1 //==-- WebAssemblyTargetStreamer.cpp - WebAssembly Target Streamer Methods --=//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file defines WebAssembly-specific target streamer classes.
11 /// These are for implementing support for target-specific assembly directives.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "MCTargetDesc/WebAssemblyTargetStreamer.h"
16 #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
17 #include "Utils/WebAssemblyTypeUtilities.h"
18 #include "llvm/MC/MCContext.h"
19 #include "llvm/MC/MCSectionWasm.h"
20 #include "llvm/MC/MCSubtargetInfo.h"
21 #include "llvm/MC/MCSymbolWasm.h"
22 #include "llvm/Support/Casting.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/FormattedStream.h"
25 using namespace llvm;
26 
27 WebAssemblyTargetStreamer::WebAssemblyTargetStreamer(MCStreamer &S)
28     : MCTargetStreamer(S) {}
29 
30 void WebAssemblyTargetStreamer::emitValueType(wasm::ValType Type) {
31   Streamer.emitIntValue(uint8_t(Type), 1);
32 }
33 
34 WebAssemblyTargetAsmStreamer::WebAssemblyTargetAsmStreamer(
35     MCStreamer &S, formatted_raw_ostream &OS)
36     : WebAssemblyTargetStreamer(S), OS(OS) {}
37 
38 WebAssemblyTargetWasmStreamer::WebAssemblyTargetWasmStreamer(MCStreamer &S)
39     : WebAssemblyTargetStreamer(S) {}
40 
41 static void printTypes(formatted_raw_ostream &OS,
42                        ArrayRef<wasm::ValType> Types) {
43   bool First = true;
44   for (auto Type : Types) {
45     if (First)
46       First = false;
47     else
48       OS << ", ";
49     OS << WebAssembly::typeToString(Type);
50   }
51   OS << '\n';
52 }
53 
54 void WebAssemblyTargetAsmStreamer::emitLocal(ArrayRef<wasm::ValType> Types) {
55   if (!Types.empty()) {
56     OS << "\t.local  \t";
57     printTypes(OS, Types);
58   }
59 }
60 
61 void WebAssemblyTargetAsmStreamer::emitEndFunc() { OS << "\t.endfunc\n"; }
62 
63 void WebAssemblyTargetAsmStreamer::emitFunctionType(const MCSymbolWasm *Sym) {
64   assert(Sym->isFunction());
65   OS << "\t.functype\t" << Sym->getName() << " ";
66   OS << WebAssembly::signatureToString(Sym->getSignature());
67   OS << "\n";
68 }
69 
70 void WebAssemblyTargetAsmStreamer::emitGlobalType(const MCSymbolWasm *Sym) {
71   assert(Sym->isGlobal());
72   OS << "\t.globaltype\t" << Sym->getName() << ", "
73      << WebAssembly::typeToString(
74             static_cast<wasm::ValType>(Sym->getGlobalType().Type));
75   if (!Sym->getGlobalType().Mutable)
76     OS << ", immutable";
77   OS << '\n';
78 }
79 
80 void WebAssemblyTargetAsmStreamer::emitTableType(const MCSymbolWasm *Sym) {
81   assert(Sym->isTable());
82   const wasm::WasmTableType &Type = Sym->getTableType();
83   OS << "\t.tabletype\t" << Sym->getName() << ", "
84      << WebAssembly::typeToString(static_cast<wasm::ValType>(Type.ElemType));
85   bool HasMaximum = Type.Limits.Flags & wasm::WASM_LIMITS_FLAG_HAS_MAX;
86   if (Type.Limits.Minimum != 0 || HasMaximum) {
87     OS << ", " << Type.Limits.Minimum;
88     if (HasMaximum)
89       OS << ", " << Type.Limits.Maximum;
90   }
91   OS << '\n';
92 }
93 
94 void WebAssemblyTargetAsmStreamer::emitTagType(const MCSymbolWasm *Sym) {
95   assert(Sym->isTag());
96   OS << "\t.tagtype\t" << Sym->getName() << " ";
97   OS << WebAssembly::typeListToString(Sym->getSignature()->Params);
98   OS << "\n";
99 }
100 
101 void WebAssemblyTargetAsmStreamer::emitImportModule(const MCSymbolWasm *Sym,
102                                                     StringRef ImportModule) {
103   OS << "\t.import_module\t" << Sym->getName() << ", "
104                              << ImportModule << '\n';
105 }
106 
107 void WebAssemblyTargetAsmStreamer::emitImportName(const MCSymbolWasm *Sym,
108                                                   StringRef ImportName) {
109   OS << "\t.import_name\t" << Sym->getName() << ", "
110                            << ImportName << '\n';
111 }
112 
113 void WebAssemblyTargetAsmStreamer::emitExportName(const MCSymbolWasm *Sym,
114                                                   StringRef ExportName) {
115   OS << "\t.export_name\t" << Sym->getName() << ", "
116                            << ExportName << '\n';
117 }
118 
119 void WebAssemblyTargetAsmStreamer::emitIndIdx(const MCExpr *Value) {
120   OS << "\t.indidx  \t" << *Value << '\n';
121 }
122 
123 void WebAssemblyTargetWasmStreamer::emitLocal(ArrayRef<wasm::ValType> Types) {
124   SmallVector<std::pair<wasm::ValType, uint32_t>, 4> Grouped;
125   for (auto Type : Types) {
126     if (Grouped.empty() || Grouped.back().first != Type)
127       Grouped.push_back(std::make_pair(Type, 1));
128     else
129       ++Grouped.back().second;
130   }
131 
132   Streamer.emitULEB128IntValue(Grouped.size());
133   for (auto Pair : Grouped) {
134     Streamer.emitULEB128IntValue(Pair.second);
135     emitValueType(Pair.first);
136   }
137 }
138 
139 void WebAssemblyTargetWasmStreamer::emitEndFunc() {
140   llvm_unreachable(".end_func is not needed for direct wasm output");
141 }
142 
143 void WebAssemblyTargetWasmStreamer::emitIndIdx(const MCExpr *Value) {
144   llvm_unreachable(".indidx encoding not yet implemented");
145 }
146