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Re: Fix CFG WRT __builtin_return
> Move this function to gimple.[ch], call it
> gimple_call_builtin_p implemented like
>
> bool
> gimple_call_builtin_p (gimple stmt, enum built_in_function code)
> {
> tree fndecl;
> return (is_gimple_call (stmt)
> && (fndecl = gimple_call_fndecl (stmt)) != NULL
> && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
> && DECL_FUNCTION_CODE (fndecl) == code);
> }
>
> note the correctness check for BUILT_IN_NORMAL you miss.
>
> Ok with that change.
Sure,
this is updated patch I am testing now and intende to commit later.
Thanks,
Honza
* gimple.c (gimple_call_builtin_p): New function.
* gimple.h (gimple_call_builtin_p): Declare.
* tree-cfg.c (make_edges): Produce edge from BUILT_IN_RETURN
to exit.
(execute_warn_function_return): BUILT_IN_RETURN is return.
(split_critical_edges): Return edges are not critical.
(is_ctrl_altering_stmt): Builtin_in_return is altering.
(gimple_verify_flow_info): Handle built_in_return.
(execute_warn_function_return): Handle built_in_return.
* ipa-pure-const.c (check_call): Ignore builtin_return.
* gcc.dg/builtin-apply4.c: Compile with -Wmissing-return.
Index: testsuite/gcc.dg/builtin-apply4.c
===================================================================
*** testsuite/gcc.dg/builtin-apply4.c (revision 160037)
--- testsuite/gcc.dg/builtin-apply4.c (working copy)
***************
*** 1,5 ****
/* PR tree-optimization/20076 */
! /* { dg-options "-O2" } */
/* { dg-options "-O2 -mno-mmx" { target { { i?86-*-* x86_64-*-* } && ilp32 } } } */
/* { dg-do run } */
--- 1,5 ----
/* PR tree-optimization/20076 */
! /* { dg-options "-O2 -Wmissing-noreturn" } */
/* { dg-options "-O2 -mno-mmx" { target { { i?86-*-* x86_64-*-* } && ilp32 } } } */
/* { dg-do run } */
Index: builtins.def
===================================================================
*** builtins.def (revision 160037)
--- builtins.def (working copy)
*************** DEF_GCC_BUILTIN (BUILT_IN_POPCOUN
*** 691,697 ****
DEF_GCC_BUILTIN (BUILT_IN_POPCOUNTLL, "popcountll", BT_FN_INT_ULONGLONG, ATTR_CONST_NOTHROW_LIST)
DEF_GCC_BUILTIN (BUILT_IN_PREFETCH, "prefetch", BT_FN_VOID_CONST_PTR_VAR, ATTR_NOVOPS_LIST)
DEF_LIB_BUILTIN (BUILT_IN_REALLOC, "realloc", BT_FN_PTR_PTR_SIZE, ATTR_NOTHROW_LIST)
! DEF_GCC_BUILTIN (BUILT_IN_RETURN, "return", BT_FN_VOID_PTR, ATTR_NORETURN_NOTHROW_LIST)
DEF_GCC_BUILTIN (BUILT_IN_RETURN_ADDRESS, "return_address", BT_FN_PTR_UINT, ATTR_NULL)
DEF_GCC_BUILTIN (BUILT_IN_SAVEREGS, "saveregs", BT_FN_PTR_VAR, ATTR_NULL)
DEF_GCC_BUILTIN (BUILT_IN_SETJMP, "setjmp", BT_FN_INT_PTR, ATTR_NULL)
--- 691,697 ----
DEF_GCC_BUILTIN (BUILT_IN_POPCOUNTLL, "popcountll", BT_FN_INT_ULONGLONG, ATTR_CONST_NOTHROW_LIST)
DEF_GCC_BUILTIN (BUILT_IN_PREFETCH, "prefetch", BT_FN_VOID_CONST_PTR_VAR, ATTR_NOVOPS_LIST)
DEF_LIB_BUILTIN (BUILT_IN_REALLOC, "realloc", BT_FN_PTR_PTR_SIZE, ATTR_NOTHROW_LIST)
! DEF_GCC_BUILTIN (BUILT_IN_RETURN, "return", BT_FN_VOID_PTR, ATTR_NOTHROW_LIST)
DEF_GCC_BUILTIN (BUILT_IN_RETURN_ADDRESS, "return_address", BT_FN_PTR_UINT, ATTR_NULL)
DEF_GCC_BUILTIN (BUILT_IN_SAVEREGS, "saveregs", BT_FN_PTR_VAR, ATTR_NULL)
DEF_GCC_BUILTIN (BUILT_IN_SETJMP, "setjmp", BT_FN_INT_PTR, ATTR_NULL)
Index: ipa-pure-const.c
===================================================================
*** ipa-pure-const.c (revision 160051)
--- ipa-pure-const.c (working copy)
*************** check_call (funct_state local, gimple ca
*** 369,374 ****
--- 369,377 ----
graph. */
if (callee_t)
{
+ /* built_in_return is really just an return statemnt. */
+ if (gimple_call_builtin_p (call, BUILT_IN_RETURN))
+ return;
/* When bad things happen to bad functions, they cannot be const
or pure. */
if (setjmp_call_p (callee_t))
Index: gimple.c
===================================================================
*** gimple.c (revision 160037)
--- gimple.c (working copy)
*************** gimple_decl_printable_name (tree decl, i
*** 4732,4735 ****
--- 4732,4747 ----
return IDENTIFIER_POINTER (DECL_NAME (decl));
}
+ /* Return true when STMT is builtins call to CODE. */
+
+ bool
+ gimple_call_builtin_p (gimple stmt, enum built_in_function code)
+ {
+ tree fndecl;
+ return (is_gimple_call (stmt)
+ && (fndecl = gimple_call_fndecl (stmt)) != NULL
+ && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
+ && DECL_FUNCTION_CODE (fndecl) == code);
+ }
+
#include "gt-gimple.h"
Index: gimple.h
===================================================================
*** gimple.h (revision 160037)
--- gimple.h (working copy)
*************** extern bool walk_stmt_load_store_ops (gi
*** 961,966 ****
--- 961,967 ----
bool (*)(gimple, tree, void *),
bool (*)(gimple, tree, void *));
extern bool gimple_ior_addresses_taken (bitmap, gimple);
+ extern bool gimple_call_builtin_p (gimple, enum built_in_function);
/* In gimplify.c */
extern tree create_tmp_var_raw (tree, const char *);
Index: tree-cfg.c
===================================================================
*** tree-cfg.c (revision 160037)
--- tree-cfg.c (working copy)
*************** make_edges (void)
*** 568,575 ****
create abnormal edges to them. */
make_eh_edges (last);
/* Some calls are known not to return. */
! fallthru = !(gimple_call_flags (last) & ECF_NORETURN);
break;
case GIMPLE_ASSIGN:
--- 568,579 ----
create abnormal edges to them. */
make_eh_edges (last);
+ /* BUILTIN_RETURN is really a return statement. */
+ if (gimple_call_builtin_p (last, BUILT_IN_RETURN))
+ make_edge (bb, EXIT_BLOCK_PTR, 0), fallthru = false;
/* Some calls are known not to return. */
! else
! fallthru = !(gimple_call_flags (last) & ECF_NORETURN);
break;
case GIMPLE_ASSIGN:
*************** is_ctrl_altering_stmt (gimple t)
*** 2248,2253 ****
--- 2252,2261 ----
/* A call also alters control flow if it does not return. */
if (flags & ECF_NORETURN)
return true;
+
+ /* BUILT_IN_RETURN call is same as return statement. */
+ if (gimple_call_builtin_p (t, BUILT_IN_RETURN))
+ return true;
}
break;
*************** gimple_verify_flow_info (void)
*** 4422,4427 ****
--- 4430,4439 ----
}
break;
+ case GIMPLE_CALL:
+ if (!gimple_call_builtin_p (stmt, BUILT_IN_RETURN))
+ break;
+ /* ... fallthru ... */
case GIMPLE_RETURN:
if (!single_succ_p (bb)
|| (single_succ_edge (bb)->flags
*************** split_critical_edges (void)
*** 7036,7042 ****
gsi = gsi_last_bb (e->src);
if (!gsi_end_p (gsi)
&& stmt_ends_bb_p (gsi_stmt (gsi))
! && gimple_code (gsi_stmt (gsi)) != GIMPLE_RETURN)
split_edge (e);
}
}
--- 7048,7056 ----
gsi = gsi_last_bb (e->src);
if (!gsi_end_p (gsi)
&& stmt_ends_bb_p (gsi_stmt (gsi))
! && (gimple_code (gsi_stmt (gsi)) != GIMPLE_RETURN
! && !gimple_call_builtin_p (gsi_stmt (gsi),
! BUILT_IN_RETURN)))
split_edge (e);
}
}
*************** execute_warn_function_return (void)
*** 7134,7140 ****
FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
{
last = last_stmt (e->src);
! if (gimple_code (last) == GIMPLE_RETURN
&& (location = gimple_location (last)) != UNKNOWN_LOCATION)
break;
}
--- 7148,7155 ----
FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
{
last = last_stmt (e->src);
! if ((gimple_code (last) == GIMPLE_RETURN
! || gimple_call_builtin_p (last, BUILT_IN_RETURN))
&& (location = gimple_location (last)) != UNKNOWN_LOCATION)
break;
}