[clang] bad error message on incorrect string literal #18079 (PR #81670)

[Jon Roelofs via cfe-commits]

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@@ -0,0 +1,5 @@
+// RUN: not  %clang_cc1 -E %s 2>&1 | grep 'error: invalid newline character in raw string delimiter; use PREFIX( )PREFIX to delimit raw string'
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jroelofs wrote:

Please use `-fsyntax-only -verify` instead of `grep` for checking diagnostics. There are some examples in sibling files, but the gist of it is that you'll need a `// expected-error at +1{{invalid newline character...}}` on the line before the declaration.

https://github.com/llvm/llvm-project/pull/81670