Move code to mark a variable as odr-used adjacement to all the related

code.

No functional change intended.

llvm-svn: 361890

2 files changed, 39 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 3a12c2dd84f..cc3dea9ead0 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -15013,6 +15013,42 @@ void Sema::MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func,
   }
 }
 
+/// Directly mark a variable odr-used. Given a choice, prefer to use
+/// MarkVariableReferenced since it does additional checks and then
+/// calls MarkVarDeclODRUsed.
+/// If the variable must be captured:
+///  - if FunctionScopeIndexToStopAt is null, capture it in the CurContext
+///  - else capture it in the DeclContext that maps to the
+///    *FunctionScopeIndexToStopAt on the FunctionScopeInfo stack.
+static void
+MarkVarDeclODRUsed(VarDecl *Var, SourceLocation Loc, Sema &SemaRef,
+                   const unsigned *const FunctionScopeIndexToStopAt) {
+  // Keep track of used but undefined variables.
+  // FIXME: We shouldn't suppress this warning for static data members.
+  if (Var->hasDefinition(SemaRef.Context) == VarDecl::DeclarationOnly &&
+      (!Var->isExternallyVisible() || Var->isInline() ||
+       SemaRef.isExternalWithNoLinkageType(Var)) &&
+      !(Var->isStaticDataMember() && Var->hasInit())) {
+    SourceLocation &old = SemaRef.UndefinedButUsed[Var->getCanonicalDecl()];
+    if (old.isInvalid())
+      old = Loc;
+  }
+  QualType CaptureType, DeclRefType;
+  SemaRef.tryCaptureVariable(Var, Loc, Sema::TryCapture_Implicit,
+    /*EllipsisLoc*/ SourceLocation(),
+    /*BuildAndDiagnose*/ true,
+    CaptureType, DeclRefType,
+    FunctionScopeIndexToStopAt);
+
+  Var->markUsed(SemaRef.Context);
+}
+
+void Sema::MarkCaptureUsedInEnclosingContext(VarDecl *Capture,
+                                             SourceLocation Loc,
+                                             unsigned CapturingScopeIndex) {
+  MarkVarDeclODRUsed(Capture, Loc, *this, &CapturingScopeIndex);
+}
+
 static void
 diagnoseUncapturableValueReference(Sema &S, SourceLocation loc,
                                    ValueDecl *var, DeclContext *DC) {
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index e3286e8943f..ef27fc2d719 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -7495,11 +7495,9 @@ static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
     // capture the variable in that lambda (and all its enclosing lambdas).
     if (const Optional<unsigned> Index =
             getStackIndexOfNearestEnclosingCaptureCapableLambda(
-                S.FunctionScopes, Var, S)) {
-      const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
-      MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S,
-                         &FunctionScopeIndexOfCapturableLambda);
-    }
+                S.FunctionScopes, Var, S))
+      S.MarkCaptureUsedInEnclosingContext(Var, VarExpr->getExprLoc(),
+                                          Index.getValue());
     const bool IsVarNeverAConstantExpression =
         VariableCanNeverBeAConstantExpression(Var, S.Context);
     if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) {