1//===- bolt/RuntimeLibs/HugifyRuntimeLibrary.cpp - Hugify RT Library ------===//
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// This file implements the HugifyRuntimeLibrary class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "bolt/RuntimeLibs/HugifyRuntimeLibrary.h"
14#include "bolt/Core/BinaryContext.h"
15#include "bolt/Core/Linker.h"
16#include "llvm/MC/MCStreamer.h"
17#include "llvm/Support/CommandLine.h"
18
19using namespace llvm;
20using namespace bolt;
21
22namespace opts {
23
24extern cl::OptionCategory BoltOptCategory;
25
26extern cl::opt<bool> HotText;
27
28cl::opt<bool>
29 Hugify("hugify",
30 cl::desc("Automatically put hot code on 2MB page(s) (hugify) at "
31 "runtime. No manual call to hugify is needed in the binary "
32 "(which is what --hot-text relies on)."),
33 cl::cat(BoltOptCategory));
34
35static cl::opt<std::string>
36 RuntimeHugifyLib("runtime-hugify-lib",
37 cl::desc("specify path of the runtime hugify library"),
38 cl::init(Val: "libbolt_rt_hugify.a"), cl::cat(BoltOptCategory));
39
40} // namespace opts
41
42void HugifyRuntimeLibrary::adjustCommandLineOptions(
43 const BinaryContext &BC) const {
44 if (opts::HotText) {
45 errs()
46 << "BOLT-ERROR: -hot-text should be applied to binaries with "
47 "pre-compiled manual hugify support, while -hugify will add hugify "
48 "support automatically. These two options cannot both be present.\n";
49 exit(status: 1);
50 }
51 // After the check, we set HotText to be true because automated hugify support
52 // relies on it.
53 opts::HotText = true;
54 if (!BC.StartFunctionAddress) {
55 errs() << "BOLT-ERROR: hugify runtime libraries require a known entry "
56 "point of "
57 "the input binary\n";
58 exit(status: 1);
59 }
60}
61
62void HugifyRuntimeLibrary::link(BinaryContext &BC, StringRef ToolPath,
63 BOLTLinker &Linker,
64 BOLTLinker::SectionsMapper MapSections) {
65
66 std::string LibPath = getLibPath(ToolPath, LibFileName: opts::RuntimeHugifyLib);
67 loadLibrary(LibPath, Linker, MapSections);
68
69 assert(!RuntimeStartAddress &&
70 "We don't currently support linking multiple runtime libraries");
71 auto StartSymInfo = Linker.lookupSymbolInfo(Name: "__bolt_hugify_self");
72 if (!StartSymInfo) {
73 errs() << "BOLT-ERROR: hugify library does not define __bolt_hugify_self: "
74 << LibPath << "\n";
75 exit(status: 1);
76 }
77 RuntimeStartAddress = StartSymInfo->Address;
78}
79

source code of bolt/lib/RuntimeLibs/HugifyRuntimeLibrary.cpp