[llvm] r252626 - [ThinLTO] WeakAny fixes/cleanup
Teresa Johnson via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 10 10:20:11 PST 2015
Author: tejohnson
Date: Tue Nov 10 12:20:11 2015
New Revision: 252626
URL: http://llvm.org/viewvc/llvm-project?rev=252626&view=rev
Log:
[ThinLTO] WeakAny fixes/cleanup
Ensure WeakAny variables are imported as ExternalWeak declarations. To
handle WeakAny more consistently and fix this issue:
1) Update helper doImportAsDefinition to properly flag WeakAny variables
and aliases as not importing defintions.
Update callers of doImportAsDefinition to remove now redundant checks for
WeakAny aliases, or ignore aliases, as appropriate.
2) Add any !doImportAsDefinition GVs to DoNotLinkFromSource set during
linking of the GV prototype, where we usually add GVs to the
DoNotLinkFromSource set for other reasons.
Remove now unnecessary adding of WeakAny aliases to
DoNotLinkFromSource set from copyGlobalAliasProto.
Remove now unnecessary guard against linking non-imported function
bodies from ModuleLinker::run.
Modified:
llvm/trunk/lib/Linker/LinkModules.cpp
llvm/trunk/test/Linker/funcimport.ll
Modified: llvm/trunk/lib/Linker/LinkModules.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Linker/LinkModules.cpp?rev=252626&r1=252625&r2=252626&view=diff
==============================================================================
--- llvm/trunk/lib/Linker/LinkModules.cpp (original)
+++ llvm/trunk/lib/Linker/LinkModules.cpp Tue Nov 10 12:20:11 2015
@@ -626,9 +626,7 @@ void ModuleLinker::copyGVAttributes(Glob
// being imported as a declaration. In that case copy the attributes from the
// base object.
if (GA && !dyn_cast<GlobalAlias>(NewGV)) {
- assert(isPerformingImport() &&
- (GA->hasWeakAnyLinkage() ||
- !doImportAsDefinition(GA->getBaseObject())));
+ assert(isPerformingImport() && !doImportAsDefinition(GA));
NewGV->copyAttributesFrom(GA->getBaseObject());
} else
NewGV->copyAttributesFrom(SrcGV);
@@ -651,12 +649,19 @@ static bool isLessConstraining(GlobalVal
bool ModuleLinker::doImportAsDefinition(const GlobalValue *SGV) {
if (!isPerformingImport())
return false;
+ auto *GA = dyn_cast<GlobalAlias>(SGV);
+ if (GA) {
+ if (GA->hasWeakAnyLinkage())
+ return false;
+ return doImportAsDefinition(GA->getBaseObject());
+ }
// Always import GlobalVariable definitions. The linkage changes
// described in ModuleLinker::getLinkage ensure the correct behavior (e.g.
// global variables with external linkage are transformed to
- // available_externally defintions, which are ultimately turned into
- // declaratios after the EliminateAvailableExternally pass).
- if (dyn_cast<GlobalVariable>(SGV) && !SGV->isDeclaration())
+ // available_externally definitions, which are ultimately turned into
+ // declarations after the EliminateAvailableExternally pass).
+ if (dyn_cast<GlobalVariable>(SGV) && !SGV->isDeclaration() &&
+ !SGV->hasWeakAnyLinkage())
return true;
// Only import the function requested for importing.
auto *SF = dyn_cast<Function>(SGV);
@@ -725,7 +730,7 @@ GlobalValue::LinkageTypes ModuleLinker::
// definitions upon import, so that they are available for inlining
// and/or optimization, but are turned into declarations later
// during the EliminateAvailableExternally pass.
- if (doImportAsDefinition(SGV))
+ if (doImportAsDefinition(SGV) && !dyn_cast<GlobalAlias>(SGV))
return GlobalValue::AvailableExternallyLinkage;
// An imported external declaration stays external.
return SGV->getLinkage();
@@ -758,7 +763,7 @@ GlobalValue::LinkageTypes ModuleLinker::
// equivalent, so the issue described above for weak_any does not exist,
// and the definition can be imported. It can be treated similarly
// to an imported externally visible global value.
- if (doImportAsDefinition(SGV))
+ if (doImportAsDefinition(SGV) && !dyn_cast<GlobalAlias>(SGV))
return GlobalValue::AvailableExternallyLinkage;
else
return GlobalValue::ExternalLinkage;
@@ -775,7 +780,7 @@ GlobalValue::LinkageTypes ModuleLinker::
// If we are promoting the local to global scope, it is handled
// similarly to a normal externally visible global.
if (doPromoteLocalToGlobal(SGV)) {
- if (doImportAsDefinition(SGV))
+ if (doImportAsDefinition(SGV) && !dyn_cast<GlobalAlias>(SGV))
return GlobalValue::AvailableExternallyLinkage;
else
return GlobalValue::ExternalLinkage;
@@ -834,8 +839,7 @@ GlobalValue *ModuleLinker::copyGlobalAli
// as a declaration as well, which involves converting it to a non-alias.
// See comments in ModuleLinker::getLinkage for why we cannot import
// weak_any defintions.
- if (isPerformingImport() && (SGA->hasWeakAnyLinkage() ||
- !doImportAsDefinition(SGA->getBaseObject()))) {
+ if (isPerformingImport() && !doImportAsDefinition(SGA)) {
// Need to convert to declaration. All aliases must be definitions.
const GlobalValue *GVal = SGA->getBaseObject();
GlobalValue *NewGV;
@@ -852,8 +856,6 @@ GlobalValue *ModuleLinker::copyGlobalAli
NewGV->setLinkage(GlobalValue::ExternalWeakLinkage);
else
NewGV->setLinkage(GlobalValue::ExternalLinkage);
- // Don't attempt to link body, needs to be a declaration.
- DoNotLinkFromSource.insert(SGA);
return NewGV;
}
// If there is no linkage to be performed or we're linking from the source,
@@ -1427,6 +1429,9 @@ bool ModuleLinker::linkGlobalValueProto(
}
NewGV = copyGlobalValueProto(TypeMap, SGV, DGV);
+
+ if (isPerformingImport() && !doImportAsDefinition(SGV))
+ DoNotLinkFromSource.insert(SGV);
}
NewGV->setUnnamedAddr(HasUnnamedAddr);
@@ -1892,10 +1897,6 @@ bool ModuleLinker::run() {
if (DoNotLinkFromSource.count(&SF))
continue;
- // When importing, only materialize the function requested for import.
- if (isPerformingImport() && &SF != ImportFunction)
- continue;
-
if (linkGlobalValueBody(SF))
return true;
}
Modified: llvm/trunk/test/Linker/funcimport.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/funcimport.ll?rev=252626&r1=252625&r2=252626&view=diff
==============================================================================
--- llvm/trunk/test/Linker/funcimport.ll (original)
+++ llvm/trunk/test/Linker/funcimport.ll Tue Nov 10 12:20:11 2015
@@ -85,6 +85,7 @@
; reference should turned into an external_weak declaration.
; RUN: llvm-link %t2.bc -functionindex=%t3.thinlto.bc -import=callweakfunc:%t.bc -import=weakfunc:%t.bc -S 2>&1 | FileCheck %s --check-prefix=IMPORTWEAKFUNC
; IMPORTWEAKFUNC: Ignoring import request for weak-any function weakfunc
+; IMPORTWEAKFUNC: @weakvar = extern_weak global i32, align 4
; IMPORTWEAKFUNC: declare extern_weak void @weakfunc
; IMPORTWEAKFUNC: define available_externally void @callweakfunc
@@ -158,6 +159,7 @@ entry:
ret void
}
+ at weakvar = weak global i32 1, align 4
define weak void @weakfunc() #0 {
entry:
ret void
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