From 25f0609b21fe75b1e4b4a20ddee8c8f936318b81 Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Wed, 3 Aug 2016 19:05:45 +0000 Subject: [PATCH] re PR middle-end/71876 (longjmp is miscompiled with -ffreestanding) 2016-08-03 Bernd Edlinger PR middle-end/71876 * calls.c (special_function_p): Remove special handling of "setjmp_syscall", "qsetjmp", "longjmp", "siglongjmp" and the prefix "__x". Recognize "savectx", "vfork" and "getcontext" only without prefix. Remove potentially unsafe ECF_LEAF and ECF_NORETURN. From-SVN: r239092 --- gcc/ChangeLog | 8 ++++++++ gcc/calls.c | 51 ++++++++++++++------------------------------------- 2 files changed, 22 insertions(+), 37 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8dcd430a6c7..fd09ec1c96c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2016-08-03 Bernd Edlinger + + PR middle-end/71876 + * calls.c (special_function_p): Remove special handling of + "setjmp_syscall", "qsetjmp", "longjmp", "siglongjmp" and the + prefix "__x". Recognize "savectx", "vfork" and "getcontext" only + without prefix. Remove potentially unsafe ECF_LEAF and ECF_NORETURN. + 2016-08-03 Vladimir Makarov PR middle-end/72778 diff --git a/gcc/calls.c b/gcc/calls.c index c04d00f7f44..949a92e3fe3 100644 --- a/gcc/calls.c +++ b/gcc/calls.c @@ -468,15 +468,13 @@ emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNU anti_adjust_stack (GEN_INT (n_popped)); } -/* Determine if the function identified by NAME and FNDECL is one with - special properties we wish to know about. +/* Determine if the function identified by FNDECL is one with + special properties we wish to know about. Modify FLAGS accordingly. For example, if the function might return more than one time (setjmp), then - set RETURNS_TWICE to a nonzero value. + set ECF_RETURNS_TWICE. - Similarly set NORETURN if the function is in the longjmp family. - - Set MAY_BE_ALLOCA for any memory allocation function that might allocate + Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate space from the stack such as alloca. */ static int @@ -491,7 +489,7 @@ special_function_p (const_tree fndecl, int flags) name_decl = DECL_NAME (cgraph_node::get (fndecl)->orig_decl); if (fndecl && name_decl - && IDENTIFIER_LENGTH (name_decl) <= 17 + && IDENTIFIER_LENGTH (name_decl) <= 11 /* Exclude functions not at the file scope, or not `extern', since they are not the magic functions we would otherwise think they are. @@ -514,43 +512,22 @@ special_function_p (const_tree fndecl, int flags) && ! strcmp (name, "alloca")) flags |= ECF_MAY_BE_ALLOCA; - /* Disregard prefix _, __ or __x. */ + /* Disregard prefix _ or __. */ if (name[0] == '_') { - if (name[1] == '_' && name[2] == 'x') - tname += 3; - else if (name[1] == '_') + if (name[1] == '_') tname += 2; else tname += 1; } - if (tname[0] == 's') - { - if ((tname[1] == 'e' - && (! strcmp (tname, "setjmp") - || ! strcmp (tname, "setjmp_syscall"))) - || (tname[1] == 'i' - && ! strcmp (tname, "sigsetjmp")) - || (tname[1] == 'a' - && ! strcmp (tname, "savectx"))) - flags |= ECF_RETURNS_TWICE | ECF_LEAF; - - if (tname[1] == 'i' - && ! strcmp (tname, "siglongjmp")) - flags |= ECF_NORETURN; - } - else if ((tname[0] == 'q' && tname[1] == 's' - && ! strcmp (tname, "qsetjmp")) - || (tname[0] == 'v' && tname[1] == 'f' - && ! strcmp (tname, "vfork")) - || (tname[0] == 'g' && tname[1] == 'e' - && !strcmp (tname, "getcontext"))) - flags |= ECF_RETURNS_TWICE | ECF_LEAF; - - else if (tname[0] == 'l' && tname[1] == 'o' - && ! strcmp (tname, "longjmp")) - flags |= ECF_NORETURN; + /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */ + if (! strcmp (tname, "setjmp") + || ! strcmp (tname, "sigsetjmp") + || ! strcmp (name, "savectx") + || ! strcmp (name, "vfork") + || ! strcmp (name, "getcontext")) + flags |= ECF_RETURNS_TWICE; } if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) -- 2.30.2