Error reporting when the generated code size exceeds JVM limits (65,535 bytes per method). Closed #4573. review by extempore.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@24985 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala

@@ -82,7 +82,13 @@ abstract class GenJVM extends SubComponent with GenJVMUtil with GenAndroid with
           else new ClassBytecodeWriter with JavapBytecodeWriter { }
       }
       val codeGenerator = new BytecodeGenerator(bytecodeWriter)
-      classes.values foreach (codeGenerator genClass _)
+      classes.values foreach { c =>
+        try codeGenerator.genClass(c)
+        catch {
+          case e: JCode.CodeSizeTooBigException =>
+            log("Skipped class %s because it has methods that are too long.".format(c.toString))
+        }
+      }
       bytecodeWriter.close()
       classes.clear()
     }
@@ -785,6 +791,14 @@ abstract class GenJVM extends SubComponent with GenJVMUtil with GenAndroid with
       addExceptionsAttribute(jmethod, excs)
       addAnnotations(jmethod, others)
       addParamAnnotations(jmethod, m.params.map(_.sym.annotations))
+      
+      // check for code size
+      try jmethod.freeze()
+      catch {
+        case e: JCode.CodeSizeTooBigException =>
+          clasz.cunit.error(m.symbol.pos, "Code size exceeds JVM limits: %d".format(e.codeSize))
+          throw e
+      }
     }
 
     private def addRemoteException(jmethod: JMethod, meth: Symbol) {

src/fjbg/ch/epfl/lamp/fjbg/JCode.java

@@ -21,6 +21,8 @@ import ch.epfl.lamp.util.ByteArray;
 
 public class JCode {
     protected boolean frozen = false;
+    
+    public static int MAX_CODE_SIZE = 65535;
 
     protected final FJBGContext context;
     protected final JMethod owner;
@@ -57,8 +59,8 @@ public class JCode {
         this.owner = owner;
         owner.setCode(this);
         int size = stream.readInt();
-        if (size >= 65536) // section 4.10
-            throw new Error("code size must be less than 65536: " + size);
+        if (size > MAX_CODE_SIZE) // section 4.10
+            throw new Error("code size must be less than " + MAX_CODE_SIZE + ": " + size);
         this.codeArray = new ByteArray(stream, size);
     }
 
@@ -97,8 +99,19 @@ public class JCode {
     // Freezing
     //////////////////////////////////////////////////////////////////////
 
+    public static class CodeSizeTooBigException extends OffsetTooBigException {
+        public int codeSize;
+        
+        public CodeSizeTooBigException(int size) {
+          codeSize = size;
+        }
+    }
+    
     public void freeze() throws OffsetTooBigException {
         assert !frozen;
+        
+        if (getSize() > MAX_CODE_SIZE) throw new CodeSizeTooBigException(getSize());
+        
         patchAllOffset();
         codeArray.freeze();
         frozen = true;