Clang Project

clang_source_code/lib/Driver/ToolChains/BareMetal.cpp
1//===-- BareMetal.cpp - Bare Metal ToolChain --------------------*- C++ -*-===//
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#include "BareMetal.h"
10
11#include "CommonArgs.h"
12#include "InputInfo.h"
13#include "Gnu.h"
14
15#include "clang/Driver/Compilation.h"
16#include "clang/Driver/Driver.h"
17#include "clang/Driver/DriverDiagnostic.h"
18#include "clang/Driver/Options.h"
19#include "llvm/Option/ArgList.h"
20#include "llvm/Support/Path.h"
21#include "llvm/Support/VirtualFileSystem.h"
22#include "llvm/Support/raw_ostream.h"
23
24using namespace llvm::opt;
25using namespace clang;
26using namespace clang::driver;
27using namespace clang::driver::tools;
28using namespace clang::driver::toolchains;
29
30BareMetal::BareMetal(const Driver &D, const llvm::Triple &Triple,
31                           const ArgList &Args)
32    : ToolChain(D, Triple, Args) {
33  getProgramPaths().push_back(getDriver().getInstalledDir());
34  if (getDriver().getInstalledDir() != getDriver().Dir)
35    getProgramPaths().push_back(getDriver().Dir);
36}
37
38BareMetal::~BareMetal() {}
39
40/// Is the triple {arm,thumb}-none-none-{eabi,eabihf} ?
41static bool isARMBareMetal(const llvm::Triple &Triple) {
42  if (Triple.getArch() != llvm::Triple::arm &&
43      Triple.getArch() != llvm::Triple::thumb)
44    return false;
45
46  if (Triple.getVendor() != llvm::Triple::UnknownVendor)
47    return false;
48
49  if (Triple.getOS() != llvm::Triple::UnknownOS)
50    return false;
51
52  if (Triple.getEnvironment() != llvm::Triple::EABI &&
53      Triple.getEnvironment() != llvm::Triple::EABIHF)
54    return false;
55
56  return true;
57}
58
59bool BareMetal::handlesTarget(const llvm::Triple &Triple) {
60  return isARMBareMetal(Triple);
61}
62
63Tool *BareMetal::buildLinker() const {
64  return new tools::baremetal::Linker(*this);
65}
66
67std::string BareMetal::getRuntimesDir() const {
68  SmallString<128> Dir(getDriver().ResourceDir);
69  llvm::sys::path::append(Dir, "lib", "baremetal");
70  return Dir.str();
71}
72
73void BareMetal::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
74                                          ArgStringList &CC1Args) const {
75  if (DriverArgs.hasArg(options::OPT_nostdinc))
76    return;
77
78  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
79    SmallString<128> Dir(getDriver().ResourceDir);
80    llvm::sys::path::append(Dir, "include");
81    addSystemInclude(DriverArgs, CC1Args, Dir.str());
82  }
83
84  if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {
85    SmallString<128> Dir(getDriver().SysRoot);
86    llvm::sys::path::append(Dir, "include");
87    addSystemInclude(DriverArgs, CC1Args, Dir.str());
88  }
89}
90
91void BareMetal::addClangTargetOptions(const ArgList &DriverArgs,
92                                      ArgStringList &CC1Args,
93                                      Action::OffloadKind) const {
94  CC1Args.push_back("-nostdsysteminc");
95}
96
97void BareMetal::AddClangCXXStdlibIncludeArgs(
98    const ArgList &DriverArgs, ArgStringList &CC1Args) const {
99  if (DriverArgs.hasArg(options::OPT_nostdinc) ||
100      DriverArgs.hasArg(options::OPT_nostdlibinc) ||
101      DriverArgs.hasArg(options::OPT_nostdincxx))
102    return;
103
104  StringRef SysRoot = getDriver().SysRoot;
105  if (SysRoot.empty())
106    return;
107
108  switch (GetCXXStdlibType(DriverArgs)) {
109  case ToolChain::CST_Libcxx: {
110    SmallString<128> Dir(SysRoot);
111    llvm::sys::path::append(Dir, "include", "c++", "v1");
112    addSystemInclude(DriverArgs, CC1Args, Dir.str());
113    break;
114  }
115  case ToolChain::CST_Libstdcxx: {
116    SmallString<128> Dir(SysRoot);
117    llvm::sys::path::append(Dir, "include", "c++");
118    std::error_code EC;
119    Generic_GCC::GCCVersion Version = {"", -1, -1, -1, "", "", ""};
120    // Walk the subdirs, and find the one with the newest gcc version:
121    for (llvm::vfs::directory_iterator
122             LI = getDriver().getVFS().dir_begin(Dir.str(), EC),
123             LE;
124         !EC && LI != LE; LI = LI.increment(EC)) {
125      StringRef VersionText = llvm::sys::path::filename(LI->path());
126      auto CandidateVersion = Generic_GCC::GCCVersion::Parse(VersionText);
127      if (CandidateVersion.Major == -1)
128        continue;
129      if (CandidateVersion <= Version)
130        continue;
131      Version = CandidateVersion;
132    }
133    if (Version.Major == -1)
134      return;
135    llvm::sys::path::append(Dir, Version.Text);
136    addSystemInclude(DriverArgs, CC1Args, Dir.str());
137    break;
138  }
139  }
140}
141
142void BareMetal::AddCXXStdlibLibArgs(const ArgList &Args,
143                                    ArgStringList &CmdArgs) const {
144  switch (GetCXXStdlibType(Args)) {
145  case ToolChain::CST_Libcxx:
146    CmdArgs.push_back("-lc++");
147    CmdArgs.push_back("-lc++abi");
148    break;
149  case ToolChain::CST_Libstdcxx:
150    CmdArgs.push_back("-lstdc++");
151    CmdArgs.push_back("-lsupc++");
152    break;
153  }
154  CmdArgs.push_back("-lunwind");
155}
156
157void BareMetal::AddLinkRuntimeLib(const ArgList &Args,
158                                  ArgStringList &CmdArgs) const {
159  CmdArgs.push_back(Args.MakeArgString("-lclang_rt.builtins-" +
160                                       getTriple().getArchName() + ".a"));
161}
162
163void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
164                                     const InputInfo &Output,
165                                     const InputInfoList &Inputs,
166                                     const ArgList &Args,
167                                     const char *LinkingOutput) const {
168  ArgStringList CmdArgs;
169
170  auto &TC = static_cast<const toolchains::BareMetal&>(getToolChain());
171
172  AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
173
174  CmdArgs.push_back("-Bstatic");
175
176  CmdArgs.push_back(Args.MakeArgString("-L" + TC.getRuntimesDir()));
177
178  Args.AddAllArgs(CmdArgs, {options::OPT_L, options::OPT_T_Group,
179                            options::OPT_e, options::OPT_s, options::OPT_t,
180                            options::OPT_Z_Flag, options::OPT_r});
181
182  if (TC.ShouldLinkCXXStdlib(Args))
183    TC.AddCXXStdlibLibArgs(Args, CmdArgs);
184  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
185    CmdArgs.push_back("-lc");
186    CmdArgs.push_back("-lm");
187
188    TC.AddLinkRuntimeLib(Args, CmdArgs);
189  }
190
191  CmdArgs.push_back("-o");
192  CmdArgs.push_back(Output.getFilename());
193
194  C.addCommand(llvm::make_unique<Command>(JA, *this,
195                                          Args.MakeArgString(TC.GetLinkerPath()),
196                                          CmdArgs, Inputs));
197}
198
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