Change compound assignment operators to keep track of both the promoted

LHS type and the computation result type; this encodes information into 
the AST which is otherwise non-obvious.  Fix Sema to always come up with the 
right answer for both of these types.  Fix IRGen and the analyzer to 
account for these changes.  This fixes PR2601.  The approach is inspired 
by PR2601 comment 2.

Note that this changes real *= complex in CodeGen from a silent 
miscompilation to an explicit error.

I'm not really sure that the analyzer changes are correct, or how to 
test them... someone more familiar with the analyzer should check those 
changes.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67889 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 7 deletions

diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index 2f3f0bf5cc..70e6647c27 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -2810,16 +2810,18 @@ void GRExprEngine::VisitBinaryOperator(BinaryOperator* B,
         //  The RHS is not Unknown.
         
         // Get the computation type.
-        QualType CTy = cast<CompoundAssignOperator>(B)->getComputationType();
+        QualType CTy = cast<CompoundAssignOperator>(B)->getComputationResultType();
         CTy = getContext().getCanonicalType(CTy);
-        
+
+        QualType CLHSTy = cast<CompoundAssignOperator>(B)->getComputationLHSType();
+        CLHSTy = getContext().getCanonicalType(CTy);
+
         QualType LTy = getContext().getCanonicalType(LHS->getType());
         QualType RTy = getContext().getCanonicalType(RHS->getType());
-          
-        // Perform promotions.
-        if (LTy != CTy) V = EvalCast(V, CTy);
-        if (RTy != CTy) RightV = EvalCast(RightV, CTy);
-          
+
+        // Promote LHS.
+        V = EvalCast(V, CLHSTy);
+
         // Evaluate operands and promote to result type.                    
         if (RightV.isUndef()) {            
           // Propagate undefined values (right-side).