In
struct ucontext;
typedef struct ucontext ucontext_t;
extern int (*bar) (ucontext_t *__restrict __oucp,
const ucontext_t *__restrict __ucp)
__attribute__((__indirect_return__));
extern int res;
void
foo (ucontext_t *oucp, ucontext_t *ucp)
{
res = bar (oucp, ucp);
}
bar() may return via indirect branch. This patch changes indirect_return
to type attribute to allow indirect_return attribute on variable or type
of function pointer so that ENDBR can be inserted after call to bar().
Tested on i386 and x86-64. OK for trunk?
Thanks.
H.J.
---
gcc/
PR target/86560
* config/i386/i386.c (rest_of_insert_endbranch): Lookup
indirect_return as function type attribute.
(ix86_attribute_table): Change indirect_return to function
type attribute.
* doc/extend.texi: Update indirect_return attribute.
gcc/testsuite/
PR target/86560
* gcc.target/i386/pr86560-1.c: New test.
* gcc.target/i386/pr86560-2.c: Likewise.
* gcc.target/i386/pr86560-3.c: Likewise.
---
gcc/config/i386/i386.c | 23 +++++++++++++++--------
gcc/doc/extend.texi | 5 +++--
gcc/testsuite/gcc.target/i386/pr86560-1.c | 16 ++++++++++++++++
gcc/testsuite/gcc.target/i386/pr86560-2.c | 16 ++++++++++++++++
gcc/testsuite/gcc.target/i386/pr86560-3.c | 17 +++++++++++++++++
5 files changed, 67 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr86560-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr86560-2.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr86560-3.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index aec739c3974..ac27248370b 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2627,16 +2627,23 @@ rest_of_insert_endbranch (void)
{
rtx call = get_call_rtx_from (insn);
rtx fnaddr = XEXP (call, 0);
+ tree fndecl = NULL_TREE;
/* Also generate ENDBRANCH for non-tail call which
may return via indirect branch. */
- if (MEM_P (fnaddr)
- && GET_CODE (XEXP (fnaddr, 0)) == SYMBOL_REF)
+ if (GET_CODE (XEXP (fnaddr, 0)) == SYMBOL_REF)
+ fndecl = SYMBOL_REF_DECL (XEXP (fnaddr, 0));
+ if (fndecl == NULL_TREE)
+ fndecl = MEM_EXPR (fnaddr);
+ if (fndecl
+ && TREE_CODE (TREE_TYPE (fndecl)) != FUNCTION_TYPE
+ && TREE_CODE (TREE_TYPE (fndecl)) != METHOD_TYPE)
+ fndecl = NULL_TREE;
+ if (fndecl && TYPE_ARG_TYPES (TREE_TYPE (fndecl)))
{
- tree fndecl = SYMBOL_REF_DECL (XEXP (fnaddr, 0));
- if (fndecl
- && lookup_attribute ("indirect_return",
- DECL_ATTRIBUTES (fndecl)))
+ tree fntype = TREE_TYPE (fndecl);
+ if (lookup_attribute ("indirect_return",
+ TYPE_ATTRIBUTES (fntype)))
need_endbr = true;
}
}
@@ -46101,8 +46108,8 @@ static const struct attribute_spec
ix86_attribute_table[] =
ix86_handle_fndecl_attribute, NULL },
{ "function_return", 1, 1, true, false, false, false,
ix86_handle_fndecl_attribute, NULL },
- { "indirect_return", 0, 0, true, false, false, false,
- ix86_handle_fndecl_attribute, NULL },
+ { "indirect_return", 0, 0, false, true, true, false,
+ NULL, NULL },
/* End element. */
{ NULL, 0, 0, false, false, false, false, NULL, NULL }
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 8b4d3fd9de3..edeaec6d872 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -5861,8 +5861,9 @@ foo (void)
@item indirect_return
@cindex @code{indirect_return} function attribute, x86
-The @code{indirect_return} attribute on a function is used to inform
-the compiler that the function may return via indirect branch.
+The @code{indirect_return} attribute can be applied to a function,
+as well as variable or type of function pointer to inform the
+compiler that the function may return via indirect branch.
@end table
diff --git a/gcc/testsuite/gcc.target/i386/pr86560-1.c
b/gcc/testsuite/gcc.target/i386/pr86560-1.c
new file mode 100644
index 00000000000..a2b702695c5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr86560-1.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcf-protection" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+struct ucontext;
+
+extern int (*bar) (struct ucontext *)
+ __attribute__((__indirect_return__));
+
+extern int res;
+
+void
+foo (struct ucontext *oucp)
+{
+ res = bar (oucp);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr86560-2.c
b/gcc/testsuite/gcc.target/i386/pr86560-2.c
new file mode 100644
index 00000000000..6f01b385afd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr86560-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcf-protection" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+struct ucontext;
+
+typedef int (*bar_p) (struct ucontext *)
+ __attribute__((__indirect_return__));
+
+extern int res;
+
+void
+foo (bar_p bar, struct ucontext *oucp)
+{
+ res = bar (oucp);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr86560-3.c
b/gcc/testsuite/gcc.target/i386/pr86560-3.c
new file mode 100644
index 00000000000..05328e24509
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr86560-3.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcf-protection" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+struct ucontext;
+
+extern int (*bar) (struct ucontext *);
+
+extern int res;
+
+void
+foo (struct ucontext *oucp)
+{
+ int (*f) (struct ucontext *) __attribute__((__indirect_return__))
+ = bar;
+ res = f (oucp);
+}
--
2.17.1
