Add flag to build C API on-demand via launcher.

Author: fangerer

graalpython/com.oracle.graal.python.shell/src/com/oracle/graal/python/shell/GraalPythonMain.java

@@ -71,6 +71,7 @@ public static void main(String[] args) {
     private boolean quietFlag = false;
     private boolean noUserSite = false;
     private boolean noSite = false;
+    private boolean ensureCapi = false;
     private boolean stdinIsInteractive = System.console() != null;
     private boolean runLLI = false;
     private boolean unbufferedIO = false;
@@ -159,6 +160,13 @@ protected List<String> preprocessArguments(List<String> givenArgs, Map<String, S
                         unrecognized.add(arg);
                     }
                     break;
+                case "-ensure-capi":
+                    if (wantsExperimental) {
+                        ensureCapi = true;
+                    } else {
+                        unrecognized.add(arg);
+                    }
+                    break;
                 case "-debug-java":
                     if (wantsExperimental) {
                         if (!isAOT()) {
@@ -400,6 +408,9 @@ protected void launch(Builder contextBuilder) {
                     print("Type \"help\", \"copyright\", \"credits\" or \"license\" for more information.");
                 }
             }
+            if (ensureCapi) {
+                evalInternal(context, "import build_capi; build_capi.ensure_capi([" + (quietFlag ? "'-q'" : "") + "])\n");
+            }
             if (!noSite) {
                 evalInternal(context, "import site\n");
             }

graalpython/lib-python/3/build_capi.py

@@ -65,6 +65,14 @@ def configure_logging(args):
         logging.basicConfig(level=logging.INFO)
 
 
+def ensure_capi(args=[]):
+    configure_logging(args)
+    from distutils.sysconfig import get_config_var
+    if not os.path.exists(os.path.join(capi_home, "libpython" + get_config_var("EXT_SUFFIX"))):
+        return load_setup().build(capi_home, capi_module_home)
+    return 0
+
+
 def build(args=[]):
     configure_logging(args)
     return load_setup().build(capi_home, capi_module_home)

mx.graalpython/mx_graalpython.py

@@ -132,6 +132,7 @@ def do_run_python(args, extra_vm_args=None, env=None, jdk=None, **kwargs):
             mx.logv("CHROMEINSPECTOR was not built, not including it automatically")
 
     graalpython_args.insert(0, '--experimental-options=true')
+    graalpython_args.insert(1, '-ensure-capi')
 
     vm_args += mx.get_runtime_jvm_args(dists, jdk=jdk)