1 //===----- LLJITDumpObjects.cpp - How to dump JIT'd objects with LLJIT ----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 ///
11 /// This example demonstrates how to use LLJIT to:
12 /// - Add absolute symbol definitions.
13 /// - Run static constructors for a JITDylib.
14 /// - Run static destructors for a JITDylib.
15 ///
16 /// This example does not call any functions (e.g. main or equivalent) between
17 /// running the static constructors and running the static destructors.
18 ///
19 //===----------------------------------------------------------------------===//
20
21 #include "llvm/ADT/StringMap.h"
22 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
23 #include "llvm/Support/InitLLVM.h"
24 #include "llvm/Support/TargetSelect.h"
25 #include "llvm/Support/raw_ostream.h"
26
27 #include "../ExampleModules.h"
28
29 using namespace llvm;
30 using namespace llvm::orc;
31
32 ExitOnError ExitOnErr;
33
34 const llvm::StringRef ModuleWithInitializer =
35 R"(
36
37 @InitializersRunFlag = external global i32
38 @DeinitializersRunFlag = external global i32
39
40 declare i32 @__cxa_atexit(void (i8*)*, i8*, i8*)
41 @__dso_handle = external hidden global i8
42
43 @llvm.global_ctors =
44 appending global [1 x { i32, void ()*, i8* }]
45 [{ i32, void ()*, i8* } { i32 65535, void ()* @init_func, i8* null }]
46
47 define internal void @init_func() {
48 entry:
49 store i32 1, i32* @InitializersRunFlag
50 %0 = call i32 @__cxa_atexit(void (i8*)* @deinit_func, i8* null,
51 i8* @__dso_handle)
52 ret void
53 }
54
55 define internal void @deinit_func(i8* %0) {
56 store i32 1, i32* @DeinitializersRunFlag
57 ret void
58 }
59
60 )";
61
main(int argc,char * argv[])62 int main(int argc, char *argv[]) {
63 // Initialize LLVM.
64 InitLLVM X(argc, argv);
65
66 InitializeNativeTarget();
67 InitializeNativeTargetAsmPrinter();
68
69 cl::ParseCommandLineOptions(argc, argv, "LLJITWithInitializers");
70 ExitOnErr.setBanner(std::string(argv[0]) + ": ");
71
72 auto J = ExitOnErr(LLJITBuilder().create());
73 auto M = ExitOnErr(parseExampleModule(ModuleWithInitializer, "M"));
74
75 // Load the module.
76 ExitOnErr(J->addIRModule(std::move(M)));
77
78 int32_t InitializersRunFlag = 0;
79 int32_t DeinitializersRunFlag = 0;
80
81 ExitOnErr(J->getMainJITDylib().define(absoluteSymbols(
82 {{J->mangleAndIntern("InitializersRunFlag"),
83 JITEvaluatedSymbol::fromPointer(&InitializersRunFlag)},
84 {J->mangleAndIntern("DeinitializersRunFlag"),
85 JITEvaluatedSymbol::fromPointer(&DeinitializersRunFlag)}})));
86
87 // Run static initializers.
88 ExitOnErr(J->initialize(J->getMainJITDylib()));
89
90 // Run deinitializers.
91 ExitOnErr(J->deinitialize(J->getMainJITDylib()));
92
93 outs() << "InitializerRanFlag = " << InitializersRunFlag << "\n"
94 << "DeinitializersRunFlag = " << DeinitializersRunFlag << "\n";
95
96 return 0;
97 }
98