From 2aa9e219e7f42edc6c9f6b0c080db4026dbf6039 Mon Sep 17 00:00:00 2001
From: Robert Scott <code@humanleg.org.uk>
Date: Sun, 26 Jan 2020 19:22:44 +0000
Subject: [PATCH] Instrumentor: also skip classes with methods now too large
 for JVM's 64k limit

---
 .../sv/kelinci/instrumentor/Instrumentor.java | 40 ++++++++++++++-----
 1 file changed, 31 insertions(+), 9 deletions(-)

diff --git a/instrumentor/src/main/java/edu/cmu/sv/kelinci/instrumentor/Instrumentor.java b/instrumentor/src/main/java/edu/cmu/sv/kelinci/instrumentor/Instrumentor.java
index 855e2ec..8f5a070 100644
--- a/instrumentor/src/main/java/edu/cmu/sv/kelinci/instrumentor/Instrumentor.java
+++ b/instrumentor/src/main/java/edu/cmu/sv/kelinci/instrumentor/Instrumentor.java
@@ -42,7 +42,8 @@ public static void main(String[] args) {
 		// load all classes to instrument (instrument library classes?)
 		Set<String> inputClasses = Options.v().getInput();
 		
-		Set<String> skipped = new HashSet<>();
+		Set<String> skipped_jsr_ret = new HashSet<>();
+		Set<String> skipped_largemethod = new HashSet<>();
 		
 		for (String cls : inputClasses) {
 			System.out.println("Instrumenting class: " + cls);
@@ -64,21 +65,32 @@ public static void main(String[] args) {
 				byte[] bytes = cw.toByteArray();
 				writeClass(cls, bytes);
 			} catch (RuntimeException rte) {
-				if (rte.getMessage().contains("JSR/RET")) {
+				final String msg = rte.getMessage();
+				if (msg.contains("JSR/RET")) {
 					/**
 					 * This is an exception related to a particular construct in the bytecode that
 					 * is not supported by ASM. It is deprecated and should not be present in bytecode
 					 * generated by a recent compiler. However, the JDK contains it and it may occur elsewhere.
+					 *
 					 * This catch simply skips the class and warns the user.
 					 */
-					System.out.println("\n[WARNING] RuntimeException thrown during instrumentation: " + rte.getMessage());
-					System.out.println("Skipping instrumentation of class " + cls + "\n");
-					// include original, uninstrumented class in output
-					loadAndWriteResource(cls);
-					skipped.add(cls);
+					skipped_jsr_ret.add(cls);
+				} else if (msg.contains("Method code too large")) {
+					/**
+					 * Adding instrumentation to classes might push some large
+					 * methods' size over the JVM's 64k method limit.
+					 *
+					 * This catch simply skips the class and warns the user.
+					 */
+					skipped_largemethod.add(cls);
 				} else {
 					throw rte;
 				}
+				
+				System.out.println("\n[WARNING] RuntimeException thrown during instrumentation: " + rte.getMessage());
+				System.out.println("Skipping instrumentation of class " + cls + "\n");
+				// include original, uninstrumented class in output
+				loadAndWriteResource(cls);
 			}
 			
 		}
@@ -97,14 +109,24 @@ public static void main(String[] args) {
 			loadAndWriteResource(resource);
 		}
 		
-		if (skipped.size() > 0) {
+		if (skipped_jsr_ret.size() > 0) {
 			System.out.println("\nWARNING!!! Instrumentation of some classes has been skipped.");
 			System.out.println("This is due to the JSR/RET bytecode construct that is not supported by ASM.");
 			System.out.println("It is deprecated and should not be present in bytecode generated by a recent compiler.");
 			System.out.println("If this is your code, try using a different compiler.");
 			System.out.println("If this is a library, there might be not too much harm in skipping instrumentation of these classes.");
 			System.out.println("Classes that were skipped:");
-			for (String cls : skipped)
+			for (String cls : skipped_jsr_ret)
+				System.out.println(cls);
+		}
+		
+		if (skipped_largemethod.size() > 0) {
+			System.out.println("\nWARNING!!! Instrumentation of some classes has been skipped.");
+			System.out.println("This is due to the instrumentation pushing the size of a.");
+			System.out.println("method over the JVM's 64k method limit");
+			System.out.println("If this is your code, try splitting it into smaller methods.");
+			System.out.println("Classes that were skipped:");
+			for (String cls : skipped_largemethod)
 				System.out.println(cls);
 		}
 	}