4 files changed, 6 insertions, 2 deletions
diff --git a/Misc/ACKS b/Misc/ACKS
index a4a4cdc..150d37a 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1663,3 +1663,4 @@ Gennadiy Zlobin
 Doug Zongker
 Peter Åstrand
 evilzero
+Chi Hsuan Yen
diff --git a/Misc/NEWS b/Misc/NEWS
index 243f126..6b2b419 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -145,6 +145,9 @@ Windows
 Build
 -----
 
+- Issue #27453: CPP invocation in configure must use CPPFLAGS. Patch by
+  Chi Hsuan Yen.
+
 - Issue #27490: Do not build pgen when cross-compiling.  Patch by Thomas
   Perl.
 
diff --git a/configure b/configure
index f0cf515..bb89a5a 100755
--- a/configure
+++ b/configure
@@ -5369,7 +5369,7 @@ cat >> conftest.c <<EOF
 
 EOF
 
-if $CPP conftest.c >conftest.out 2>/dev/null; then
+if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
   PLATFORM_TRIPLET=`grep -v '^#' conftest.out | grep -v '^ *$' | tr -d ' 	'`
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PLATFORM_TRIPLET" >&5
 $as_echo "$PLATFORM_TRIPLET" >&6; }
diff --git a/configure.ac b/configure.ac
index bf2a348..8135c71 100644
--- a/configure.ac
+++ b/configure.ac
@@ -870,7 +870,7 @@ cat >> conftest.c <<EOF
 
 EOF
 
-if $CPP conftest.c >conftest.out 2>/dev/null; then
+if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
   PLATFORM_TRIPLET=`grep -v '^#' conftest.out | grep -v '^ *$' | tr -d ' 	'`
   AC_MSG_RESULT([$PLATFORM_TRIPLET])
 else