[ObjC] Warn on unguarded use of partial declaration

This commit adds a traversal of the AST after Sema of a function that diagnoses
unguarded references to declarations that are partially available (based on
availability attributes). This traversal is only done when we would otherwise
emit -Wpartial-availability.

This commit is part of a feature I proposed here:
http://lists.llvm.org/pipermail/cfe-dev/2016-July/049851.html

Differential revision: https://reviews.llvm.org/D23003

llvm-svn: 278826

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/Sema/ScopeInfo.cpp b/clang/lib/Sema/ScopeInfo.cpp
index 4b2e13e20de..76240bcbfc9 100644
--- a/clang/lib/Sema/ScopeInfo.cpp
+++ b/clang/lib/Sema/ScopeInfo.cpp
@@ -29,6 +29,7 @@ void FunctionScopeInfo::Clear() {
   HasIndirectGoto = false;
   HasDroppedStmt = false;
   HasOMPDeclareReductionCombiner = false;
+  HasPotentialAvailabilityViolations = false;
   ObjCShouldCallSuper = false;
   ObjCIsDesignatedInit = false;
   ObjCWarnForNoDesignatedInitChain = false;