Introduce "itf" suffix to invokestatic calls

src/main/java/me/coley/recaf/parse/bytecode/Disassembler.java

@@ -297,6 +297,9 @@ private void visitMethodInsn(StringBuilder line, MethodInsnNode insn) {
 		String name = EscapeUtil.escapeCommon(insn.name);
 		String desc = EscapeUtil.escapeCommon(insn.desc);
 		line.append(' ').append(owner).append('.').append(name).append(desc);
+		if (insn.getOpcode() == Opcodes.INVOKESTATIC && insn.itf) {
+			line.append(" itf");
+		}
 	}
 
 	private void visitJumpInsn(StringBuilder line, JumpInsnNode insn) {

src/main/java/me/coley/recaf/parse/bytecode/ast/ItfAST.java

@@ -0,0 +1,16 @@
+package me.coley.recaf.parse.bytecode.ast;
+
+public class ItfAST extends AST {
+	/**
+	 * @param line  Line number this node is written on.
+	 * @param start Offset from line start this node starts at.
+	 */
+	public ItfAST(int line, int start) {
+		super(line, start);
+	}
+
+	@Override
+	public String print() {
+		return "itf";
+	}
+}

src/main/java/me/coley/recaf/parse/bytecode/ast/MethodInsnAST.java

@@ -2,6 +2,7 @@
 
 import me.coley.recaf.parse.bytecode.MethodCompilation;
 import me.coley.recaf.parse.bytecode.exception.AssemblerException;
+import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.*;
 
 /**
@@ -13,6 +14,7 @@ public class MethodInsnAST extends InsnAST {
 	private final TypeAST owner;
 	private final NameAST name;
 	private final DescAST desc;
+	private final ItfAST itf;
 
 	/**
 	 * @param line
@@ -29,13 +31,37 @@ public class MethodInsnAST extends InsnAST {
 	 * 		Method descriptor AST.
 	 */
 	public MethodInsnAST(int line, int start, OpcodeAST opcode, TypeAST owner, NameAST name, DescAST desc) {
+		this(line, start, opcode, owner, name, desc, null);
+	}
+
+	/**
+	 * @param line
+	 * 		Line number this node is written on.
+	 * @param start
+	 * 		Offset from line start this node starts at.
+	 * @param opcode
+	 * 		Opcode AST.
+	 * @param owner
+	 * 		Method owner type AST.
+	 * @param name
+	 * 		Method name AST.
+	 * @param desc
+	 * 		Method descriptor AST.
+	 * @param itf
+	 *      Present on invokestatic if this is an interface method ref
+	 */
+	public MethodInsnAST(int line, int start, OpcodeAST opcode, TypeAST owner, NameAST name, DescAST desc, ItfAST itf) {
 		super(line, start, opcode);
 		this.owner = owner;
 		this.name = name;
 		this.desc = desc;
+		this.itf = itf;
 		addChild(owner);
 		addChild(name);
 		addChild(desc);
+		if (itf != null) {
+			addChild(itf);
+		}
 	}
 
 	/**
@@ -59,14 +85,28 @@ public DescAST getDesc() {
 		return desc;
 	}
 
+	public ItfAST getItf() {
+		return itf;
+	}
+
 	@Override
 	public String print() {
-		return getOpcode().print() + " " + owner.print() + "." + name.print() + desc.print();
+		String ret = getOpcode().print() + " " + owner.print() + "." + name.print() + desc.print();
+		if (itf != null) {
+			ret += " " + itf.print();
+		}
+		return ret;
 	}
 
 	@Override
 	public void compile(MethodCompilation compilation) throws AssemblerException {
-		compilation.addInstruction(new MethodInsnNode(getOpcode().getOpcode(), getOwner().getType(),
-				getName().getName(), getDesc().getDesc()), this);
+		int opcode = getOpcode().getOpcode();
+		if (opcode == Opcodes.INVOKESTATIC) {
+			compilation.addInstruction(new MethodInsnNode(opcode, getOwner().getType(),
+					getName().getName(), getDesc().getDesc(), itf != null), this);
+		} else {
+			compilation.addInstruction(new MethodInsnNode(opcode, getOwner().getType(),
+					getName().getName(), getDesc().getDesc()), this);
+		}
 	}
 }

src/main/java/me/coley/recaf/parse/bytecode/parser/MethodInsnParser.java

@@ -4,6 +4,7 @@
 import me.coley.recaf.parse.bytecode.ast.*;
 import me.coley.recaf.parse.bytecode.exception.ASTParseException;
 import me.coley.recaf.util.AutoCompleteUtil;
+import org.objectweb.asm.Opcodes;
 
 import java.util.Collections;
 import java.util.List;
@@ -49,17 +50,33 @@ public MethodInsnAST visit(int lineNo, String line) throws ASTParseException {
 			DescParser descParser = new DescParser();
 			descParser.setOffset(line.indexOf('('));
 			DescAST desc = descParser.visit(lineNo, descS);
-			return new MethodInsnAST(lineNo, start, op, owner, name, desc);
+			// itf
+			ItfAST itf = null;
+			if (op.getOpcode() == Opcodes.INVOKESTATIC) {
+				if (trim.length > 2 && "itf".equals(trim[2])) {
+					itf = new ItfAST(lineNo, line.indexOf("itf", desc.getStart() + desc.getDesc().length()));
+				}
+			}
+			return new MethodInsnAST(lineNo, start, op, owner, name, desc, itf);
 		} catch(Exception ex) {
 			throw new ASTParseException(ex, lineNo, "Bad format for method instruction");
 		}
 	}
 
 	@Override
 	public List<String> suggest(ParseResult<RootAST> lastParse, String text) {
-		// METHOD owner.name+desc
+		// METHOD owner.name+desc [itf]
 		int space = text.indexOf(' ');
 		if (space >= 0) {
+			int secondSpace = text.indexOf(' ', space + 1);
+			if (secondSpace >= 0) {
+				if ("INVOKESTATIC".equals(text.substring(0, space))) {
+					return Collections.singletonList("itf");
+				} else {
+					return Collections.emptyList();
+				}
+			}
+
 			String sub = text.substring(space + 1);
 			int dot = sub.indexOf('.');
 			if (dot == -1)

src/test/java/me/coley/recaf/AssemblyAstTest.java

@@ -281,6 +281,30 @@ public void testMethodInsnArrayReturn() {
 			assertEquals("()[B", methodAST.getDesc().getDesc());
 		}
 
+		@Test
+		public void testMethodInsnInvokeStatic() {
+			String text = "INVOKESTATIC java/lang/System.exit(I)V";
+			MethodInsnAST methodAST = single(text);
+			assertEquals(text, methodAST.print());
+			assertEquals("INVOKESTATIC", methodAST.getOpcode().print());
+			assertEquals("java/lang/System", methodAST.getOwner().getType());
+			assertEquals("exit", methodAST.getName().getName());
+			assertEquals("(I)V", methodAST.getDesc().getDesc());
+			assertNull(methodAST.getItf());
+		}
+
+		@Test
+		public void testMethodInsnInvokeStaticItf() {
+			String text = "INVOKESTATIC java/util/function/Function.identity()Ljava/util/function/Function; itf";
+			MethodInsnAST methodAST = single(text);
+			assertEquals(text, methodAST.print());
+			assertEquals("INVOKESTATIC", methodAST.getOpcode().print());
+			assertEquals("java/util/function/Function", methodAST.getOwner().getType());
+			assertEquals("identity", methodAST.getName().getName());
+			assertEquals("()Ljava/util/function/Function;", methodAST.getDesc().getDesc());
+			assertNotNull(methodAST.getItf());
+		}
+
 		@Test
 		public void testLdcInsn() {
 			// int
@@ -512,6 +536,15 @@ public void testMemberSuggestFromMethod() {
 			assertTrue(suggestions.contains("println(Ljava/lang/String;)V"));
 		}
 
+		@Test
+		public void testItfSuggest() {
+			List<String> suggestions = suggest(null, "INVOKESTATIC java/util/function/Function.identity()Ljava/util/function/Function; i");
+			assertTrue(suggestions.contains("itf"));
+			//
+			suggestions = suggest(null, "INVOKEVIRTUAL java/io/PrintStream.println i");
+			assertFalse(suggestions.contains("itf"));
+		}
+
 		@Test
 		public void testVariableSuggestFromInsns() {
 			ParseResult<RootAST> ast = Parse.parse("ISTORE example\nISTORE other\nISTORE also");

src/test/java/me/coley/recaf/AssemblyCasesTest.java

@@ -8,6 +8,7 @@
 import me.coley.recaf.parse.bytecode.exception.VerifierException;
 import me.coley.recaf.workspace.LazyClasspathResource;
 import org.junit.jupiter.api.*;
+import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.*;
 import org.objectweb.asm.tree.analysis.Frame;
 
@@ -687,6 +688,21 @@ public void testMergeWithOpaquePredicate() {
 			assertNotEquals(one, retFrameLocal.getValue());
 			assertEquals(two, retFrameLocal.getValue());
 		}
+
+		@Test
+		public void testInterfaceMethodRef() {
+			try {
+				MethodNode method = compile(parse(
+						"INVOKESTATIC java/util/function/Function.identity()Ljava/util/function/Function; itf\n" +
+							"POP\n" +
+							"RETURN"));
+				AbstractInsnNode invokeStaticInsn = method.instructions.get(1);
+				assertEquals(Opcodes.INVOKESTATIC, invokeStaticInsn.getOpcode());
+				assertTrue(((MethodInsnNode) invokeStaticInsn).itf, "INVOKESTATIC instruction must have itf=true");
+			} catch (AssemblerException ex) {
+				fail(ex);
+			}
+		}
 	}
 
 	// =============================================================== //