Hi!
The following patch fixes various issues in patchable_function_entry
handling:
1) most importantly, it adds a warning if the argument(s) aren't integer
constants or if they are negative and drops the attribute
2) if (tree_fits_uhwi_p (x)) y = tree_to_uhwi (x); else gcc_unreachable ();
makes no sense, as tree_to_uhwi has the same gcc_assert already
3) list_length () > 1 might look cool, but we should have guaranteed it
is only 1 or 2 argument and even if it was longer, computing whole
length and then comparing it against 1 is inefficient
4) warnings shouldn't start with a capital letter
5) formatting fixes
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-04-12 Jakub Jelinek <ja...@redhat.com>
PR c/89946
* varasm.c (assemble_start_function): Don't use tree_fits_uhwi_p
and gcc_unreachable if it fails, just call tree_to_uhwi which
verifies that too. Test TREE_CHAIN instead of list_length > 1.
Start warning message with a lower-case letter. Formatting fixes.
c-family/
* c-attribs.c (handle_patchable_function_entry_attribute): Add
function comment. Warn if arguments of the attribute are not positive
integer constants.
testsuite/
* c-c++-common/pr89946.c: New test.
--- gcc/varasm.c.jj 2019-02-28 08:14:58.438559862 +0100
+++ gcc/varasm.c 2019-04-11 15:34:46.933248354 +0200
@@ -1865,28 +1865,20 @@ assemble_start_function (tree decl, cons
tree pp_val = TREE_VALUE (patchable_function_entry_attr);
tree patchable_function_entry_value1 = TREE_VALUE (pp_val);
- if (tree_fits_uhwi_p (patchable_function_entry_value1))
- patch_area_size = tree_to_uhwi (patchable_function_entry_value1);
- else
- gcc_unreachable ();
-
+ patch_area_size = tree_to_uhwi (patchable_function_entry_value1);
patch_area_entry = 0;
- if (list_length (pp_val) > 1)
+ if (TREE_CHAIN (pp_val) != NULL_TREE)
{
- tree patchable_function_entry_value2 =
- TREE_VALUE (TREE_CHAIN (pp_val));
-
- if (tree_fits_uhwi_p (patchable_function_entry_value2))
- patch_area_entry = tree_to_uhwi (patchable_function_entry_value2);
- else
- gcc_unreachable ();
+ tree patchable_function_entry_value2
+ = TREE_VALUE (TREE_CHAIN (pp_val));
+ patch_area_entry = tree_to_uhwi (patchable_function_entry_value2);
}
}
if (patch_area_entry > patch_area_size)
{
if (patch_area_size > 0)
- warning (OPT_Wattributes, "Patchable function entry > size");
+ warning (OPT_Wattributes, "patchable function entry > size");
patch_area_entry = 0;
}
@@ -1906,7 +1898,8 @@ assemble_start_function (tree decl, cons
/* And the area after the label. Record it if we haven't done so yet. */
if (patch_area_size > patch_area_entry)
targetm.asm_out.print_patchable_function_entry (asm_out_file,
- patch_area_size-patch_area_entry,
+ patch_area_size
+ - patch_area_entry,
patch_area_entry == 0);
if (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (decl)))
--- gcc/c-family/c-attribs.c.jj 2019-04-08 10:11:26.706250584 +0200
+++ gcc/c-family/c-attribs.c 2019-04-11 15:51:45.851326928 +0200
@@ -3988,10 +3988,29 @@ handle_fallthrough_attribute (tree *, tr
return NULL_TREE;
}
+/* Handle a "patchable_function_entry" attributes; arguments as in
+ struct attribute_spec.handler. */
+
static tree
-handle_patchable_function_entry_attribute (tree *, tree, tree, int, bool *)
+handle_patchable_function_entry_attribute (tree *, tree name, tree args,
+ int, bool *no_add_attrs)
{
- /* Nothing to be done here. */
+ for (; args; args = TREE_CHAIN (args))
+ {
+ tree val = TREE_VALUE (args);
+ if (val && TREE_CODE (val) != IDENTIFIER_NODE
+ && TREE_CODE (val) != FUNCTION_DECL)
+ val = default_conversion (val);
+
+ if (!tree_fits_uhwi_p (val))
+ {
+ warning (OPT_Wattributes,
+ "%qE attribute argument %qE is not an integer constant",
+ name, val);
+ *no_add_attrs = true;
+ return NULL_TREE;
+ }
+ }
return NULL_TREE;
}
--- gcc/testsuite/c-c++-common/pr89946.c.jj 2019-04-11 15:52:33.616532035
+0200
+++ gcc/testsuite/c-c++-common/pr89946.c 2019-04-11 15:51:29.303602307
+0200
@@ -0,0 +1,7 @@
+/* PR c/89946 */
+
+__attribute__((patchable_function_entry (-1))) void foo (void) {} /* {
dg-warning "'patchable_function_entry' attribute argument '-1' is not an
integer constant" } */
+__attribute__((patchable_function_entry (5, -5))) void bar (void) {} /* {
dg-warning "'patchable_function_entry' attribute argument '-5' is not an
integer constant" } */
+int i, j;
+__attribute__((patchable_function_entry (i))) void baz (void) {} /* {
dg-warning "'patchable_function_entry' attribute argument 'i' is not an integer
constant" } */
+__attribute__((patchable_function_entry (2, j))) void qux (void) {} /* {
dg-warning "'patchable_function_entry' attribute argument 'j' is not an integer
constant" } */
Jakub
