From f5569e29cc15e93a9e058b202084f76daa922755 Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <alx@kernel.org>
Date: Wed, 5 Nov 2025 17:29:05 +0100
Subject: [PATCH] src/bin/grepc_c: -tum: Split regex part for the replacement
 list

While splitting, improve the regex part in two ways:

-  Use a non-capturing group.  This improves performance.
-  Use negative lookahead instead of '[^\\]$'.  This allows matching
   a macro where the searched identifier is the last thing in the
   replacement list.

Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 src/bin/grepc_c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/bin/grepc_c b/src/bin/grepc_c
index 9ca87a1ba..c752dec19 100755
--- a/src/bin/grepc_c
+++ b/src/bin/grepc_c
@@ -119,6 +119,7 @@ grepc_c_mf_decl_()      { grepc_c_m_decl_ "$1";
 grepc_c_mo_decl_()      { grepc_c_m_decl_ "$1";
                           printf '%s' '(?!\()'; }
 grepc_c_m_repl_()       { printf '%s' '.*?(?<!\\)$'; }
+grepc_c_um_repl_()      { printf '%s' '(?:(?![^\\]$).)*'"$1"'.*?(?<!\\)$'; }
 
 
 grepc_c_e()             { echo '(?s)^([\w[]+[\w\s]*)?\benum\b[ \t]*([\w \t[\]]|::)*\n*([ \t]*){[^}]*^[ \t]*'"$1"'\b\s*[=,].*?^\3}.*?;'; }
@@ -153,7 +154,9 @@ grepc_c_uf_linux_def()  { grepc_c_fld_decl_ '\w+';
                           grepc_c_f_body_ "$1";
                           echo; }
 grepc_c_um()            { grepc_c_m_decl_ '\w+'
-                          echo '(\([^\)]*\))?(?:(?![^\\]$).)*'"$1"'.*?[^\\]$'; }
+                          printf '%s' '(?:\([^\)]*\))?';
+                          grepc_c_um_repl_ "$1";
+                          echo; }
 grepc_c_ut_su()         { echo '(?s)^(?!^[ \t]*typedef\b)([\w[]([\w\s\(,\)[\]*]|::)*[\w\s\)*\]]\s+)?\b(struct|union)\b([\w \t[\]]|::)*\w+[ \t]*\n*([ \t]*){(?:(?!^\5?}).)*?'"$1"'.*?^\5}.*?;'; }
 grepc_c_ut_td_simple()  { echo '(?s)^[ \t]*typedef\s+[^{};]*'"$1"'[^{};]+;'; }
 grepc_c_ut_td_su()      { echo '(?s)^[ \t]*typedef\s+(struct|union)\b([\w \t[\]]|::)*\n*([ \t]*){(?:(?!^\3?}|^\s*typedef).)*'"$1"'(?:(?!^\3?}|^\s*typedef).)*^\3}\s*\w+;'; }
-- 
2.47.3