Index: test/TestRunner.sh
===================================================================
--- test/TestRunner.sh	(revision 48417)
+++ test/TestRunner.sh	(working copy)
@@ -39,18 +39,38 @@
    exit 1
 )
 
+# Run clang under Valgrind, if asked to by the user.
+if [ -n "$VG" ]; then
+  CLANG="valgrind --leak-check=full -q --log-file-exactly=$OUTPUT.vg clang"
+else
+  CLANG="clang"
+fi
+
 SCRIPT=$OUTPUT.script
-grep 'RUN:' $FILENAME | sed "s|^.*RUN:\(.*\)$|\1|g;s|%s|$SUBST|g;s|%llvmgcc|llvm-gcc -emit-llvm|g;s|%llvmgxx|llvm-g++ -emit-llvm|g;s|%prcontext|prcontext.tcl|g" > $SCRIPT  
+grep 'RUN:' $FILENAME | \
+  sed -e "s|^.*RUN:\(.*\)$|\1|g" \
+      -e "s|%s|$SUBST|g" \
+      -e "s|%llvmgcc|llvm-gcc -emit-llvm|g" \
+      -e "s|%llvmgxx|llvm-g++ -emit-llvm|g" \
+      -e "s|%prcontext|prcontext.tcl|g" \
+      -e "s|clang|$CLANG|g" > $SCRIPT
 
 grep -q XFAIL $FILENAME && (printf "XFAILED '$TESTNAME': "; grep XFAIL $FILENAME)
 
-/bin/sh $SCRIPT > $OUTPUT 2>&1 || (
+/bin/sh $SCRIPT > $OUTPUT 2>&1
+STATUS=$?
+if [ $STATUS -ne 0 -o -n "$VG" -a -s $OUTPUT.vg ]; then
   echo "******************** TEST '$TESTNAME' FAILED! ********************"
-  echo "Command: "
+  echo "Command:"
   cat $SCRIPT
-  echo "Output:"
-  cat $OUTPUT
-  rm $OUTPUT
+  if [ $STATUS -ne 0 ]; then
+    echo "Incorrect Output:"
+    cat $OUTPUT
+  fi
+  if [ -n "$VG" -a -s $OUTPUT.vg ]; then
+    echo "Valgrind Errors:"
+    cat $OUTPUT.vg
+  fi
   echo "******************** TEST '$TESTNAME' FAILED! ********************"
-)
+fi
 
Index: test/Makefile
===================================================================
--- test/Makefile	(revision 48417)
+++ test/Makefile	(working copy)
@@ -9,6 +9,6 @@
 endif
 
 all::
-	PATH=$$PATH:$(ToolDir):$(LLVM_SRC_ROOT)/test/Scripts \
+	PATH=$$PATH:$(ToolDir):$(LLVM_SRC_ROOT)/test/Scripts VG=${VG} \
           find $(TESTDIRS) \( -name '*.c' -or -name '*.cpp' -or -name '*.m' \) \
 	      -print -exec ./TestRunner.sh {} \;