debug environment variable refined.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@12651 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

main.c

@@ -29,9 +29,21 @@ objcdummyfunction(void)
 int
 main(int argc, char **argv, char **envp)
 {
-#ifdef RUBY_GC_STRESS
+#ifdef RUBY_DEBUG_ENV
     RUBY_EXTERN int gc_stress;
-    gc_stress = getenv("RUBY_GC_STRESS") != NULL;
+    RUBY_EXTERN int enable_coredump;
+    char *str;
+    str = getenv("RUBY_DEBUG");
+    if (str) {
+        for (str = strtok(str, ","); str; str = strtok(NULL, ",")) {
+            if (strcmp(str, "gc_stress") == 0)
+              gc_stress = 1;
+            else if (strcmp(str, "core") == 0)
+              enable_coredump = 1;
+            else
+              fprintf(stderr, "unexpected debug option: %s\n", str);
+        }
+    }
 #endif
 #ifdef _WIN32
     NtInitialize(&argc, &argv);

signal.c

@@ -993,6 +993,10 @@ init_sigchld(int sig)
 #endif
 }
 
+#ifdef RUBY_DEBUG_ENV
+int enable_coredump = 0;
+#endif
+
 /*
  * Many operating systems allow signals to be sent to running
  * processes. Some signals have a defined effect on the process, while
@@ -1065,12 +1069,18 @@ Init_signal(void)
     install_sighandler(SIGUSR2, sighandler);
 #endif
 
+#ifdef RUBY_DEBUG_ENV
+    if (!enable_coredump) {
+#endif
 #ifdef SIGBUS
     install_sighandler(SIGBUS, sigbus);
 #endif
 #ifdef SIGSEGV
     install_sighandler(SIGSEGV, sigsegv);
 #endif
+#ifdef RUBY_DEBUG_ENV
+    }
+#endif
 #ifdef SIGPIPE
     install_sighandler(SIGPIPE, sigpipe);
 #endif