Clang uses
C99 inline semantics, which means these functions need to be declared static. Try this patch:
diff --git a/afni_src/mri_warp.c b/afni_src/mri_warp.c
index 2bc65d8..ef37ac5 100644
--- a/afni_src/mri_warp.c
+++ b/afni_src/mri_warp.c
@@ -23,7 +23,7 @@
static float sx_scale , sy_scale ; /* global scaler data */
-INLINE void xxMRI_scaler( float xpr, float ypr, float *xx , float *yy )
+static INLINE void xxMRI_scaler( float xpr, float ypr, float *xx , float *yy )
{
*xx = sx_scale * xpr ;
*yy = sy_scale * ypr ;
@@ -338,7 +338,7 @@ MRI_IMAGE *mri_warp_bilinear( MRI_IMAGE *im , int nxnew , in
static float rot_dx , rot_dy , rot_cph , rot_sph ; /* global rotfunc data */
-INLINE void xxMRI_rotfunc( float xpr , float ypr , float *xx , float *yy )
+static INLINE void xxMRI_rotfunc( float xpr , float ypr , float *xx , float *yy
{
*xx = rot_cph * xpr + rot_sph * ypr + rot_dx ;
*yy = -rot_sph * xpr + rot_cph * ypr + rot_dy ;