1 //=====- NVPTXTargetStreamer.cpp - NVPTXTargetStreamer class ------------=====//
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 // This file implements the NVPTXTargetStreamer class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "NVPTXTargetStreamer.h"
14 #include "llvm/MC/MCAsmInfo.h"
15 #include "llvm/MC/MCContext.h"
16 #include "llvm/MC/MCObjectFileInfo.h"
17 
18 using namespace llvm;
19 
20 //
21 // NVPTXTargetStreamer Implemenation
22 //
23 NVPTXTargetStreamer::NVPTXTargetStreamer(MCStreamer &S) : MCTargetStreamer(S) {}
24 NVPTXTargetStreamer::~NVPTXTargetStreamer() = default;
25 
26 NVPTXAsmTargetStreamer::NVPTXAsmTargetStreamer(MCStreamer &S)
27     : NVPTXTargetStreamer(S) {}
28 NVPTXAsmTargetStreamer::~NVPTXAsmTargetStreamer() = default;
29 
30 void NVPTXTargetStreamer::outputDwarfFileDirectives() {
31   for (const std::string &S : DwarfFiles)
32     getStreamer().emitRawText(S);
33   DwarfFiles.clear();
34 }
35 
36 void NVPTXTargetStreamer::closeLastSection() {
37   if (HasSections)
38     getStreamer().emitRawText("\t}");
39 }
40 
41 void NVPTXTargetStreamer::emitDwarfFileDirective(StringRef Directive) {
42   DwarfFiles.emplace_back(Directive);
43 }
44 
45 static bool isDwarfSection(const MCObjectFileInfo *FI,
46                            const MCSection *Section) {
47   // FIXME: the checks for the DWARF sections are very fragile and should be
48   // fixed up in a followup patch.
49   if (!Section || Section->getKind().isText() ||
50       Section->getKind().isWriteable())
51     return false;
52   return Section == FI->getDwarfAbbrevSection() ||
53          Section == FI->getDwarfInfoSection() ||
54          Section == FI->getDwarfMacinfoSection() ||
55          Section == FI->getDwarfFrameSection() ||
56          Section == FI->getDwarfAddrSection() ||
57          Section == FI->getDwarfRangesSection() ||
58          Section == FI->getDwarfARangesSection() ||
59          Section == FI->getDwarfLocSection() ||
60          Section == FI->getDwarfStrSection() ||
61          Section == FI->getDwarfLineSection() ||
62          Section == FI->getDwarfStrOffSection() ||
63          Section == FI->getDwarfLineStrSection() ||
64          Section == FI->getDwarfPubNamesSection() ||
65          Section == FI->getDwarfPubTypesSection() ||
66          Section == FI->getDwarfSwiftASTSection() ||
67          Section == FI->getDwarfTypesDWOSection() ||
68          Section == FI->getDwarfAbbrevDWOSection() ||
69          Section == FI->getDwarfAccelObjCSection() ||
70          Section == FI->getDwarfAccelNamesSection() ||
71          Section == FI->getDwarfAccelTypesSection() ||
72          Section == FI->getDwarfAccelNamespaceSection() ||
73          Section == FI->getDwarfLocDWOSection() ||
74          Section == FI->getDwarfStrDWOSection() ||
75          Section == FI->getDwarfCUIndexSection() ||
76          Section == FI->getDwarfInfoDWOSection() ||
77          Section == FI->getDwarfLineDWOSection() ||
78          Section == FI->getDwarfTUIndexSection() ||
79          Section == FI->getDwarfStrOffDWOSection() ||
80          Section == FI->getDwarfDebugNamesSection() ||
81          Section == FI->getDwarfDebugInlineSection() ||
82          Section == FI->getDwarfGnuPubNamesSection() ||
83          Section == FI->getDwarfGnuPubTypesSection();
84 }
85 
86 void NVPTXTargetStreamer::changeSection(const MCSection *CurSection,
87                                         MCSection *Section,
88                                         const MCExpr *SubSection,
89                                         raw_ostream &OS) {
90   assert(!SubSection && "SubSection is not null!");
91   const MCObjectFileInfo *FI = getStreamer().getContext().getObjectFileInfo();
92   // Emit closing brace for DWARF sections only.
93   if (isDwarfSection(FI, CurSection))
94     OS << "\t}\n";
95   if (isDwarfSection(FI, Section)) {
96     // Emit DWARF .file directives in the outermost scope.
97     outputDwarfFileDirectives();
98     OS << "\t.section";
99     Section->printSwitchToSection(*getStreamer().getContext().getAsmInfo(),
100                                   getStreamer().getContext().getTargetTriple(),
101                                   OS, SubSection);
102     // DWARF sections are enclosed into braces - emit the open one.
103     OS << "\t{\n";
104     HasSections = true;
105   }
106 }
107 
108 void NVPTXTargetStreamer::emitRawBytes(StringRef Data) {
109   MCTargetStreamer::emitRawBytes(Data);
110   // TODO: enable this once the bug in the ptxas with the packed bytes is
111   // resolved. Currently, (it is confirmed by NVidia) it causes a crash in
112   // ptxas.
113 #if 0
114   const MCAsmInfo *MAI = Streamer.getContext().getAsmInfo();
115   const char *Directive = MAI->getData8bitsDirective();
116   unsigned NumElements = Data.size();
117   const unsigned MaxLen = 40;
118   unsigned NumChunks = 1 + ((NumElements - 1) / MaxLen);
119   // Split the very long directives into several parts if the limit is
120   // specified.
121   for (unsigned I = 0; I < NumChunks; ++I) {
122     SmallString<128> Str;
123     raw_svector_ostream OS(Str);
124 
125     const char *Label = Directive;
126     for (auto It = std::next(Data.bytes_begin(), I * MaxLen),
127               End = (I == NumChunks - 1)
128                         ? Data.bytes_end()
129                         : std::next(Data.bytes_begin(), (I + 1) * MaxLen);
130          It != End; ++It) {
131       OS << Label << (unsigned)*It;
132       if (Label == Directive)
133         Label = ",";
134     }
135     Streamer.emitRawText(OS.str());
136   }
137 #endif
138 }
139 
140