diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -2353,12 +2353,14 @@ array subscript access and structure/union member access are relocatable under bpf compile-once run-everywhere framework. Debuginfo (typically with ``-g``) is needed, otherwise, the compiler will exit with an error. +The return type for the intrinsic is the same as the type of the +argument, and must be a pointer type. **Syntax**: .. code-block:: c - const void * __builtin_preserve_access_index(const void * ptr) + PointerT __builtin_preserve_access_index(PointerT ptr) **Example of Use**: diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def --- a/clang/include/clang/Basic/Builtins.def +++ b/clang/include/clang/Basic/Builtins.def @@ -1470,7 +1470,7 @@ BUILTIN(__builtin_operator_delete, "vv*", "tn") BUILTIN(__builtin_char_memchr, "c*cC*iz", "n") BUILTIN(__builtin_dump_struct, "ivC*v*", "tn") -BUILTIN(__builtin_preserve_access_index, "vC*vC*", "nU") +BUILTIN(__builtin_preserve_access_index, "v.", "t") // Safestack builtins BUILTIN(__builtin___get_unsafe_stack_start, "v*", "Fn") diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -9922,4 +9922,7 @@ "__builtin_bit_cast %select{source|destination}0 type must be trivially copyable">; def err_bit_cast_type_size_mismatch : Error< "__builtin_bit_cast source size does not equal destination size (%0 vs %1)">; + +def err_builtin_preserve_access_index_invalid_arg : Error< + "__builtin_preserve_access_index argument must a pointer type instead of %0">; } // end of sema component. diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -191,12 +191,22 @@ return false; } -/// Check the number of arguments, and set the result type to +/// Check the number of arguments and arg type, and set the result type to /// the argument type. static bool SemaBuiltinPreserveAI(Sema &S, CallExpr *TheCall) { if (checkArgCount(S, TheCall, 1)) return true; + // The argument type must be a pointer + ExprResult Arg = TheCall->getArg(0); + QualType Ty = Arg.get()->getType(); + if (!Ty->isPointerType()) { + S.Diag(Arg.get()->getBeginLoc(), + diag::err_builtin_preserve_access_index_invalid_arg) + << Ty << Arg.get()->getSourceRange(); + return true; + } + TheCall->setType(TheCall->getArg(0)->getType()); return false; } diff --git a/clang/test/Sema/builtin-preserve-access-index.c b/clang/test/Sema/builtin-preserve-access-index.c --- a/clang/test/Sema/builtin-preserve-access-index.c +++ b/clang/test/Sema/builtin-preserve-access-index.c @@ -4,10 +4,28 @@ return __builtin_preserve_access_index(&arg[1], 1); // expected-error {{too many arguments to function call, expected 1, have 2}} } -void *invalid2(const int *arg) { - return __builtin_preserve_access_index(&arg[1]); // expected-warning {{returning 'const void *' from a function with result type 'void *' discards qualifiers}} +const void *invalid2(const int *arg) { + return __builtin_preserve_access_index(1); // expected-error {{__builtin_preserve_access_index argument must a pointer type instead of 'int'}} } -const void *invalid3(const int *arg) { - return __builtin_preserve_access_index(1); // expected-warning {{incompatible integer to pointer conversion passing 'int' to parameter of type 'const void *'}} +void *invalid3(const int *arg) { + return __builtin_preserve_access_index(&arg[1]); // expected-warning {{returning 'const int *' from a function with result type 'void *' discards qualifiers}} +} + +const void *invalid4(volatile const int *arg) { + return __builtin_preserve_access_index(arg); // expected-warning {{returning 'const volatile int *' from a function with result type 'const void *' discards qualifiers}} +} + +int *valid5(int *arg) { + return __builtin_preserve_access_index(arg); +} + +int valid6(const volatile int *arg) { + return *__builtin_preserve_access_index(arg); +} + +struct s { int a; int b; }; + +int valid7(struct s *arg) { + return *__builtin_preserve_access_index(&arg->b); }