On 04/09/2014 12:21 PM, Randy Dunlap wrote:
> On 03/30/2014 08:47 PM, Jonathan Callen wrote:
>> The sample wrapper currently fails on some Java 7 .class files.  This
>> updates the wrapper to properly handle those files.
>>
>> Signed-off-by: Jonathan Callen <jcal...@gentoo.org>
> 
> Applied.  Thanks.
> 
> How would I test this?
> 

I have attached a hand-crafted HelloWorld.class file that fails unless this 
patch is applied.  This
.class file intentionally has extra entries in its constant pool that are not 
used by Java, but the
file does pass validation.

A complete disassembly of that file, showing the purpose of each byte, is 
attached as HelloWorld.jj.

> 
>> ---
>>  Documentation/java.txt | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/Documentation/java.txt b/Documentation/java.txt
>> index e6a7232..4180205 100644
>> --- a/Documentation/java.txt
>> +++ b/Documentation/java.txt
>> @@ -188,6 +188,9 @@ shift
>>  #define CP_METHODREF 10
>>  #define CP_INTERFACEMETHODREF 11
>>  #define CP_NAMEANDTYPE 12
>> +#define CP_METHODHANDLE 15
>> +#define CP_METHODTYPE 16
>> +#define CP_INVOKEDYNAMIC 18
>>  
>>  /* Define some commonly used error messages */
>>  
>> @@ -242,14 +245,19 @@ void skip_constant(FILE *classfile, u_int16_t *cur)
>>              break;
>>      case CP_CLASS:
>>      case CP_STRING:
>> +    case CP_METHODTYPE:
>>              seekerr = fseek(classfile, 2, SEEK_CUR);
>>              break;
>> +    case CP_METHODHANDLE:
>> +            seekerr = fseek(classfile, 3, SEEK_CUR);
>> +            break;
>>      case CP_INTEGER:
>>      case CP_FLOAT:
>>      case CP_FIELDREF:
>>      case CP_METHODREF:
>>      case CP_INTERFACEMETHODREF:
>>      case CP_NAMEANDTYPE:
>> +    case CP_INVOKEDYNAMIC:
>>              seekerr = fseek(classfile, 4, SEEK_CUR);
>>              break;
>>      case CP_LONG:
>>
> 
> 

Attachment: HelloWorld.class
Description: application/java-vm

{
        u4 magic = cafebabe;
        u2 minor_version = 0000;
        u2 major_version = 0033;
        u2 constant_pool_count = 001c;
        cp_info constant_pool[constant_pool_count-1] = {
                { // 0001 = Methodref java/lang/Object.<init>:()V
                        u1 tag = 0a; // CONSTANT_Methodref
                        u2 class_index = 0006; // Class java/lang/Object
                        u2 name_and_type_index = 000c; // NameAndType <init>:()V
                },
                { // 0002 = Fieldref java/lang/System.out:Ljava/io/PrintStream;
                        u1 tag = 09; // CONSTANT_Fieldref
                        u2 class_index = 000d; // Class java/lang/System
                        u2 name_and_type_index = 000e; // NameAndType 
out:Ljava/io/PrintStream;
                },
                { // 0003 = String "Hello, world!"
                        u1 tag = 08; // CONSTANT_String_info
                        u2 string_index = 000f; // Utf8 Hello, world!
                },
                { // 0004 = Methodref 
java/io/PrintStream.println:(Ljava/lang/String;)V
                        u1 tag = 0a; // CONSTANT_Methodref
                        u2 class_index = 0010; // Class java/io/PrintStream
                        u2 name_and_type_index = 0011; // NameAndType 
println:(Ljava/lang/String;)V
                },
                { // 0005 = Class HelloWorld
                        u1 tag = 07; // CONSTANT_Class_info
                        u2 name_index = 0012; // Utf8 HelloWorld
                },
                { // 0006 = Class java/lang/Object
                        u1 tag = 07; // CONSTANT_Class_info
                        u2 name_index = 0013; // Utf8 java/lang/Object
                },
                { // 0007 = Utf8 <init>
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0006;
                        u1 bytes[] = {3c,69,6e,69,74,3e}; // <init>
                },
                { // 0008 = Utf8 ()V
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0003;
                        u1 bytes[] = {28,29,56}; // ()V
                },
                { // 0009 = Utf8 Code
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0004;
                        u1 bytes[] = {43,6f,64,65}; // Code
                },
                { // 000a = Utf8 main
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0004;
                        u1 bytes[] = {6d,61,69,6e}; // main
                },
                { // 000b = Utf8 ([Ljava/lang/String;)V
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0016;
                        u1 bytes[] = 
{28,5b,4c,6a,61,76,61,2f,6c,61,6e,67,2f,53,74,72,69,6e,67,3b,29,56}; // 
([Ljava/lang/String;)V
                },
                { // 000c = NameAndType <init>:()V
                        u1 tag = 0c; // CONSTANT_NameAndType
                        u2 name_index = 0007; // Utf8 <init>
                        u2 descriptor_index = 0008; // Utf8 ()V
                },
                { // 000d = Class java/lang/System
                        u1 tag = 07; // CONSTANT_Class_info
                        u2 name_index = 0014; // Utf8 java/lang/System
                },
                { // 000e = NameAndType out:Ljava/io/PrintStream;
                        u1 tag = 0c; // CONSTANT_NameAndType
                        u2 name_index = 0015; // Utf8 out
                        u2 descriptor_index = 0016; // Utf8 
Ljava/io/PrintStream;
                },
                { // 000f = Utf8 Hello, world!
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 000d;
                        u1 bytes[] = {48,65,6c,6c,6f,2c,20,77,6f,72,6c,64,21}; 
// Hello, world!
                },
                { // 0010 = Class java/io/PrintStream
                        u1 tag = 07;
                        u2 name_index = 0017; // Utf8 java/io/PrintStream
                },
                { // 0011 = NameAndType println:(Ljava/lang/String;)V
                        u1 tag = 0c; // CONSTANT_NameAndType
                        u2 name_index = 0018; // Utf8 println
                        u2 descriptor_index = 0019; // Utf8 
(Ljava/lang/String;)V
                },
                { // 0012 = Utf8 HelloWorld
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 000a;
                        u1 bytes[] = {48,65,6c,6c,6f,57,6f,72,6c,64}; // 
HelloWorld
                },
                { // 0013 = Utf8 java/lang/Object
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0010;
                        u1 bytes[] = 
{6a,61,76,61,2f,6c,61,6e,67,2f,4f,62,6a,65,63,74}; // java/lang/Object
                },
                { // 0014 = Utf8 java/lang/System
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0010;
                        u1 bytes[] = 
{6a,61,76,61,2f,6c,61,6e,67,2f,53,79,73,74,65,6d}; // java/lang/System
                },
                { // 0015 = Utf8 out
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0003;
                        u1 bytes[] = {6f,75,74}; // out
                },
                { // 0016 = Utf8 Ljava/io/PrintStream;
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0015;
                        u1 bytes[] = 
{4c,6a,61,76,61,2f,69,6f,2f,50,72,69,6e,74,53,74,72,65,61,6d,3b}; // 
Ljava/io/PrintStream;
                },
                { // 0017 = Utf8 java/io/PrintStream
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0013;
                        u1 bytes[] = 
{6a,61,76,61,2f,69,6f,2f,50,72,69,6e,74,53,74,72,65,61,6d}; // 
java/io/PrintStream
                },
                { // 0018 = Utf8 println
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0007;
                        u1 bytes[] = {70,72,69,6e,74,6c,6e}; // println
                },
                { // 0019 = Utf8 (Ljava/lang/String;)V
                        u1 tag = 01; // CONSTANT_Utf8
                        u2 length = 0015;
                        u1 bytes[] = 
{28,4c,6a,61,76,61,2f,6c,61,6e,67,2f,53,74,72,69,6e,67,3b,29,56}; // 
(Ljava/lang/String;)V
                },
                { // 001a = MethodHandle getStatic 
java/lang/System.out:Ljava/io/PrintStream;
                        u1 tag = 0f; // CONSTANT_MethodHandle
                        u1 reference_kind = 02; // REF_getStatic
                        u2 reference_index = 0002; // Field 
java/lang/System.out:Ljava/io/PrintStream;
                },
                { // 001b = MethodType (Ljava/lang/String;)V
                        u1 tag = 10; // CONSTANT_MethodType
                        u2 descriptor_index = 0019;
                },
        };
        u2 access_flags = 0021; // ACC_PUBLIC | ACC_SUPER
        u2 this_class = 0005; // Class: HelloWorld
        u2 super_class = 0006; // Class: java/lang/Object
        u2 interfaces_count = 0000;
        u2 interfaces[interfaces_count] = {};
        u2 fields_count = 0000;
        field_info fields[fields_count] = {};
        u2 methods_count = 0002;
        method_info methods[methods_count] = {
                {
                        u2 access_flags = 0001; // ACC_PUBLIC
                        u2 name_index = 0007; // Utf8 <init>
                        u2 descriptor_index = 0008; // Utf8 ()V
                        u2 attributes_count = 0001;
                        attribute_info attributes[attributes_count] = {
                                {
                                        u2 attribute_name_index = 0009; // Utf8 
Code
                                        u4 attribute_length = 00000011;
                                        u2 max_stack = 0001;
                                        u2 max_locals = 0001;
                                        u4 code_length = 00000005;
                                        u1 code[code_length] = {
                                                2a, // aload_0
                                                b7, 00,01, // invokespecial 
0001 // Method java/lang/Object.<init>:()V
                                                b1, // return
                                        };
                                        u2 exception_table_length = 0000;
                                        exception_table_item 
exception_table[exception_table_length] = {};
                                        u2 attributes_count = 0000;
                                        attribute_info 
attributes[attributes_count] = {};
                                },
                        };
                },
                {
                        u2 access_flags = 0009; // ACC_PUBLIC | ACC_STATIC
                        u2 name_index = 000a; // Utf8 main
                        u2 descriptor_index = 000b; // Utf8 
([Ljava/lang/String;)V
                        u2 attributes_count = 0001;
                        attribute_info attributes[attributes_count] = {
                                {
                                        u2 attribute_name_index = 0009; // Utf8 
Code
                                        u4 attribute_length = 00000015;
                                        u2 max_stack = 0002;
                                        u2 max_locals = 0001;
                                        u4 code_length = 00000009;
                                        u1 code[code_length] = {
                                                b2, 00,02, // getstatic 0002 // 
Field java/lang/System.out:Ljava/io/PrintStream;
                                                12, 03, // ldc 03 // String 
"Hello, world!"
                                                b6, 00,04, // invokevirtual 
0004 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
                                                b1, // return
                                        };
                                        u2 exception_table_length = 0000;
                                        exception_table_item 
exception_table[exception_table_length] = {};
                                        u2 attributes_count = 0000;
                                        attribute_info 
attributes[attributes_count] = {};
                                },
                        };
                },
        };
        u2 attributes_count = 0000;
        attribute_info attributes[attributes_count] = {};
}

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