[PATCH 1/2] docs: kdoc: Expand 'at_least' when creating parameter list

[Eric Biggers <ebiggers@kernel.org>]

sphinx doesn't know that the kernel headers do:

    #define at_least static

Do this replacement before declarations are passed to it.

This prevents errors like the following from appearing once the
lib/crypto/ kerneldoc is wired up to the sphinx build:

   linux/Documentation/crypto/libcrypto:128: ./include/crypto/sha2.h:773: WARNING: Error in declarator or parameters
Error in declarator or parameters
Invalid C declaration: Expected ']' in end of array operator. [error at 59]
  void sha512_final (struct sha512_ctx *ctx, u8 out[at_least SHA512_DIGEST_SIZE])

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 tools/lib/python/kdoc/kdoc_parser.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/lib/python/kdoc/kdoc_parser.py b/tools/lib/python/kdoc/kdoc_parser.py
index 74af7ae47aa47..f982db7fddac2 100644
--- a/tools/lib/python/kdoc/kdoc_parser.py
+++ b/tools/lib/python/kdoc/kdoc_parser.py
@@ -437,10 +437,15 @@ class KernelDoc:
 
         for arg in args.split(splitter):
             # Ignore argument attributes
             arg = KernRe(r'\sPOS0?\s').sub(' ', arg)
 
+            # Replace '[at_least ' with '[static '.  This allows sphinx to parse
+            # array parameter declarations like 'char A[at_least 4]', where
+            # 'at_least' is #defined to 'static' by the kernel headers.
+            arg = KernRe(r'\[at_least ').sub('[static ', arg)
+
             # Strip leading/trailing spaces
             arg = arg.strip()
             arg = KernRe(r'\s+').sub(' ', arg, count=1)
 
             if arg.startswith('#'):
-- 
2.53.0