error.c(exc_full_message): Exception#full_message

Add a method to retrieve a String expression of an exception,
formatted in the same way that Ruby prints an uncaught exception out.

[Feature #14141]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61154 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -31,6 +31,10 @@ with all sufficient information, see the ChangeLog file or Redmine
 
   * Now deprecated [Feature #3072]
 
+* Exception
+
+  * Exception#full_message [Feature #14141] [experimental]
+
 * Dir
 
   * Dir.glob provides new optional keyword argument, :base.

error.c

@@ -921,6 +921,25 @@ exc_to_s(VALUE exc)
     return rb_String(mesg);
 }
 
+/*
+ * call-seq:
+ *   exception.full_message  ->  string
+ *
+ * Returns formatted string of <i>exception</i>.
+ * The returned string is formatted using the same format that Ruby uses
+ * when printing an uncaught exceptions to stderr. So it may differ by
+ * <code>$stderr.tty?</code> at the timing of a call.
+ */
+
+static VALUE
+exc_full_message(VALUE exc)
+{
+    VALUE str = rb_str_new2("");
+    VALUE errat = rb_get_backtrace(exc);
+    rb_ec_error_write(exc, errat, str);
+    return str;
+}
+
 /*
  * call-seq:
  *   exception.message   ->  string
@@ -2189,6 +2208,7 @@ Init_Exception(void)
     rb_define_method(rb_eException, "==", exc_equal, 1);
     rb_define_method(rb_eException, "to_s", exc_to_s, 0);
     rb_define_method(rb_eException, "message", exc_message, 0);
+    rb_define_method(rb_eException, "full_message", exc_full_message, 0);
     rb_define_method(rb_eException, "inspect", exc_inspect, 0);
     rb_define_method(rb_eException, "backtrace", exc_backtrace, 0);
     rb_define_method(rb_eException, "backtrace_locations", exc_backtrace_locations, 0);

eval_error.c

@@ -4,25 +4,38 @@
  */
 
 #ifdef HAVE_BUILTIN___BUILTIN_CONSTANT_P
+#define write_warn(str, x) RB_GNUC_EXTENSION_BLOCK( \
+        NIL_P(str) ? \
+            warn_print(x) : ( \
+            (__builtin_constant_p(x)) ? 		\
+                rb_str_concat((str), rb_str_new((x), (long)strlen(x))) : \
+                rb_str_concat((str), rb_str_new2(x)) \
+            ) \
+        )
 #define warn_print(x) RB_GNUC_EXTENSION_BLOCK(	\
     (__builtin_constant_p(x)) ? 		\
 	rb_write_error2((x), (long)strlen(x)) : \
 	rb_write_error(x)			\
 )
 #else
+#define write_warn(str, x) NIL_P(str) ? rb_write_error((x)) : rb_str_concat((str), rb_str_new2(x))
 #define warn_print(x) rb_write_error(x)
 #endif
+
+#define write_warn2(str,x,l) NIL_P(str) ? warn_print2(x,l) : rb_str_concat((str), rb_str_new((x),(l)))
 #define warn_print2(x,l) rb_write_error2((x),(l))
+
+#define write_warn_str(str,x) NIL_P(str) ? rb_write_error_str(x) : rb_str_concat((str), (x))
 #define warn_print_str(x) rb_write_error_str(x)
 
 static VALUE error_pos_str(void);
 
 static void
-error_pos(void)
+error_pos(const VALUE str)
 {
-    VALUE str = error_pos_str();
+    VALUE pos = error_pos_str();
-    if (!NIL_P(str)) {
+    if (!NIL_P(pos)) {
-	warn_print_str(str);
+	write_warn_str(str, pos);
     }
 }
 
@@ -73,7 +86,7 @@ error_print(rb_execution_context_t *ec)
 }
 
 static void
-print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, int colored)
+print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, const VALUE str, int colored)
 {
     static const char underline[] = "\033[4;1m";
     static const char bold[] = "\033[1m";
@@ -85,14 +98,14 @@ print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, int colo
     if (emesg != Qundef) {
 	if (NIL_P(errat) || RARRAY_LEN(errat) == 0 ||
 	    NIL_P(mesg = RARRAY_AREF(errat, 0))) {
-	    error_pos();
+	    error_pos(str);
 	}
 	else {
-	    warn_print_str(mesg);
+	    write_warn_str(str, mesg);
-	    warn_print(": ");
+	    write_warn(str, ": ");
 	}
 
-        if (colored) warn_print(bold);
+        if (colored) write_warn(str, bold);
 
 	if (!NIL_P(emesg)) {
 	    einfo = RSTRING_PTR(emesg);
@@ -101,17 +114,17 @@ print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, int colo
     }
 
     if (eclass == rb_eRuntimeError && elen == 0) {
-        if (colored) warn_print(underline);
+        if (colored) write_warn(str, underline);
-	warn_print("unhandled exception\n");
+	write_warn(str, "unhandled exception\n");
     }
     else {
 	VALUE epath;
 
 	epath = rb_class_name(eclass);
 	if (elen == 0) {
-            if (colored) warn_print(underline);
+            if (colored) write_warn(str, underline);
-	    warn_print_str(epath);
+	    write_warn_str(str, epath);
-	    warn_print("\n");
+	    write_warn(str, "\n");
 	}
 	else {
 	    const char *tail = 0;
@@ -123,26 +136,26 @@ print_errinfo(const VALUE eclass, const VALUE errat, const VALUE emesg, int colo
 		len = tail - einfo;
 		tail++;		/* skip newline */
 	    }
-	    warn_print_str(tail ? rb_str_subseq(emesg, 0, len) : emesg);
+	    write_warn_str(str, tail ? rb_str_subseq(emesg, 0, len) : emesg);
 	    if (epath) {
-		warn_print(" (");
+		write_warn(str, " (");
-                if (colored) warn_print(underline);
+                if (colored) write_warn(str, underline);
-                warn_print_str(epath);
+                write_warn_str(str, epath);
-                if (colored) warn_print(reset);
+                if (colored) write_warn(str, reset);
-                if (colored) warn_print(bold);
+                if (colored) write_warn(str, bold);
-		warn_print(")\n");
+		write_warn(str, ")\n");
 	    }
 	    if (tail) {
-		warn_print_str(rb_str_subseq(emesg, tail - einfo, elen - len - 1));
+		write_warn_str(str, rb_str_subseq(emesg, tail - einfo, elen - len - 1));
 	    }
-	    if (tail ? einfo[elen-1] != '\n' : !epath) warn_print2("\n", 1);
+	    if (tail ? einfo[elen-1] != '\n' : !epath) write_warn2(str, "\n", 1);
 	}
     }
-    if (colored) warn_print(reset);
+    if (colored) write_warn(str, reset);
 }
 
 static void
-print_backtrace(const VALUE eclass, const VALUE errat, int reverse)
+print_backtrace(const VALUE eclass, const VALUE errat, const VALUE str, int reverse)
 {
     if (!NIL_P(errat)) {
 	long i;
@@ -161,12 +174,12 @@ print_backtrace(const VALUE eclass, const VALUE errat, int reverse)
 	for (i = 1; i < len; i++) {
 	    VALUE line = RARRAY_AREF(errat, reverse ? len - i : i);
 	    if (RB_TYPE_P(line, T_STRING)) {
-		VALUE str = rb_str_new_cstr("\t");
+		VALUE bt = rb_str_new_cstr("\t");
-		if (reverse) rb_str_catf(str, "%*ld: ", width, len - i);
+		if (reverse) rb_str_catf(bt, "%*ld: ", width, len - i);
-		warn_print_str(rb_str_catf(str, "from %"PRIsVALUE"\n", line));
+		write_warn_str(str, rb_str_catf(bt, "from %"PRIsVALUE"\n", line));
 	    }
 	    if (skip && i == TRACE_HEAD && len > TRACE_MAX) {
-		warn_print_str(rb_sprintf("\t ... %ld levels...\n",
+		write_warn_str(str, rb_sprintf("\t ... %ld levels...\n",
 					  len - TRACE_HEAD - TRACE_TAIL));
 		i = len - TRACE_TAIL;
 	    }
@@ -175,26 +188,16 @@ print_backtrace(const VALUE eclass, const VALUE errat, int reverse)
 }
 
 void
-rb_ec_error_print(rb_execution_context_t * volatile ec, volatile VALUE errinfo)
+rb_ec_error_write(volatile VALUE errinfo, volatile VALUE errat, volatile VALUE str)
 {
-    volatile VALUE errat = Qundef;
-    volatile int raised_flag = ec->raised_flag;
     volatile VALUE eclass = Qundef, emesg = Qundef;
 
     if (NIL_P(errinfo))
 	return;
-    rb_ec_raised_clear(ec);
 
-    EC_PUSH_TAG(ec);
+    if (errat == Qundef) {
-    if (EC_EXEC_TAG() == TAG_NONE) {
-	errat = rb_get_backtrace(errinfo);
-    }
-    else if (errat == Qundef) {
 	errat = Qnil;
     }
-    else if (eclass == Qundef || emesg != Qundef) {
-	goto error;
-    }
     if ((eclass = CLASS_OF(errinfo)) != Qundef) {
 	VALUE e = rb_check_funcall(errinfo, rb_intern("message"), 0, 0);
 	if (e != Qundef) {
@@ -203,15 +206,33 @@ rb_ec_error_print(rb_execution_context_t * volatile ec, volatile VALUE errinfo)
 	}
     }
     if (rb_stderr_tty_p()) {
-	warn_print("\033[1mTraceback \033[m(most recent call last):\n");
+	write_warn(str, "\033[1mTraceback \033[m(most recent call last):\n");
-	print_backtrace(eclass, errat, TRUE);
+	print_backtrace(eclass, errat, str, TRUE);
-	print_errinfo(eclass, errat, emesg, TRUE);
+	print_errinfo(eclass, errat, emesg, str, TRUE);
     }
     else {
-	print_errinfo(eclass, errat, emesg, FALSE);
+	print_errinfo(eclass, errat, emesg, str, FALSE);
-	print_backtrace(eclass, errat, FALSE);
+	print_backtrace(eclass, errat, str, FALSE);
     }
-  error:
+}
+
+void
+rb_ec_error_print(rb_execution_context_t * volatile ec, volatile VALUE errinfo)
+{
+    volatile int raised_flag = ec->raised_flag;
+    volatile VALUE errat;
+
+    if (NIL_P(errinfo))
+	return;
+    rb_ec_raised_clear(ec);
+
+    EC_PUSH_TAG(ec);
+    if (EC_EXEC_TAG() == TAG_NONE) {
+	errat = rb_get_backtrace(errinfo);
+    }
+
+    rb_ec_error_write(errinfo, errat, Qnil);
+
     EC_POP_TAG();
     ec->errinfo = errinfo;
     rb_ec_raised_set(ec, raised_flag);
@@ -290,28 +311,28 @@ error_handle(int ex)
 	break;
 
       case TAG_RETURN:
-	error_pos();
+	error_pos(Qnil);
 	warn_print("unexpected return\n");
 	break;
       case TAG_NEXT:
-	error_pos();
+	error_pos(Qnil);
 	warn_print("unexpected next\n");
 	break;
       case TAG_BREAK:
-	error_pos();
+	error_pos(Qnil);
 	warn_print("unexpected break\n");
 	break;
       case TAG_REDO:
-	error_pos();
+	error_pos(Qnil);
 	warn_print("unexpected redo\n");
 	break;
       case TAG_RETRY:
-	error_pos();
+	error_pos(Qnil);
 	warn_print("retry outside of rescue clause\n");
 	break;
       case TAG_THROW:
 	/* TODO: fix me */
-	error_pos();
+	error_pos(Qnil);
 	warn_print("unexpected throw\n");
 	break;
       case TAG_RAISE: {

test/ruby/test_exception.rb

@@ -1094,4 +1094,15 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
       }
     end;
   end
+
+  def test_full_message
+    test_method = "def foo; raise 'testerror'; end"
+
+    out1, err1, status1 = EnvUtil.invoke_ruby(['-e', "#{test_method}; begin; foo; rescue => e; puts e.full_message; end"], '', true, true)
+    assert(status1.success?)
+    assert(err1.empty?, "expected nothing wrote to $stdout by #long_message")
+
+    _, err2, status1 = EnvUtil.invoke_ruby(['-e', "#{test_method}; begin; foo; end"], '', true, true)
+    assert_equal(err2, out1)
+  end
 end