From: Jakub Jelinek <jakub@redhat.com>
To: Richard Biener <rguenther@suse.de>
Cc: gcc-patches@gcc.gnu.org
Subject: [PATCH] Replace IFN_TRAP with BUILT_IN_UNREACHABLE_TRAP [PR107300]
Date: Thu, 2 Feb 2023 10:12:32 +0100 [thread overview]
Message-ID: <Y9t+gOQrO/wBHlxY@tucnak> (raw)
Hi!
For PR106099 I've added IFN_TRAP as an alternative to __builtin_trap
meant for __builtin_unreachable purposes (e.g. with -funreachable-traps
or some sanitizers) which doesn't need vops because __builtin_unreachable
doesn't need them either. This works in various cases, but unfortunately
IPA likes to decide on the redirection to unreachable just by tweaking
the cgraph edge to point to a different FUNCTION_DECL. As internal
functions don't have a decl, this causes problems like in the following
testcase.
The following patch fixes it by removing IFN_TRAP again and replacing
it with user inaccessible BUILT_IN_UNREACHABLE_TRAP, so that e.g.
builtin_decl_unreachable can return it directly and we don't need to tweak
it later in wherever we actually replace the call stmt.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2023-02-02 Jakub Jelinek <jakub@redhat.com>
PR ipa/107300
* builtins.def (BUILT_IN_UNREACHABLE_TRAP): New builtin.
* internal-fn.def (TRAP): Remove.
* internal-fn.cc (expand_TRAP): Remove.
* tree.cc (build_common_builtin_nodes): Define
BUILT_IN_UNREACHABLE_TRAP if not yet defined.
(builtin_decl_unreachable): Use BUILT_IN_UNREACHABLE_TRAP
instead of BUILT_IN_TRAP.
* gimple.cc (gimple_build_builtin_unreachable): Remove
emitting internal function for BUILT_IN_TRAP.
* asan.cc (maybe_instrument_call): Handle BUILT_IN_UNREACHABLE_TRAP.
* cgraph.cc (cgraph_edge::verify_corresponds_to_fndecl): Handle
BUILT_IN_UNREACHABLE_TRAP instead of BUILT_IN_TRAP.
* ipa-devirt.cc (possible_polymorphic_call_target_p): Handle
BUILT_IN_UNREACHABLE_TRAP.
* builtins.cc (expand_builtin, is_inexpensive_builtin): Likewise.
* tree-cfg.cc (verify_gimple_call,
pass_warn_function_return::execute): Likewise.
* attribs.cc (decl_attributes): Don't report exclusions on
BUILT_IN_UNREACHABLE_TRAP either.
* gcc.dg/pr107300.c: New test.
--- gcc/builtins.def.jj 2023-01-02 09:32:37.988059844 +0100
+++ gcc/builtins.def 2023-02-01 19:19:15.382475912 +0100
@@ -1048,6 +1048,7 @@ DEF_GCC_BUILTIN (BUILT_IN_SETJMP,
DEF_EXT_LIB_BUILTIN (BUILT_IN_STRFMON, "strfmon", BT_FN_SSIZE_STRING_SIZE_CONST_STRING_VAR, ATTR_FORMAT_STRFMON_NOTHROW_3_4)
DEF_LIB_BUILTIN (BUILT_IN_STRFTIME, "strftime", BT_FN_SIZE_STRING_SIZE_CONST_STRING_CONST_TM_PTR, ATTR_FORMAT_STRFTIME_NOTHROW_3_0)
DEF_GCC_BUILTIN (BUILT_IN_TRAP, "trap", BT_FN_VOID, ATTR_NORETURN_NOTHROW_LEAF_COLD_LIST)
+DEF_GCC_BUILTIN (BUILT_IN_UNREACHABLE_TRAP, "unreachable trap", BT_FN_VOID, ATTR_CONST_NORETURN_NOTHROW_LEAF_COLD_LIST)
DEF_GCC_BUILTIN (BUILT_IN_UNREACHABLE, "unreachable", BT_FN_VOID, ATTR_CONST_NORETURN_NOTHROW_LEAF_COLD_LIST)
DEF_GCC_BUILTIN (BUILT_IN_UNWIND_INIT, "unwind_init", BT_FN_VOID, ATTR_NULL)
DEF_GCC_BUILTIN (BUILT_IN_UPDATE_SETJMP_BUF, "update_setjmp_buf", BT_FN_VOID_PTR, ATTR_NULL)
--- gcc/internal-fn.def.jj 2023-01-02 09:32:38.771048530 +0100
+++ gcc/internal-fn.def 2023-02-01 19:19:52.239936390 +0100
@@ -457,11 +457,6 @@ DEF_INTERNAL_FN (SHUFFLEVECTOR, ECF_CONS
/* <=> optimization. */
DEF_INTERNAL_FN (SPACESHIP, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
-/* __builtin_trap created from/for __builtin_unreachable. */
-DEF_INTERNAL_FN (TRAP, ECF_CONST | ECF_LEAF | ECF_NORETURN
- | ECF_NOTHROW | ECF_COLD | ECF_LOOPING_CONST_OR_PURE,
- NULL)
-
/* [[assume (cond)]]. */
DEF_INTERNAL_FN (ASSUME, ECF_CONST | ECF_LEAF | ECF_NOTHROW
| ECF_LOOPING_CONST_OR_PURE, NULL)
--- gcc/internal-fn.cc.jj 2023-01-02 09:32:22.206287869 +0100
+++ gcc/internal-fn.cc 2023-02-01 19:16:52.939561023 +0100
@@ -4518,12 +4518,6 @@ expand_SPACESHIP (internal_fn, gcall *st
}
void
-expand_TRAP (internal_fn, gcall *)
-{
- expand_builtin_trap ();
-}
-
-void
expand_ASSUME (internal_fn, gcall *)
{
}
--- gcc/tree.cc.jj 2023-01-27 20:09:16.151971051 +0100
+++ gcc/tree.cc 2023-02-01 20:37:01.287315982 +0100
@@ -9758,6 +9758,7 @@ build_common_builtin_nodes (void)
if (!builtin_decl_explicit_p (BUILT_IN_UNREACHABLE)
|| !builtin_decl_explicit_p (BUILT_IN_TRAP)
+ || !builtin_decl_explicit_p (BUILT_IN_UNREACHABLE_TRAP)
|| !builtin_decl_explicit_p (BUILT_IN_ABORT))
{
ftype = build_function_type (void_type_node, void_list_node);
@@ -9767,6 +9768,12 @@ build_common_builtin_nodes (void)
"__builtin_unreachable",
ECF_NOTHROW | ECF_LEAF | ECF_NORETURN
| ECF_CONST | ECF_COLD);
+ if (!builtin_decl_explicit_p (BUILT_IN_UNREACHABLE_TRAP))
+ local_define_builtin ("__builtin_unreachable trap", ftype,
+ BUILT_IN_UNREACHABLE_TRAP,
+ "__builtin_unreachable trap",
+ ECF_NOTHROW | ECF_LEAF | ECF_NORETURN
+ | ECF_CONST | ECF_COLD);
if (!builtin_decl_explicit_p (BUILT_IN_ABORT))
local_define_builtin ("__builtin_abort", ftype, BUILT_IN_ABORT,
"abort",
@@ -10908,7 +10915,7 @@ builtin_decl_unreachable ()
if (sanitize_flags_p (SANITIZE_UNREACHABLE)
? (flag_sanitize_trap & SANITIZE_UNREACHABLE)
: flag_unreachable_traps)
- fncode = BUILT_IN_TRAP;
+ fncode = BUILT_IN_UNREACHABLE_TRAP;
/* For non-trapping sanitize, we will rewrite __builtin_unreachable () later,
in the sanopt pass. */
--- gcc/gimple.cc.jj 2023-01-02 09:32:44.443966564 +0100
+++ gcc/gimple.cc 2023-02-01 19:20:45.634154800 +0100
@@ -430,16 +430,7 @@ gimple_build_builtin_unreachable (locati
{
tree data = NULL_TREE;
tree fn = sanitize_unreachable_fn (&data, loc);
- gcall *g;
- if (DECL_FUNCTION_CODE (fn) != BUILT_IN_TRAP)
- g = gimple_build_call (fn, data != NULL_TREE, data);
- else
- {
- /* Instead of __builtin_trap use .TRAP, so that it doesn't
- need vops. */
- gcc_checking_assert (data == NULL_TREE);
- g = gimple_build_call_internal (IFN_TRAP, 0);
- }
+ gcall *g = gimple_build_call (fn, data != NULL_TREE, data);
gimple_call_set_ctrl_altering (g, true);
gimple_set_location (g, loc);
return g;
--- gcc/asan.cc.jj 2023-01-02 09:32:30.191172498 +0100
+++ gcc/asan.cc 2023-02-01 20:40:02.132674664 +0100
@@ -2951,6 +2951,7 @@ maybe_instrument_call (gimple_stmt_itera
switch (DECL_FUNCTION_CODE (callee))
{
case BUILT_IN_UNREACHABLE:
+ case BUILT_IN_UNREACHABLE_TRAP:
case BUILT_IN_TRAP:
/* Don't instrument these. */
return false;
--- gcc/cgraph.cc.jj 2023-01-30 10:57:03.433236251 +0100
+++ gcc/cgraph.cc 2023-02-01 20:37:39.878752332 +0100
@@ -3248,11 +3248,11 @@ cgraph_edge::verify_corresponds_to_fndec
node = node->ultimate_alias_target ();
/* Optimizers can redirect unreachable calls or calls triggering undefined
- behavior to __builtin_unreachable or __builtin_trap. */
+ behavior to __builtin_unreachable or __builtin_unreachable trap. */
if (fndecl_built_in_p (callee->decl, BUILT_IN_NORMAL)
&& (DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_UNREACHABLE
- || DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_TRAP))
+ || DECL_FUNCTION_CODE (callee->decl) == BUILT_IN_UNREACHABLE_TRAP))
return false;
if (callee->former_clone_of != node->decl
--- gcc/ipa-devirt.cc.jj 2023-02-01 17:26:28.241878107 +0100
+++ gcc/ipa-devirt.cc 2023-02-01 20:42:46.472274417 +0100
@@ -3471,8 +3471,10 @@ possible_polymorphic_call_target_p (tree
unsigned int i;
bool final;
- if (fndecl_built_in_p (n->decl, BUILT_IN_UNREACHABLE)
- || fndecl_built_in_p (n->decl, BUILT_IN_TRAP))
+ if (fndecl_built_in_p (n->decl, BUILT_IN_NORMAL)
+ && (DECL_FUNCTION_CODE (n->decl) == BUILT_IN_UNREACHABLE
+ || DECL_FUNCTION_CODE (n->decl) == BUILT_IN_TRAP
+ || DECL_FUNCTION_CODE (n->decl) == BUILT_IN_UNREACHABLE_TRAP))
return true;
if (is_cxa_pure_virtual_p (n->decl))
--- gcc/builtins.cc.jj 2023-01-02 09:32:20.735309123 +0100
+++ gcc/builtins.cc 2023-02-01 20:39:28.727162564 +0100
@@ -7844,6 +7844,7 @@ expand_builtin (tree exp, rtx target, rt
break;
case BUILT_IN_TRAP:
+ case BUILT_IN_UNREACHABLE_TRAP:
expand_builtin_trap ();
return const0_rtx;
@@ -11310,6 +11311,7 @@ is_inexpensive_builtin (tree decl)
case BUILT_IN_VA_ARG_PACK_LEN:
case BUILT_IN_VA_COPY:
case BUILT_IN_TRAP:
+ case BUILT_IN_UNREACHABLE_TRAP:
case BUILT_IN_SAVEREGS:
case BUILT_IN_POPCOUNTL:
case BUILT_IN_POPCOUNTLL:
--- gcc/tree-cfg.cc.jj 2023-01-02 09:32:27.879205904 +0100
+++ gcc/tree-cfg.cc 2023-02-01 20:44:44.826545812 +0100
@@ -3503,6 +3503,7 @@ verify_gimple_call (gcall *stmt)
switch (DECL_FUNCTION_CODE (fndecl))
{
case BUILT_IN_UNREACHABLE:
+ case BUILT_IN_UNREACHABLE_TRAP:
case BUILT_IN_TRAP:
if (gimple_call_num_args (stmt) > 0)
{
@@ -9681,6 +9682,8 @@ pass_warn_function_return::execute (func
&& ((LOCATION_LOCUS (gimple_location (last))
== BUILTINS_LOCATION
&& (gimple_call_builtin_p (last, BUILT_IN_UNREACHABLE)
+ || gimple_call_builtin_p (last,
+ BUILT_IN_UNREACHABLE_TRAP)
|| gimple_call_builtin_p (last, BUILT_IN_TRAP)))
|| gimple_call_builtin_p (last, ubsan_missing_ret)))
{
--- gcc/attribs.cc.jj 2023-01-13 17:37:45.056485561 +0100
+++ gcc/attribs.cc 2023-02-01 20:54:16.134198166 +0100
@@ -846,6 +846,7 @@ decl_attributes (tree *node, tree attrib
|| !DECL_P (*anode)
|| DECL_BUILT_IN_CLASS (*anode) != BUILT_IN_NORMAL
|| (DECL_FUNCTION_CODE (*anode) != BUILT_IN_UNREACHABLE
+ && DECL_FUNCTION_CODE (*anode) != BUILT_IN_UNREACHABLE_TRAP
&& (DECL_FUNCTION_CODE (*anode)
!= BUILT_IN_UBSAN_HANDLE_BUILTIN_UNREACHABLE)))
{
--- gcc/testsuite/gcc.dg/pr107300.c.jj 2023-02-01 20:55:36.602021915 +0100
+++ gcc/testsuite/gcc.dg/pr107300.c 2023-02-01 20:55:25.298187139 +0100
@@ -0,0 +1,19 @@
+/* PR ipa/107300 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fipa-cp-clone -funreachable-traps -fno-inline" } */
+
+void
+bar (int x, int y)
+{
+ if (x)
+ __builtin_unreachable ();
+
+ if (y)
+ __builtin_abort ();
+}
+
+void
+foo (void)
+{
+ bar (0, 0);
+}
Jakub
next reply other threads:[~2023-02-02 9:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-02 9:12 Jakub Jelinek [this message]
2023-02-02 9:19 ` Richard Biener
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