[llvm] r303458 - Fix off-by-one bug in AttributeList::addAttributes index handling

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Fri May 19 17:23:47 2017
New Revision: 303458

URL: http://llvm.org/viewvc/llvm-project?rev=303458&view=rev
Log:
Fix off-by-one bug in AttributeList::addAttributes index handling

getParamAlignment expects an argument number, not an AttributeList
index.

Johan Englan, who works on LDC, found this bug and told me about it off
list.

Modified:
    llvm/trunk/lib/IR/Attributes.cpp
    llvm/trunk/unittests/IR/AttributesTest.cpp

Modified: llvm/trunk/lib/IR/Attributes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Attributes.cpp?rev=303458&r1=303457&r2=303458&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Attributes.cpp (original)
+++ llvm/trunk/lib/IR/Attributes.cpp Fri May 19 17:23:47 2017
@@ -1058,7 +1058,7 @@ AttributeList AttributeList::addAttribut
 #ifndef NDEBUG
   // FIXME it is not obvious how this should work for alignment. For now, say
   // we can't change a known alignment.
-  unsigned OldAlign = getParamAlignment(Index);
+  unsigned OldAlign = getAttributes(Index).getAlignment();
   unsigned NewAlign = B.getAlignment();
   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
          "Attempt to change alignment!");

Modified: llvm/trunk/unittests/IR/AttributesTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/AttributesTest.cpp?rev=303458&r1=303457&r2=303458&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/AttributesTest.cpp (original)
+++ llvm/trunk/unittests/IR/AttributesTest.cpp Fri May 19 17:23:47 2017
@@ -63,4 +63,23 @@ TEST(Attributes, AddAttributes) {
   EXPECT_TRUE(AL.hasFnAttribute(Attribute::NoReturn));
 }
 
+TEST(Attributes, AddMatchingAlignAttr) {
+  LLVMContext C;
+  AttributeList AL;
+  AL = AL.addAttribute(C, AttributeList::FirstArgIndex,
+                       Attribute::getWithAlignment(C, 8));
+  AL = AL.addAttribute(C, AttributeList::FirstArgIndex + 1,
+                       Attribute::getWithAlignment(C, 32));
+  EXPECT_EQ(8U, AL.getParamAlignment(0));
+  EXPECT_EQ(32U, AL.getParamAlignment(1));
+
+  AttrBuilder B;
+  B.addAttribute(Attribute::NonNull);
+  B.addAlignmentAttr(8);
+  AL = AL.addAttributes(C, AttributeList::FirstArgIndex, B);
+  EXPECT_EQ(8U, AL.getParamAlignment(0));
+  EXPECT_EQ(32U, AL.getParamAlignment(1));
+  EXPECT_TRUE(AL.hasParamAttribute(0, Attribute::NonNull));
+}
+
 } // end anonymous namespace