[llvm] [JITLink][AArch32] Unittest for error paths of readAddend functionality (PR #69636)

[Eymen Ünay via llvm-commits]

https://github.com/eymay created https://github.com/llvm/llvm-project/pull/69636

This commit is part of an effort to increase coverage of AArch32 backend.


>From 6bad67fd44160421c6874f6a1fd1554c0d7d1e5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eymen=20=C3=9Cnay?= <eymenunay at outlook.com>
Date: Thu, 19 Oct 2023 22:38:05 +0300
Subject: [PATCH] [JITLink][AArch32] Unittest for error paths of readAddend
 functionality

This commit is part of an effort to increase coverage of AArch32 backend.
---
 .../ExecutionEngine/JITLink/AArch32Tests.cpp  | 82 +++++++++++++++++++
 1 file changed, 82 insertions(+)

diff --git a/llvm/unittests/ExecutionEngine/JITLink/AArch32Tests.cpp b/llvm/unittests/ExecutionEngine/JITLink/AArch32Tests.cpp
index dcc8d3b237ff318..66fb3cde4352465 100644
--- a/llvm/unittests/ExecutionEngine/JITLink/AArch32Tests.cpp
+++ b/llvm/unittests/ExecutionEngine/JITLink/AArch32Tests.cpp
@@ -9,6 +9,7 @@
 #include <llvm/BinaryFormat/ELF.h>
 #include <llvm/ExecutionEngine/JITLink/aarch32.h>
 
+#include "llvm/Testing/Support/Error.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
@@ -67,6 +68,87 @@ TEST(AArch32_ELF, EdgeKinds) {
   }
 }
 
+
+struct ThumbRelocation {
+  /// Create a read-only reference to a Thumb32 fixup.
+  ThumbRelocation(const char *FixupPtr)
+      : Hi{*reinterpret_cast<const support::ulittle16_t *>(FixupPtr)},
+        Lo{*reinterpret_cast<const support::ulittle16_t *>(FixupPtr + 2)} {}
+
+  const support::ulittle16_t &Hi; // First halfword
+  const support::ulittle16_t &Lo; // Second halfword
+};
+
+struct ArmRelocation {
+
+  ArmRelocation(const char *FixupPtr)
+      : Wd{*reinterpret_cast<const support::ulittle32_t *>(FixupPtr)} {}
+
+  const support::ulittle32_t &Wd;
+};
+
+std::string makeUnexpectedOpcodeError(const LinkGraph &G, const ThumbRelocation &R,
+                                Edge::Kind Kind) {
+  return formatv("Invalid opcode [ {0:x4}, {1:x4} ] for relocation: {2}",
+              static_cast<uint16_t>(R.Hi), static_cast<uint16_t>(R.Lo),
+              G.getEdgeKindName(Kind));
+}
+
+std::string makeUnexpectedOpcodeError(const LinkGraph &G, const ArmRelocation &R,
+                                Edge::Kind Kind) {
+  return formatv("Invalid opcode {0:x8} for relocation: {1}",
+              static_cast<uint32_t>(R.Wd), G.getEdgeKindName(Kind));
+}
+
+TEST(AArch32_ELF, readAddends) {
+  auto G = std::make_unique<LinkGraph>("foo", Triple("armv7-linux-gnueabi"), 4,
+                                       llvm::endianness::little,
+                                       getGenericEdgeKindName);
+
+  ArrayRef<char> Content = "hello, world!";
+  auto &Sec =
+      G->createSection("__data", orc::MemProt::Read | orc::MemProt::Write);
+  orc::ExecutorAddr B1Addr(0x1000);
+  auto &B = G->createContentBlock(Sec, Content, B1Addr, 4, 0);
+
+  Symbol &TargetSymbol = G->addAnonymousSymbol(B, 0, 4, false, false);
+  Edge InvalidEdge(FirstDataRelocation - 1, 0, TargetSymbol, 0);
+
+  auto ArmCfg = getArmConfigForCPUArch(ARMBuildAttrs::v7);
+
+  auto makeReadAddendError = [](LinkGraph &G, Block &B, Edge &E){
+    return ("In graph " + G.getName() + ", section " + B.getSection().getName() +
+        " can not read implicit addend for aarch32 edge kind " +
+        G.getEdgeKindName(E.getKind())).str();
+  };
+
+  EXPECT_THAT_EXPECTED(readAddend(*G, B, InvalidEdge, ArmCfg), FailedWithMessage(makeReadAddendError(*G, B, InvalidEdge)));
+
+
+  ArmRelocation R_Arm(B.getContent().data());
+  ThumbRelocation R_Thumb(B.getContent().data());
+
+  for (Edge::Kind K = FirstDataRelocation; K < LastDataRelocation; K += 1) {
+    Edge E(K, 0, TargetSymbol, 0);
+    EXPECT_THAT_EXPECTED(readAddendData(*G, B, E), Succeeded());
+    EXPECT_THAT_EXPECTED(readAddendArm(*G, B, E), FailedWithMessage(makeReadAddendError(*G, B, E)));
+    EXPECT_THAT_EXPECTED(readAddendThumb(*G, B, E, ArmCfg), FailedWithMessage(makeReadAddendError(*G, B, E)));
+  }
+  for (Edge::Kind K = FirstArmRelocation; K < LastArmRelocation; K += 1) {
+    Edge E(K, 0, TargetSymbol, 0);
+    EXPECT_THAT_EXPECTED(readAddendData(*G, B, E), FailedWithMessage(makeReadAddendError(*G, B, E)));
+    EXPECT_THAT_EXPECTED(readAddendArm(*G, B, E), FailedWithMessage(makeUnexpectedOpcodeError(*G, R_Arm, K)));
+    EXPECT_THAT_EXPECTED(readAddendThumb(*G, B, E, ArmCfg), FailedWithMessage(makeReadAddendError(*G, B, E)));
+  }
+  for (Edge::Kind K = FirstThumbRelocation; K < LastThumbRelocation; K += 1) {
+    Edge E(K, 0, TargetSymbol, 0);
+    EXPECT_THAT_EXPECTED(readAddendData(*G, B, E), FailedWithMessage(makeReadAddendError(*G, B, E)));
+    EXPECT_THAT_EXPECTED(readAddendArm(*G, B, E), FailedWithMessage(makeReadAddendError(*G, B, E)));
+    EXPECT_THAT_EXPECTED(readAddendThumb(*G, B, E, ArmCfg), FailedWithMessage(makeUnexpectedOpcodeError(*G, R_Thumb, K)));
+  }
+ 
+}
+
 namespace llvm {
 namespace jitlink {
 namespace aarch32 {