gh-95065: Argument Clinic: Pretty-print long C strings in generated code (#107712)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 30 insertions, 7 deletions

diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index 2bed98c..3a8431c 100755
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -221,6 +221,20 @@ def c_repr(s: str) -> str:
     return '"' + s + '"'
 
 
+def wrapped_c_string_literal(
+        text: str,
+        *,
+        width: int = 72,
+        suffix: str = '',
+        initial_indent: int = 0,
+        subsequent_indent: int = 4
+) -> str:
+    wrapped = textwrap.wrap(text, width=width, replace_whitespace=False,
+                            drop_whitespace=False, break_on_hyphens=False)
+    separator = '"' + suffix + '\n' + subsequent_indent * ' ' + '"'
+    return initial_indent * ' ' + '"' + separator.join(wrapped) + '"'
+
+
 is_legal_c_identifier = re.compile('^[A-Za-z_][A-Za-z0-9_]*$').match
 
 def is_legal_py_identifier(s: str) -> bool:
@@ -837,17 +851,22 @@ class CLanguage(Language):
     """)
     DEPRECATED_POSITIONAL_PROTOTYPE: Final[str] = r"""
         #if PY_VERSION_HEX >= 0x{major:02x}{minor:02x}00C0
-        #  error "{cpp_message}"
+        #  error \
+                {cpp_message}
         #elif PY_VERSION_HEX >= 0x{major:02x}{minor:02x}00A0
         #  ifdef _MSC_VER
-        #    pragma message ("{cpp_message}")
+        #    pragma message ( \
+                {cpp_message})
         #  else
-        #    warning "{cpp_message}"
+        #    warning \
+                {cpp_message}
         #  endif
         #endif
         if ({condition}) {{{{
-            if (PyErr_WarnEx(PyExc_DeprecationWarning, "{depr_message}", 1)) {{{{
-                goto exit;
+            if (PyErr_WarnEx(PyExc_DeprecationWarning,
+                    {depr_message}, 1))
+            {{{{
+                    goto exit;
             }}}}
         }}}}
     """
@@ -899,6 +918,7 @@ class CLanguage(Language):
             f"In {source}, update parameter(s) {pstr} in the clinic "
             f"input of {func.full_name!r} to be keyword-only."
         )
+
         # Format the deprecation message.
         if first_pos == 0:
             preamble = "Passing positional arguments to "
@@ -926,8 +946,11 @@ class CLanguage(Language):
             condition=condition,
             major=major,
             minor=minor,
-            cpp_message=cpp_message,
-            depr_message=depr_message,
+            cpp_message=wrapped_c_string_literal(cpp_message, suffix=" \\",
+                                                 width=64,
+                                                 subsequent_indent=16),
+            depr_message=wrapped_c_string_literal(depr_message, width=64,
+                                                  subsequent_indent=20),
         )
         return normalize_snippet(code, indent=4)