1 //===- lib/MC/MCSectionWasm.cpp - Wasm Code Section Representation --------===//
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 #include "llvm/MC/MCSectionWasm.h"
10 #include "llvm/MC/MCAsmInfo.h"
11 #include "llvm/MC/MCExpr.h"
12 #include "llvm/MC/MCSymbol.h"
13 #include "llvm/Support/raw_ostream.h"
14 
15 using namespace llvm;
16 
17 // Decides whether a '.section' directive
18 // should be printed before the section name.
19 bool MCSectionWasm::shouldOmitSectionDirective(StringRef Name,
20                                                const MCAsmInfo &MAI) const {
21   return MAI.shouldOmitSectionDirective(Name);
22 }
23 
24 static void printName(raw_ostream &OS, StringRef Name) {
25   if (Name.find_first_not_of("0123456789_."
26                              "abcdefghijklmnopqrstuvwxyz"
27                              "ABCDEFGHIJKLMNOPQRSTUVWXYZ") == Name.npos) {
28     OS << Name;
29     return;
30   }
31   OS << '"';
32   for (const char *B = Name.begin(), *E = Name.end(); B < E; ++B) {
33     if (*B == '"') // Unquoted "
34       OS << "\\\"";
35     else if (*B != '\\') // Neither " or backslash
36       OS << *B;
37     else if (B + 1 == E) // Trailing backslash
38       OS << "\\\\";
39     else {
40       OS << B[0] << B[1]; // Quoted character
41       ++B;
42     }
43   }
44   OS << '"';
45 }
46 
47 void MCSectionWasm::PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
48                                          raw_ostream &OS,
49                                          const MCExpr *Subsection) const {
50 
51   if (shouldOmitSectionDirective(SectionName, MAI)) {
52     OS << '\t' << getSectionName();
53     if (Subsection) {
54       OS << '\t';
55       Subsection->print(OS, &MAI);
56     }
57     OS << '\n';
58     return;
59   }
60 
61   OS << "\t.section\t";
62   printName(OS, getSectionName());
63   OS << ",\"";
64 
65   // TODO: Print section flags.
66 
67   OS << '"';
68 
69   OS << ',';
70 
71   // If comment string is '@', e.g. as on ARM - use '%' instead
72   if (MAI.getCommentString()[0] == '@')
73     OS << '%';
74   else
75     OS << '@';
76 
77   // TODO: Print section type.
78 
79   if (isUnique())
80     OS << ",unique," << UniqueID;
81 
82   OS << '\n';
83 
84   if (Subsection) {
85     OS << "\t.subsection\t";
86     Subsection->print(OS, &MAI);
87     OS << '\n';
88   }
89 }
90 
91 bool MCSectionWasm::UseCodeAlign() const { return false; }
92 
93 bool MCSectionWasm::isVirtualSection() const { return false; }
94