MAINT: Try a much simpler BLAS handling check

Author: HaoZeke

meson.build

@@ -21,49 +21,25 @@ print(incdir)
 '''], check: true).stdout().strip()
 
 # Get BLAS
-blas_deps = []
-if get_option('link_mkl')
-    blas_deps = [cc.find_library('mkl_rt', required : false)]
-    if not blas_deps[0].found()
-        blas_deps = [dependency('mkl-sdl', required : false)]
-    endif
+blas_dep = dependency('', required: false)
+if host_machine.system() == 'darwin'
+  message('Host is macOS, attempting to link with Accelerate framework...')
+  blas_dep = dependency('accelerate')
 else
-    if host_machine.system() == 'darwin'
-        blas_deps = [dependency('Accelerate')]
-    else
-        blas_deps = [cc.find_library('openblas', static: get_option('link_blas_statically'), required : false)]
-        if not blas_deps[0].found()
-            blas_deps = [dependency(['openblas', 'OpenBLAS'], static: get_option('link_blas_statically'), required : false)]
-        endif
-    endif
-
-    # try to find blas/cblas (e.g., Linux)
-    if not blas_deps[0].found()
-        blas_deps = [cc.find_library('blas', static: get_option('link_blas_statically'), required : false)]
-        if not blas_deps[0].found()
-            blas_deps = [dependency('blas', static: get_option('link_blas_statically'), required : false)]
-        endif
-        lapack_dep = cc.find_library('lapack', static: get_option('link_blas_statically'), required : false)
-        if not lapack_dep.found()
-            lapack_dep = dependency('lapack', static: get_option('link_blas_statically'), required : false)
-        endif
-        if lapack_dep.found()
-            blas_deps += lapack_dep
-        endif
-        cblas_dep = cc.find_library('cblas', static: get_option('link_blas_statically'), required : false)
-        if not cblas_dep.found()
-            cblas_dep = dependency('cblas', static: get_option('link_blas_statically'), required : false)
-        endif
-        if cblas_dep.found()
-            blas_deps += cblas_dep
-        endif
-    endif
+  message('Searching for a BLAS/LAPACK implementation (OpenBLAS, MKL, etc.)...')
+  # This will find the MKL-backed openblas from Conda when link_mkl is true,
+  # or the system's OpenBLAS otherwise.
+  blas_dep = dependency('blas', static: get_option('link_blas_statically'), required: false)
+endif
+
+# Final check
+if not blas_dep.found() and not get_option('sdist_mode')
+  error('A required BLAS/LAPACK implementation (MKL, Accelerate, or OpenBLAS) was not found.')
 endif
 
-# Since nothing above was required, we stop here if failed.
-# When creating an sdist we are not compiling / linking, so don't need to fail.
-if not blas_deps[0].found() and not get_option('sdist_mode')
-    error('OpenBLAS or Netlib BLAS/CBLAS is required on all platforms, and was not found.')
+# Sanity check
+if get_option('link_mkl') and not ('mkl' in blas_dep.name() or blas_dep.name().to_lower() == 'accelerate')
+  error('Requested MKL but was not found in library')
 endif
 
 # Common
@@ -76,7 +52,7 @@ common_includes = [
   'scs_source/linsys',
   incdir_numpy
 ]
-_deps = [blas_deps]
+_deps = [blas_dep]
 if get_option('use_openmp')
   _deps += dependency('openmp')
 endif