Take command line arguments from environment, and add argument to disable tracebacks

Not sure if this is really a good feature for users, but taking
command line arguments from an environment variable is definitely
helpful for testing things like virtualenv which spawns a number (~10)
of subprocess.

src/codegen/unwinding.cpp

@@ -513,6 +513,15 @@ BoxedTraceback* getTraceback() {
         return new BoxedTraceback();
     }
 
+    if (!ENABLE_TRACEBACKS) {
+        static bool printed_warning = false;
+        if (!printed_warning) {
+            printed_warning = true;
+            fprintf(stderr, "Warning: can't get traceback since ENABLE_TRACEBACKS=0\n");
+        }
+        return new BoxedTraceback();
+    }
+
     Timer _t("getTraceback", 1000);
 
     std::vector<const LineInfo*> entries;

src/core/options.cpp

@@ -41,6 +41,7 @@ bool ENABLE_INTERPRETER = true;
 bool ENABLE_PYPA_PARSER = true;
 bool USE_REGALLOC_BASIC = true;
 bool PAUSE_AT_ABORT = false;
+bool ENABLE_TRACEBACKS = true;
 
 int OSR_THRESHOLD_INTERPRETER = 500;
 int REOPT_THRESHOLD_INTERPRETER = 200;

src/core/options.h

@@ -38,7 +38,7 @@ extern int SPECULATION_THRESHOLD;
 extern int MAX_OBJECT_CACHE_ENTRIES;
 
 extern bool SHOW_DISASM, FORCE_INTERPRETER, FORCE_OPTIMIZE, PROFILE, DUMPJIT, TRAP, USE_STRIPPED_STDLIB,
-    CONTINUE_AFTER_FATAL, ENABLE_INTERPRETER, ENABLE_PYPA_PARSER, USE_REGALLOC_BASIC, PAUSE_AT_ABORT;
+    CONTINUE_AFTER_FATAL, ENABLE_INTERPRETER, ENABLE_PYPA_PARSER, USE_REGALLOC_BASIC, PAUSE_AT_ABORT, ENABLE_TRACEBACKS;
 
 extern bool ENABLE_ICS, ENABLE_ICGENERICS, ENABLE_ICGETITEMS, ENABLE_ICSETITEMS, ENABLE_ICDELITEMS, ENABLE_ICBINEXPS,
     ENABLE_ICNONZEROS, ENABLE_ICCALLSITES, ENABLE_ICSETATTRS, ENABLE_ICGETATTRS, ENALBE_ICDELATTRS, ENABLE_ICGETGLOBALS,

src/jit.cpp

@@ -87,20 +87,10 @@ static bool handle_toplevel_exn(const ExcInfo& e, int* retcode) {
     return false;
 }
 
-static int main(int argc, char** argv) {
-    Timer _t("for jit startup");
-    // llvm::sys::PrintStackTraceOnErrorSignal();
-    // llvm::PrettyStackTraceProgram X(argc, argv);
-    llvm::llvm_shutdown_obj Y;
+static bool force_repl = false;
+static bool unbuffered = false;
 
-    int code;
-    bool force_repl = false;
-    bool unbuffered = false;
-    const char* command = NULL;
-
-    // Suppress getopt errors so we can throw them ourselves
-    opterr = 0;
-    while ((code = getopt(argc, argv, "+:OqdIibpjtrsSvnxEc:FuP")) != -1) {
+int handleArg(char code) {
     if (code == 'O')
         FORCE_OPTIMIZE = true;
     else if (code == 't')
@@ -139,24 +129,53 @@ static int main(int argc, char** argv) {
         PAUSE_AT_ABORT = true;
     } else if (code == 'F') {
         CONTINUE_AFTER_FATAL = true;
-        } else if (code == 'c') {
+    } else if (code == 'T') {
+        ENABLE_TRACEBACKS = false;
+    } else {
+        fprintf(stderr, "Unknown option: -%c\n", code);
+        return 2;
+    }
+    return 0;
+}
+
+static int main(int argc, char** argv) {
+    Timer _t("for jit startup");
+    // llvm::sys::PrintStackTraceOnErrorSignal();
+    // llvm::PrettyStackTraceProgram X(argc, argv);
+    llvm::llvm_shutdown_obj Y;
+
+    int code;
+    const char* command = NULL;
+
+    char* env_args = getenv("PYSTON_RUN_ARGS");
+
+    if (env_args) {
+        while (*env_args) {
+            int r = handleArg(*env_args);
+            if (r)
+                return r;
+            env_args++;
+        }
+    }
+
+    // Suppress getopt errors so we can throw them ourselves
+    opterr = 0;
+    while ((code = getopt(argc, argv, "+:OqdIibpjtrsSvnxEc:FuPT")) != -1) {
+        if (code == 'c') {
             assert(optarg);
             command = optarg;
             // no more option parsing; the rest of our arguments go into sys.argv.
             break;
-        } else {
-            if (code == ':') {
+        } else if (code == ':') {
             fprintf(stderr, "Argument expected for the -%c option\n", optopt);
             return 2;
-            }
-
-            if (code == '?') {
+        } else if (code == '?') {
             fprintf(stderr, "Unknown option: -%c\n", optopt);
             return 2;
-            }
-
-            fprintf(stderr, "Unknown getopt() error.  '%c' '%c'\n", code, optopt);
-            abort();
+        } else {
+            int r = handleArg(code);
+            if (r)
+                return r;
         }
     }