Change build and link to take only the needed routines from libgfortran

CHANGELOG.md

@@ -1,9 +1,24 @@
 ## OpenBLAS v0.3.34 (v0.3.34)
 
-### 0.3.34.237.0 (2026-09~06)
+### 0.3.34.237.1 (2026-10-09)
+
+- Build every manylinux and musllinux wheel without a runtime dependency on
+  libgfortran, and therefore without libquadmath, which is only ever pulled in
+  as a dependency of libgfortran itself.  This drops ~1MB (compressed) from the
+  wheels that bundled both and, since libquadmath is LGPL-2.1-or-later with no
+  GCC Runtime Library Exception, removes an LGPL obligation along with it.  The
+  two `x**n` entry points are taken as-is out of the toolchain's libgfortran.a
+  so results stay bit-for-bit identical; see tools/gfortran_compat.sh.  macOS
+  is unchanged for now (ld64 has no -Wl,--exclude-libs), and Windows already
+  static-links libgfortran.  A toolchain that cannot support it falls back to
+  linking libgfortran as before.
+= Update windows devstudio 2022 to 2026
+
+
+### 0.3.34.237.0 (2026-09-06)
 - pick up a fix for SVE indentification
 
-### 0.3.34.106.0 (2026-08~08)
+### 0.3.34.106.0 (2026-08-08)
 - pick up a fix for windows threading
 
 ### 0.3.34.0.0 (2026-07-17)

ci-repair-wheel.sh

@@ -22,13 +22,22 @@ else
     # Add an RPATH to libgfortran:
     # https://github.com/pypa/auditwheel/issues/451
     # Use zipfile since the manylinux images do not have `zip`
-    python3 -c "
+    #
+    # Platforms built with NO_LIBGFORTRAN=1 bundle no libgfortran (and so no
+    # libquadmath, which is the only reason this fixup is needed at all), so
+    # there is nothing to repair there.  Count what we extracted and skip the
+    # rest when the wheel is already clean.
+    n_gfortran=$(python3 -c "
 import re, sys, zipfile, pathlib
 whl = next(pathlib.Path(sys.argv[1]).glob('*.whl'))
 with zipfile.ZipFile(whl, 'a') as z:
     members = [m for m in z.namelist() if re.search(r'libgfortran', m)]
     z.extractall(members=members)
-    " "$1"
+print(len(members))
+    " "$1")
+    if [ "$n_gfortran" = "0" ]; then
+        echo "wheel bundles no libgfortran; skipping the auditwheel #451 rpath fixup"
+    else
     patchelf --force-rpath --set-rpath '$ORIGIN' */lib/libgfortran*
     python3 -c "
 import sys, zipfile, pathlib, glob
@@ -46,6 +55,7 @@ with zipfile.ZipFile(whl, 'w', compression=zipfile.ZIP_DEFLATED) as z:
     for item, data in entries.items():
         z.writestr(item, data)    
 " "$1"
+    fi
     mkdir -p /output
     # copy libs/openblas*.tar.gz to dist/
     cp libs/openblas*.tar.gz /output/

ci-test.sh

@@ -30,3 +30,43 @@ fi
 
 $PYTHON -m pip install pkgconf
 $PYTHON -m pkgconf scipy-openblas --cflags
+
+# Check the Fortran-runtime story of the installed wheel.
+#
+# Note this asks the *library* what happened rather than asking
+# want_no_libgfortran what we intended: build_gfortran_compat falls back to
+# linking libgfortran on toolchains it cannot support (no static
+# libgfortran.a on riscv64, for instance), and such a wheel legitimately
+# still bundles the runtime.  The build already asserts the clean case on the
+# library it produces; repeating it here catches anything
+# auditwheel/delocate might reintroduce while repairing the wheel.
+source tools/gfortran_compat.sh
+
+if [ "${INTERFACE64}" != "1" ]; then
+    pkgdir=$($PYTHON -c "import scipy_openblas32 as m, pathlib; print(pathlib.Path(m.__file__).parent)")
+else
+    pkgdir=$($PYTHON -c "import scipy_openblas64 as m, pathlib; print(pathlib.Path(m.__file__).parent)")
+fi
+echo "checking installed package $pkgdir"
+
+openblas_lib=$(ls "$pkgdir"/lib/libscipy_openblas*.so "$pkgdir"/lib/libscipy_openblas*.dylib 2>/dev/null | head -1 || true)
+if [ -z "$openblas_lib" ]; then
+    echo "FAIL: no OpenBLAS library found under $pkgdir/lib"
+    exit 1
+fi
+
+if [ -n "$(fortran_runtime_deps "$openblas_lib")" ]; then
+    echo "NOTE: $(basename "$openblas_lib") links the Fortran runtime, so this"
+    echo "      platform took the fallback path in build_gfortran_compat and the"
+    echo "      wheel is expected to bundle it.  Nothing to assert."
+else
+    # The library needs no Fortran runtime, so the wheel must not ship one.
+    found=$(find "$pkgdir" \( -name 'libgfortran*' -o -name 'libquadmath*' \) -print)
+    if [ -n "$found" ]; then
+        echo "FAIL: $(basename "$openblas_lib") needs no Fortran runtime, yet the"
+        echo "      wheel still bundles it:"
+        echo "$found"
+        exit 1
+    fi
+    assert_no_fortran_runtime "$openblas_lib"
+fi

patches/0001-allow-building-without-libgfortran.patch

@@ -0,0 +1,68 @@
+diff --git a/Makefile.system b/Makefile.system
+index e8e732e9c..90c814ebd 100644
+--- a/Makefile.system
++++ b/Makefile.system
+@@ -1207,15 +1207,17 @@ FCOMMON_OPT += -Wall
+ FCOMMON_OPT += -frecursive
+ # work around ABI problem with passing single-character arguments
+ FCOMMON_OPT += -fno-optimize-sibling-calls
+-#Don't include -lgfortran, when NO_LAPACK=1 or lsbcc
++#Don't include -lgfortran, when NO_LAPACK=1 or lsbcc or NO_LIBGFORTRAN=1
+ ifneq ($(NOFORTRAN), 1)
+ ifneq ($(NOFORTRAN), 2)
+ ifneq ($(NO_LAPACK), 1)
++ifneq ($(NO_LIBGFORTRAN), 1)
+ EXTRALIB += -lgfortran
+ endif
+ endif
+ endif
+ endif
++endif
+ ifdef NO_BINARY_MODE
+ ifeq ($(ARCH), $(filter $(ARCH),mips64))
+ ifdef BINARY64
+@@ -1917,6 +1919,31 @@ export CROSS
+ export CROSS_SUFFIX
+ export NOFORTRAN
+ export C_LAPACK
++# NO_LIBGFORTRAN=1 builds a library with no runtime dependency on the Fortran
++# runtime.  LIBGFORTRAN_COMPAT must point at an archive supplying the few
++# libgfortran entry points the Fortran LAPACK sources reference; the link
++# fails loudly if it does not cover them all.  libquadmath goes away along
++# with libgfortran, being only ever a dependency of libgfortran itself.
++#
++# The archive is kept out of EXTRALIB on purpose: EXTRALIB is what
++# Makefile.install writes into the installed .pc file, and a build-time
++# absolute path has no business being there.  It goes into
++# LIBGFORTRAN_COMPAT_LINK, which the shared-library link rules add directly,
++# and into FEXTRALIB, which is what the macOS dylib rule uses.
++#
++# Kept here, at the end and at top level, so it sees the final value of
++# FEXTRALIB whatever the USE_OPENMP and compiler conditionals above did.
++ifeq ($(NO_LIBGFORTRAN), 1)
++FEXTRALIB := $(filter-out -lgfortran -lquadmath,$(FEXTRALIB))
++ifneq ($(LIBGFORTRAN_COMPAT), )
++LIBGFORTRAN_COMPAT_LINK = -Wl,--exclude-libs,$(notdir $(LIBGFORTRAN_COMPAT)) $(LIBGFORTRAN_COMPAT)
++FEXTRALIB += $(LIBGFORTRAN_COMPAT_LINK)
++endif
++endif
++
++export LIBGFORTRAN_COMPAT
++export LIBGFORTRAN_COMPAT_LINK
++export NO_LIBGFORTRAN
+ export NO_FBLAS
+ export EXTRALIB
+ export CEXTRALIB
+diff --git a/exports/Makefile b/exports/Makefile
+index c4633143b..55f086297 100644
+--- a/exports/Makefile
++++ b/exports/Makefile
+@@ -213,7 +213,7 @@ else
+ ifneq ($(C_COMPILER), LSB)
+ 	$(CC) $(CFLAGS) $(LDFLAGS) -shared -o ../$(LIBSONAME) \
+ 	-Wl,--whole-archive $< -Wl,--no-whole-archive \
+-	-Wl,-soname,$(INTERNALNAME) $(EXTRALIB)
++	-Wl,-soname,$(INTERNALNAME) $(EXTRALIB) $(LIBGFORTRAN_COMPAT_LINK)
+ 	$(CC) $(CFLAGS) $(LDFLAGS) -w -o linktest linktest.c ../$(LIBSONAME) $(FEXTRALIB) && echo OK.
+ else
+ #for LSB

pyproject.toml

@@ -9,7 +9,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "scipy-openblas64"
 # v0.3.34-237-g1ad90fb1
-version = "0.3.34.237.0"
+version = "0.3.34.237.1"
 requires-python = ">=3.7"
 description = "Provides OpenBLAS for python packaging"
 readme = "README.md"

tools/build_steps.sh

@@ -7,6 +7,38 @@ ROOT_DIR=$(dirname $(dirname "${BASH_SOURCE[0]}"))
 
 MB_PYTHON_VERSION=3.9
 
+source $(dirname "${BASH_SOURCE[0]}")/gfortran_compat.sh
+
+# Whether to build without a runtime dependency on libgfortran (and so
+# without libquadmath, which is only ever a dependency of libgfortran itself).
+#
+# Enabled for every manylinux and musllinux target.  The set of libgfortran
+# entry points the Fortran LAPACK sources reference is identical on all of
+# them -- _gfortran_concat_string and _gfortran_etime, plus _gfortran_pow_r*_i8
+# for INTERFACE64 -- because it comes from the LAPACK Fortran itself
+# (`SIDE // TRANS`, `x**n`) rather than from anything architecture specific.
+# If a toolchain cannot support it anyway, build_gfortran_compat returns
+# non-zero and the build falls back to linking libgfortran as before.
+#
+# macOS is excluded for now: the link needs -Wl,--exclude-libs to keep the
+# compat symbols out of the dylib's export table, and ld64 has no equivalent,
+# so it would be a hard link failure rather than a fallback.  See
+# tools/gfortran_compat.sh.  Windows never gets here -- it uses
+# tools/build_steps_windows.sh, which already static-links libgfortran and
+# asserts that libquadmath is not pulled in.
+#
+# Set NO_LIBGFORTRAN=0 in a CI matrix row to opt that row out, or
+# NO_LIBGFORTRAN=1 to force it on.
+function want_no_libgfortran {
+    # want_no_libgfortran <plat>   (plat accepted but not currently needed --
+    # the decision is per-OS, and callers already have it to hand)
+    [ -n "$NO_LIBGFORTRAN" ] && { [ "$NO_LIBGFORTRAN" = "1" ]; return $?; }
+    case "$(uname -s)" in
+        Linux) return 0 ;;
+        *)     return 1 ;;
+    esac
+}
+
 function before_build {
     # install gfortran, objconv on macOS
     if [ "$(uname -s)" == "Darwin" ]; then
@@ -169,6 +201,25 @@ function build_lib {
             ;;
     esac
     interface_flags="$interface_flags SYMBOLPREFIX=scipy_ LIBNAMEPREFIX=scipy_ FIXED_LIBNAME=1"
+
+    # Drop the libgfortran/libquadmath runtime dependency where we can.  If
+    # the toolchain cannot support it (no static libgfortran.a, or the
+    # objects we need are no longer self-contained) fall back to the old
+    # behaviour rather than failing the build -- see tools/gfortran_compat.sh.
+    local compat_lib=""
+    if want_no_libgfortran "$plat"; then
+        if compat_lib=$(build_gfortran_compat "$PWD/build/gfortran_compat" "$interface64"); then
+            # TIMER=NONE selects LAPACK's second_NONE.f/dsecnd_NONE.f, which
+            # removes the only reference to _gfortran_etime.  SECOND/DSECND
+            # then return 0.0, as they already do in a C_LAPACK build.
+            interface_flags="$interface_flags NO_LIBGFORTRAN=1 LIBGFORTRAN_COMPAT=$compat_lib TIMER=NONE"
+            echo "building without a libgfortran runtime dependency"
+        else
+            compat_lib=""
+            echo "WARNING: cannot drop libgfortran on ${MB_ML_LIBC:-manylinux}-$plat, linking it as usual"
+        fi
+    fi
+
     mkdir -p libs
     set -x
     git config --global --add safe.directory '*'
@@ -218,6 +269,26 @@ function build_lib {
     rm $BUILD_PREFIX/lib/pkgconfig/scipy-openblas.pc.bak
     fi
 
+    if [ -n "$compat_lib" ]; then
+        # The shared library picked these up from the link line (see
+        # LIBGFORTRAN_COMPAT_LINK in the patch), but the static library is
+        # assembled from OpenBLAS's own objects only.  Add them so
+        # that linking libscipy_openblas*.a does not need libgfortran either
+        # -- the .pc file no longer advertises -lgfortran in Libs.private.
+        # Done after the INTERFACE64 branch above, which overwrites the
+        # installed archive with the symbol-renamed one.  The renaming does
+        # not touch _gfortran_* names, so order is safe either way.
+        local compat_dir=$(dirname "$compat_lib")
+        for static_lib in $BUILD_PREFIX/lib/libscipy_openblas*.a; do
+            # An unmatched glob arrives as a literal, and `ar crs` would
+            # happily create an archive at that bogus path.
+            [ -f "$static_lib" ] || continue
+            ar crs "$static_lib" "$compat_dir"/*.o
+        done
+        assert_no_fortran_runtime $BUILD_PREFIX/lib/libscipy_openblas*.so \
+                                  $BUILD_PREFIX/lib/libscipy_openblas*.dylib
+    fi
+
     local out_name="openblas.tar.gz"
     tar zcvf libs/$out_name \
         $BUILD_PREFIX/include/*blas* \

tools/build_steps_win_arm64.bat

@@ -80,7 +80,10 @@ REM sed -e "s/^VERSION = .*/VERSION = ${version}/" -i.bak Makefile.rule
 
 for /f "tokens=3 delims= " %%v in ('findstr /b "version = " ..\pyproject.toml') do set version=%%v
 set version=%version:"=%
-powershell -Command "(Get-Content OpenBLAS/Makefile.rule) -replace '^VERSION = .*', 'VERSION = %version%' | Set-Content Makefile.rule"
+REM cwd is already OpenBLAS here, so the source is Makefile.rule, not
+REM OpenBLAS/Makefile.rule -- that path never existed, Get-Content errored,
+REM and the VERSION substitution silently never happened.
+powershell -Command "(Get-Content Makefile.rule) -replace '^VERSION = .*', 'VERSION = %version%' | Set-Content Makefile.rule"
 
 REM Set suffixed-ILP64 flags
 if "%if_bits%"=="64" (
@@ -94,9 +97,47 @@ if exist build (rmdir /S /Q build || exit /b 1)
 mkdir build || exit /b 1 & cd build || exit /b 1
 
 echo Setting up ARM64 Developer Command Prompt and running CMake...
-
-REM Initialize VS ARM64 environment
-CALL "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsarm64.bat"
+
+REM Initialize VS ARM64 environment.
+REM
+REM Ask vswhere where Visual Studio is rather than hardcoding the version and
+REM edition: the windows-11-arm image migrated from VS 2022 to VS 2026 in
+REM September 2026 (actions/runner-images#14602), which broke the old
+REM hardcoded 2022\Enterprise path.  That failed silently -- CALL on a missing
+REM batch file sets no errorlevel worth checking here -- so the vcvars
+REM environment was simply never applied and the first visible symptom was
+REM CMake reporting "CMAKE_MT-NOTFOUND" and "Detecting C compiler ABI info -
+REM failed", because mt.exe and the MSVC/SDK paths were missing.  Fail loudly
+REM instead, so the next image change is obvious from the log.
+set "VSWHERE=%ProgramFiles(x86)%\Microsoft Visual Studio\Installer\vswhere.exe"
+if not exist "%VSWHERE%" set "VSWHERE=%ProgramFiles%\Microsoft Visual Studio\Installer\vswhere.exe"
+if not exist "%VSWHERE%" (
+    echo Error: cannot find vswhere.exe, so cannot locate Visual Studio.
+    exit /b 1
+)
+set "VSINSTALL="
+for /f "usebackq delims=" %%i in (`"%VSWHERE%" -latest -prerelease -products * -property installationPath`) do set "VSINSTALL=%%i"
+if not defined VSINSTALL (
+    echo Error: vswhere.exe reported no Visual Studio installation.
+    exit /b 1
+)
+set "VCVARSALL=%VSINSTALL%\VC\Auxiliary\Build\vcvarsall.bat"
+if not exist "%VCVARSALL%" (
+    echo Error: no VC\Auxiliary\Build\vcvarsall.bat under "%VSINSTALL%".
+    exit /b 1
+)
+echo Using Visual Studio at "%VSINSTALL%"
+CALL "%VCVARSALL%" arm64
+if errorlevel 1 (
+    echo Error: "%VCVARSALL%" arm64 failed.
+    exit /b 1
+)
+where mt.exe >NUL 2>&1
+if errorlevel 1 (
+    echo Error: mt.exe is not on PATH after vcvarsall; CMake will fail with
+    echo CMAKE_MT-NOTFOUND. The Windows SDK component may be missing.
+    exit /b 1
+)
 
 REM Prefer LLVM flang
 PATH=C:\Program Files\LLVM\bin;%PATH%