1 //===--- BaremMetal.cpp - Bare Metal ToolChain ------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "BareMetal.h"
11 
12 #include "CommonArgs.h"
13 #include "InputInfo.h"
14 #include "Gnu.h"
15 
16 #include "clang/Basic/VirtualFileSystem.h"
17 #include "clang/Driver/Compilation.h"
18 #include "clang/Driver/Driver.h"
19 #include "clang/Driver/DriverDiagnostic.h"
20 #include "clang/Driver/Options.h"
21 #include "llvm/Option/ArgList.h"
22 #include "llvm/Support/Path.h"
23 #include "llvm/Support/raw_ostream.h"
24 
25 using namespace llvm::opt;
26 using namespace clang;
27 using namespace clang::driver;
28 using namespace clang::driver::tools;
29 using namespace clang::driver::toolchains;
30 
31 BareMetal::BareMetal(const Driver &D, const llvm::Triple &Triple,
32                            const ArgList &Args)
33     : ToolChain(D, Triple, Args) {
34   getProgramPaths().push_back(getDriver().getInstalledDir());
35   if (getDriver().getInstalledDir() != getDriver().Dir)
36     getProgramPaths().push_back(getDriver().Dir);
37 }
38 
39 BareMetal::~BareMetal() {}
40 
41 /// Is the triple {arm,thumb}-none-none-{eabi,eabihf} ?
42 static bool isARMBareMetal(const llvm::Triple &Triple) {
43   if (Triple.getArch() != llvm::Triple::arm &&
44       Triple.getArch() != llvm::Triple::thumb)
45     return false;
46 
47   if (Triple.getVendor() != llvm::Triple::UnknownVendor)
48     return false;
49 
50   if (Triple.getOS() != llvm::Triple::UnknownOS)
51     return false;
52 
53   if (Triple.getEnvironment() != llvm::Triple::EABI &&
54       Triple.getEnvironment() != llvm::Triple::EABIHF)
55     return false;
56 
57   return true;
58 }
59 
60 bool BareMetal::handlesTarget(const llvm::Triple &Triple) {
61   return isARMBareMetal(Triple);
62 }
63 
64 Tool *BareMetal::buildLinker() const {
65   return new tools::baremetal::Linker(*this);
66 }
67 
68 std::string BareMetal::getRuntimesDir() const {
69   SmallString<128> Dir(getDriver().ResourceDir);
70   llvm::sys::path::append(Dir, "lib", "baremetal");
71   return Dir.str();
72 }
73 
74 void BareMetal::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
75                                           ArgStringList &CC1Args) const {
76   if (DriverArgs.hasArg(options::OPT_nostdinc))
77     return;
78 
79   if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
80     SmallString<128> Dir(getDriver().ResourceDir);
81     llvm::sys::path::append(Dir, "include");
82     addSystemInclude(DriverArgs, CC1Args, Dir.str());
83   }
84 
85   if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {
86     SmallString<128> Dir(getDriver().SysRoot);
87     llvm::sys::path::append(Dir, "include");
88     addSystemInclude(DriverArgs, CC1Args, Dir.str());
89   }
90 }
91 
92 void BareMetal::addClangTargetOptions(const ArgList &DriverArgs,
93                                       ArgStringList &CC1Args,
94                                       Action::OffloadKind) const {
95   CC1Args.push_back("-nostdsysteminc");
96 }
97 
98 std::string BareMetal::findLibCxxIncludePath(CXXStdlibType LibType) const {
99   StringRef SysRoot = getDriver().SysRoot;
100   if (SysRoot.empty())
101     return "";
102 
103   switch (LibType) {
104   case ToolChain::CST_Libcxx: {
105     SmallString<128> Dir(SysRoot);
106     llvm::sys::path::append(Dir, "include", "c++", "v1");
107     return Dir.str();
108   }
109   case ToolChain::CST_Libstdcxx: {
110     SmallString<128> Dir(SysRoot);
111     llvm::sys::path::append(Dir, "include", "c++");
112     std::error_code EC;
113     Generic_GCC::GCCVersion Version = {"", -1, -1, -1, "", "", ""};
114     // Walk the subdirs, and find the one with the newest gcc version:
115     for (vfs::directory_iterator LI =
116            getDriver().getVFS().dir_begin(Dir.str(), EC), LE;
117          !EC && LI != LE; LI = LI.increment(EC)) {
118       StringRef VersionText = llvm::sys::path::filename(LI->getName());
119       auto CandidateVersion = Generic_GCC::GCCVersion::Parse(VersionText);
120       if (CandidateVersion.Major == -1)
121         continue;
122       if (CandidateVersion <= Version)
123         continue;
124       Version = CandidateVersion;
125     }
126     if (Version.Major == -1)
127       return "";
128     llvm::sys::path::append(Dir, Version.Text);
129     return Dir.str();
130   }
131   }
132   llvm_unreachable("unhandled LibType");
133 }
134 
135 void BareMetal::AddClangCXXStdlibIncludeArgs(
136     const ArgList &DriverArgs, ArgStringList &CC1Args) const {
137   if (DriverArgs.hasArg(options::OPT_nostdinc) ||
138       DriverArgs.hasArg(options::OPT_nostdlibinc) ||
139       DriverArgs.hasArg(options::OPT_nostdincxx))
140     return;
141 
142   std::string Path = findLibCxxIncludePath(GetCXXStdlibType(DriverArgs));
143   if (!Path.empty())
144     addSystemInclude(DriverArgs, CC1Args, Path);
145 }
146 
147 void BareMetal::AddCXXStdlibLibArgs(const ArgList &Args,
148                                     ArgStringList &CmdArgs) const {
149   switch (GetCXXStdlibType(Args)) {
150   case ToolChain::CST_Libcxx:
151     CmdArgs.push_back("-lc++");
152     CmdArgs.push_back("-lc++abi");
153     break;
154   case ToolChain::CST_Libstdcxx:
155     CmdArgs.push_back("-lstdc++");
156     CmdArgs.push_back("-lsupc++");
157     break;
158   }
159   CmdArgs.push_back("-lunwind");
160 }
161 
162 void BareMetal::AddLinkRuntimeLib(const ArgList &Args,
163                                   ArgStringList &CmdArgs) const {
164   CmdArgs.push_back(Args.MakeArgString("-lclang_rt.builtins-" +
165                                        getTriple().getArchName() + ".a"));
166 }
167 
168 void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,
169                                      const InputInfo &Output,
170                                      const InputInfoList &Inputs,
171                                      const ArgList &Args,
172                                      const char *LinkingOutput) const {
173   ArgStringList CmdArgs;
174 
175   auto &TC = static_cast<const toolchains::BareMetal&>(getToolChain());
176 
177   AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
178 
179   CmdArgs.push_back("-Bstatic");
180 
181   CmdArgs.push_back(Args.MakeArgString("-L" + TC.getRuntimesDir()));
182 
183   Args.AddAllArgs(CmdArgs, {options::OPT_L, options::OPT_T_Group,
184                             options::OPT_e, options::OPT_s, options::OPT_t,
185                             options::OPT_Z_Flag, options::OPT_r});
186 
187   if (TC.ShouldLinkCXXStdlib(Args))
188     TC.AddCXXStdlibLibArgs(Args, CmdArgs);
189   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
190     CmdArgs.push_back("-lc");
191     CmdArgs.push_back("-lm");
192 
193     TC.AddLinkRuntimeLib(Args, CmdArgs);
194   }
195 
196   CmdArgs.push_back("-o");
197   CmdArgs.push_back(Output.getFilename());
198 
199   C.addCommand(llvm::make_unique<Command>(JA, *this,
200                                           Args.MakeArgString(TC.GetLinkerPath()),
201                                           CmdArgs, Inputs));
202 }
203