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,
43                        ArrayRef<wasm::ValType> Types) {
44   bool First = true;
45   for (auto Type : Types) {
46     if (First)
47       First = false;
48     else
49       OS << ", ";
50     OS << WebAssembly::TypeToString(Type);
51   }
52   OS << '\n';
53 }
54 
55 void WebAssemblyTargetAsmStreamer::emitLocal(ArrayRef<wasm::ValType> Types) {
56   if (!Types.empty()) {
57     OS << "\t.local  \t";
58     printTypes(OS, Types);
59   }
60 }
61 
62 void WebAssemblyTargetAsmStreamer::emitEndFunc() { OS << "\t.endfunc\n"; }
63 
64 void WebAssemblyTargetAsmStreamer::emitFunctionType(const MCSymbolWasm *Sym) {
65   assert(Sym->isFunction());
66   OS << "\t.functype\t" << Sym->getName() << " (";
67   auto &Params = Sym->getSignature()->Params;
68   for (auto &Ty : Params) {
69     if (&Ty != &Params[0]) OS << ", ";
70     OS << WebAssembly::TypeToString(Ty);
71   }
72   OS << ") -> (";
73   auto &Returns = Sym->getSignature()->Returns;
74   for (auto &Ty : Returns) {
75     if (&Ty != &Returns[0]) OS << ", ";
76     OS << WebAssembly::TypeToString(Ty);
77   }
78   OS << ")\n";
79 }
80 
81 void WebAssemblyTargetAsmStreamer::emitGlobalType(const MCSymbolWasm *Sym) {
82   assert(Sym->isGlobal());
83   OS << "\t.globaltype\t" << Sym->getName() << ", " <<
84         WebAssembly::TypeToString(
85           static_cast<wasm::ValType>(Sym->getGlobalType().Type)) <<
86         '\n';
87 }
88 
89 void WebAssemblyTargetAsmStreamer::emitEventType(const MCSymbolWasm *Sym) {
90   assert(Sym->isEvent());
91   OS << "\t.eventtype\t" << Sym->getName();
92   if (Sym->getSignature()->Returns.empty())
93     OS << ", void";
94   else {
95     assert(Sym->getSignature()->Returns.size() == 1);
96     OS << ", "
97        << WebAssembly::TypeToString(Sym->getSignature()->Returns.front());
98   }
99   for (auto Ty : Sym->getSignature()->Params)
100     OS << ", " << WebAssembly::TypeToString(Ty);
101   OS << '\n';
102 }
103 
104 void WebAssemblyTargetAsmStreamer::emitImportModule(const MCSymbolWasm *Sym,
105                                                     StringRef ModuleName) {
106   OS << "\t.import_module\t" << Sym->getName() << ", " << ModuleName << '\n';
107 }
108 
109 void WebAssemblyTargetAsmStreamer::emitIndIdx(const MCExpr *Value) {
110   OS << "\t.indidx  \t" << *Value << '\n';
111 }
112 
113 void WebAssemblyTargetWasmStreamer::emitLocal(ArrayRef<wasm::ValType> Types) {
114   SmallVector<std::pair<wasm::ValType, uint32_t>, 4> Grouped;
115   for (auto Type : Types) {
116     if (Grouped.empty() || Grouped.back().first != Type)
117       Grouped.push_back(std::make_pair(Type, 1));
118     else
119       ++Grouped.back().second;
120   }
121 
122   Streamer.EmitULEB128IntValue(Grouped.size());
123   for (auto Pair : Grouped) {
124     Streamer.EmitULEB128IntValue(Pair.second);
125     emitValueType(Pair.first);
126   }
127 }
128 
129 void WebAssemblyTargetWasmStreamer::emitEndFunc() {
130   llvm_unreachable(".end_func is not needed for direct wasm output");
131 }
132 
133 void WebAssemblyTargetWasmStreamer::emitIndIdx(const MCExpr *Value) {
134   llvm_unreachable(".indidx encoding not yet implemented");
135 }
136