Experiment building scipy using openblas-flang

recipes/recipes_emscripten/scipy_flang/build.sh

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+set -ex
+
+LLVM_PKG_URL="https://github.com/IsabelParedes/llvm-project/releases/download/v20.1.7_emscripten-wasm32/llvm_emscripten-wasm32-20.1.7-h2e33cc4_5.tar.bz2"
+LLVM_PKG="llvm.tar.bz2"
+export LLVM_DIR=$HOME/llvm
+
+if [ ! -d "$LLVM_DIR" ]; then
+    wget -O "$LLVM_PKG" "$LLVM_PKG_URL"
+    mkdir -p $LLVM_DIR
+    tar -xjvf $LLVM_PKG -C $LLVM_DIR --exclude='info/*' --exclude='share/*' --exclude='libexec/*'
+fi
+
+export EM_LLVM_ROOT=$LLVM_DIR
+
+echo "LLVM installation complete."
+
+# https://github.com/mesonbuild/meson/blob/e542901af6e30865715d3c3c18f703910a096ec0/mesonbuild/backend/ninjabackend.py#L94
+# Prevent from using response file. The response file that meson generates is not compatible to pyodide-build
+export MESON_RSP_THRESHOLD=131072
+
+export CFLAGS="-I$PREFIX/include/python3.13 $CFLAGS"
+export CXXFLAGS="-I$PREFIX/include/python3.13 $CXXFLAGS"
+
+# Patch mesonbuild/linkers/linkers.py - not sure what version we are patching?
+# meson 1.9.1 conda-forge, meson-python 0.18.0 conda-forge
+cp $RECIPE_DIR/meson_linkers.py $BUILD_PREFIX/lib/python3.13/site-packages/mesonbuild/linkers/linkers.py
+
+# Remove whitespace after '-s' in LDFLAGS
+export LDFLAGS="$(echo "${LDFLAGS}" | sed -E 's/-s +/-s/g')"
+
+# Use local flang-new-wrapper that does some arg mangling.
+cp $RECIPE_DIR/flang-new-wrapper $LLVM_DIR/bin/flang-new-wrapper
+
+export FC=$LLVM_DIR/bin/flang-new-wrapper
+export FFLAGS="-g --target=wasm32-unknown-emscripten -fPIC"
+export FCLIBS="-lFortranRuntime"
+
+export CFLAGS="$CFLAGS -fwasm-exceptions -sSUPPORT_LONGJMP=wasm"
+export CXXFLAGS="$CXXFLAGS -fwasm-exceptions -sSUPPORT_LONGJMP=wasm"
+
+# Note bracket after function name is important or 'sgesv' will also match 'sgesvd'
+cat void_to_int_return.txt | xargs -i sed -i -r 's/^void ({})\(/int \1(/g' scipy/linalg/cython_lapack_signatures.txt
+# Underscore after name is important
+cat void_to_int_return.txt | xargs -i sed -i -r 's/^void ({})_/int \1_/g' scipy/linalg/_matfuncs_expm.h
+
+# Add -Wl,--fatal-warnings to flags - this does not work
+export LDFLAGS="$LDFLAGS -Wl,--no-fatal-warnings"
+
+${PYTHON} -m pip install . ${PIP_ARGS} --no-build-isolation \
+    -Csetup-args="--cross-file=$RECIPE_DIR/emscripten.meson.cross" \
+    -Csetup-args="-Dfortran_std=none" \
+    -Csetup-args="-Duse-pythran=false" \
+    -Cbuild-dir="_build" \
+    -Ccompile-args="--verbose"

recipes/recipes_emscripten/scipy_flang/emscripten.meson.cross

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+[properties]
+needs_exe_wrapper = true
+skip_sanity_check = true
+longdouble_format = 'IEEE_QUAD_LE' # for numpy
+
+[host_machine]
+system = 'emscripten'
+cpu_family = 'wasm32'
+cpu = 'wasm'
+endian = 'little'
+
+[binaries]
+exe_wrapper = 'node'
+pkgconfig = 'pkg-config'

recipes/recipes_emscripten/scipy_flang/flang-new-wrapper

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+#!/bin/bash
+
+args=()
+for arg in "$@"; do
+    if [[ "${arg}" != -s* ]]; then
+        args+=("${arg}")
+    fi
+done
+
+exec "$LLVM_DIR/bin/flang-new" "-v" "${args[@]}"