[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372 Martin Sebor changed: What|Removed |Added See Also||https://gcc.gnu.org/bugzill ||a/show_bug.cgi?id=88506 --- Comment #7 from Martin Sebor --- Bug 88506 tracks the missing warning.
[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372 Martin Sebor changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #6 from Martin Sebor --- Fixed for GCC 9 in r267158. A warning when a function without the attribute is assigned to a pointer with it should also be implemented to help detect bugs that this might lead to.
[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372 --- Comment #5 from Martin Sebor --- Author: msebor Date: Fri Dec 14 22:45:55 2018 New Revision: 267158 URL: https://gcc.gnu.org/viewcvs?rev=267158=gcc=rev Log: PR tree-optimization/88372 - alloc_size attribute is ignored on function pointers gcc/ChangeLog: PR tree-optimization/88372 * calls.c (maybe_warn_alloc_args_overflow): Handle function pointers. * tree-object-size.c (alloc_object_size): Same. Simplify. * doc/extend.texi (Object Size Checking): Update. (Other Builtins): Add __builtin_object_size. (Common Type Attributes): Add alloc_size. (Common Variable Attributes): Ditto. gcc/testsuite/ChangeLog: PR tree-optimization/88372 * gcc.dg/Walloc-size-larger-than-18.c: New test. * gcc.dg/builtin-object-size-19.c: Same. Added: trunk/gcc/testsuite/gcc.dg/Walloc-size-larger-than-18.c trunk/gcc/testsuite/gcc.dg/builtin-object-size-19.c Modified: trunk/gcc/ChangeLog trunk/gcc/calls.c trunk/gcc/doc/extend.texi trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-object-size.c
[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372 Martin Sebor changed: What|Removed |Added Keywords||patch --- Comment #4 from Martin Sebor --- Patch: https://gcc.gnu.org/ml/gcc-patches/2018-12/msg00401.html
[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372 Martin Sebor changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot gnu.org --- Comment #3 from Martin Sebor --- Testing a patch.
[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372 --- Comment #2 from Richard Biener --- + /* If there is no function, look at the type of the called +expression in case it's been declared attribute alloc_size. */ + callee = gimple_call_fn (call); + if (callee && TREE_CODE (TREE_TYPE (callee)) == POINTER_TYPE) + callee = TREE_TYPE (callee); you should alway suse gimple_call_fntype here.
[Bug tree-optimization/88372] alloc_size attribute is ignored on function pointers
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88372
Martin Sebor changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed||2018-12-05
CC||msebor at gcc dot gnu.org
Component|c |tree-optimization
Ever confirmed|0 |1
--- Comment #1 from Martin Sebor ---
This attribute is already accepted on the function pointer so it should work
just like alloc_align does. The reason why __builtin_object_size doesn't
report the size is because it only considers attributes on the called functions
in function calls and doesn't try to look for attributes on the types of
function pointers. So I'd consider this limitation a bug rather than
enhancement request. With that, accepting [[gnu::alloc_size(N)]] should make
sense as well.
With the very lightly tested patch below __builtin_object_size reports the same
size in both functions in the test case.
Index: gcc/tree-object-size.c
===
--- gcc/tree-object-size.c (revision 266799)
+++ gcc/tree-object-size.c (working copy)
@@ -414,8 +414,18 @@ alloc_object_size (const gcall *call, int object_s
gcc_assert (is_gimple_call (call));
+ /* Lopok for the called function. */
callee = gimple_call_fndecl (call);
if (!callee)
+{
+ /* If there is no function, look at the type of the called
+expression in case it's been declared attribute alloc_size. */
+ callee = gimple_call_fn (call);
+ if (callee && TREE_CODE (TREE_TYPE (callee)) == POINTER_TYPE)
+ callee = TREE_TYPE (callee);
+}
+
+ if (!callee)
return unknown[object_size_type];
alloc_size = lookup_attribute ("alloc_size",
@@ -429,7 +439,8 @@ alloc_object_size (const gcall *call, int object_s
arg2 = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (p)))-1;
}
- if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
+ if (DECL_P (callee)
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
switch (DECL_FUNCTION_CODE (callee))
{
case BUILT_IN_CALLOC:
