1 //==-- WebAssemblyTargetStreamer.cpp - WebAssembly Target Streamer Methods --=//
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 /// \file
11 /// This file defines WebAssembly-specific target streamer classes.
12 /// These are for implementing support for target-specific assembly directives.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "WebAssemblyTargetStreamer.h"
17 #include "InstPrinter/WebAssemblyInstPrinter.h"
18 #include "WebAssemblyMCTargetDesc.h"
19 #include "llvm/MC/MCContext.h"
20 #include "llvm/MC/MCSectionWasm.h"
21 #include "llvm/MC/MCSubtargetInfo.h"
22 #include "llvm/MC/MCSymbolWasm.h"
23 #include "llvm/Support/Casting.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/FormattedStream.h"
26 using namespace llvm;
27 
28 WebAssemblyTargetStreamer::WebAssemblyTargetStreamer(MCStreamer &S)
29     : MCTargetStreamer(S) {}
30 
31 void WebAssemblyTargetStreamer::emitValueType(wasm::ValType Type) {
32   Streamer.EmitIntValue(uint8_t(Type), 1);
33 }
34 
35 WebAssemblyTargetAsmStreamer::WebAssemblyTargetAsmStreamer(
36     MCStreamer &S, formatted_raw_ostream &OS)
37     : WebAssemblyTargetStreamer(S), OS(OS) {}
38 
39 WebAssemblyTargetWasmStreamer::WebAssemblyTargetWasmStreamer(MCStreamer &S)
40     : WebAssemblyTargetStreamer(S) {}
41 
42 static void PrintTypes(formatted_raw_ostream &OS, ArrayRef<MVT> Types) {
43   bool First = true;
44   for (MVT Type : Types) {
45     if (First)
46       First = false;
47     else
48       OS << ", ";
49     OS << WebAssembly::TypeToString(WebAssembly::toValType(Type));
50   }
51   OS << '\n';
52 }
53 
54 void WebAssemblyTargetAsmStreamer::emitParam(MCSymbol *Symbol,
55                                              ArrayRef<MVT> Types) {
56   if (!Types.empty()) {
57     OS << "\t.param  \t";
58 
59     // FIXME: Currently this applies to the "current" function; it may
60     // be cleaner to specify an explicit symbol as part of the directive.
61 
62     PrintTypes(OS, Types);
63   }
64 }
65 
66 void WebAssemblyTargetAsmStreamer::emitResult(MCSymbol *Symbol,
67                                               ArrayRef<MVT> Types) {
68   if (!Types.empty()) {
69     OS << "\t.result \t";
70 
71     // FIXME: Currently this applies to the "current" function; it may
72     // be cleaner to specify an explicit symbol as part of the directive.
73 
74     PrintTypes(OS, Types);
75   }
76 }
77 
78 void WebAssemblyTargetAsmStreamer::emitLocal(ArrayRef<MVT> Types) {
79   if (!Types.empty()) {
80     OS << "\t.local  \t";
81     PrintTypes(OS, Types);
82   }
83 }
84 
85 void WebAssemblyTargetAsmStreamer::emitEndFunc() { OS << "\t.endfunc\n"; }
86 
87 void WebAssemblyTargetAsmStreamer::emitIndirectFunctionType(
88     MCSymbolWasm *Symbol) {
89   OS << "\t.functype\t" << Symbol->getName();
90   if (Symbol->getSignature()->Returns.empty())
91     OS << ", void";
92   else {
93     assert(Symbol->getSignature()->Returns.size() == 1);
94     OS << ", "
95        << WebAssembly::TypeToString(Symbol->getSignature()->Returns.front());
96   }
97   for (auto Ty : Symbol->getSignature()->Params)
98     OS << ", " << WebAssembly::TypeToString(Ty);
99   OS << '\n';
100 }
101 
102 void WebAssemblyTargetAsmStreamer::emitGlobalType(MCSymbolWasm *Sym) {
103   OS << "\t.globaltype\t" << Sym->getName() << ", " <<
104         WebAssembly::TypeToString(
105           static_cast<wasm::ValType>(Sym->getGlobalType().Type)) <<
106         '\n';
107 }
108 
109 void WebAssemblyTargetAsmStreamer::emitImportModule(MCSymbolWasm *Sym,
110                                                     StringRef ModuleName) {
111   OS << "\t.import_module\t" << Sym->getName() << ", " << ModuleName << '\n';
112 }
113 
114 void WebAssemblyTargetAsmStreamer::emitIndIdx(const MCExpr *Value) {
115   OS << "\t.indidx  \t" << *Value << '\n';
116 }
117 
118 void WebAssemblyTargetWasmStreamer::emitParam(MCSymbol *Symbol,
119                                               ArrayRef<MVT> Types) {
120   // The Symbol already has its signature
121 }
122 
123 void WebAssemblyTargetWasmStreamer::emitResult(MCSymbol *Symbol,
124                                                ArrayRef<MVT> Types) {
125   // The Symbol already has its signature
126 }
127 
128 void WebAssemblyTargetWasmStreamer::emitLocal(ArrayRef<MVT> Types) {
129   SmallVector<std::pair<MVT, uint32_t>, 4> Grouped;
130   for (MVT Type : Types) {
131     if (Grouped.empty() || Grouped.back().first != Type)
132       Grouped.push_back(std::make_pair(Type, 1));
133     else
134       ++Grouped.back().second;
135   }
136 
137   Streamer.EmitULEB128IntValue(Grouped.size());
138   for (auto Pair : Grouped) {
139     Streamer.EmitULEB128IntValue(Pair.second);
140     emitValueType(WebAssembly::toValType(Pair.first));
141   }
142 }
143 
144 void WebAssemblyTargetWasmStreamer::emitEndFunc() {
145   llvm_unreachable(".end_func is not needed for direct wasm output");
146 }
147 
148 void WebAssemblyTargetWasmStreamer::emitIndIdx(const MCExpr *Value) {
149   llvm_unreachable(".indidx encoding not yet implemented");
150 }
151 
152 void WebAssemblyTargetWasmStreamer::emitIndirectFunctionType(
153     MCSymbolWasm *Symbol) {
154   // Symbol already has its arguments and result set.
155   Symbol->setType(wasm::WASM_SYMBOL_TYPE_FUNCTION);
156 }
157 
158 void WebAssemblyTargetWasmStreamer::emitGlobalType(MCSymbolWasm *Sym) {
159   // Not needed.
160 }
161 
162 void WebAssemblyTargetWasmStreamer::emitImportModule(MCSymbolWasm *Sym,
163                                                      StringRef ModuleName) {
164   Sym->setModuleName(ModuleName);
165 }
166