[PATCH] D37322: [Sema] Correct typos in LHS, RHS before building a binop expression.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai created this revision.

Specifically, typo correction should be done before dispatching between
different kinds of binary operations like pseudo-object assignment,
overloaded binary operation, etc.

Without this change we hit an assertion

  Assertion failed: (!LHSExpr->hasPlaceholderType(BuiltinType::PseudoObject)), function CheckAssignmentOperands

when in Objective-C we reference a property without `self` and there are
2 equally good typo correction candidates: ivar and a class name. In
this case LHS expression in `BuildBinOp` is

  CXXDependentScopeMemberExpr
  `-TypoExpr

and instead of handling Obj-C property assignment as pseudo-object
assignment, we call `CreateBuiltinBinOp` which corrects typo to

  ObjCPropertyRefExpr '<pseudo-object type>'
  `-ImplicitCastExpr
    `-ObjCIvarRefExpr
      `-ImplicitCastExpr
        `-DeclRefExpr

but cannot handle pseudo-objects and asserts about it (indirectly,
through `CheckAssignmentOperands`).

There is no crash in Objective-C++ but I've added a test case because in
the fix we execute different paths for C and C++. I've also considered
removing typo correction from `CreateBuiltinBinOp` and it doesn't cause
any test failures. But I decided to keep it because `CreateBuiltinBinOp`
sometimes is called directly, not through `BuildBinOp`.

rdar://problem/33102722


https://reviews.llvm.org/D37322

Files:
  clang/lib/Sema/SemaExpr.cpp
  clang/test/SemaObjC/typo-correction.m
  clang/test/SemaObjCXX/typo-correction.mm

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