implement rdar://9289524 - case followed immediately by break results in empty IR block,
a -O0 code quality issue.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129652 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCleanup.cpp b/lib/CodeGen/CGCleanup.cpp
index 1d7901a..41ecd81 100644
--- a/lib/CodeGen/CGCleanup.cpp
+++ b/lib/CodeGen/CGCleanup.cpp
@@ -870,6 +870,29 @@
}
}
+/// isObviouslyBranchWithoutCleanups - Return true if a branch to the
+/// specified destination obviously has no cleanups to run. 'false' is always
+/// a conservatively correct answer for this method.
+bool CodeGenFunction::isObviouslyBranchWithoutCleanups(JumpDest Dest) const {
+ assert(Dest.getScopeDepth().encloses(EHStack.stable_begin())
+ && "stale jump destination");
+
+ // Calculate the innermost active normal cleanup.
+ EHScopeStack::stable_iterator TopCleanup =
+ EHStack.getInnermostActiveNormalCleanup();
+
+ // If we're not in an active normal cleanup scope, or if the
+ // destination scope is within the innermost active normal cleanup
+ // scope, we don't need to worry about fixups.
+ if (TopCleanup == EHStack.stable_end() ||
+ TopCleanup.encloses(Dest.getScopeDepth())) // works for invalid
+ return true;
+
+ // Otherwise, we might need some cleanups.
+ return false;
+}
+
+
/// Terminate the current block by emitting a branch which might leave
/// the current cleanup-protected scope. The target scope may not yet
/// be known, in which case this will require a fixup.