implement `pyston -c command`

src/jit.cpp

@@ -47,6 +47,20 @@
 
 using namespace pyston;
 
+// returns true iff we got a request to exit, i.e. SystemExit, placing the
+// return code in `*retcode`. does not touch `*retcode* if it returns false.
+static bool handle_toplevel_exn(const ExcInfo& e, int* retcode) {
+    if (e.matches(SystemExit)) {
+        Box* code = e.value->getattr("code");
+        *retcode = 1;
+        if (code && isSubclass(code->cls, pyston::int_cls))
+            *retcode = static_cast<BoxedInt*>(code)->n;
+        return true;
+    }
+    e.printExcAndTraceback();
+    return false;
+}
+
 int main(int argc, char** argv) {
     Timer _t("for jit startup");
     // llvm::sys::PrintStackTraceOnErrorSignal();
@@ -55,9 +69,9 @@ int main(int argc, char** argv) {
 
     int code;
     bool force_repl = false;
-    bool repl = true;
     bool stats = false;
-    while ((code = getopt(argc, argv, "+OqcdIibpjtrsvnx")) != -1) {
+    const char* command = NULL;
+    while ((code = getopt(argc, argv, "+OqdIibpjtrsvnxc:")) != -1) {
         if (code == 'O')
             FORCE_OPTIMIZE = true;
         else if (code == 't')
@@ -86,7 +100,11 @@ int main(int argc, char** argv) {
             USE_REGALLOC_BASIC = false;
         } else if (code == 'x') {
             ENABLE_PYPA_PARSER = true;
-        } else if (code == '?')
+        } else if (code == 'c') {
+            command = optarg;
+            // no more option parsing; the rest of our arguments go into sys.argv.
+            break;
+        } else
             abort();
     }
 
@@ -100,19 +118,24 @@ int main(int argc, char** argv) {
         initCodegen();
     }
 
-    if (optind != argc) {
+    // Arguments left over after option parsing are of the form:
+    //     [ script | - ] [ arguments... ]
+    // unless we've been already parsed a `-c command` option, in which case only:
+    //     [ arguments...]
+    // are parsed.
+    if (command)
+        addToSysArgv("-c");
+    else if (optind != argc) {
+        addToSysArgv(argv[optind]);
+        if (strcmp("-", argv[optind]) != 0)
             fn = argv[optind];
-        if (strcmp("-", fn) == 0)
-            fn = NULL;
-        else if (!force_repl)
-            repl = false;
+        ++optind;
+    } else
+        addToSysArgv("");
 
     for (int i = optind; i < argc; i++) {
         addToSysArgv(argv[i]);
     }
-    } else {
-        addToSysArgv("");
-    }
 
     std::string self_path = llvm::sys::fs::getMainExecutable(argv[0], (void*)main);
     assert(self_path.size());
@@ -133,6 +156,20 @@ int main(int argc, char** argv) {
 
     _t.split("to run");
     BoxedModule* main_module = NULL;
+
+    // if the user invoked `pyston -c command`
+    if (command != NULL) {
+        main_module = createModule("__main__", "<string>");
+        AST_Module* m = parse_string(command);
+        try {
+            compileAndRunModule(m, main_module);
+        } catch (ExcInfo e) {
+            int retcode = 1;
+            (void)handle_toplevel_exn(e, &retcode);
+            return retcode;
+        }
+    }
+
     if (fn != NULL) {
         llvm::SmallString<128> path;
 
@@ -150,20 +187,13 @@ int main(int argc, char** argv) {
         try {
             main_module = createAndRunModule("__main__", fn);
         } catch (ExcInfo e) {
-            if (e.matches(SystemExit)) {
-                Box* code = e.value->getattr("code");
-                int rtncode = 1;
-                if (code && isSubclass(code->cls, pyston::int_cls))
-                    rtncode = static_cast<BoxedInt*>(code)->n;
-                return rtncode;
-            } else {
-                e.printExcAndTraceback();
-                return 1;
-            }
+            int retcode = 1;
+            (void)handle_toplevel_exn(e, &retcode);
+            return retcode;
         }
     }
 
-    if (repl) {
+    if (force_repl || !(command || fn)) {
         printf("Pyston v%d.%d (rev " STRINGIFY(GITREV) ")", PYSTON_VERSION_MAJOR, PYSTON_VERSION_MINOR);
         printf(", targeting Python %d.%d.%d\n", PYTHON_VERSION_MAJOR, PYTHON_VERSION_MINOR, PYTHON_VERSION_MICRO);
 
@@ -173,12 +203,11 @@ int main(int argc, char** argv) {
             main_module->fn = "<stdin>";
         }
 
-        while (repl) {
+        for (;;) {
             char* line = readline(">> ");
+            if (!line)
+                break;
 
-            if (!line) {
-                repl = false;
-            } else {
             add_history(line);
 
             AST_Module* m = parse_string(line);
@@ -206,16 +235,9 @@ int main(int argc, char** argv) {
             try {
                 compileAndRunModule(m, main_module);
             } catch (ExcInfo e) {
-                    if (e.matches(SystemExit)) {
-                        Box* code = e.value->getattr("code");
-                        int rtncode = 1;
-                        if (code && isSubclass(code->cls, pyston::int_cls))
-                            rtncode = static_cast<BoxedInt*>(code)->n;
-                        return rtncode;
-                    } else {
-                        e.printExcAndTraceback();
-                    }
-                }
+                int retcode = 0xdeadbeef; // should never be seen
+                if (handle_toplevel_exn(e, &retcode))
+                    return retcode;
             }
         }
     }