Add XSPICE support to libngspice and test

- Enable XSPICE in libngspice build with --enable-xspice
- Build cmpp natively for code model generation (wasm can't execute)
- Package XSPICE code model libraries (*.cm files) to /usr/lib/ngspice/
- Add XSPICE mixed-signal test with ADC bridge
- Use NgSpiceShared.new_instance() to avoid cffi duplicate declarations
- Fix verilog install hook to prevent build errors

Author: claude

packages/inspice/test_inspice.py

@@ -3,9 +3,12 @@
 
 @run_in_pyodide(packages=["inspice"])
 def test_inspice(selenium):
+    """Test basic ngspice analog simulation"""
     from InSpice.Spice.NgSpice.Shared import NgSpiceShared
 
-    ngspice = NgSpiceShared()
+    # Use new_instance() singleton factory to avoid cffi duplicate declarations
+    ngspice = NgSpiceShared.new_instance()
+
     circuit = """
     .title Voltage Multiplier
 
@@ -51,3 +54,45 @@ def test_inspice(selenium):
     ngspice.run()
     plot = ngspice.plot(simulation=None, plot_name=ngspice.last_plot)
     assert "V(6)" in plot
+
+
+@run_in_pyodide(packages=["inspice"])
+def test_inspice_xspice(selenium):
+    """Test XSPICE mixed-signal simulation with ADC bridge"""
+    from InSpice.Spice.NgSpice.Shared import NgSpiceShared
+
+    # Use new_instance() singleton factory - reuses same instance as test_inspice
+    # This avoids cffi duplicate declaration errors with global ffi.cdef()
+    ngspice = NgSpiceShared.new_instance()
+
+    # Load XSPICE code model
+    ngspice.exec_command("codemodel /usr/lib/ngspice/digital.cm")
+
+    # Simple XSPICE test: Analog sine -> ADC bridge
+    # NOTE: lowercase 'a' for XSPICE device instance names
+    circuit = """
+    .title XSPICE ADC Bridge Test
+
+    vdummy dummy 0 DC=0
+
+    * Analog sine wave source
+    vin in 0 SIN(0 2.5 1e6 0 0)
+
+    * ADC bridge: Convert analog to digital
+    aadc [in] [dout] adc1
+    .model adc1 adc_bridge(in_low = 1.0 in_high = 2.0)
+
+    * Resistor to complete circuit
+    R1 in 0 1MEG
+
+    .tran 0.01us 5us
+    .end
+    """
+
+    ngspice.load_circuit(circuit)
+    ngspice.run()
+    plot = ngspice.plot(simulation=None, plot_name=ngspice.last_plot)
+
+    # Verify analog input exists (proves simulation ran)
+    # Note: plot keys are lowercase node names without V() prefix
+    assert "in" in plot

packages/libngspice/meta.yaml

@@ -10,15 +10,22 @@ source:
   patches:
     - patches/0001-keep-alive-API-functions.patch
     - patches/0001-no-hicum2.patch
+    - patches/0003-fix-verilog-install-hook.patch
 
 build:
   type: shared_library
   script: |
     bash ./autogen.sh
 
+    # First build cmpp natively for build-time code generation
+    mkdir build-native && cd build-native
+    ../configure --enable-xspice --disable-debug --without-x --with-readline=no
+    make -C src/xspice/cmpp -j ${PYODIDE_JOBS:-3}
+    cd ..
+
     configure_args=(
       --prefix=${WASM_LIBRARY_DIR}
-      --disable-xspice
+      --enable-xspice
       --disable-debug
       --disable-dependency-tracking
       --enable-cider
@@ -30,10 +37,24 @@ build:
 
     mkdir release-lib && cd release-lib
     emconfigure ../configure "${configure_args[@]}" CFLAGS="${SIDE_MODULE_CFLAGS}"
+
+    # Build everything except xspice/cmpp first
+    emmake make -j ${PYODIDE_JOBS:-3} -C src/xspice/cmpp LDFLAGS="${SIDE_MODULE_LDFLAGS}"
+
+    # Now replace the wasm cmpp with the native one and touch to prevent rebuild
+    cp ../build-native/src/xspice/cmpp/cmpp src/xspice/cmpp/cmpp
+    touch src/xspice/cmpp/cmpp
+
+    # Continue building the rest
     emmake make -j ${PYODIDE_JOBS:-3} LDFLAGS="${SIDE_MODULE_LDFLAGS}"
     emmake make install
     cp ${WASM_LIBRARY_DIR}/lib/libngspice.so ${DISTDIR}
 
+    # Copy XSPICE code model libraries to ngspice/*.cm
+    # Since shared_library packages extract to /usr/lib/, the final path will be /usr/lib/ngspice/*.cm
+    mkdir -p ${DISTDIR}/ngspice
+    cp ${WASM_LIBRARY_DIR}/lib/ngspice/*.cm ${DISTDIR}/ngspice/
+
 about:
   home: http://ngspice.sourceforge.net
   license: BSD-3-Clause

packages/libngspice/patches/0003-fix-verilog-install-hook.patch

@@ -0,0 +1,17 @@
+diff --git a/src/xspice/verilog/Makefile.am b/src/xspice/verilog/Makefile.am
+index 1234567..abcdefg 100644
+--- a/src/xspice/verilog/Makefile.am
++++ b/src/xspice/verilog/Makefile.am
+@@ -45,9 +45,11 @@ endif
+ # On Windows, the dummy libvvp.* files are removed also.
+
+ install-exec-hook:
+ 	cd $(DESTDIR)$(pkglibdir); \
+ 	rm -f ivlng*a libvvp* ; \
+-	mv ivlngvpi.* ivlng.vpi
++	if [ -f ivlngvpi.so ] || [ -f ivlngvpi.dll ] || [ -f ivlngvpi.dylib ]; then \
++		mv ivlngvpi.* ivlng.vpi; \
++	fi
+
+ uninstall-hook:
+ 	rm -f $(DESTDIR)$(pkglibdir)/ivlng.vpi $(DESTDIR)$(pkglibdir)/ivlng.so