[clang][PAC] ptrauth_qualifier must be a feature rather than an extensionusers/ojhunt/ptrauth-qualifier-is-a-feature

Under `-pedantic-errors` extensions (as detected by __has_extension) are
not enabled (or rather the tests return false). As the ptrauth qualifier
impacts the ABI this is not sound, so this PR returns the ptrauth qualifier
to being detected through a feature check.

4 files changed, 16 insertions, 4 deletions

diff --git a/clang/include/clang/Basic/Features.def b/clang/include/clang/Basic/Features.def
index c58e3f2..404ae9e 100644
--- a/clang/include/clang/Basic/Features.def
+++ b/clang/include/clang/Basic/Features.def
@@ -148,7 +148,7 @@ FEATURE(thread_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Thread))
 FEATURE(dataflow_sanitizer, LangOpts.Sanitize.has(SanitizerKind::DataFlow))
 FEATURE(scudo, LangOpts.Sanitize.hasOneOf(SanitizerKind::Scudo))
 FEATURE(ptrauth_intrinsics, LangOpts.PointerAuthIntrinsics)
-EXTENSION(ptrauth_qualifier, LangOpts.PointerAuthIntrinsics)
+FEATURE(ptrauth_qualifier, LangOpts.PointerAuthIntrinsics)
 FEATURE(ptrauth_calls, LangOpts.PointerAuthCalls)
 FEATURE(ptrauth_returns, LangOpts.PointerAuthReturns)
 FEATURE(ptrauth_vtable_pointer_address_discrimination, LangOpts.PointerAuthVTPtrAddressDiscrimination)
diff --git a/clang/test/Preprocessor/ptrauth_extension.c b/clang/test/Preprocessor/ptrauth_extension.c
index d6b7918..5a0fbaa 100644
--- a/clang/test/Preprocessor/ptrauth_extension.c
+++ b/clang/test/Preprocessor/ptrauth_extension.c
@@ -1,10 +1,16 @@
 // RUN: %clang_cc1 -E %s -triple=aarch64 -fptrauth-intrinsics | \
 // RUN:   FileCheck %s --check-prefixes=INTRIN
 
+// RUN: %clang_cc1 -E %s -triple=aarch64 -fptrauth-intrinsics -pedantic-errors | \
+// RUN:   FileCheck %s --check-prefixes=INTRIN
+
 // RUN: %clang_cc1 -E %s -triple=aarch64 -fptrauth-calls | \
 // RUN:   FileCheck %s --check-prefixes=NOINTRIN
 
-#if __has_extension(ptrauth_qualifier)
+// RUN: %clang_cc1 -E %s -triple=aarch64 -fptrauth-calls -pedantic-errors | \
+// RUN:   FileCheck %s --check-prefixes=NOINTRIN
+
+#if __has_feature(ptrauth_qualifier)
 // INTRIN: has_ptrauth_qualifier
 void has_ptrauth_qualifier() {}
 #else
diff --git a/clang/test/Sema/ptrauth-qualifier.c b/clang/test/Sema/ptrauth-qualifier.c
index 5d932b7..18fada5 100644
--- a/clang/test/Sema/ptrauth-qualifier.c
+++ b/clang/test/Sema/ptrauth-qualifier.c
@@ -1,7 +1,8 @@
 // RUN: %clang_cc1 -triple arm64-apple-ios -std=c23 -fsyntax-only -verify -fptrauth-intrinsics %s
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -std=c23 -fsyntax-only -verify -fptrauth-intrinsics %s
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -std=c23 -fsyntax-only -verify -fptrauth-intrinsics -pedantic-errors -DPEDANTIC_ERRORS %s
 
-#if !__has_extension(ptrauth_qualifier)
+#if !__has_feature(ptrauth_qualifier)
 // This error means that the __ptrauth qualifier availability test says  that it
 // is not available. This error is not expected in the output, if it is seen
 // there is a feature detection regression.
@@ -66,6 +67,7 @@ intp redeclaration3 = 0;                       // expected-error{{redefinition o
 void illegal0(intp __ptrauth(VALID_DATA_KEY)); // expected-error {{parameter type may not be qualified with '__ptrauth'; type is '__ptrauth(2,0,0) intp' (aka 'int *__ptrauth(2,0,0)')}}
 intp __ptrauth(VALID_DATA_KEY) illegal1(void); // expected-error {{return type may not be qualified with '__ptrauth'; type is '__ptrauth(2,0,0) intp' (aka 'int *__ptrauth(2,0,0)')}}
 
+#ifndef PEDANTIC_ERRORS
 static_assert(_Generic(typeof(valid0), int * __ptrauth(VALID_DATA_KEY) : 1, int * : 0, default : 0));
 static_assert(_Generic(typeof(valid0), int * __ptrauth(VALID_CODE_KEY) : 0, default : 1));
 static_assert(_Generic(typeof_unqual(valid0), int * __ptrauth(VALID_DATA_KEY) : 0, int * : 1, default : 0));
@@ -73,6 +75,7 @@ static_assert(_Generic(valid0, int * __ptrauth(VALID_DATA_KEY) : 0, int * : 1, d
 
 static_assert(_Generic(array0, int * __ptrauth(VALID_DATA_KEY) * : 1, default : 0));
 static_assert(_Generic(*array1, int * : 1, default : 0));
+#endif
 
 void test_code(intp p) {
   p = (intp __ptrauth(VALID_DATA_KEY)) 0; // expected-error {{cannot cast to '__ptrauth'-qualified type '__ptrauth(2,0,0) intp' (aka 'int *__ptrauth(2,0,0)')}}
@@ -99,8 +102,10 @@ void test_array(void) {
 __attribute__((overloadable)) int overload_func(int **);
 __attribute__((overloadable)) float overload_func(int * __ptrauth(VALID_DATA_KEY) *);
 
+#ifndef PEDANTIC_ERRORS
 static_assert(_Generic(typeof(overload_func(&ptr0)), int : 1, default : 0));
 static_assert(_Generic(typeof(overload_func(&valid0)), float : 1, default : 0));
+#endif
 
 void func(int array[__ptrauth(VALID_DATA_KEY) 10]); // expected-error {{'__ptrauth' qualifier only applies to pointer or pointer sized integer types; 'int[10]' is invalid}}
 
diff --git a/clang/test/SemaObjC/ptrauth-qualifier.m b/clang/test/SemaObjC/ptrauth-qualifier.m
index 74bbe6f0..bd64dc8 100644
--- a/clang/test/SemaObjC/ptrauth-qualifier.m
+++ b/clang/test/SemaObjC/ptrauth-qualifier.m
@@ -1,7 +1,8 @@
 // RUN: %clang_cc1 -triple arm64-apple-ios -fsyntax-only -verify -fptrauth-intrinsics %s
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -fsyntax-only -verify -fptrauth-intrinsics %s
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -fsyntax-only -verify -fptrauth-intrinsics -pedantic-errors %s
 
-#if !__has_extension(ptrauth_qualifier)
+#if !__has_feature(ptrauth_qualifier)
 // This error means that the __ptrauth qualifier availability test says  that it
 // is not available. This error is not expected in the output, if it is seen
 // there is a feature detection regression.