replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

MS ABI: Mangle char16_t and char32_t string literals 

We previously had support for char and wchar_t string literals.  VS 2015
added support for char16_t and char32_t.

String literals must be mangled in the MS ABI in order for them to be
deduplicated across translation units: their linker has no notion of
mergeable section.  Instead, they use the mangled name to make a COMDAT
for the string literal; the COMDAT will merge with other COMDATs in
other object files.

This allows strings in object files generated by clang to get merged
with strings in object files generated by MSVC.

llvm-svn: 222564
This commit is contained in:
David Majnemer 2014-11-21 19:57:25 +00:00
parent f0a582bada
commit 98e77a2512
2 changed files with 11 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
clang/lib/AST/MicrosoftMangle.cpp
View File

@ -338,9 +338,7 @@ bool MicrosoftMangleContextImpl::shouldMangleCXXName(const NamedDecl *D) {
bool
MicrosoftMangleContextImpl::shouldMangleStringLiteral(const StringLiteral *SL) {
return SL->isAscii() || SL->isWide();
// TODO: This needs to be updated when MSVC gains support for Unicode
// literals.
return SL->isAscii() || SL->isWide() || SL->isUTF16() || SL->isUTF32();
}
void MicrosoftCXXNameMangler::mangle(const NamedDecl *D, StringRef Prefix) {
@ -2439,14 +2437,10 @@ void MicrosoftMangleContextImpl::mangleStringLiteral(const StringLiteral *SL,
Mangler.getStream() << "\01??_C@_";
// <char-type>: The "kind" of string literal is encoded into the mangled name.
// TODO: This needs to be updated when MSVC gains support for unicode
// literals.
if (SL->isAscii())
Mangler.getStream() << '0';
else if (SL->isWide())
if (SL->isWide())
Mangler.getStream() << '1';
else
llvm_unreachable("unexpected string literal kind!");
Mangler.getStream() << '0';
// <literal-length>: The next part of the mangled name consists of the length
// of the string.
@ -2569,7 +2563,10 @@ void MicrosoftMangleContextImpl::mangleStringLiteral(const StringLiteral *SL,
unsigned NumCharsToMangle = std::min(32U, SL->getLength());
for (unsigned I = 0, E = NumCharsToMangle * SL->getCharByteWidth(); I != E;
++I)
MangleByte(GetBigEndianByte(I));
if (SL->isWide())
MangleByte(GetBigEndianByte(I));
else
MangleByte(GetLittleEndianByte(I));
// Encode the NUL terminator if there is room.
if (NumCharsToMangle < 32)

4
clang/test/CodeGenCXX/mangle-ms-string-literals.cpp
View File

@ -719,3 +719,7 @@ const wchar_t *LongWideString = L"012345678901234567890123456789ABCDEF";
// CHECK: @"\01??_C@_1EK@KFPEBLPK@?$AA0?$AA1?$AA2?$AA3?$AA4?$AA5?$AA6?$AA7?$AA8?$AA9?$AA0?$AA1?$AA2?$AA3?$AA4?$AA5?$AA6?$AA7?$AA8?$AA9?$AA0?$AA1?$AA2?$AA3?$AA4?$AA5?$AA6?$AA7?$AA8?$AA9?$AAA?$AAB@"
const wchar_t *UnicodeLiteral = L"\ud7ff";
// CHECK: @"\01??_C@_13IIHIAFKH@?W?$PP?$AA?$AA@"
const char16_t *U16Literal = u"hi";
// CHECK: @"\01??_C@_05OMLEGLOC@h?$AAi?$AA?$AA?$AA@"
const char32_t *U32Literal = U"hi";
// CHECK: @"\01??_C@_0M@GFNAJIPG@h?$AA?$AA?$AAi?$AA?$AA?$AA?$AA?$AA?$AA?$AA@"