From 86cae58d2f342f8a3b49dd70dca8989cb271c504 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Thu, 29 Jan 2026 12:43:40 +0000
Subject: [PATCH] build: Add `-Wleading-whitespace=spaces` compiler flag

---
 CMakeLists.txt | 1 +
 configure.ac   | 1 +
 2 files changed, 2 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4953a4b4..4ef69c08 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -217,6 +217,7 @@ else()
   try_append_c_flags(-Wcast-align=strict) # GCC >= 8.0.
   try_append_c_flags(-Wconditional-uninitialized) # Clang >= 3.0 only.
   try_append_c_flags(-Wextra) # GCC >= 3.4, this is the newer name of -W, which we don't use because older GCCs will warn about unused functions.
+  try_append_c_flags(-Wleading-whitespace=spaces) # GCC >= 15.0
   try_append_c_flags(-Wnested-externs)
   try_append_c_flags(-Wno-long-long) # GCC >= 3.0, -Wlong-long is implied by -pedantic.
   try_append_c_flags(-Wno-overlength-strings) # GCC >= 4.2, -Woverlength-strings is implied by -pedantic.
diff --git a/configure.ac b/configure.ac
index e68af3ca..a21447ce 100644
--- a/configure.ac
+++ b/configure.ac
@@ -112,6 +112,7 @@ AC_DEFUN([SECP_TRY_APPEND_DEFAULT_CFLAGS], [
       SECP_TRY_APPEND_CFLAGS([-Wconditional-uninitialized], $1) # Clang >= 3.0 only
       SECP_TRY_APPEND_CFLAGS([-Wreserved-identifier], $1) # Clang >= 13.0 only
       SECP_TRY_APPEND_CFLAGS([-Wtrailing-whitespace=any], $1) # GCC >= 15.0
+      SECP_TRY_APPEND_CFLAGS([-Wleading-whitespace=spaces], $1) # GCC >= 15.0
 
       CFLAGS="$SECP_TRY_APPEND_DEFAULT_CFLAGS_saved_CFLAGS"
     fi