1 //===--- WebAssembly.cpp - WebAssembly ToolChain Implementation -*- 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 "WebAssembly.h"
11 #include "CommonArgs.h"
12 #include "clang/Driver/Compilation.h"
13 #include "clang/Driver/Driver.h"
14 #include "clang/Driver/Options.h"
15 #include "llvm/Option/ArgList.h"
16 
17 using namespace clang::driver;
18 using namespace clang::driver::tools;
19 using namespace clang::driver::toolchains;
20 using namespace clang;
21 using namespace llvm::opt;
22 
23 wasm::Linker::Linker(const ToolChain &TC)
24   : GnuTool("wasm::Linker", "lld", TC) {}
25 
26 bool wasm::Linker::isLinkJob() const {
27   return true;
28 }
29 
30 bool wasm::Linker::hasIntegratedCPP() const {
31   return false;
32 }
33 
34 void wasm::Linker::ConstructJob(Compilation &C, const JobAction &JA,
35                                 const InputInfo &Output,
36                                 const InputInfoList &Inputs,
37                                 const ArgList &Args,
38                                 const char *LinkingOutput) const {
39 
40   const ToolChain &ToolChain = getToolChain();
41   const Driver &D = ToolChain.getDriver();
42   const char *Linker = Args.MakeArgString(ToolChain.GetLinkerPath());
43   ArgStringList CmdArgs;
44   CmdArgs.push_back("-flavor");
45   CmdArgs.push_back("ld");
46 
47   // Enable garbage collection of unused input sections by default, since code
48   // size is of particular importance. This is significantly facilitated by
49   // the enabling of -ffunction-sections and -fdata-sections in
50   // Clang::ConstructJob.
51   if (areOptimizationsEnabled(Args))
52     CmdArgs.push_back("--gc-sections");
53 
54   if (Args.hasArg(options::OPT_rdynamic))
55     CmdArgs.push_back("-export-dynamic");
56   if (Args.hasArg(options::OPT_s))
57     CmdArgs.push_back("--strip-all");
58   if (Args.hasArg(options::OPT_shared))
59     CmdArgs.push_back("-shared");
60   if (Args.hasArg(options::OPT_static))
61     CmdArgs.push_back("-Bstatic");
62 
63   Args.AddAllArgs(CmdArgs, options::OPT_L);
64   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
65 
66   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
67     if (Args.hasArg(options::OPT_shared))
68       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("rcrt1.o")));
69     else if (Args.hasArg(options::OPT_pie))
70       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
71     else
72       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
73 
74     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
75   }
76 
77   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
78 
79   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
80     if (D.CCCIsCXX())
81       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
82 
83     if (Args.hasArg(options::OPT_pthread))
84       CmdArgs.push_back("-lpthread");
85 
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("crtn.o")));
92 
93   CmdArgs.push_back("-o");
94   CmdArgs.push_back(Output.getFilename());
95 
96   C.addCommand(llvm::make_unique<Command>(JA, *this, Linker, CmdArgs, Inputs));
97 }
98 
99 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
100                          const llvm::opt::ArgList &Args)
101   : ToolChain(D, Triple, Args) {
102 
103   assert(Triple.isArch32Bit() != Triple.isArch64Bit());
104   getFilePaths().push_back(
105       getDriver().SysRoot + "/lib" + (Triple.isArch32Bit() ? "32" : "64"));
106 }
107 
108 bool WebAssembly::IsMathErrnoDefault() const { return false; }
109 
110 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
111 
112 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
113 
114 bool WebAssembly::isPICDefault() const { return false; }
115 
116 bool WebAssembly::isPIEDefault() const { return false; }
117 
118 bool WebAssembly::isPICDefaultForced() const { return false; }
119 
120 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
121 
122 // TODO: Support Objective C stuff.
123 bool WebAssembly::SupportsObjCGC() const { return false; }
124 
125 bool WebAssembly::hasBlocksRuntime() const { return false; }
126 
127 // TODO: Support profiling.
128 bool WebAssembly::SupportsProfiling() const { return false; }
129 
130 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
131 
132 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
133                                         ArgStringList &CC1Args) const {
134   if (DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
135                          options::OPT_fno_use_init_array, true))
136     CC1Args.push_back("-fuse-init-array");
137 }
138 
139 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
140   return ToolChain::RLT_CompilerRT;
141 }
142 
143 ToolChain::CXXStdlibType WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
144   return ToolChain::CST_Libcxx;
145 }
146 
147 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
148                                             ArgStringList &CC1Args) const {
149   if (!DriverArgs.hasArg(options::OPT_nostdinc))
150     addSystemInclude(DriverArgs, CC1Args, getDriver().SysRoot + "/include");
151 }
152 
153 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
154                                                ArgStringList &CC1Args) const {
155   if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
156       !DriverArgs.hasArg(options::OPT_nostdincxx))
157     addSystemInclude(DriverArgs, CC1Args,
158                      getDriver().SysRoot + "/include/c++/v1");
159 }
160 
161 Tool *WebAssembly::buildLinker() const {
162   return new tools::wasm::Linker(*this);
163 }
164