From 7f42b75c0fba0dfc97cba65ec25b0cdaf129be7e Mon Sep 17 00:00:00 2001
From: Harmen Stoppels <harmenstoppels@gmail.com>
Date: Mon, 8 Nov 2021 20:30:50 +0100
Subject: [PATCH] Allow system versions of libwhich and libblastrampoline
 (#43000)

---
 Make.inc      | 6 ++++++
 base/Makefile | 2 +-
 deps/Makefile | 2 ++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Make.inc b/Make.inc
index 4719a3d49b039d..eda72170a71c07 100644
--- a/Make.inc
+++ b/Make.inc
@@ -1085,6 +1085,12 @@ else
 PATCHELF := $(build_depsbindir)/patchelf
 endif
 
+ifeq ($(USE_SYSTEM_LIBWHICH), 1)
+LIBWHICH := libwhich
+else
+LIBWHICH := $(build_depsbindir)/libwhich
+endif
+
 # On aarch64 and powerpc64le, we assume the page size is 64K.  Our binutils linkers
 # and such already assume this, but `patchelf` seems to be behind the times.  We
 # explicitly tell it to use this large page size so that when we rewrite rpaths and
diff --git a/base/Makefile b/base/Makefile
index 2bef6aab7f1f4c..355310ce17c264 100644
--- a/base/Makefile
+++ b/base/Makefile
@@ -170,7 +170,7 @@ endif
 
 define symlink_system_library
 libname_$2 := $$(notdir $(call versioned_libname,$2,$3))
-libpath_$2 := $$(shell $$(call spawn,$$(build_depsbindir)/libwhich) -p $$(libname_$2) 2>/dev/null)
+libpath_$2 := $$(shell $$(call spawn,$$(LIBWHICH)) -p $$(libname_$2) 2>/dev/null)
 symlink_$2: $$(build_private_libdir)/$$(libname_$2)
 $$(build_private_libdir)/$$(libname_$2):
 	@if [ -e "$$(libpath_$2)" ]; then \
diff --git a/deps/Makefile b/deps/Makefile
index 3d3f79513135b3..50ca806307576c 100644
--- a/deps/Makefile
+++ b/deps/Makefile
@@ -159,9 +159,11 @@ DEP_LIBS += lapack
 endif
 endif
 
+ifeq ($(USE_SYSTEM_LIBWHICH), 0)
 ifneq ($(OS), WINNT)
 DEP_LIBS += libwhich
 endif
+endif
 
 # unlist targets that have not been converted to use the staged-install
 DEP_LIBS_STAGED := $(filter-out suitesparse-wrapper,$(DEP_LIBS))