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Allow dso_local on ifunc.

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It was never fully disallowed. We were rejecting it in the asm parser,
but not in the verifier.

Currently TargetMachine::shouldAssumeDSOLocal returns true for hidden
ifuncs. I considered changing it and moving the check from the asm
parser to the verifier.

The reason for deciding to allow it instead is that all linkers handle
a direct reference just fine. They use the plt address as the address
of the function. In fact doing that means that clang doesn't have the
same bug as gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83782.

This patch then removes the check from the asm parser and updates the
bitcode reader and writer.

llvm-svn: 322378
This commit is contained in:
Rafael Espindola
2018-01-12 17:03:43 +00:00
parent 84652cc63c
commit 3b9843f0ff
5 changed files with 16 additions and 18 deletions
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19
llvm/lib/Bitcode/Reader/BitcodeReader.cpp
View File

@@ -3054,14 +3054,17 @@ Error BitcodeReader::parseGlobalIndirectSymbolRecord(
// FIXME: Change to an error if non-default in 4.0.
NewGA->setVisibility(getDecodedVisibility(Record[VisInd]));
}
if (OpNum != Record.size())
NewGA->setDLLStorageClass(getDecodedDLLStorageClass(Record[OpNum++]));
else
upgradeDLLImportExportLinkage(NewGA, Linkage);
if (OpNum != Record.size())
NewGA->setThreadLocalMode(getDecodedThreadLocalMode(Record[OpNum++]));
if (OpNum != Record.size())
NewGA->setUnnamedAddr(getDecodedUnnamedAddrType(Record[OpNum++]));
if (BitCode == bitc::MODULE_CODE_ALIAS ||
BitCode == bitc::MODULE_CODE_ALIAS_OLD) {
if (OpNum != Record.size())
NewGA->setDLLStorageClass(getDecodedDLLStorageClass(Record[OpNum++]));
else
upgradeDLLImportExportLinkage(NewGA, Linkage);
if (OpNum != Record.size())
NewGA->setThreadLocalMode(getDecodedThreadLocalMode(Record[OpNum++]));
if (OpNum != Record.size())
NewGA->setUnnamedAddr(getDecodedUnnamedAddrType(Record[OpNum++]));
}
if (OpNum != Record.size())
NewGA->setDSOLocal(getDecodedDSOLocal(Record[OpNum++]));
ValueList.push_back(NewGA);

3
llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
View File

@@ -1302,7 +1302,7 @@ void ModuleBitcodeWriter::writeModuleInfo() {
// Emit the ifunc information.
for (const GlobalIFunc &I : M.ifuncs()) {
// IFUNC: [strtab offset, strtab size, ifunc type, address space, resolver
// val#, linkage, visibility]
// val#, linkage, visibility, DSO_Local]
Vals.push_back(addToStrtab(I.getName()));
Vals.push_back(I.getName().size());
Vals.push_back(VE.getTypeID(I.getValueType()));
@@ -1310,6 +1310,7 @@ void ModuleBitcodeWriter::writeModuleInfo() {
Vals.push_back(VE.getValueID(I.getResolver()));
Vals.push_back(getEncodedLinkage(I));
Vals.push_back(getEncodedVisibility(I));
Vals.push_back(I.isDSOLocal());
Stream.EmitRecord(bitc::MODULE_CODE_IFUNC, Vals);
Vals.clear();
}