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 char *Linker = Args.MakeArgString(ToolChain.GetLinkerPath());
42   ArgStringList CmdArgs;
43   CmdArgs.push_back("-flavor");
44   CmdArgs.push_back("wasm");
45 
46   // Enable garbage collection of unused input sections by default, since code
47   // size is of particular importance. This is significantly facilitated by
48   // the enabling of -ffunction-sections and -fdata-sections in
49   // Clang::ConstructJob.
50   if (areOptimizationsEnabled(Args))
51     CmdArgs.push_back("--gc-sections");
52 
53   if (Args.hasArg(options::OPT_rdynamic))
54     CmdArgs.push_back("-export-dynamic");
55   if (Args.hasArg(options::OPT_s))
56     CmdArgs.push_back("--strip-all");
57   if (Args.hasArg(options::OPT_shared))
58     CmdArgs.push_back("-shared");
59   if (Args.hasArg(options::OPT_static))
60     CmdArgs.push_back("-Bstatic");
61 
62   Args.AddAllArgs(CmdArgs, options::OPT_L);
63   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
64 
65   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
66     if (Args.hasArg(options::OPT_shared))
67       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("rcrt1.o")));
68     else if (Args.hasArg(options::OPT_pie))
69       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("Scrt1.o")));
70     else
71       CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt1.o")));
72 
73     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crti.o")));
74   }
75 
76   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
77 
78   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
79     if (ToolChain.ShouldLinkCXXStdlib(Args))
80       ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
81 
82     if (Args.hasArg(options::OPT_pthread))
83       CmdArgs.push_back("-lpthread");
84 
85     CmdArgs.push_back("-allow-undefined-file");
86     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("wasm.syms")));
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("crtn.o")));
93 
94   CmdArgs.push_back("-o");
95   CmdArgs.push_back(Output.getFilename());
96 
97   C.addCommand(llvm::make_unique<Command>(JA, *this, Linker, CmdArgs, Inputs));
98 }
99 
100 WebAssembly::WebAssembly(const Driver &D, const llvm::Triple &Triple,
101                          const llvm::opt::ArgList &Args)
102   : ToolChain(D, Triple, Args) {
103 
104   assert(Triple.isArch32Bit() != Triple.isArch64Bit());
105 
106   getProgramPaths().push_back(getDriver().getInstalledDir());
107 
108   getFilePaths().push_back(getDriver().SysRoot + "/lib");
109 }
110 
111 bool WebAssembly::IsMathErrnoDefault() const { return false; }
112 
113 bool WebAssembly::IsObjCNonFragileABIDefault() const { return true; }
114 
115 bool WebAssembly::UseObjCMixedDispatch() const { return true; }
116 
117 bool WebAssembly::isPICDefault() const { return false; }
118 
119 bool WebAssembly::isPIEDefault() const { return false; }
120 
121 bool WebAssembly::isPICDefaultForced() const { return false; }
122 
123 bool WebAssembly::IsIntegratedAssemblerDefault() const { return true; }
124 
125 // TODO: Support Objective C stuff.
126 bool WebAssembly::SupportsObjCGC() const { return false; }
127 
128 bool WebAssembly::hasBlocksRuntime() const { return false; }
129 
130 // TODO: Support profiling.
131 bool WebAssembly::SupportsProfiling() const { return false; }
132 
133 bool WebAssembly::HasNativeLLVMSupport() const { return true; }
134 
135 void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
136                                         ArgStringList &CC1Args,
137                                         Action::OffloadKind) const {
138   if (DriverArgs.hasFlag(clang::driver::options::OPT_fuse_init_array,
139                          options::OPT_fno_use_init_array, true))
140     CC1Args.push_back("-fuse-init-array");
141 }
142 
143 ToolChain::RuntimeLibType WebAssembly::GetDefaultRuntimeLibType() const {
144   return ToolChain::RLT_CompilerRT;
145 }
146 
147 ToolChain::CXXStdlibType WebAssembly::GetCXXStdlibType(const ArgList &Args) const {
148   return ToolChain::CST_Libcxx;
149 }
150 
151 void WebAssembly::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
152                                             ArgStringList &CC1Args) const {
153   if (!DriverArgs.hasArg(options::OPT_nostdinc))
154     addSystemInclude(DriverArgs, CC1Args, getDriver().SysRoot + "/include");
155 }
156 
157 void WebAssembly::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
158                                                ArgStringList &CC1Args) const {
159   if (!DriverArgs.hasArg(options::OPT_nostdlibinc) &&
160       !DriverArgs.hasArg(options::OPT_nostdincxx))
161     addSystemInclude(DriverArgs, CC1Args,
162                      getDriver().SysRoot + "/include/c++/v1");
163 }
164 
165 Tool *WebAssembly::buildLinker() const {
166   return new tools::wasm::Linker(*this);
167 }
168