[clang] [clang][ThreadSafety] Check trylock function success and return types (PR #95290)

[Aaron Puchert via cfe-commits]

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@@ -756,7 +771,68 @@ void etf_fun_params(int lvar EXCLUSIVE_TRYLOCK_FUNCTION(1)); // \
 
 // Check argument parsing.
 
-// legal attribute arguments
+int global_int = 0;
+int* etf_fun_with_global_ptr_success() EXCLUSIVE_TRYLOCK_FUNCTION(&global_int, &mu1); //\
+  // expected-error {{'exclusive_trylock_function' attribute requires parameter 1 to be nullptr or a bool, int, or enum literal}}
+
+#ifdef CPP11
+constexpr int kTrylockSuccess = 1;
+int etf_succ_constexpr() EXCLUSIVE_TRYLOCK_FUNCTION(kTrylockSuccess, mu2); // \
+  // expected-error {{'exclusive_trylock_function' attribute requires parameter 1 to be nullptr or a bool, int, or enum literal}}
+
+int success_value_non_constant = 1;
+
+bool etf_succ_variable() EXCLUSIVE_TRYLOCK_FUNCTION(success_value_non_constant, mu2); //\
+  // expected-error {{attribute requires parameter 1 to be nullptr or a bool, int, or enum literal}}
+#endif
+
+
+// Legal permutations of the first argument and function return type.
+struct TrylockResult;
+
+#ifdef CPP11
+int* etf_fun_with_nullptr_success() EXCLUSIVE_TRYLOCK_FUNCTION(nullptr, &mu1);
+#endif
+
+#ifndef __cplusplus
+int* etf_fun_with_nullptr_success() EXCLUSIVE_TRYLOCK_FUNCTION(NULL, &mu1);
+#endif
+
+int etf_succ_1_ret_i() EXCLUSIVE_TRYLOCK_FUNCTION(1, mu2);
+bool etf_succ_1_ret_b() EXCLUSIVE_TRYLOCK_FUNCTION(1, mu2);
+TrylockResult *etf_succ_1_ret_p() EXCLUSIVE_TRYLOCK_FUNCTION(1, mu2);
+
+int etf_succ_true_ret_i() EXCLUSIVE_TRYLOCK_FUNCTION(true, mu2);
+bool etf_succ_true_ret_b() EXCLUSIVE_TRYLOCK_FUNCTION(true, mu2);
+TrylockResult *etf_succ_true_ret_p() EXCLUSIVE_TRYLOCK_FUNCTION(true, mu2);
+
+int etf_succ_false_ret_i() EXCLUSIVE_TRYLOCK_FUNCTION(false, mu2);
+bool etf_succ_false_ret_b() EXCLUSIVE_TRYLOCK_FUNCTION(false, mu2);
+TrylockResult *etf_succ_false_ret_p() EXCLUSIVE_TRYLOCK_FUNCTION(false, mu2);
+
+enum TrylockSuccessEnum { TrylockNotAcquired = 0, TrylockAcquired };
+int etf_succ_enum_ret_i() EXCLUSIVE_TRYLOCK_FUNCTION(TrylockAcquired, mu2);
+bool etf_succ_enum_ret_b() EXCLUSIVE_TRYLOCK_FUNCTION(TrylockAcquired, mu2);
+TrylockResult *etf_succ_enum_ret_p()
+    EXCLUSIVE_TRYLOCK_FUNCTION(TrylockAcquired, mu2);
+
+#ifdef CPP11
+enum class TrylockSuccessEnumClass { NotAcquired = 0, Acquired};
+int etf_succ_enum_class_ret_i()
+    EXCLUSIVE_TRYLOCK_FUNCTION(TrylockSuccessEnumClass::Acquired, mu2);
+bool etf_succ_enum_class_ret_b()
+    EXCLUSIVE_TRYLOCK_FUNCTION(TrylockSuccessEnumClass::Acquired, mu2);
+TrylockResult *etf_succ_enum_class_ret_p()
+    EXCLUSIVE_TRYLOCK_FUNCTION(TrylockSuccessEnumClass::Acquired, mu2);
+#endif
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aaronpuchert wrote:

I think `enum class` should not be allowed for now, because we can't convert it to `bool`.

Should we add proper support for enumerations, we should probably not convert them to `bool` but rather check for equality.

https://github.com/llvm/llvm-project/pull/95290