Merge pull request #27832 from bgogul/fix_asan_errors

Fix memory error in the implementation of IndexSubset.

Author: DougGregor

include/swift/AST/IndexSubset.h

@@ -57,6 +57,10 @@ class IndexSubset : public llvm::FoldingSetNode {
   /// The number of bit words in the index subset.
   unsigned numBitWords;
 
+  static unsigned getNumBytesNeededForCapacity(unsigned capacity) {
+    return getNumBitWordsNeededForCapacity(capacity) * bitWordSize;
+  }
+
   BitWord *getBitWordsData() {
     return reinterpret_cast<BitWord *>(this + 1);
   }

lib/AST/ASTContext.cpp

@@ -4637,7 +4637,7 @@ IndexSubset::get(ASTContext &ctx, const SmallBitVector &indices) {
   if (existing)
     return existing;
   auto sizeToAlloc = sizeof(IndexSubset) +
-      getNumBitWordsNeededForCapacity(capacity);
+      getNumBytesNeededForCapacity(capacity);
   auto *buf = reinterpret_cast<IndexSubset *>(
       ctx.Allocate(sizeToAlloc, alignof(IndexSubset)));
   auto *newNode = new (buf) IndexSubset(indices);

unittests/AST/IndexSubsetTests.cpp

@@ -46,7 +46,7 @@ TEST(IndexSubset, BitWordIndexAndOffset) {
             std::make_pair(1u, 0u));
 }
 
-TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Equality) {
+TEST(IndexSubset, Equality) {
   TestContext ctx;
   EXPECT_EQ(IndexSubset::get(ctx.Ctx, /*capacity*/ 5, /*indices*/ {0}),
             IndexSubset::get(ctx.Ctx, /*capacity*/ 5, /*indices*/ {0}));
@@ -60,7 +60,7 @@ TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Equality) {
             IndexSubset::get(ctx.Ctx, /*capacity*/ 5, /*indices*/ {}));
 }
 
-TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Initializers) {
+TEST(IndexSubset, Initializers) {
   TestContext ctx;
   // Default init.
   EXPECT_EQ(IndexSubset::getDefault(ctx.Ctx, /*capacity*/ 5,
@@ -101,7 +101,7 @@ TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Initializers) {
             IndexSubset::get(ctx.Ctx, /*capacity*/ 0, /*indices*/ {}));
 }
 
-TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Bits) {
+TEST(IndexSubset, Bits) {
   TestContext ctx;
   auto *indices1 = IndexSubset::get(ctx.Ctx, /*capacity*/ 5,
                                     /*indices*/ {0, 2, 4});
@@ -124,7 +124,7 @@ TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Bits) {
   EXPECT_FALSE(indices2->contains(4));
 }
 
-TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Iteration) {
+TEST(IndexSubset, Iteration) {
   TestContext ctx;
   // Test 1
   {
@@ -164,7 +164,7 @@ TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Iteration) {
   }
 }
 
-TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_SupersetAndSubset) {
+TEST(IndexSubset, SupersetAndSubset) {
   TestContext ctx;
   auto *indices1 = IndexSubset::get(ctx.Ctx, /*capacity*/ 5,
                                     /*indices*/ {0, 2, 4});
@@ -178,7 +178,7 @@ TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_SupersetAndSubset) {
   EXPECT_TRUE(indices2->isSubsetOf(indices1));
 }
 
-TEST(IndexSubset, /* rdar://problem/56338898 */DISABLED_Insertion) {
+TEST(IndexSubset, Insertion) {
   TestContext ctx;
   auto *indices1 = IndexSubset::get(ctx.Ctx, 5, {0, 2, 4});
   EXPECT_EQ(indices1->adding(0, ctx.Ctx), indices1);