Merge pull request #42 from emilycares/dynamic_constant

Add DynamicConstant

Author: Palmr

src/constant_info/parser.rs

@@ -119,6 +119,18 @@ fn const_method_type(input: &[u8]) -> ConstantInfoResult<'_> {
     ))
 }
 
+fn const_dynamic(input: &[u8]) -> ConstantInfoResult<'_> {
+    let (input, bootstrap_method_attr_index) = be_u16(input)?;
+    let (input, name_and_type_index) = be_u16(input)?;
+    Ok((
+        input,
+        ConstantInfo::Dynamic(DynamicConstant {
+            bootstrap_method_attr_index,
+            name_and_type_index,
+        }),
+    ))
+}
+
 fn const_invoke_dynamic(input: &[u8]) -> ConstantInfoResult<'_> {
     let (input, bootstrap_method_attr_index) = be_u16(input)?;
     let (input, name_and_type_index) = be_u16(input)?;
@@ -159,6 +171,7 @@ fn const_block_parser(input: &[u8], const_type: u8) -> ConstantInfoResult<'_> {
         12 => const_name_and_type(input),
         15 => const_method_handle(input),
         16 => const_method_type(input),
+        17 => const_dynamic(input),
         18 => const_invoke_dynamic(input),
         19 => const_module(input),
         20 => const_package(input),

src/constant_info/types.rs

@@ -16,6 +16,7 @@ pub enum ConstantInfo {
     NameAndType(NameAndTypeConstant),
     MethodHandle(MethodHandleConstant),
     MethodType(MethodTypeConstant),
+    Dynamic(DynamicConstant),
     InvokeDynamic(InvokeDynamicConstant),
     Module(ModuleConstant),
     Package(PackageConstant),
@@ -106,6 +107,13 @@ pub struct MethodTypeConstant {
     pub descriptor_index: u16,
 }
 
+#[derive(Clone, Debug)]
+#[binrw]
+pub struct DynamicConstant {
+    pub bootstrap_method_attr_index: u16,
+    pub name_and_type_index: u16,
+}
+
 #[derive(Clone, Debug)]
 #[binrw]
 pub struct InvokeDynamicConstant {

src/parser.rs

@@ -34,7 +34,7 @@ pub fn class_parser(input: &[u8]) -> IResult<&[u8], ClassFile> {
     let (input, minor_version) = be_u16(input)?;
     let (input, major_version) = be_u16(input)?;
     let (input, const_pool_size) = be_u16(input)?;
-    let (input, const_pool) = constant_parser(input, (const_pool_size - 1) as usize)?;
+    let (input, const_pool) = constant_parser(input, (const_pool_size.saturating_sub(1)) as usize)?;
     let (input, access_flags) = be_u16(input)?;
     let (input, this_class) = be_u16(input)?;
     let (input, super_class) = be_u16(input)?;