QPDFArgParser: support adding/printing help information

1 files changed, 85 insertions, 1 deletions

diff --git a/generate_auto_job b/generate_auto_job
index 2dc51105..556b374c 100755
--- a/generate_auto_job
+++ b/generate_auto_job
@@ -19,7 +19,7 @@ def warn(*args, **kwargs):
 
 
 class Main:
-    SOURCES = [whoami, 'job.yml']
+    SOURCES = [whoami, 'job.yml', 'manual/cli.rst']
     DESTS = {
         'decl': 'libqpdf/qpdf/auto_job_decl.hh',
         'init': 'libqpdf/qpdf/auto_job_init.hh',
@@ -87,6 +87,88 @@ class Main:
             for k, v in hashes.items():
                 print(f'{k} {v}', file=f)
 
+    def generate_doc(self, df, f):
+        st_top = 0
+        st_topic = 1
+        st_option = 2
+        st_option_help = 3
+        state = st_top
+
+        indent = None
+        topic = None
+        option = None
+        short_text = None
+        long_text = None
+
+        print('this->ap.addHelpFooter("For detailed help, visit'
+              ' the qpdf manual: https://qpdf.readthedocs.io\\n");', file=f)
+
+        def set_indent(x):
+            nonlocal indent
+            indent = ' ' * len(x)
+
+        def append_long_text(line):
+            nonlocal indent, long_text
+            if line == '\n':
+                long_text += '\n'
+            elif line.startswith(indent):
+                long_text += line[len(indent):]
+            else:
+                long_text = long_text.strip()
+                if long_text != '':
+                    long_text += '\n'
+                return True
+            return False
+
+        lineno = 0
+        for line in df.readlines():
+            lineno += 1
+            if state == st_top:
+                m = re.match(r'^(\s*\.\. )help-topic (\S+): (.*)$', line)
+                if m:
+                    set_indent(m.group(1))
+                    topic = m.group(2)
+                    short_text = m.group(3)
+                    long_text = ''
+                    state = st_topic
+                    continue
+                m = re.match(r'^(\s*\.\. )qpdf:option:: (([^=\s]+)(=(\S+))?)$',
+                             line)
+                if m:
+                    if topic is None:
+                        raise Exception('option seen before topic')
+                    set_indent(m.group(1))
+                    option = m.group(3)
+                    synopsis = m.group(2)
+                    if synopsis.endswith('`'):
+                        raise Exception(
+                            f'stray ` at end of option line (line {lineno})')
+                    if synopsis != option:
+                        long_text = synopsis + '\n'
+                    else:
+                        long_text = ''
+                    state = st_option
+                    continue
+            elif state == st_topic:
+                if append_long_text(line):
+                    print(f'this->ap.addHelpTopic("{topic}", "{short_text}",'
+                          f' R"({long_text})");', file=f)
+                    state = st_top
+            elif state == st_option:
+                if line == '\n' or line.startswith(indent):
+                    m = re.match(r'^(\s*\.\. )help: (.*)$', line)
+                    if m:
+                        set_indent(m.group(1))
+                        short_text = m.group(2)
+                        state = st_option_help
+                else:
+                    state = st_top
+            elif state == st_option_help:
+                if append_long_text(line):
+                    print(f'this->ap.addOptionHelp("{option}", "{topic}",'
+                          f' "{short_text}", R"({long_text})");', file=f)
+                    state = st_top
+
     def generate(self):
         warn(f'{whoami}: regenerating auto job files')
 
@@ -230,6 +312,8 @@ class Main:
             for j in ft['options']:
                 print('this->ap.copyFromOtherTable'
                       f'("{j}", "{other_table}");', file=f)
+        with open('manual/cli.rst', 'r') as df:
+            self.generate_doc(df, f)
 
 
 if __name__ == '__main__':