[llvm] [LLVM][PDB] Use IsUnsigned flag for APInt correctly (PR #131598)

[Aleksandr Korepanov via llvm-commits]

https://github.com/AlexK0 updated https://github.com/llvm/llvm-project/pull/131598

>From 7c8f4ee72700a461744efd07abea91cc458851b6 Mon Sep 17 00:00:00 2001
From: Aleksandr Korepanov <alexander.korepanov at jetbrains.com>
Date: Mon, 17 Mar 2025 11:21:55 +0100
Subject: [PATCH 1/2] [LLVM][PDB] Use IsUnsigned flag for APInt correctly

---
 llvm/include/llvm/DebugInfo/PDB/PDBTypes.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h b/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h
index b6a794ad7e760..a64a2e888e9b9 100644
--- a/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h
+++ b/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h
@@ -510,7 +510,9 @@ struct Variant {
 
 #define VARIANT_APSINT(Enum, NumBits, IsUnsigned)                              \
   case PDB_VariantType::Enum:                                                  \
-    return APSInt(APInt(NumBits, Value.Enum), IsUnsigned);
+    return APSInt(                                                             \
+        APInt(NumBits, static_cast<uint64_t>(Value.Enum), !IsUnsigned),        \
+        IsUnsigned);
 
   APSInt toAPSInt() const {
     switch (Type) {

>From 94135a469e7f46ef6caa9674b918c3ef65922ffc Mon Sep 17 00:00:00 2001
From: Aleksandr Korepanov <alexander.korepanov at jetbrains.com>
Date: Tue, 18 Mar 2025 10:31:56 +0100
Subject: [PATCH 2/2] [LLVM][PDB] Add a unittest for pdb::Variant::toAPSInt()

---
 llvm/unittests/DebugInfo/PDB/CMakeLists.txt   |  1 +
 .../DebugInfo/PDB/PDBVariantTest.cpp          | 56 +++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 llvm/unittests/DebugInfo/PDB/PDBVariantTest.cpp

diff --git a/llvm/unittests/DebugInfo/PDB/CMakeLists.txt b/llvm/unittests/DebugInfo/PDB/CMakeLists.txt
index c8c2659277a63..ba2a732848f4d 100644
--- a/llvm/unittests/DebugInfo/PDB/CMakeLists.txt
+++ b/llvm/unittests/DebugInfo/PDB/CMakeLists.txt
@@ -10,6 +10,7 @@ add_llvm_unittest_with_input_files(DebugInfoPDBTests
   NativeSymbolReuseTest.cpp
   StringTableBuilderTest.cpp
   PDBApiTest.cpp
+  PDBVariantTest.cpp
   )
 
 target_link_libraries(DebugInfoPDBTests PRIVATE LLVMTestingSupport)
diff --git a/llvm/unittests/DebugInfo/PDB/PDBVariantTest.cpp b/llvm/unittests/DebugInfo/PDB/PDBVariantTest.cpp
new file mode 100644
index 0000000000000..11f4589b321ab
--- /dev/null
+++ b/llvm/unittests/DebugInfo/PDB/PDBVariantTest.cpp
@@ -0,0 +1,56 @@
+//===- llvm/unittest/DebugInfo/PDB/PDBVariantTest.cpp ---------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+
+#include "llvm/DebugInfo/PDB/PDBTypes.h"
+
+using namespace llvm;
+using namespace llvm::pdb;
+
+template <typename T>
+class PDBVariantIntegerTest : public testing::Test {
+public:
+  std::vector<T> getTestIntegers() {
+    if constexpr (std::is_same_v<T, bool>) {
+      return {true, false};
+    } else {
+      std::vector<T> Integers{0, 1, 32, std::numeric_limits<T>::min(),
+                              std::numeric_limits<T>::max()};
+      if constexpr (std::is_signed_v<T>) {
+        Integers.emplace_back(-1);
+        Integers.emplace_back(-65);
+      }
+      return Integers;
+    }
+  }
+};
+
+using TestTypes = testing::Types<bool, int8_t, uint8_t, int16_t, uint16_t,
+                                 int32_t, uint32_t, int64_t, uint64_t>;
+TYPED_TEST_SUITE(PDBVariantIntegerTest, TestTypes);
+
+TYPED_TEST(PDBVariantIntegerTest, ToAPSInt) {
+  for (TypeParam IntegerValue : this->getTestIntegers()) {
+    const Variant VariantValue(IntegerValue);
+
+    const APSInt APSIntValue = VariantValue.toAPSInt();
+    EXPECT_EQ(APSIntValue.isSigned(), std::is_signed_v<TypeParam>)
+        << "Unexpected 'isSigned()' result for '" << IntegerValue << "'";
+    bool IsNegative = false;
+    if constexpr (!std::is_same_v<TypeParam, bool>) {
+      IsNegative = IntegerValue < 0;
+    }
+    EXPECT_EQ(APSIntValue.isNegative(), IsNegative)
+        << "Unexpected 'isNegative()' result for '" << IntegerValue << "'";
+
+    SmallString<20> String;
+    APSIntValue.toString(String);
+    EXPECT_EQ(String.str().str(), std::to_string(IntegerValue));
+  }
+}