[PATCH] D77502: [clang][CodeGen] Handle throw expression in conditional operator constant folding

[Raul Tambre via Phabricator via cfe-commits]

tambre added inline comments.


================
Comment at: clang/lib/CodeGen/CGExpr.cpp:4337
+        EmitCXXThrowExpr(ThrowExpr);
+        return EmitLValue(dead);
+      }
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rsmith wrote:
> The IR we emit for the dead operand is unreachable; it's a bit wasteful to generate it here and (hopefully!) leave it to the optimizer to remove it again. Perhaps we could produce an `undef` lvalue instead? See `CodeGenFunction::EmitUnsupportedLValue` for an example of how to build such a value.
Done.


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Comment at: clang/test/CodeGenCXX/throw-expressions.cpp:84-87
+  void conditional_throw() {
+    int a, b;
+    (true ? throw 0 : a) = 0;
+  }
----------------
rsmith wrote:
> Please add some `CHECK`s in here to make sure we actually emit a call to `__cxa_throw`.
Done.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77502/new/

https://reviews.llvm.org/D77502