1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
//===--- LLJITWithLazyReexports.cpp - LLJIT example with custom laziness --===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// In this example we will use the lazy re-exports utility to lazily compile
// IR modules. We will do this in seven steps:
//
// 1. Create an LLJIT instance.
// 2. Install a transform so that we can see what is being compiled.
// 3. Create an indirect stubs manager and lazy call-through manager.
// 4. Add two modules that will be conditionally compiled, plus a main module.
// 5. Add lazy-rexports of the symbols in the conditionally compiled modules.
// 6. Dump the ExecutionSession state to see the symbol table prior to
// executing any code.
// 7. Verify that only modules containing executed code are compiled.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringMap.h"
#include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h"
#include "llvm/ExecutionEngine/Orc/LLJIT.h"
#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include "../ExampleModules.h"
using namespace llvm;
using namespace llvm::orc;
ExitOnError ExitOnErr;
// Example IR modules.
//
// Note that in the conditionally compiled modules, FooMod and BarMod, functions
// have been given an _body suffix. This is to ensure that their names do not
// clash with their lazy-reexports.
// For clients who do not wish to rename function bodies (e.g. because they want
// to re-use cached objects between static and JIT compiles) techniques exist to
// avoid renaming. See the lazy-reexports section of the ORCv2 design doc.
const llvm::StringRef FooMod =
R"(
define i32 @foo_body() {
entry:
ret i32 1
}
)";
const llvm::StringRef BarMod =
R"(
define i32 @bar_body() {
entry:
ret i32 2
}
)";
const llvm::StringRef MainMod =
R"(
define i32 @entry(i32 %argc) {
entry:
%and = and i32 %argc, 1
%tobool = icmp eq i32 %and, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
%call = tail call i32 @foo() #2
br label %return
if.end: ; preds = %entry
%call1 = tail call i32 @bar() #2
br label %return
return: ; preds = %if.end, %if.then
%retval.0 = phi i32 [ %call, %if.then ], [ %call1, %if.end ]
ret i32 %retval.0
}
declare i32 @foo()
declare i32 @bar()
)";
cl::list<std::string> InputArgv(cl::Positional,
cl::desc("<program arguments>..."));
int main(int argc, char *argv[]) {
// Initialize LLVM.
InitLLVM X(argc, argv);
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
cl::ParseCommandLineOptions(argc, argv, "LLJITWithLazyReexports");
ExitOnErr.setBanner(std::string(argv[0]) + ": ");
// (1) Create LLJIT instance.
auto J = ExitOnErr(LLJITBuilder().create());
// (2) Install transform to print modules as they are compiled:
J->getIRTransformLayer().setTransform(
[](ThreadSafeModule TSM,
const MaterializationResponsibility &R) -> Expected<ThreadSafeModule> {
TSM.withModuleDo([](Module &M) { dbgs() << "---Compiling---\n" << M; });
return std::move(TSM); // Not a redundant move: fix build on gcc-7.5
});
// (3) Create stubs and call-through managers:
std::unique_ptr<IndirectStubsManager> ISM;
{
auto ISMBuilder =
createLocalIndirectStubsManagerBuilder(J->getTargetTriple());
if (!ISMBuilder())
ExitOnErr(make_error<StringError>("Could not create stubs manager for " +
J->getTargetTriple().str(),
inconvertibleErrorCode()));
ISM = ISMBuilder();
}
auto LCTM = ExitOnErr(createLocalLazyCallThroughManager(
J->getTargetTriple(), J->getExecutionSession(), 0));
// (4) Add modules.
ExitOnErr(J->addIRModule(ExitOnErr(parseExampleModule(FooMod, "foo-mod"))));
ExitOnErr(J->addIRModule(ExitOnErr(parseExampleModule(BarMod, "bar-mod"))));
ExitOnErr(J->addIRModule(ExitOnErr(parseExampleModule(MainMod, "main-mod"))));
// (5) Add lazy reexports.
MangleAndInterner Mangle(J->getExecutionSession(), J->getDataLayout());
SymbolAliasMap ReExports(
{{Mangle("foo"),
{Mangle("foo_body"),
JITSymbolFlags::Exported | JITSymbolFlags::Callable}},
{Mangle("bar"),
{Mangle("bar_body"),
JITSymbolFlags::Exported | JITSymbolFlags::Callable}}});
ExitOnErr(J->getMainJITDylib().define(
lazyReexports(*LCTM, *ISM, J->getMainJITDylib(), std::move(ReExports))));
// (6) Dump the ExecutionSession state.
dbgs() << "---Session state---\n";
J->getExecutionSession().dump(dbgs());
dbgs() << "\n";
// (7) Execute the JIT'd main function and pass the example's command line
// arguments unmodified. This should cause either ExampleMod1 or ExampleMod2
// to be compiled, and either "1" or "2" returned depending on the number of
// arguments passed.
// Look up the JIT'd function, cast it to a function pointer, then call it.
auto EntrySym = ExitOnErr(J->lookup("entry"));
auto *Entry = (int (*)(int))EntrySym.getAddress();
int Result = Entry(argc);
outs() << "---Result---\n"
<< "entry(" << argc << ") = " << Result << "\n";
return 0;
}
|
