1 //===--- CloudABI.cpp - CloudABI ToolChain Implementations ------*- 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 "CloudABI.h"
10 #include "CommonArgs.h"
11 #include "clang/Driver/Compilation.h"
12 #include "clang/Driver/Driver.h"
13 #include "clang/Driver/InputInfo.h"
14 #include "clang/Driver/Options.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/Option/ArgList.h"
17 #include "llvm/Support/Path.h"
18 
19 using namespace clang::driver;
20 using namespace clang::driver::tools;
21 using namespace clang::driver::toolchains;
22 using namespace clang;
23 using namespace llvm::opt;
24 
25 void cloudabi::Linker::ConstructJob(Compilation &C, const JobAction &JA,
26                                     const InputInfo &Output,
27                                     const InputInfoList &Inputs,
28                                     const ArgList &Args,
29                                     const char *LinkingOutput) const {
30   const ToolChain &ToolChain = getToolChain();
31   const Driver &D = ToolChain.getDriver();
32   ArgStringList CmdArgs;
33 
34   // Silence warning for "clang -g foo.o -o foo"
35   Args.ClaimAllArgs(options::OPT_g_Group);
36   // and "clang -emit-llvm foo.o -o foo"
37   Args.ClaimAllArgs(options::OPT_emit_llvm);
38   // and for "clang -w foo.o -o foo". Other warning options are already
39   // handled somewhere else.
40   Args.ClaimAllArgs(options::OPT_w);
41 
42   if (!D.SysRoot.empty())
43     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
44 
45   // CloudABI only supports static linkage.
46   CmdArgs.push_back("-Bstatic");
47   CmdArgs.push_back("--no-dynamic-linker");
48 
49   // Provide PIE linker flags in case PIE is default for the architecture.
50   if (ToolChain.isPIEDefault(Args)) {
51     CmdArgs.push_back("-pie");
52     CmdArgs.push_back("-zrelro");
53   }
54 
55   CmdArgs.push_back("--eh-frame-hdr");
56   CmdArgs.push_back("--gc-sections");
57 
58   if (Output.isFilename()) {
59     CmdArgs.push_back("-o");
60     CmdArgs.push_back(Output.getFilename());
61   } else {
62     assert(Output.isNothing() && "Invalid output.");
63   }
64 
65   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
66     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
67     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtbegin.o")));
68   }
69 
70   Args.AddAllArgs(CmdArgs, options::OPT_L);
71   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
72   Args.AddAllArgs(CmdArgs,
73                   {options::OPT_T_Group, options::OPT_e, options::OPT_s,
74                    options::OPT_t, options::OPT_Z_Flag, options::OPT_r});
75 
76   if (D.isUsingLTO()) {
77     assert(!Inputs.empty() && "Must have at least one input.");
78     addLTOOptions(ToolChain, Args, CmdArgs, Output, Inputs[0],
79                   D.getLTOMode() == LTOK_Thin);
80   }
81 
82   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
83 
84   if (ToolChain.ShouldLinkCXXStdlib(Args))
85     ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
86   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
87     CmdArgs.push_back("-lc");
88     CmdArgs.push_back("-lcompiler_rt");
89   }
90 
91   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles))
92     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crtend.o")));
93 
94   const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
95   C.addCommand(std::make_unique<Command>(JA, *this,
96                                          ResponseFileSupport::AtFileCurCP(),
97                                          Exec, CmdArgs, Inputs, Output));
98 }
99 
100 // CloudABI - CloudABI tool chain which can call ld(1) directly.
101 
102 CloudABI::CloudABI(const Driver &D, const llvm::Triple &Triple,
103                    const ArgList &Args)
104     : Generic_ELF(D, Triple, Args) {
105   SmallString<128> P(getDriver().Dir);
106   llvm::sys::path::append(P, "..", getTriple().str(), "lib");
107   getFilePaths().push_back(std::string(P.str()));
108 }
109 
110 void CloudABI::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
111                                      llvm::opt::ArgStringList &CC1Args) const {
112   SmallString<128> P(getDriver().Dir);
113   llvm::sys::path::append(P, "..", getTriple().str(), "include/c++/v1");
114   addSystemInclude(DriverArgs, CC1Args, P.str());
115 }
116 
117 void CloudABI::AddCXXStdlibLibArgs(const ArgList &Args,
118                                    ArgStringList &CmdArgs) const {
119   CmdArgs.push_back("-lc++");
120   if (Args.hasArg(options::OPT_fexperimental_library))
121     CmdArgs.push_back("-lc++experimental");
122   CmdArgs.push_back("-lc++abi");
123   CmdArgs.push_back("-lunwind");
124 }
125 
126 Tool *CloudABI::buildLinker() const {
127   return new tools::cloudabi::Linker(*this);
128 }
129 
130 bool CloudABI::isPIEDefault(const llvm::opt::ArgList &Args) const {
131   // Only enable PIE on architectures that support PC-relative
132   // addressing. PC-relative addressing is required, as the process
133   // startup code must be able to relocate itself.
134   switch (getTriple().getArch()) {
135   case llvm::Triple::aarch64:
136   case llvm::Triple::x86_64:
137     return true;
138   default:
139     return false;
140   }
141 }
142 
143 SanitizerMask CloudABI::getSupportedSanitizers() const {
144   SanitizerMask Res = ToolChain::getSupportedSanitizers();
145   Res |= SanitizerKind::SafeStack;
146   return Res;
147 }
148 
149 SanitizerMask CloudABI::getDefaultSanitizers() const {
150   return SanitizerKind::SafeStack;
151 }
152