[clang] clang_EvalResult_getAsCXString impl (PR #134551)

[Aaron Ballman via cfe-commits]

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@@ -5918,12 +5918,19 @@ clang_EvalResult_getAsUnsigned(CXEvalResult E);
 CINDEX_LINKAGE double clang_EvalResult_getAsDouble(CXEvalResult E);
 
 /**
- * Returns the evaluation result as a constant string if the
- * kind is other than Int or float. User must not free this pointer,
- * instead call clang_EvalResult_dispose on the CXEvalResult returned
- * by clang_Cursor_Evaluate.
+ * This function behaves the same as clang_EvalResult_getAsCXString, with 2
+ * exceptions:
+ * - the string literal will be truncated if a nul byte is found in the string.
+ * For this reason clang_EvalResult_getAsCXString is recommended.
+ * - User must not free this pointer, instead call clang_EvalResult_dispose on
+ * the CXEvalResult returned by clang_Cursor_Evaluate.
  */
 CINDEX_LINKAGE const char *clang_EvalResult_getAsStr(CXEvalResult E);
+/**
+ * Returns the evaluation result as a constant string if the
+ * kind is other than Int or float. This might include zero bytes.
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AaronBallman wrote:

We should document that the caller is responsible for destroying the returned object.

https://github.com/llvm/llvm-project/pull/134551