From 00ca84730a21578dcc6b47bd8e08b78ab9b2dded Mon Sep 17 00:00:00 2001
From: Vladimir Marko <vmarko@google.com>
Date: Mon, 26 Jan 2015 14:06:46 +0000
Subject: [PATCH] Quick: Fix range check for intrinsic String.charAt() on x86.

Bug: 19125146
Change-Id: I274190a7a60cd2e29a854738ed1ec99a9e611969
---
 compiler/dex/quick/x86/target_x86.cc  |  2 +-
 test/082-inline-execute/src/Main.java | 38 ++++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/compiler/dex/quick/x86/target_x86.cc b/compiler/dex/quick/x86/target_x86.cc
index bfa24ccd2..a38efd32e 100755
--- a/compiler/dex/quick/x86/target_x86.cc
+++ b/compiler/dex/quick/x86/target_x86.cc
@@ -2510,7 +2510,7 @@ bool X86Mir2Lir::GenInlinedCharAt(CallInfo* info) {
     if (rl_idx.is_const) {
       LIR* comparison;
       range_check_branch = OpCmpMemImmBranch(
-          kCondUlt, RegStorage::InvalidReg(), rl_obj.reg, count_offset,
+          kCondLs, RegStorage::InvalidReg(), rl_obj.reg, count_offset,
           mir_graph_->ConstantValue(rl_idx.orig_sreg), nullptr, &comparison);
       MarkPossibleNullPointerExceptionAfter(0, comparison);
     } else {
diff --git a/test/082-inline-execute/src/Main.java b/test/082-inline-execute/src/Main.java
index a737ccdb7..5561a09c8 100644
--- a/test/082-inline-execute/src/Main.java
+++ b/test/082-inline-execute/src/Main.java
@@ -130,7 +130,11 @@ public class Main {
     Assert.assertEquals('N', testStr.charAt(0));
     Assert.assertEquals('o', testStr.charAt(1));
     Assert.assertEquals(' ', testStr.charAt(10));
-    Assert.assertEquals('e', testStr.charAt(testStr.length()-1));
+    Assert.assertEquals('e', testStr.charAt(14));  // 14 = testStr.length()-1 as a constant.
+    Assert.assertEquals('N', test_String_charAt_inner(testStr, 0));
+    Assert.assertEquals('o', test_String_charAt_inner(testStr, 1));
+    Assert.assertEquals(' ', test_String_charAt_inner(testStr, 10));
+    Assert.assertEquals('e', test_String_charAt_inner(testStr, testStr.length()-1));
 
     test_String_charAtExc();
     test_String_charAtExc2();
@@ -148,6 +152,33 @@ public class Main {
       Assert.fail();
     } catch (StringIndexOutOfBoundsException expected) {
     }
+    try {
+      testStr.charAt(15);  // 15 = "Now is the time".length()
+      Assert.fail();
+    } catch (StringIndexOutOfBoundsException expected) {
+    }
+    try {
+      test_String_charAt_inner(testStr, -1);
+      Assert.fail();
+    } catch (StringIndexOutOfBoundsException expected) {
+    }
+    try {
+      test_String_charAt_inner(testStr, 80);
+      Assert.fail();
+    } catch (StringIndexOutOfBoundsException expected) {
+    }
+    try {
+      test_String_charAt_inner(testStr, 15);  // 15 = "Now is the time".length()
+      Assert.fail();
+    } catch (StringIndexOutOfBoundsException expected) {
+    }
+
+    String strEmpty = "";
+    try {
+      strEmpty.charAt(0);
+      Assert.fail();
+    } catch (StringIndexOutOfBoundsException expected) {
+    }
 
     String strNull = null;
     try {
@@ -157,6 +188,11 @@ public class Main {
     }
   }
 
+  private static char test_String_charAt_inner(String s, int index) {
+    // Using non-constant index here (assuming that this method wasn't inlined).
+    return s.charAt(index);
+  }
+
   private static void test_String_charAtExc2() {
     try {
       test_String_charAtExc3();
-- 
2.11.0