Incorporate libblastrampoline (LBT)

All BLAS and LAPACK are now routed through LBT.
SuiteSparse is also linked against LBT.
OpenBLAS is still installed as before, and is
what LBT forwards to by default.

Make.inc

@@ -60,25 +60,9 @@ USE_SYSTEM_P7ZIP:=0
 # Link to the LLVM shared library
 USE_LLVM_SHLIB := 1
 
-## Settings for various Intel tools
-# Set to 1 to use MKL
-USE_INTEL_MKL ?= 0
-# Set to 1 to use Intel LIBM
-USE_INTEL_LIBM ?= 0
-# Set to 1 to enable profiling with Intel VTune Amplifier
-USE_INTEL_JITEVENTS ?= 0
-# Set to 1 to use Intel C, C++, and FORTRAN compilers
-USEICC  ?= 0
-USEIFC  ?= 0
-
 # Enable threading with one thread
 JULIA_THREADS := 1
 
-ifeq ($(USE_MKL), 1)
-$(warning "The julia make variable USE_MKL has been renamed to USE_INTEL_MKL")
-USE_INTEL_MKL := 1
-endif
-
 # Set to 1 to enable profiling with OProfile
 USE_OPROFILE_JITEVENTS ?= 0
 
@@ -1081,11 +1065,7 @@ endif
 # Use ILP64 BLAS interface when building openblas from source on 64-bit architectures
 ifeq ($(BINARY), 64)
 ifeq ($(USE_SYSTEM_BLAS), 1)
-ifeq ($(USE_INTEL_MKL), 1)
-USE_BLAS64 ?= 1
-else # non MKL system blas is most likely LP64
 USE_BLAS64 ?= 0
-endif
 else
 USE_BLAS64 ?= 1
 endif
@@ -1181,7 +1161,7 @@ BB_TRIPLET_CXXABI := $(subst $(SPACE),-,$(filter-out libgfortran%,$(subst -,$(SP
 BB_TRIPLET := $(subst $(SPACE),-,$(filter-out cxx%,$(filter-out libgfortran%,$(subst -,$(SPACE),$(BB_TRIPLET_LIBGFORTRAN_CXXABI)))))
 
 # This is the set of projects that BinaryBuilder dependencies are hooked up for.
-BB_PROJECTS := OPENBLAS LLVM SUITESPARSE OPENLIBM GMP MBEDTLS LIBSSH2 NGHTTP2 MPFR CURL LIBGIT2 PCRE LIBUV LIBUNWIND DSFMT OBJCONV ZLIB P7ZIP CSL
+BB_PROJECTS := BLASTRAMPOLINE OPENBLAS LLVM SUITESPARSE OPENLIBM GMP MBEDTLS LIBSSH2 NGHTTP2 MPFR CURL LIBGIT2 PCRE LIBUV LIBUNWIND DSFMT OBJCONV ZLIB P7ZIP CSL
 define SET_BB_DEFAULT
 # First, check to see if BB is disabled on a global setting
 ifeq ($$(USE_BINARYBUILDER),0)
@@ -1345,63 +1325,13 @@ ifeq ($(USE_PERF_JITEVENTS), 1)
 JCPPFLAGS += -DJL_USE_PERF_JITEVENTS
 endif
 
-
-# Intel libraries
-
-ifeq ($(USE_INTEL_LIBM), 1)
-USE_SYSTEM_LIBM := 1
-LIBM := -L$(MKLROOT)/../compiler/lib/intel64 -limf
-LIBMNAME := libimf
-endif
-
-ifeq ($(USE_INTEL_MKL), 1)
-ifeq ($(USE_BLAS64), 1)
-export MKL_INTERFACE_LAYER := ILP64
-MKLLIB := $(MKLROOT)/lib/intel64
-else
-MKLLIB := $(MKLROOT)/lib/ia32
-endif
-USE_SYSTEM_BLAS:=1
-USE_SYSTEM_LAPACK:=1
-LIBBLASNAME := libmkl_rt
-LIBLAPACKNAME := libmkl_rt
-MKL_LDFLAGS := -L$(MKLLIB) -lmkl_rt
-ifneq ($(strip $(MKLLIB)),)
-  ifeq ($(OS), Linux)
-    RPATH_MKL := -Wl,-rpath,$(MKLLIB)
-    RPATH     += $(RPATH_MKL)
-    MKL_LDFLAGS += $(RPATH_MKL)
-  endif
-endif
-LIBBLAS   := $(MKL_LDFLAGS)
-LIBLAPACK := $(MKL_LDFLAGS)
-endif
-
 ifeq ($(HAVE_SSP),1)
 JCPPFLAGS += -DHAVE_SSP=1
 ifeq ($(USEGCC),1)
 OSLIBS += -lssp
 endif
 endif
 
-# ATLAS
-
-# ATLAS must have been previously  installed to usr/lib/libatlas
-# (built as a shared library, for your platform, single threaded)
-USE_ATLAS := 0
-ATLAS_LIBDIR := $(build_libdir)
-#or ATLAS_LIBDIR := /path/to/system/atlas/lib
-
-ifeq ($(USE_ATLAS), 1)
-USE_BLAS64 := 0
-USE_SYSTEM_BLAS := 1
-USE_SYSTEM_LAPACK := 1
-LIBBLAS := -L$(ATLAS_LIBDIR) -lsatlas
-LIBLAPACK := $(LIBBLAS)
-LIBBLASNAME := libsatlas
-LIBLAPACKNAME := $(LIBBLASNAME)
-endif
-
 # Renaming OpenBLAS symbols, see #4923 and #8734
 ifeq ($(USE_SYSTEM_BLAS), 0)
 ifeq ($(USE_BLAS64), 1)

Makefile

@@ -164,7 +164,7 @@ JL_TARGETS += julia-debug
 endif
 
 # private libraries, that are installed in $(prefix)/lib/julia
-JL_PRIVATE_LIBS-0 := libccalltest libllvmcalltest libjulia-internal
+JL_PRIVATE_LIBS-0 := libccalltest libllvmcalltest libjulia-internal libblastrampoline
 ifeq ($(BUNDLE_DEBUG_LIBS),1)
 JL_PRIVATE_LIBS-0 += libjulia-internal-debug
 endif
@@ -360,7 +360,7 @@ endif
 		$(call stringreplace,$${DEBUG_TARGET},sys-debug.$(SHLIB_EXT)$$,$(private_libdir_rel)/sys-debug.$(SHLIB_EXT)); \
 	fi;
 endif
-	
+
 	# Set rpath for libjulia-internal, which is moving from `../lib` to `../lib/julia`.  We only need to do this for Linux/FreeBSD
 ifneq (,$(findstring $(OS),Linux FreeBSD))
 	$(PATCHELF) --set-rpath '$$ORIGIN:$$ORIGIN/$(reverse_private_libdir_rel)' $(DESTDIR)$(private_libdir)/libjulia-internal.$(SHLIB_EXT)

deps/Makefile

@@ -24,7 +24,7 @@ BUILDDIR := $(BUILDDIR)$(MAYBE_HOST)
 # if you are adding a new target, it can help to copy an similar, existing target
 #
 # autoconf configure-driven scripts: pcre unwind gmp mpfr patchelf libuv curl
-# custom Makefile rules: openlibm dsfmt suitesparse-wrapper suitesparse lapack openblas utf8proc objconv osxunwind libwhich
+# custom Makefile rules: openlibm dsfmt suitesparse-wrapper suitesparse lapack blastrampoline openblas utf8proc objconv osxunwind libwhich
 # CMake libs: llvm libgit2 libssh2 mbedtls
 #
 # downloadable via git: llvm-svn, libuv, libopenlibm, utf8proc, libgit2, libssh2
@@ -39,6 +39,9 @@ unexport CONFIG_SITE
 
 DEP_LIBS :=
 
+# Always use libblastrampoline
+DEP_LIBS += blastrampoline
+
 ifeq ($(USE_SYSTEM_CSL), 0)
 DEP_LIBS += csl
 endif
@@ -187,7 +190,7 @@ install: $(addprefix install-, $(DEP_LIBS))
 cleanall: $(addprefix clean-, $(DEP_LIBS))
 distcleanall: $(addprefix distclean-, $(DEP_LIBS))
 	rm -rf $(build_prefix)
-getall: get-llvm get-libuv get-pcre get-openlibm get-dsfmt get-openblas get-lapack get-suitesparse get-unwind get-gmp get-mpfr get-patchelf get-utf8proc get-objconv get-mbedtls get-libssh2 get-nghttp2 get-curl get-libgit2 get-libwhich get-zlib get-p7zip get-csl
+getall: get-llvm get-libuv get-pcre get-openlibm get-dsfmt get-blastrampoline get-openblas get-lapack get-suitesparse get-unwind get-gmp get-mpfr get-patchelf get-utf8proc get-objconv get-mbedtls get-libssh2 get-nghttp2 get-curl get-libgit2 get-libwhich get-zlib get-p7zip get-csl
 
 # If we're building for MacOS, no matter what, `getall` should include `osxunwind`
 ifeq ($(OS),Darwin)
@@ -206,7 +209,8 @@ include $(SRCDIR)/pcre.mk
 include $(SRCDIR)/openlibm.mk
 include $(SRCDIR)/dsfmt.mk
 include $(SRCDIR)/objconv.mk
-include $(SRCDIR)/blas.mk
+include $(SRCDIR)/blastrampoline.mk
+include $(SRCDIR)/openblas.mk
 include $(SRCDIR)/utf8proc.mk
 include $(SRCDIR)/suitesparse.mk
 include $(SRCDIR)/unwind.mk

deps/Versions.make

@@ -70,6 +70,10 @@ OBJCONV_VER := 2.49.1
 OBJCONV_JLL_NAME := Objconv
 OBJCONV_JLL_VER  := 2.49.1+0
 
+# blastrampoline
+BLASTRAMPOLINE_VER := 1.0.0
+BLASTRAMPOLINE_JLL_NAME := libblastrampoline
+
 # OpenBLAS
 OPENBLAS_VER := 0.3.10
 OPENBLAS_JLL_NAME := OpenBLAS
@@ -96,7 +100,7 @@ PCRE_JLL_NAME := PCRE2
 
 # SuiteSparse
 SUITESPARSE_VER := 5.4.0
-SUITESPARSE_JLL_NAME := SuiteSparse
+SUITESPARSE_JLL_NAME := SuiteSparse_LBT
 
 # unwind
 UNWIND_VER := 1.3.2

deps/blastrampoline.mk

@@ -0,0 +1,37 @@
+## blastrampoline ##
+
+ifneq ($(USE_BINARYBUILDER_BLASTRAMPOLINE),1)
+
+BLASTRAMPOLINE_GIT_URL := git://github.com/staticfloat/libblastrampoline.git
+BLASTRAMPOLINE_TAR_URL = https://api.github.com/repos/staticfloat/libblastrampoline/tarball/$1
+$(eval $(call git-external,blastrampoline,BLASTRAMPOLINE,,,$(BUILDDIR)))
+
+$(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/build-configured: $(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/source-extracted
+	mkdir -p $(dir $@)
+	echo 1 > $@
+
+$(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/build-compiled: $(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/build-configured
+	cd $(dir $@)/src && $(MAKE) $(MAKE_COMMON)
+	echo 1 > $@
+
+define BLASTRAMPOLINE_INSTALL
+	$(MAKE) -C $(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/src $(MAKE_COMMON) install
+endef
+$(eval $(call staged-install, \
+	blastrampoline,$(BLASTRAMPOLINE_SRC_DIR), \
+	BLASTRAMPOLINE_INSTALL,, \
+	$$(BLASTRAMPOLINE_OBJ_TARGET), \
+	$$(INSTALL_NAME_CMD)libblastrampoline.$$(SHLIB_EXT) $$(build_shlibdir)/libblastrampoline.$$(SHLIB_EXT)))
+
+get-blastrampoline: $(BLASTRAMPOLINE_SRC_FILE)
+extract-blastrampoline: $(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/source-extracted
+configure-blastrampoline: extract-blastrampoline
+compile-blastrampoline: $(BUILDDIR)/$(BLASTRAMPOLINE_SRC_DIR)/build-compiled
+fastcheck-blastrampoline: check-blastrampoline
+check-blastrampoline: compile-blastrampoline
+
+else
+
+$(eval $(call bb-install,blastrampoline,BLASTRAMPOLINE,false))
+
+endif # USE_BINARYBUILDER_BLASTRAMPOLINE

deps/blastrampoline.version

@@ -0,0 +1,2 @@
+BLASTRAMPOLINE_BRANCH=main
+BLASTRAMPOLINE_SHA1=0c723926f96ba431713c4873b46e81a5fd600d0c

deps/checksums/libblastrampoline-068f3f7831fb9fd62a87f0869429fb1744bfb9a1.tar.gz/md5

@@ -0,0 +1 @@
+30edb3916c34dfb577f0d3f69f1fafff

deps/checksums/libblastrampoline-068f3f7831fb9fd62a87f0869429fb1744bfb9a1.tar.gz/sha512

@@ -0,0 +1 @@
+ce716f97eda04ebf121d52faded2b7128635b3ca8cc21f61af5fa87fcef24adc480f912c3940b9361ac6b0175d81fb012c8634c2c3d9023fc0d86dcf73bf50e1

deps/suitesparse.mk

@@ -4,14 +4,12 @@ ifeq ($(USE_BLAS64), 1)
 UMFPACK_CONFIG := -DLONGBLAS='long long'
 CHOLMOD_CONFIG := -DLONGBLAS='long long'
 SPQR_CONFIG := -DLONGBLAS='long long'
-ifeq ($(OPENBLAS_SYMBOLSUFFIX), 64_)
 UMFPACK_CONFIG += -DSUN64
 CHOLMOD_CONFIG += -DSUN64
 SPQR_CONFIG += -DSUN64
 endif
-endif
 
-# Disable trying to link against libmetis
+# Disable linking to libmetis
 CHOLMOD_CONFIG += -DNPARTITION
 
 ifneq ($(USE_BINARYBUILDER_SUITESPARSE), 1)
@@ -23,7 +21,7 @@ SUITE_SPARSE_LIB := $(LDFLAGS) -L"$(abspath $(BUILDDIR))/SuiteSparse-$(SUITESPAR
 ifeq ($(OS), Darwin)
 SUITE_SPARSE_LIB += $(RPATH_ESCAPED_ORIGIN)
 endif
-SUITESPARSE_MFLAGS := CC="$(CC)" CXX="$(CXX)" F77="$(FC)" AR="$(AR)" RANLIB="$(RANLIB)" BLAS="$(LIBBLAS)" LAPACK="$(LIBLAPACK)" \
+SUITESPARSE_MFLAGS := CC="$(CC)" CXX="$(CXX)" F77="$(FC)" AR="$(AR)" RANLIB="$(RANLIB)" BLAS="-L$(build_shlibdir) -lblastrampoline" LAPACK="-L$(build_shlibdir) -lblastrampoline" \
 	  LDFLAGS="$(SUITE_SPARSE_LIB)" CFOPENMP="" CUDA=no CUDA_PATH="" \
 	  UMFPACK_CONFIG="$(UMFPACK_CONFIG)" CHOLMOD_CONFIG="$(CHOLMOD_CONFIG)" SPQR_CONFIG="$(SPQR_CONFIG)"
 ifeq ($(OS),WINNT)
@@ -53,11 +51,7 @@ $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/SuiteSparse-shlib.patch-applied: $(BU
 $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/build-compiled: $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/SuiteSparse-winclang.patch-applied
 $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/build-compiled: $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/SuiteSparse-shlib.patch-applied
 
-ifeq ($(USE_SYSTEM_BLAS), 0)
-$(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/build-compiled: | $(build_prefix)/manifest/openblas
-else ifeq ($(USE_SYSTEM_LAPACK), 0)
-$(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/build-compiled: | $(build_prefix)/manifest/lapack
-endif
+$(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/build-compiled: | $(build_prefix)/manifest/blastrampoline
 
 $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/build-compiled: $(BUILDDIR)/SuiteSparse-$(SUITESPARSE_VER)/source-extracted
 	$(MAKE) -C $(dir $<)SuiteSparse_config library config $(SUITESPARSE_MFLAGS)
@@ -153,6 +147,6 @@ clean-suitesparse-wrapper: clean-suitesparse
 distclean-suitesparse-wrapper: distclean-suitesparse
 install-suitesparse-wrapper: install-suitesparse
 
-# suitesparse depends on OpenBLAS
-compile-suitesparse: | $(build_prefix)/manifest/openblas
+# suitesparse depends on blastrampoline
+compile-suitesparse: | $(build_prefix)/manifest/blastrampoline
 endif

stdlib/LinearAlgebra/src/LinearAlgebra.jl

@@ -433,21 +433,50 @@ function versioninfo(io::IO=stdout)
     println(io, "LAPACK: ",Base.liblapack_name)
 end
 
-function __init__()
-    try
-        BLAS.check()
-        if BLAS.vendor() === :mkl
-            ccall((:MKL_Set_Interface_Layer, Base.libblas_name), Cvoid, (Cint,), USE_BLAS64 ? 1 : 0)
+function get_blas_lapack_path()
+    shlib_ext = if Sys.iswindows()
+         ".dll"
+    elseif Sys.isapple()
+         ".dylib"
+    else
+         ".so"
+    end
+    libblas_path = joinpath(Sys.BINDIR, Base.LIBDIR, "julia", string(Base.libblas_name, shlib_ext))
+    if !isfile(libblas_path)
+        libblas_path = joinpath(Sys.BINDIR, Base.LIBDIR, string(Base.libblas_name, shlib_ext))
+        if !isfile(libblas_path)
+            error("Cannot find BLAS at ", libblas_path)
+        end
+    end
+    liblapack_path = joinpath(Sys.BINDIR, Base.LIBDIR, "julia", string(Base.liblapack_name, shlib_ext))
+    if !isfile(liblapack_path)
+        liblapack_path = joinpath(Sys.BINDIR, Base.LIBDIR, string(Base.liblapack_name, shlib_ext))
+        if !isfile(liblapack_path)
+            error("Cannot find LAPACK at ", liblapack_path)
         end
-        Threads.resize_nthreads!(Abuf)
-        Threads.resize_nthreads!(Bbuf)
-        Threads.resize_nthreads!(Cbuf)
-    catch ex
-        Base.showerror_nostdio(ex,
-            "WARNING: Error during initialization of module LinearAlgebra")
     end
-    # register a hook to disable BLAS threading
-    Base.at_disable_library_threading(() -> BLAS.set_num_threads(1))
+
+    return (libblas_path, liblapack_path)
+end
+
+function __init__()
+     try
+         libblas_path, liblapack_path = get_blas_lapack_path()
+         ccall((:load_blas_funcs, "libblastrampoline"), Cvoid, (Cstring,Cint,Cint), libblas_path,   1, 0)
+         ccall((:load_blas_funcs, "libblastrampoline"), Cvoid, (Cstring,Cint,Cint), liblapack_path, 0, 0)
+# 	 BLAS.check()
+#        if BLAS.vendor() === :mkl
+#            ccall((:MKL_Set_Interface_Layer, Base.libblas_name), Cvoid, (Cint,), USE_BLAS64 ? 1 : 0)
+#        end
+#        Threads.resize_nthreads!(Abuf)
+#        Threads.resize_nthreads!(Bbuf)
+#        Threads.resize_nthreads!(Cbuf)
+     catch ex
+         Base.showerror_nostdio(ex,
+             "WARNING: Error during initialization of module LinearAlgebra")
+     end
+     # register a hook to disable BLAS threading
+     Base.at_disable_library_threading(() -> BLAS.set_num_threads(1))
 end
 
 end # module LinearAlgebra

stdlib/LinearAlgebra/src/blas.jl

@@ -6,7 +6,7 @@ Interface to BLAS subroutines.
 module BLAS
 
 import ..axpy!, ..axpby!
-import Base: copyto!
+import Base: copyto!, USE_BLAS64
 using Base: require_one_based_indexing
 
 export
@@ -63,8 +63,8 @@ export
     trsm
 
 
-const libblas = Base.libblas_name
-const liblapack = Base.liblapack_name
+const libblas = "libblastrampoline"
+const liblapack = "libblastrampoline"
 
 import LinearAlgebra
 import LinearAlgebra: BlasReal, BlasComplex, BlasFloat, BlasInt, DimensionMismatch, checksquare, stride1, chkstride1, axpy!
@@ -94,7 +94,7 @@ end
 const _vendor = determine_vendor()
 vendor() = _vendor
 
-if vendor() === :openblas64
+if USE_BLAS64
     macro blasfunc(x)
         return Expr(:quote, Symbol(x, "64_"))
     end

stdlib/LinearAlgebra/src/lapack.jl

@@ -5,7 +5,7 @@ module LAPACK
 Interfaces to LAPACK subroutines.
 """ LAPACK
 
-const liblapack = Base.liblapack_name
+const liblapack = "libblastrampoline"
 
 import ..LinearAlgebra.BLAS.@blasfunc
 

stdlib/Makefile

@@ -16,7 +16,7 @@ $(build_datarootdir)/julia/stdlib/$(VERSDIR):
 	mkdir -p $@
 
 JLLS = DSFMT GMP CURL LIBGIT2 LLVM LIBSSH2 LIBUV MBEDTLS MPFR NGHTTP2 \
-       OPENBLAS OPENLIBM P7ZIP PCRE SUITESPARSE ZLIB OSXUNWIND CSL \
+       BLASTRAMPOLINE OPENBLAS OPENLIBM P7ZIP PCRE SUITESPARSE ZLIB OSXUNWIND CSL \
        UNWIND
 
 # Initialize this with JLLs that aren't in deps/Versions.make

stdlib/SuiteSparse_LBT_jll/Project.toml

@@ -0,0 +1,14 @@
+name = "SuiteSparse_LBT_jll"
+uuid = "8a7bcfce-81ee-5a07-a07c-c8520ac69669"
+version = "5.4.1+0"
+
+[deps]
+JLLWrappers = "692b3bcd-3c85-4b1f-b108-f13ce0eb3210"
+libblastrampoline_jll = "8e850b90-86db-534c-a0d3-1478176c7d93"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
+
+[compat]
+JLLWrappers = "1.2.0"
+julia = "1.6"

stdlib/libblastrampoline_jll/Project.toml

@@ -0,0 +1,13 @@
+name = "libblastrampoline_jll"
+uuid = "8e850b90-86db-534c-a0d3-1478176c7d93"
+version = "1.0.0+0"
+
+[deps]
+JLLWrappers = "692b3bcd-3c85-4b1f-b108-f13ce0eb3210"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
+
+[compat]
+JLLWrappers = "1.2.0"
+julia = "1.6"

stdlib/libblastrampoline_jll/src/libblastrampoline_jll

@@ -0,0 +1,46 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+## dummy stub for https://github.com/JuliaBinaryWrappers/libblastrampoline_jll.jl
+
+baremodule blastrampoline_jll
+using Base, Libdl
+Base.Experimental.@compiler_options compile=min optimize=0 infer=false
+
+const PATH_list = String[]
+const LIBPATH_list = String[]
+
+export libblastrampoline
+
+# These get calculated in __init__()
+const PATH = Ref("")
+const LIBPATH = Ref("")
+artifact_dir = ""
+libblastrampoline_handle = C_NULL
+libblastrampoline_path = ""
+
+if Sys.iswindows()
+    const libblastrampoline = "libblastrampoline.dll"
+elseif Sys.isapple()
+    const libblastrampoline = "@rpath/libblastrampoline.dylib"
+else
+    const libblastrampoline = "libblastrampoline.so"
+end
+
+function __init__()
+    global libblastrampoline_handle = dlopen(libblastrampoline)
+    global libblastrampoline_path = dlpath(libblastrampoline_handle)
+    global artifact_dir = dirname(Sys.BINDIR)
+    LIBPATH[] = dirname(libblastrampoline_path)
+    push!(LIBPATH_list, LIBPATH[])
+end
+
+# JLLWrappers API compatibility shims.  Note that not all of these will really make sense.
+# For instance, `find_artifact_dir()` won't actually be the artifact directory, because
+# there isn't one.  It instead returns the overall Julia prefix.
+is_available() = true
+find_artifact_dir() = artifact_dir
+dev_jll() = error("stdlib JLLs cannot be dev'ed")
+best_wrapper = nothing
+get_libblastrampoline_path() = libblastrampoline_path
+
+end  # module libblastrampoline_jll

stdlib/libblastrampoline_jll/test/runtests.jl

@@ -0,0 +1,7 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+using Test, libblastrampoline_jll
+
+@testset "libblastrampoline_jll" begin
+    true
+end