[Sema] Make `&function_with_enable_if_attrs` an error
This fixes a bug where one can take the address of a conditionally
enabled function to drop its enable_if guards. For example:
int foo(int a) __attribute__((enable_if(a > 0, "")));
int (*p)(int) = &foo;
int result = p(-1); // compilation succeeds; calls foo(-1)
Overloading logic has been updated to reflect this change, as well.
Functions with enable_if attributes that are always true are still
allowed to have their address taken.
Differential Revision: http://reviews.llvm.org/D13607
llvm-svn: 250090
diff --git a/clang/test/Sema/enable_if.c b/clang/test/Sema/enable_if.c
index 7faae43..82b902a 100644
--- a/clang/test/Sema/enable_if.c
+++ b/clang/test/Sema/enable_if.c
@@ -91,6 +91,12 @@
#endif
}
+void test5() {
+ int (*p1)(int) = &isdigit2;
+ int (*p2)(int) = isdigit2;
+ void *p3 = (void *)&isdigit2;
+ void *p4 = (void *)isdigit2;
+}
#ifndef CODEGEN
__attribute__((enable_if(n == 0, "chosen when 'n' is zero"))) void f1(int n); // expected-error{{use of undeclared identifier 'n'}}
@@ -109,4 +115,23 @@
const int cst = 7;
void return_cst(void) __attribute__((overloadable)) __attribute__((enable_if(cst == 7, "chosen when 'cst' is 7")));
void test_return_cst() { return_cst(); }
+
+void f2(void) __attribute__((overloadable)) __attribute__((enable_if(1, "always chosen")));
+void f2(void) __attribute__((overloadable)) __attribute__((enable_if(0, "never chosen")));
+void f2(void) __attribute__((overloadable));
+void test6() {
+ void (*p1)(void) = &f2; // expected-error{{initializing 'void (*)(void)' with an expression of incompatible type '<overloaded function type>'}} expected-note@119{{candidate function}} expected-note@120{{candidate function made ineligible by enable_if}} expected-note@121{{candidate function}}
+ void (*p2)(void) = f2; // expected-error{{initializing 'void (*)(void)' with an expression of incompatible type '<overloaded function type>'}} expected-note@119{{candidate function}} expected-note@120{{candidate function made ineligible by enable_if}} expected-note@121{{candidate function}}
+ void *p3 = (void*)&f2; // expected-error{{address of overloaded function 'f2' is ambiguous}} expected-note@119{{candidate function}} expected-note@120{{candidate function made ineligible by enable_if}} expected-note@121{{candidate function}}
+ void *p4 = (void*)f2; // expected-error{{address of overloaded function 'f2' is ambiguous}} expected-note@119{{candidate function}} expected-note@120{{candidate function made ineligible by enable_if}} expected-note@121{{candidate function}}
+}
+
+void f3(int m) __attribute__((overloadable)) __attribute__((enable_if(m >= 0, "positive")));
+void f3(int m) __attribute__((overloadable)) __attribute__((enable_if(m < 0, "negative")));
+void test7() {
+ void (*p1)(int) = &f3; // expected-error{{initializing 'void (*)(int)' with an expression of incompatible type '<overloaded function type>'}} expected-note@129{{candidate function made ineligible by enable_if}} expected-note@130{{candidate function made ineligible by enable_if}}
+ void (*p2)(int) = f3; // expected-error{{initializing 'void (*)(int)' with an expression of incompatible type '<overloaded function type>'}} expected-note@129{{candidate function made ineligible by enable_if}} expected-note@130{{candidate function made ineligible by enable_if}}
+ void *p3 = (void*)&f3; // expected-error{{address of overloaded function 'f3' does not match required type 'void'}} expected-note@129{{candidate function made ineligible by enable_if}} expected-note@130{{candidate function made ineligible by enable_if}}
+ void *p4 = (void*)f3; // expected-error{{address of overloaded function 'f3' does not match required type 'void'}} expected-note@129{{candidate function made ineligible by enable_if}} expected-note@130{{candidate function made ineligible by enable_if}}
+}
#endif