On Thu, 23 May 2019, Alex Henrie wrote:
> ---
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86407#c6
> ---
> gcc/c-family/c.opt | 4 ++++
> gcc/c/c-decl.c | 4 +++-
> gcc/config/i386/i386-options.c | 12 ++++++++++--
> gcc/testsuite/c-c++-common/pr86407-1.c | 23 +++++++++++++++++++++++
> gcc/testsuite/c-c++-common/pr86407-2.c | 25 +++++++++++++++++++++++++
> 5 files changed, 65 insertions(+), 3 deletions(-)
> create mode 100644 gcc/testsuite/c-c++-common/pr86407-1.c
> create mode 100644 gcc/testsuite/c-c++-common/pr86407-2.c
>
> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
> index 046d489f7eb..3b99c96e53d 100644
> --- a/gcc/c-family/c.opt
> +++ b/gcc/c-family/c.opt
> @@ -776,6 +776,10 @@ Wsizeof-array-argument
> C ObjC C++ ObjC++ Var(warn_sizeof_array_argument) Warning Init(1)
> Warn when sizeof is applied on a parameter declared as an array.
>
> +Wstrict-function-attributes
> +C C++ Var(warn_strict_function_attributes) Init(1) Warning
> +Warn when function definition attributes are applied to function pointers.
> +
> Wstringop-overflow
> C ObjC C++ LTO ObjC++ Warning Alias(Wstringop-overflow=, 2, 0)
> Warn about buffer overflow in string manipulation functions like memcpy
> diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
> index 181a8c2e9aa..427d573c8d3 100644
> --- a/gcc/c/c-decl.c
> +++ b/gcc/c/c-decl.c
> @@ -6192,7 +6192,9 @@ grokdeclarator (const struct c_declarator *declarator,
> inner_decl = inner_decl->declarator;
> if (inner_decl->kind == cdk_id)
> attr_flags |= (int) ATTR_FLAG_DECL_NEXT;
> - else if (inner_decl->kind == cdk_function)
> + else if (inner_decl->kind == cdk_function
> + || (inner_decl->kind == cdk_pointer
> + && TREE_CODE (type) == FUNCTION_TYPE))
> attr_flags |= (int) ATTR_FLAG_FUNCTION_NEXT;
> else if (inner_decl->kind == cdk_array)
> attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT;
> diff --git a/gcc/config/i386/i386-options.c b/gcc/config/i386/i386-options.c
> index 0f236626005..6b50f143b05 100644
> --- a/gcc/config/i386/i386-options.c
> +++ b/gcc/config/i386/i386-options.c
> @@ -3489,8 +3489,16 @@ ix86_handle_fndecl_attribute (tree *node, tree name,
> tree args, int,
> {
> if (TREE_CODE (*node) != FUNCTION_DECL)
> {
> - warning (OPT_Wattributes, "%qE attribute only applies to functions",
> - name);
> + if (FUNCTION_POINTER_TYPE_P (TREE_TYPE (*node)))
> + {
> + warning (OPT_Wstrict_function_attributes,
> + "%qE attribute only applies to function definitions", name);
> + }
> + else
> + {
> + warning (OPT_Wattributes,
> + "%qE attribute only applies to functions", name);
> + }
I'm not sure we really need a new warning for this.
> *no_add_attrs = true;
> }
>
> diff --git a/gcc/testsuite/c-c++-common/pr86407-1.c
> b/gcc/testsuite/c-c++-common/pr86407-1.c
> new file mode 100644
> index 00000000000..37993d8c051
> --- /dev/null
> +++ b/gcc/testsuite/c-c++-common/pr86407-1.c
> @@ -0,0 +1,23 @@
> +/* PR c/86407 */
> +/* Test a function attribute that is not a calling convention and does not
> + affect the function type. There should be no warnings when using the
> + attribute on a function declaration, function pointer, or function pointer
> + typedef, but there should be a warning when using the attribute on
> + non-function-pointer variables and typedefs. */
> +
> +/* { dg-options "-Wstrict-function-attributes -Wno-ignored-attributes" } */
> +
> +int __attribute__((__ms_hook_prologue__)) func(); /* no warnings */
> +
But this is a declaration?
> +int (__attribute__((__ms_hook_prologue__)) *func_ptr)(); /* { dg-warning
> "'ms_hook_prologue' attribute only applies to function definitions" } */
> +
> +typedef int (__attribute__((__ms_hook_prologue__)) *FUNC_PTR)(); /* {
> dg-warning "'ms_hook_prologue' attribute only applies to function
> definitions" } */
> +
> +int __attribute__((__ms_hook_prologue__)) *var_ptr; /* { dg-warning
> "'ms_hook_prologue' attribute only applies to functions" } */
> +
> +typedef int __attribute__((__ms_hook_prologue__)) *VAR_PTR; /* { dg-warning
> "'ms_hook_prologue' attribute only applies to functions" } */
> +
> +int main(int argc, char **argv)
> +{
> + return 0;
> +}
> diff --git a/gcc/testsuite/c-c++-common/pr86407-2.c
> b/gcc/testsuite/c-c++-common/pr86407-2.c
> new file mode 100644
> index 00000000000..6840b0180dd
> --- /dev/null
> +++ b/gcc/testsuite/c-c++-common/pr86407-2.c
> @@ -0,0 +1,25 @@
> +/* PR c/86407 */
> +/* Test a function attribute that is not a calling convention and does not
> + affect the function type. A function pointer without the attribute may
> point
> + to a function with the attribute and vice-versa. */
> +
> +/* { dg-options "-Wno-strict-function-attributes -Wno-ignored-attributes" }
> */
> +
> +int ordinary_func()
> +{
> + return 0;
> +}
> +
> +int __attribute__((__ms_hook_prologue__)) special_func()
> +{
> + return 0;
> +}
> +
> +int main(int argc, char **argv)
> +{
> + int (*ordinary_func_ptr)() = special_func;
> +
> + int (__attribute__((__ms_hook_prologue__)) *special_func_ptr)() =
> ordinary_func;
> +
> + return 0;
> +}
>
--
Richard Biener <rguent...@suse.de>
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany;
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah; HRB 21284 (AG Nürnberg)
