[analyzer] Inline constructors for any object with a trivial destructor.

This allows us to better reason about status objects, like Clang's own
llvm::Optional (when its contents are trivially destructible), which are
often intended to be passed around by value.

We still don't inline constructors for temporaries in the general case.

<rdar://problem/11986434>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162681 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 4 deletions

diff --git a/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp b/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp
index 54cf5690c9..b1f4f623e2 100644
--- a/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/StackAddrEscapeChecker.cpp
@@ -118,8 +118,9 @@ void StackAddrEscapeChecker::checkPreStmt(const ReturnStmt *RS,
   const Expr *RetE = RS->getRetValue();
   if (!RetE)
     return;
- 
-  SVal V = C.getState()->getSVal(RetE, C.getLocationContext());
+
+  const LocationContext *LCtx = C.getLocationContext();
+  SVal V = C.getState()->getSVal(RetE, LCtx);
   const MemRegion *R = V.getAsRegion();
 
   if (!R)
@@ -132,8 +133,9 @@ void StackAddrEscapeChecker::checkPreStmt(const ReturnStmt *RS,
     return;
 
   // Return stack memory in an ancestor stack frame is fine.
-  const StackFrameContext *SFC = SS->getStackFrame();
-  if (SFC != C.getLocationContext()->getCurrentStackFrame())
+  const StackFrameContext *CurFrame = LCtx->getCurrentStackFrame();
+  const StackFrameContext *MemFrame = SS->getStackFrame();
+  if (MemFrame != CurFrame)
     return;
 
   // Automatic reference counting automatically copies blocks.
@@ -141,6 +143,11 @@ void StackAddrEscapeChecker::checkPreStmt(const ReturnStmt *RS,
       isa<BlockDataRegion>(R))
     return;
 
+  // Returning a record by value is fine. (In this case, the returned
+  // expression will be a copy-constructor.)
+  if (isa<CXXConstructExpr>(RetE) && RetE->getType()->isRecordType())
+    return;
+
   EmitStackError(C, R, RetE);
 }