Adding nocf_check attribute for cf-protection fine tuning
The patch adds nocf_check target independent attribute for disabling checks that were enabled by cf-protection flag.
The attribute can be appertained to functions and function pointers.
Attribute name follows GCC's similar attribute name.
Differential Revision: https://reviews.llvm.org/D41880
llvm-svn: 327768
diff --git a/clang/test/Sema/attr-nocf_check.cpp b/clang/test/Sema/attr-nocf_check.cpp
new file mode 100644
index 0000000..b785f98
--- /dev/null
+++ b/clang/test/Sema/attr-nocf_check.cpp
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -triple=i386-unknown-unknown -verify -fcf-protection=branch -target-feature +ibt -std=c++11 -fsyntax-only %s
+
+// Function pointer definition.
+[[gnu::nocf_check]] typedef void (*FuncPointerWithNoCfCheck)(void); // no-warning
+typedef void (*FuncPointer)(void);
+
+// Dont allow function declaration and definition mismatch.
+[[gnu::nocf_check]] void testNoCfCheck(); // expected-note {{previous declaration is here}}
+void testNoCfCheck(){}; // expected-error {{conflicting types for 'testNoCfCheck'}}
+
+// No variable or parameter declaration
+int [[gnu::nocf_check]] i; // expected-error {{'nocf_check' attribute cannot be applied to types}}
+void testNoCfCheckImpl(double i [[gnu::nocf_check]]) {} // expected-warning {{'nocf_check' attribute only applies to functions and function pointers}}
+
+// Allow attributed function pointers as well as casting between attributed
+// and non-attributed function pointers.
+void testNoCfCheckMismatch(FuncPointer f) {
+ FuncPointerWithNoCfCheck fNoCfCheck = f; // expected-error {{cannot initialize a variable of type}}
+ (*fNoCfCheck)(); // no-warning
+}
+
+// 'nocf_check' Attribute has no parameters.
+[[gnu::nocf_check(1)]] int testNoCfCheckParams(); // expected-error {{'nocf_check' attribute takes no arguments}}