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Move some logic to ModuleLinker::shouldLinkFromSource. NFC. 

llvm-svn: 217449
This commit is contained in:
Rafael Espindola 2014-09-09 15:21:00 +00:00
parent bb4fac9050
commit dbb0bd1a42
1 changed files with 51 additions and 49 deletions
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100
llvm/lib/Linker/LinkModules.cpp
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@ -420,6 +420,8 @@ namespace {
bool run();
private:
bool shouldLinkFromSource(const GlobalValue &Dest, const GlobalValue &Src);
/// emitError - Helper method for setting a message and returning an error
/// code.
bool emitError(const Twine &Message) {
@ -681,6 +683,48 @@ static bool isDeclaration(const GlobalValue &V) {
return V.isDeclaration();
}
bool ModuleLinker::shouldLinkFromSource(const GlobalValue &Dest,
const GlobalValue &Src) {
bool SrcIsDeclaration = isDeclaration(Src);
bool DestIsDeclaration = isDeclaration(Dest);
if (SrcIsDeclaration) {
// If Src is external or if both Src & Dest are external.. Just link the
// external globals, we aren't adding anything.
if (Src.hasDLLImportStorageClass())
// If one of GVs is marked as DLLImport, result should be dllimport'ed.
return DestIsDeclaration;
// If the Dest is weak, use the source linkage.
return Dest.hasExternalWeakLinkage();
}
if (DestIsDeclaration)
// If Dest is external but Src is not:
return true;
if (Src.isWeakForLinker()) {
assert(!Dest.hasExternalWeakLinkage());
assert(!Dest.hasAvailableExternallyLinkage());
if (Dest.hasLinkOnceLinkage() && Src.hasWeakLinkage())
return true;
return (Dest.hasLinkOnceLinkage() || Dest.hasWeakLinkage()) &&
Src.hasCommonLinkage();
}
if (Dest.isWeakForLinker()) {
assert(Src.hasExternalLinkage());
return true;
}
assert(!Src.hasExternalWeakLinkage());
assert(!Dest.hasExternalWeakLinkage());
assert(Dest.hasExternalLinkage() && Src.hasExternalLinkage() &&
"Unexpected linkage type!");
return emitError("Linking globals named '" + Src.getName() +
"': symbol multiply defined!");
}
/// This analyzes the two global values and determines what the result will look
/// like in the destination module. In particular, it computes the resultant
/// linkage type and visibility, computes whether the global in the source
@ -694,57 +738,15 @@ bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
assert(!Src->hasLocalLinkage() &&
"If Src has internal linkage, Dest shouldn't be set!");
bool SrcIsDeclaration = isDeclaration(*Src);
bool DestIsDeclaration = isDeclaration(*Dest);
assert(ErrorMsg.empty());
LinkFromSrc = shouldLinkFromSource(*Dest, *Src);
if (!ErrorMsg.empty())
return true;
if (SrcIsDeclaration) {
// If Src is external or if both Src & Dest are external.. Just link the
// external globals, we aren't adding anything.
if (Src->hasDLLImportStorageClass()) {
// If one of GVs is marked as DLLImport, result should be dllimport'ed.
if (DestIsDeclaration) {
LinkFromSrc = true;
LT = Src->getLinkage();
} else {
LinkFromSrc = false;
LT = Dest->getLinkage();
}
} else if (Dest->hasExternalWeakLinkage()) {
// If the Dest is weak, use the source linkage.
LinkFromSrc = true;
LT = Src->getLinkage();
} else {
LinkFromSrc = false;
LT = Dest->getLinkage();
}
} else if (DestIsDeclaration) {
// If Dest is external but Src is not:
LinkFromSrc = true;
if (LinkFromSrc)
LT = Src->getLinkage();
} else if (Src->isWeakForLinker()) {
assert(!Dest->hasExternalWeakLinkage());
assert(!Dest->hasAvailableExternallyLinkage());
if ((Dest->hasLinkOnceLinkage() && Src->hasWeakLinkage()) ||
((Dest->hasLinkOnceLinkage() || Dest->hasWeakLinkage()) &&
Src->hasCommonLinkage())) {
LinkFromSrc = true;
LT = Src->getLinkage();
} else {
LinkFromSrc = false;
LT = Dest->getLinkage();
}
} else if (Dest->isWeakForLinker()) {
assert(!Src->hasExternalWeakLinkage());
LinkFromSrc = true;
LT = GlobalValue::ExternalLinkage;
} else {
assert(!Src->hasExternalWeakLinkage());
assert(!Dest->hasExternalWeakLinkage());
assert(Dest->hasExternalLinkage() && Src->hasExternalLinkage() &&
"Unexpected linkage type!");
return emitError("Linking globals named '" + Src->getName() +
"': symbol multiply defined!");
}
else
LT = Dest->getLinkage();
// Compute the visibility. We follow the rules in the System V Application
// Binary Interface.