[clang] nonblocking/nonallocating attributes: 2nd pass caller/callee analysis (PR #99656)

[Jon Roelofs via cfe-commits]

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@@ -0,0 +1,194 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
+// These are in a separate file because errors (e.g. incompatible attributes) currently prevent
+// the AnalysisBasedWarnings pass from running at all.
+
+// This diagnostic is re-enabled and exercised in isolation later in this file.
+#pragma clang diagnostic ignored "-Wperf-constraint-implies-noexcept"
+
+// --- CONSTRAINTS ---
+
+void nl1() [[clang::nonblocking]]
+{
+	auto* pInt = new int; // expected-warning {{'nonblocking' function must not allocate or deallocate memory}}
+}
+
+void nl2() [[clang::nonblocking]]
+{
+	static int global; // expected-warning {{'nonblocking' function must not have static locals}}
+}
+
+void nl3() [[clang::nonblocking]]
+{
+	try {
+		throw 42; // expected-warning {{'nonblocking' function must not throw or catch exceptions}}
+	}
+	catch (...) { // expected-warning {{'nonblocking' function must not throw or catch exceptions}}
+	}
+}
+
+void nl4_inline() {}
+void nl4_not_inline(); // expected-note {{function cannot be inferred 'nonblocking' because it has no definition in this translation unit}}
+
+void nl4() [[clang::nonblocking]]
+{
+	nl4_inline(); // OK
+	nl4_not_inline(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
+}
+
+
+struct HasVirtual {
+	virtual void unsafe(); // expected-note {{virtual method cannot be inferred 'nonblocking'}}
+};
+
+void nl5() [[clang::nonblocking]]
+{
+ 	HasVirtual hv;
+ 	hv.unsafe(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
+}
+
+void nl6_unsafe(); // expected-note {{function cannot be inferred 'nonblocking' because it has no definition in this translation unit}}
+void nl6_transitively_unsafe()
+{
+	nl6_unsafe(); // expected-note {{function cannot be inferred 'nonblocking' because it calls non-'nonblocking' function}}
----------------
jroelofs wrote:

I think it would help to name the two functions in the diagnostic, i.e:

`function `n16_transitively_safe` cannot be inferred 'nonblocking' because it calls non-'nonblocking' function 'n16_unsafe'`

https://github.com/llvm/llvm-project/pull/99656