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