Simplification of libblastrampoline stuff in LinearAlgebra (JuliaLang#44360)

* Report libblastrampoline as Base.libblas_name and Base.liblapack_name

* Cleanup a lot of the LBT stuff

* Fix

* Remove test for LinearAlgebra.LAPACK.liblapack

* Fix

* Fix the precompile tests

Author: ViralBShah

NEWS.md

@@ -42,6 +42,12 @@ Standard library changes
 
 #### LinearAlgebra
 
+* We are now wholly reliant on libblastrampoline (LBT) for calling
+  BLAS and LAPACK. OpenBLAS is shipped by default, but building the
+  system image with other BLAS/LAPACK libraries is not
+  supported. Instead, it is recommended that the LBT mechanism be used
+  for swapping BLAS/LAPACK with vendor provided ones. ([#44360])
+
 #### Markdown
 
 #### Printf

base/Makefile

@@ -47,8 +47,6 @@ else
 	@echo "const MACHINE = \"$(XC_HOST)\"" >> $@
 endif
 	@echo "const libm_name = \"$(LIBMNAME)\"" >> $@
-	@echo "const libblas_name = \"$(LIBBLASNAME)\"" >> $@
-	@echo "const liblapack_name = \"$(LIBLAPACKNAME)\"" >> $@
 ifeq ($(USE_BLAS64), 1)
 	@echo "const USE_BLAS64 = true" >> $@
 else

stdlib/LinearAlgebra/Project.toml

@@ -4,6 +4,7 @@ uuid = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 [deps]
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 libblastrampoline_jll = "8e850b90-86db-534c-a0d3-1478176c7d93"
+OpenBLAS_jll = "4536629a-c528-5b80-bd46-f80d51c5b363"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

stdlib/LinearAlgebra/src/LinearAlgebra.jl

@@ -19,6 +19,8 @@ using Base: IndexLinear, promote_eltype, promote_op, promote_typeof,
     @propagate_inbounds, @pure, reduce, typed_hvcat, typed_vcat, require_one_based_indexing,
     splat
 using Base.Broadcast: Broadcasted, broadcasted
+using OpenBLAS_jll
+using libblastrampoline_jll
 import Libdl
 
 export
@@ -563,42 +565,9 @@ function versioninfo(io::IO=stdout)
     return nothing
 end
 
-function find_library_path(name)
-    shlib_ext = string(".", Libdl.dlext)
-    if !endswith(name, shlib_ext)
-        name_ext = string(name, shlib_ext)
-    end
-
-    # On windows, we look in `bin` and never in `lib`
-    @static if Sys.iswindows()
-        path = joinpath(Sys.BINDIR, name_ext)
-        isfile(path) && return path
-    else
-        # On other platforms, we check `lib/julia` first, and if that doesn't exist, `lib`.
-        path = joinpath(Sys.BINDIR, Base.LIBDIR, "julia", name_ext)
-        isfile(path) && return path
-
-        path = joinpath(Sys.BINDIR, Base.LIBDIR, name_ext)
-        isfile(path) && return path
-    end
-
-    # If we can't find it by absolute path, we'll try just passing this straight through to `dlopen()`
-    return name
-end
-
 function __init__()
     try
-        libblas_path = find_library_path(Base.libblas_name)
-        liblapack_path = find_library_path(Base.liblapack_name)
-        # We manually `dlopen()` these libraries here, so that we search with `libjulia-internal`'s
-        # `RPATH` and not `libblastrampoline's`.  Once it's been opened, when LBT tries to open it,
-        # it will find the library already loaded.
-        libblas_path = Libdl.dlpath(Libdl.dlopen(libblas_path))
-        BLAS.lbt_forward(libblas_path; clear=true)
-        if liblapack_path != libblas_path
-            liblapack_path = Libdl.dlpath(Libdl.dlopen(liblapack_path))
-            BLAS.lbt_forward(liblapack_path)
-        end
+        BLAS.lbt_forward(OpenBLAS_jll.libopenblas_path; clear=true)
         BLAS.check()
     catch ex
         Base.showerror_nostdio(ex, "WARNING: Error during initialization of module LinearAlgebra")

stdlib/LinearAlgebra/src/blas.jl

@@ -63,19 +63,7 @@ export
     trsm!,
     trsm
 
-# Eventually this will be replaced with `libblastrampoline_jll.libblastrampoline`
-const libblastrampoline = "libblastrampoline"
-libblastrampoline_handle = C_NULL
-
-# Legacy bindings that some packages (such as NNlib.jl) use.
-# We maintain these for backwards-compatibility but new packages
-# should not look at these, instead preferring to parse the output
-# of BLAS.get_config()
-const libblas = libblastrampoline
-const liblapack = libblastrampoline
-
-import LinearAlgebra
-using LinearAlgebra: BlasReal, BlasComplex, BlasFloat, BlasInt, DimensionMismatch, checksquare, stride1, chkstride1
+using ..LinearAlgebra: libblastrampoline, BlasReal, BlasComplex, BlasFloat, BlasInt, DimensionMismatch, checksquare, stride1, chkstride1
 
 include("lbt.jl")
 

stdlib/LinearAlgebra/src/lapack.jl

@@ -5,16 +5,9 @@ module LAPACK
 Interfaces to LAPACK subroutines.
 """ LAPACK
 
-const libblastrampoline = "libblastrampoline"
-
-# Legacy binding maintained for backwards-compatibility but new packages
-# should not look at this, instead preferring to parse the output
-# of BLAS.get_config()
-const liblapack = libblastrampoline
-
 using ..LinearAlgebra.BLAS: @blasfunc, chkuplo
 
-using ..LinearAlgebra: BlasFloat, BlasInt, LAPACKException, DimensionMismatch,
+using ..LinearAlgebra: libblastrampoline, BlasFloat, BlasInt, LAPACKException, DimensionMismatch,
     SingularException, PosDefException, chkstride1, checksquare,triu, tril, dot
 
 using Base: iszero, require_one_based_indexing

stdlib/LinearAlgebra/test/blas.jl

@@ -668,10 +668,6 @@ end
     @test BLAS.get_num_threads() === default
 end
 
-# https://github.com/JuliaLang/julia/pull/39845
-@test LinearAlgebra.BLAS.libblas == "libblastrampoline"
-@test LinearAlgebra.BLAS.liblapack == "libblastrampoline"
-
 @testset "test for 0-strides" for elty in (Float32, Float64, ComplexF32, ComplexF64)
     A = randn(elty, 10, 10);
     a = view([randn(elty)], 1 .+ 0(1:10))

stdlib/LinearAlgebra/test/lapack.jl

@@ -702,9 +702,6 @@ let A = [NaN NaN; NaN NaN]
     @test_throws ArgumentError eigen(A)
 end
 
-# # https://github.com/JuliaLang/julia/pull/39845
-@test LinearAlgebra.LAPACK.liblapack == "libblastrampoline"
-
 # Issue #42762 https://github.com/JuliaLang/julia/issues/42762
 # Tests geqrf! and gerqf! with null column dimensions
 a = zeros(2,0), zeros(0)

stdlib/libblastrampoline_jll/Project.toml

@@ -5,7 +5,6 @@ version = "5.0.1+0"
 [deps]
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
-OpenBLAS_jll = "4536629a-c528-5b80-bd46-f80d51c5b363"
 
 [compat]
 julia = "1.8"

test/precompile.jl

@@ -359,10 +359,10 @@ precompile_test_harness(false) do dir
             Dict(let m = Base.root_module(Base, s)
                      Base.PkgId(m) => Base.module_build_id(m)
                  end for s in
-                [:ArgTools, :Artifacts, :Base64, :CRC32c, :Dates, :DelimitedFiles,
-                 :Distributed, :Downloads, :FileWatching, :Future, :InteractiveUtils,
+                [:ArgTools, :Artifacts, :Base64, :CompilerSupportLibraries_jll, :CRC32c, :Dates, :DelimitedFiles,
+                 :Distributed, :Downloads, :FileWatching, :Future, :InteractiveUtils, :libblastrampoline_jll,
                  :LazyArtifacts, :LibCURL, :LibCURL_jll, :LibGit2, :Libdl, :LinearAlgebra,
-                 :Logging, :Markdown, :Mmap, :MozillaCACerts_jll, :NetworkOptions, :Pkg, :Printf,
+                 :Logging, :Markdown, :Mmap, :MozillaCACerts_jll, :NetworkOptions, :OpenBLAS_jll, :Pkg, :Printf,
                  :Profile, :p7zip_jll, :REPL, :Random, :SHA, :Serialization, :SharedArrays, :Sockets,
                  :SparseArrays, :Statistics, :SuiteSparse, :TOML, :Tar, :Test, :UUIDs, :Unicode,
                  :nghttp2_jll]