_toolchain.cxx: new toolchain.

diff --git a/nmigen/_toolchain/cxx.py b/nmigen/_toolchain/cxx.py
new file mode 100644 (file)
index 0000000..6577b31
--- /dev/null
+++ b/nmigen/_toolchain/cxx.py
@@ -0,0 +1,52 @@
+import tempfile
+import sysconfig
+import os.path
+from distutils import ccompiler
+
+
+__all__ = ["build"]
+
+
+def build(*, cxx_sources, output_name, include_dirs, macros):
+    build_dir = tempfile.TemporaryDirectory(prefix="nmigen_cxx_")
+
+    cwd = os.getcwd()
+    try:
+        # Unforuntately, `ccompiler.compile` assumes the paths are relative, and interprets
+        # the directory name of the source path specially. That makes it necessary to build in
+        # the output directory directly.
+        os.chdir(build_dir.name)
+
+        cc_driver = ccompiler.new_compiler()
+        cc_driver.output_dir = "."
+
+        cc = sysconfig.get_config_var("CC")
+        cxx = sysconfig.get_config_var("CXX")
+        cflags = sysconfig.get_config_var("CCSHARED")
+        ld_ldflags = sysconfig.get_config_var("LDCXXSHARED")
+        cc_driver.set_executables(
+            compiler=f"{cc} {cflags}",
+            compiler_so=f"{cc} {cflags}",
+            compiler_cxx=f"{cxx} {cflags}",
+            linker_so=ld_ldflags,
+        )
+
+        for include_dir in include_dirs:
+            cc_driver.add_include_dir(include_dir)
+        for macro in macros:
+            cc_driver.define_macro(macro)
+        for cxx_filename, cxx_source in cxx_sources.items():
+            with open(cxx_filename, "w") as f:
+                f.write(cxx_source)
+
+        cxx_filenames = list(cxx_sources.keys())
+        obj_filenames = cc_driver.object_filenames(cxx_filenames)
+        so_filename = cc_driver.shared_object_filename(output_name)
+
+        cc_driver.compile(cxx_filenames)
+        cc_driver.link_shared_object(obj_filenames, output_filename=so_filename, target_lang="c++")
+
+        return build_dir, so_filename
+
+    finally:
+        os.chdir(cwd)