bpo-36310: Allow pygettext.py to detect calls to gettext in f-strings. (GH-19875)

Adds support to Tools/i18n/pygettext.py for gettext calls in f-strings. This process is done by parsing the f-strings, processing each value, and flagging the ones which contain a gettext call.

Co-authored-by: Batuhan Taskaya <batuhanosmantaskaya@gmail.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/Tools/i18n/pygettext.py b/Tools/i18n/pygettext.py
index b1d281d..9dd65c2 100755
--- a/Tools/i18n/pygettext.py
+++ b/Tools/i18n/pygettext.py
@@ -162,6 +162,7 @@ import sys
 import glob
 import time
 import getopt
+import ast
 import token
 import tokenize
 
@@ -343,6 +344,58 @@ class TokenEater:
                 return
         if ttype == tokenize.NAME and tstring in opts.keywords:
             self.__state = self.__keywordseen
+            return
+        if ttype == tokenize.STRING:
+            maybe_fstring = ast.parse(tstring, mode='eval').body
+            if not isinstance(maybe_fstring, ast.JoinedStr):
+                return
+            for value in filter(lambda node: isinstance(node, ast.FormattedValue),
+                                maybe_fstring.values):
+                for call in filter(lambda node: isinstance(node, ast.Call),
+                                   ast.walk(value)):
+                    func = call.func
+                    if isinstance(func, ast.Name):
+                        func_name = func.id
+                    elif isinstance(func, ast.Attribute):
+                        func_name = func.attr
+                    else:
+                        continue
+
+                    if func_name not in opts.keywords:
+                        continue
+                    if len(call.args) != 1:
+                        print(_(
+                            '*** %(file)s:%(lineno)s: Seen unexpected amount of'
+                            ' positional arguments in gettext call: %(source_segment)s'
+                            ) % {
+                            'source_segment': ast.get_source_segment(tstring, call) or tstring,
+                            'file': self.__curfile,
+                            'lineno': lineno
+                            }, file=sys.stderr)
+                        continue
+                    if call.keywords:
+                        print(_(
+                            '*** %(file)s:%(lineno)s: Seen unexpected keyword arguments'
+                            ' in gettext call: %(source_segment)s'
+                            ) % {
+                            'source_segment': ast.get_source_segment(tstring, call) or tstring,
+                            'file': self.__curfile,
+                            'lineno': lineno
+                            }, file=sys.stderr)
+                        continue
+                    arg = call.args[0]
+                    if not isinstance(arg, ast.Constant):
+                        print(_(
+                            '*** %(file)s:%(lineno)s: Seen unexpected argument type'
+                            ' in gettext call: %(source_segment)s'
+                            ) % {
+                            'source_segment': ast.get_source_segment(tstring, call) or tstring,
+                            'file': self.__curfile,
+                            'lineno': lineno
+                            }, file=sys.stderr)
+                        continue
+                    if isinstance(arg.value, str):
+                        self.__addentry(arg.value, lineno)
 
     def __suiteseen(self, ttype, tstring, lineno):
         # skip over any enclosure pairs until we see the colon