,
+        allow_abbrev=False,
+        add_help=False,
+        epilog='If no option is specifed, --raw is the default.',
+    )
+    p.add_argument('-r', '--raw',
                    action='store_true',
-                   help='show the original JSON extracted from input files')
-    p.add_argument('--sonames',
+                   help='Show the original JSON extracted from input files')
+    p.add_argument('-s', '--sonames',
                    action='store_true',
-                   help='list all sonames and their priorities, one soname per line')
-    p.add_argument('--features',
+                   help='List all sonames and their priorities, one soname per line')
+    p.add_argument('-f', '--features',
                    nargs='?',
                    const=[],
                    type=lambda s: s.split(','),
                    action='extend',
                    metavar='FEATURE1,FEATURE2',
-                   help='describe features, can be specified multiple times')
-    p.add_argument('filenames', nargs='+', metavar='filename')
-    return p.parse_args()
+                   help='Describe features, can be specified multiple times')
+    p.add_argument('filenames',
+                   nargs='+',
+                   metavar='filename',
+                   help='Library file to extract notes from')
+    p.add_argument('-h', '--help',
+                   action='help',
+                   help='Show this help message and exit')
+    return p
+
+def parse_args():
+    args = make_parser().parse_args()
+
+    if not args.raw and args.features is None and not args.sonames:
+        # Make --raw the default if no action is specified.
+        args.raw = True
+
+    return args
 
 if __name__ == '__main__':
     args = parse_args()

docs/dlopen-description.man

@@ -0,0 +1,11 @@
+/report the contents/
+.PP
+ELF binaries store link-time dependencies in their headers, which can be parsed
+by various tools. There is no machine-readable metadata about dependencies
+loaded at build time via
+.BR \%dlopen (3)
+available by default. The ELF Dlopen Metadata specification aims to fill this
+gap, by defining a common format.
+.PP
+This tool allows parsing such a note, and printing out the result in various
+formats.