From f30cc463a948260088b496c3609dd91c83c0ce1b Mon Sep 17 00:00:00 2001
From: Brice Goglin <Brice.Goglin@inria.fr>
Date: Mon, 16 Feb 2026 15:00:53 +0100
Subject: [PATCH] configure: add --with-opencl=<dir>

For non-ROCm non-CUDA installs.

Thanks to Romain Garbage for the suggestion.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
(cherry picked from commit 462eff5a4541dfcb3db15034490c796c4f1d8ec6)
---
 config/hwloc.m4          | 18 +++++++++++++++---
 config/hwloc_internal.m4 | 13 ++++++++++++-
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/config/hwloc.m4 b/config/hwloc.m4
index e0057e8e5..4a26a7ec0 100644
--- a/config/hwloc.m4
+++ b/config/hwloc.m4
@@ -1,7 +1,7 @@
 dnl -*- Autoconf -*-
 dnl
 dnl SPDX-License-Identifier: BSD-3-Clause
-dnl Copyright © 2009-2025 Inria.  All rights reserved.
+dnl Copyright © 2009-2026 Inria.  All rights reserved.
 dnl Copyright © 2009-2012, 2015-2017, 2020, 2023, 2025 Université Bordeaux
 dnl Copyright © 2004-2005 The Trustees of Indiana University and Indiana
 dnl                         University Research and Technology
@@ -1365,6 +1365,18 @@ return rsmi_init(0);
       echo "**** OpenCL configuration"
 
       hwloc_opencl_happy=yes
+
+      if test "x$with_opencl" != x -a "x$with_opencl" != xyes; then
+        opencl_dir=$with_opencl
+        AC_MSG_NOTICE([using custom OpenCL install path $opencl_dir ...])
+      else
+        AC_MSG_NOTICE([assuming OpenCL is installed in standard directories ...])
+      fi
+      if test "x$opencl_dir" != x; then
+        HWLOC_OPENCL_CPPFLAGS="-I$opencl_dir/include/"
+        HWLOC_OPENCL_LDFLAGS="-L$opencl_dir/lib/"
+      fi
+
       case ${target} in
       *-*-darwin*)
         # On Darwin, only use the OpenCL framework
@@ -1387,8 +1399,8 @@ return clGetDeviceIDs(0, 0, 0, NULL, NULL);
       ;;
       *)
         # On Others, look for OpenCL at normal locations
-        HWLOC_OPENCL_CPPFLAGS="$HWLOC_CUDA_COMMON_CPPFLAGS"
-        HWLOC_OPENCL_LDFLAGS="$HWLOC_CUDA_COMMON_LDFLAGS"
+        HWLOC_OPENCL_CPPFLAGS="$HWLOC_OPENCL_CPPFLAGS $HWLOC_CUDA_COMMON_CPPFLAGS"
+        HWLOC_OPENCL_LDFLAGS="$HWLOC_OPENCL_LDFLAGS $HWLOC_CUDA_COMMON_LDFLAGS"
         if test "x$rocm_dir" != x; then
 	   if test -d "$rocm_dir/include/CL"; then
              HWLOC_OPENCL_CPPFLAGS="$HWLOC_OPENCL_CPPFLAGS -I$rocm_dir/include/"
diff --git a/config/hwloc_internal.m4 b/config/hwloc_internal.m4
index da6505e91..1135a245f 100644
--- a/config/hwloc_internal.m4
+++ b/config/hwloc_internal.m4
@@ -1,7 +1,7 @@
 dnl -*- Autoconf -*-
 dnl
 dnl SPDX-License-Identifier: BSD-3-Clause
-dnl Copyright © 2010-2025 Inria.  All rights reserved.
+dnl Copyright © 2010-2026 Inria.  All rights reserved.
 dnl Copyright © 2009, 2011 Université Bordeaux
 dnl Copyright © 2004-2005 The Trustees of Indiana University and Indiana
 dnl                         University Research and Technology
@@ -147,6 +147,17 @@ AC_DEFUN([HWLOC_DEFINE_ARGS],[
 		       [AC_MSG_ERROR([--with-amdgpu=<dir> missing the installation directory])])]
 		)
 
+    # OpenCL
+    AC_ARG_ENABLE([opencl],
+                  AS_HELP_STRING([--disable-opencl],
+                                 [Disable the OpenCL device discovery]))
+    AC_ARG_WITH([opencl],
+                AS_HELP_STRING([--with-opencl=<dir>],
+		               [Specify the OpenCL installation directory]),
+		[AS_IF([test "x$withval" = xyes -o "x$withval" = x],
+		       [AC_MSG_ERROR([--with-opencl=<dir> missing the installation directory])])]
+		)
+
     # LevelZero
     AC_ARG_ENABLE([levelzero],
                   AS_HELP_STRING([--disable-levelzero],