[llvm-branch-commits] [llvm] [BOLT] Add binary introspection/JIT manager (PR #81346)

[Amir Ayupov via llvm-branch-commits]

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@@ -0,0 +1,99 @@
+#include "bolt/Rewrite/JITRewriteInstance.h"
+#include "bolt/Core/BinaryContext.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/Support/TargetSelect.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace llvm::object;
+using namespace llvm::ELF;
+using namespace bolt;
+
+namespace {
+struct JITRewriteInstanceTester
+    : public testing::TestWithParam<Triple::ArchType> {
+  void SetUp() override {
+    initalizeLLVM();
+    initializeBOLT();
+  }
+
+protected:
+  void initalizeLLVM() {
+    llvm::InitializeAllTargetInfos();
+    llvm::InitializeAllTargetMCs();
+    llvm::InitializeAllAsmParsers();
+    llvm::InitializeAllDisassemblers();
+    llvm::InitializeAllTargets();
+    llvm::InitializeAllAsmPrinters();
+  }
+
+  void initializeBOLT() {
+    BOLTJIT = cantFail(bolt::JITRewriteInstance::createJITRewriteInstance(
+        {llvm::outs(), llvm::errs()}, /*IsPIC*/ false));
+    ASSERT_FALSE(!BOLTJIT);
+  }
+
+  std::unique_ptr<JITRewriteInstance> BOLTJIT;
+};
+} // namespace
+
+#ifdef X86_AVAILABLE
+
+// clang-format off
+extern "C" __attribute((naked)) int fib(int n)
+{
+  __asm__ __volatile__(
+    "pushq   %%r14\n"
+    "pushq   %%rbx\n"
+    "pushq   %%rax\n"
+    "movl    %%edi, %%r14d\n"
+    "xorl    %%ebx, %%ebx\n"
+    "cmpl    $0x2, %%edi\n"
+    "jge     .Ltmp0\n"
+    "movl    %%r14d, %%ecx\n"
+    "jmp     .Ltmp1\n"
+    ".Ltmp0:\n"
+    "xorl    %%ebx, %%ebx\n"
+    "nopw    %%cs:(%%rax,%%rax)\n"
+    ".Ltmp2:\n"
+    "leal    -0x1(%%r14), %%edi\n"
+    "callq   fib\n"
+    "leal    -0x2(%%r14), %%ecx\n"
+    "addl    %%eax, %%ebx\n"
+    "cmpl    $0x3, %%r14d\n"
+    "movl    %%ecx, %%r14d\n"
+    "ja      .Ltmp2\n"
+    ".Ltmp1:\n"
+    "addl    %%ecx, %%ebx\n"
+    "movl    %%ebx, %%eax\n"
+    "addq    $0x8, %%rsp\n"
+    "popq    %%rbx\n"
+    "popq    %%r14\n"
+    "retq\n"
+    :::);
+}
+// clang-format on
+
+INSTANTIATE_TEST_SUITE_P(X86, JITRewriteInstanceTester,
+                         ::testing::Values(Triple::x86_64));
+
+TEST_P(JITRewriteInstanceTester, DisassembleFib) {
+  EXPECT_EQ(fib(7), 13);
+
+  // BOLT JIT test/example
+  // Analyze fib function in this binary
+  // Disassemble 63 bytes
+  uint64_t Address = reinterpret_cast<uint64_t>(&fib);
+  StringRef Data = StringRef(reinterpret_cast<const char *>(&fib), 63);
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aaupov wrote:

Should JITRewriter expose symbol size so users use it directly?

https://github.com/llvm/llvm-project/pull/81346