DI: Set DILexicalBlock columns >= 65536 to 0/unknown

This fixes PR24621 and matches what we do for `DILocation`.  Although
the limit seems somewhat artificial, there are places in the backend
that also assume 16-bit columns, so we may as well just be consistent
about the limits.

llvm-svn: 246349

1 files changed, 26 insertions, 0 deletions

diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index 6741c79afc9..661f965660e 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -1591,6 +1591,32 @@ TEST_F(DILexicalBlockTest, get) {
   EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));
 }
 
+TEST_F(DILexicalBlockTest, Overflow) {
+  DISubprogram *SP = getSubprogram();
+  DIFile *F = getFile();
+  {
+    auto *LB = DILexicalBlock::get(Context, SP, F, 2, 7);
+    EXPECT_EQ(2u, LB->getLine());
+    EXPECT_EQ(7u, LB->getColumn());
+  }
+  unsigned U16 = 1u << 16;
+  {
+    auto *LB = DILexicalBlock::get(Context, SP, F, UINT32_MAX, U16 - 1);
+    EXPECT_EQ(UINT32_MAX, LB->getLine());
+    EXPECT_EQ(U16 - 1, LB->getColumn());
+  }
+  {
+    auto *LB = DILexicalBlock::get(Context, SP, F, UINT32_MAX, U16);
+    EXPECT_EQ(UINT32_MAX, LB->getLine());
+    EXPECT_EQ(0u, LB->getColumn());
+  }
+  {
+    auto *LB = DILexicalBlock::get(Context, SP, F, UINT32_MAX, U16 + 1);
+    EXPECT_EQ(UINT32_MAX, LB->getLine());
+    EXPECT_EQ(0u, LB->getColumn());
+  }
+}
+
 typedef MetadataTest DILexicalBlockFileTest;
 
 TEST_F(DILexicalBlockFileTest, get) {