java: Add new rewite rule for VMCPStringBuilder.toString()

Mon Sep 22 13:34:00 GMT 2008

VMCPStringBuilder.toString() relies on backdoor access to a private
constructor for String. We can do this via a native method, but it's
easier and more efficient to add a compiler builtin. This one performs
the transformation:
 gnu.java.lang.VMCPStringBuilder.toString(char[],int,int)
 --> java.lang.String.toString(char[],int,int)
I've also had to add a new field to the rewrite rules, that of the
destination class, but unless I've made a mistake this won't make
any difference to the existing rules.
Andrew.
2008年09月22日 Andrew Haley <aph@redhat.com>
	* expr.c (rules): Add new rule for
	gnu.java.lang.VMCPStringBuilder.toString.
	(rewrite_rule.new_classname): New field.
	(maybe_rewrite_invocation): Use new_classname field instead of
	DECL_CONTEXT (*method_p).
	Allow rewrite_arglist to be NULL.
Index: gcc/java/expr.c
===================================================================

--- gcc/java/expr.c	(revision 140485)
+++ gcc/java/expr.c	(working copy)
@@ -2075,6 +2075,7 @@
 const char *classname;
 const char *method;
 const char *signature;
+ const char *new_classname;
 const char *new_signature;
 int flags;
 tree (*rewrite_arglist) (tree arglist);
@@ -2109,20 +2110,27 @@
 static rewrite_rule rules[] =
 {{"java.lang.Class", "getClassLoader", "()Ljava/lang/ClassLoader;",
- "(Ljava/lang/Class;)Ljava/lang/ClassLoader;",
+ "java.lang.Class", "(Ljava/lang/Class;)Ljava/lang/ClassLoader;",
 ACC_FINAL|ACC_PRIVATE, rewrite_arglist_getclass},
+
 {"java.lang.Class", "forName", "(Ljava/lang/String;)Ljava/lang/Class;",
- "(Ljava/lang/String;Ljava/lang/Class;)Ljava/lang/Class;",
+ "java.lang.Class", "(Ljava/lang/String;Ljava/lang/Class;)Ljava/lang/Class;",
 ACC_FINAL|ACC_PRIVATE|ACC_STATIC, rewrite_arglist_getclass},
+
 {"gnu.classpath.VMStackWalker", "getCallingClass", "()Ljava/lang/Class;",
- "(Lgnu/gcj/RawData;)Ljava/lang/Class;",
+ "gnu.classpath.VMStackWalker", "(Lgnu/gcj/RawData;)Ljava/lang/Class;",
 ACC_FINAL|ACC_PRIVATE|ACC_STATIC, rewrite_arglist_getcaller},
+
 {"gnu.classpath.VMStackWalker", "getCallingClassLoader",
 "()Ljava/lang/ClassLoader;",
- "(Lgnu/gcj/RawData;)Ljava/lang/ClassLoader;",
+ "gnu.classpath.VMStackWalker", "(Lgnu/gcj/RawData;)Ljava/lang/ClassLoader;",
 ACC_FINAL|ACC_PRIVATE|ACC_STATIC, rewrite_arglist_getcaller},
- {NULL, NULL, NULL, NULL, 0, NULL}};
+ {"gnu.java.lang.VMCPStringBuilder", "toString", "([CII)Ljava/lang/String;",
+ "java.lang.String", "([CII)Ljava/lang/String;",
+ ACC_FINAL|ACC_PRIVATE|ACC_STATIC, NULL},
+
+ {NULL, NULL, NULL, NULL, NULL, 0, NULL}};
 /* True if this method is special, i.e. it's a private method that
 should be exported from a DSO. */
@@ -2163,20 +2171,25 @@
 	 if (get_identifier (p->method) == method
 	 && get_identifier (p->signature) == *method_signature_p)
 	 {
-	 tree maybe_method
-		= lookup_java_method (DECL_CONTEXT (*method_p),
+	 tree maybe_method;
+	 tree destination_class
+		= lookup_class (get_identifier (p->new_classname));
+	 gcc_assert (destination_class);
+	 maybe_method
+		= lookup_java_method (destination_class,
 				 method,
 				 get_identifier (p->new_signature));
 	 if (! maybe_method && ! flag_verify_invocations)
 		{
 		 maybe_method
-		 = add_method (DECL_CONTEXT (*method_p), p->flags,
+		 = add_method (destination_class, p->flags,
 				 method, get_identifier (p->new_signature));
 		 DECL_EXTERNAL (maybe_method) = 1;
 		}
 	 *method_p = maybe_method;
 	 gcc_assert (*method_p);
-	 *arg_list_p = p->rewrite_arglist (*arg_list_p);
+	 if (p->rewrite_arglist)
+		*arg_list_p = p->rewrite_arglist (*arg_list_p);
 	 *method_signature_p = get_identifier (p->new_signature);
 	 *special = integer_one_node;
