From 005510501efcd1f4e8abae605a341c2a3d35df56 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Mon, 5 Jan 2026 18:54:42 +0100
Subject: [PATCH] configure: Make check for accepting warnings stricter

Clang by default allows unknown warnings and merely emits
a Wunknown-warning-option warning which is non-fatal by default,
making it appear as if Clang supported any warning. This patch
rewrites the tests to always add the arguments to error out
in case an unrecognized option is encountered.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 configure | 53 ++++++++++++++++++++++++++++++++---------------------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/configure b/configure
index d1cba4e1a8..28d88613ab 100755
--- a/configure
+++ b/configure
@@ -7829,31 +7829,42 @@ for lang in c cxx objc; do
         append unknown_warning_${lang}flags "-Werror=unknown-warning-option"
 done
 
-# add some useful compiler flags if supported
-check_allcflags -Wall
-check_allcflags -Wdisabled-optimization
-check_allcflags -Wpointer-arith
-check_allcflags -Wredundant-decls
-check_allcflags -Wwrite-strings
-check_allcflags -Wtype-limits
-check_allcflags -Wundef
-check_allcflags -Wempty-body
-check_cflags -Wmissing-prototypes
-check_cflags -Wstrict-prototypes
-
-if enabled extra_warnings; then
-    check_allcflags -Wcast-qual
-    check_allcflags -Wextra
-    check_allcflags -Wpedantic
-fi
+check_warning(){
+    warning_flag=$1
+    flag_to_add=${2:-$1}
+    test_cflags $unknown_warning_cflags $warning_flag && add_cflags $flag_to_add
+    test_cxxflags -Werror $unknown_warning_cxxflags $warning_flag && add_cxxflags $flag_to_add
+    test_objcflags $unknown_warning_objcflags $warning_flag && add_objcflags $flag_to_add
+}
 
 check_disable_warning(){
     warning_flag=-W${1#-Wno-}
-    test_cflags $unknown_warning_cflags $warning_flag && add_cflags $1
-    test_cxxflags -Werror $unknown_warning_cxxflags $warning_flag && add_cxxflags $1
-    test_objcflags $unknown_warning_objcflags $warning_flag && add_objcflags $1
+    check_warning $warning_flag $1
 }
 
+check_c_warning(){
+    warning_flag=$1
+    test_cflags $unknown_warning_cflags $warning_flag && add_cflags $warning_flag
+}
+
+# add some useful compiler flags if supported
+check_warning -Wall
+check_warning -Wdisabled-optimization
+check_warning -Wpointer-arith
+check_warning -Wredundant-decls
+check_warning -Wwrite-strings
+check_warning -Wtype-limits
+check_warning -Wundef
+check_warning -Wempty-body
+check_c_warning -Wmissing-prototypes
+check_c_warning -Wstrict-prototypes
+
+if enabled extra_warnings; then
+    check_warning -Wcast-qual
+    check_warning -Wextra
+    check_warning -Wpedantic
+fi
+
 check_disable_warning -Wno-parentheses
 check_disable_warning -Wno-switch
 check_disable_warning -Wno-format-zero-length
@@ -7866,7 +7877,7 @@ check_disable_warning -Wno-microsoft-enum-forward-reference
 
 check_disable_warning_headers(){
     warning_flag=-W${1#-Wno-}
-    test_cflags $warning_flag && add_cflags_headers $1
+    test_cflags $unknown_warning_cflags $warning_flag && add_cflags_headers $1
 }
 
 check_disable_warning_headers -Wno-deprecated-declarations