Rework our handling of key functions. We used to track a complete list of all
dynamic classes in the translation unit and check whether each one's key
function is defined when we got to the end of the TU (and when we got to the
end of each module). This is really terrible for modules performance, since it
causes unnecessary deserialization of every dynamic class in every compilation.
We now use a much simpler (and, in a modules build, vastly more efficient)
system: when we see an out-of-line definition of a virtual function, we check
whether that function was in fact its class's key function. (If so, we need to
emit the vtable.)
llvm-svn: 230830
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e254773..eb5b715 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8011,28 +8011,8 @@
// This needs to happen first so that 'inline' propagates.
NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl));
- if (isa<CXXMethodDecl>(NewFD)) {
- // A valid redeclaration of a C++ method must be out-of-line,
- // but (unfortunately) it's not necessarily a definition
- // because of templates, which means that the previous
- // declaration is not necessarily from the class definition.
-
- // For just setting the access, that doesn't matter.
- CXXMethodDecl *oldMethod = cast<CXXMethodDecl>(OldDecl);
- NewFD->setAccess(oldMethod->getAccess());
-
- // Update the key-function state if necessary for this ABI.
- if (NewFD->isInlined() &&
- !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) {
- // setNonKeyFunction needs to work with the original
- // declaration from the class definition, and isVirtual() is
- // just faster in that case, so map back to that now.
- oldMethod = cast<CXXMethodDecl>(oldMethod->getFirstDecl());
- if (oldMethod->isVirtual()) {
- Context.setNonKeyFunction(oldMethod);
- }
- }
- }
+ if (isa<CXXMethodDecl>(NewFD))
+ NewFD->setAccess(OldDecl->getAccess());
}
}
@@ -10559,7 +10539,31 @@
!FD->isDependentContext())
computeNRVO(Body, getCurFunction());
}
-
+
+ if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
+ const CXXMethodDecl *KeyFunction;
+ if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) &&
+ MD->isVirtual() &&
+ (KeyFunction = Context.getCurrentKeyFunction(MD->getParent())) &&
+ MD == KeyFunction->getCanonicalDecl()) {
+ // Update the key-function state if necessary for this ABI.
+ if (FD->isInlined() &&
+ !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) {
+ Context.setNonKeyFunction(MD);
+
+ // If the newly-chosen key function is already defined, then we
+ // need to mark the vtable as used retroactively.
+ KeyFunction = Context.getCurrentKeyFunction(MD->getParent());
+ const FunctionDecl *Definition;
+ if (KeyFunction && KeyFunction->isDefined(Definition))
+ MarkVTableUsed(Definition->getLocation(), MD->getParent(), true);
+ } else {
+ // We just defined they key function; mark the vtable as used.
+ MarkVTableUsed(FD->getLocation(), MD->getParent(), true);
+ }
+ }
+ }
+
assert((FD == getCurFunctionDecl() || getCurLambda()->CallOperator == FD) &&
"Function parsing confused");
} else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {