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Diffstat (limited to 'gcc/gimple-warn-recursion.c')
| -rw-r--r-- | gcc/gimple-warn-recursion.c | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/gcc/gimple-warn-recursion.c b/gcc/gimple-warn-recursion.c deleted file mode 100644 index 3a50d5e..0000000 --- a/gcc/gimple-warn-recursion.c +++ /dev/null @@ -1,202 +0,0 @@ -/* -Winfinite-recursion support. - Copyright (C) 2021-2022 Free Software Foundation, Inc. - Contributed by Martin Sebor <msebor@redhat.com> - - This file is part of GCC. - - GCC is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3, or (at your option) - any later version. - - GCC is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with GCC; see the file COPYING3. If not see - <http://www.gnu.org/licenses/>. */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "backend.h" -#include "tree.h" -#include "gimple.h" -#include "tree-pass.h" -#include "ssa.h" -#include "diagnostic-core.h" -// #include "tree-dfa.h" -#include "attribs.h" -#include "gimple-iterator.h" - -namespace { - -const pass_data warn_recursion_data = -{ - GIMPLE_PASS, /* type */ - "*infinite-recursion", /* name */ - OPTGROUP_NONE, /* optinfo_flags */ - TV_NONE, /* tv_id */ - PROP_ssa, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - 0, /* todo_flags_finish */ -}; - -class pass_warn_recursion : public gimple_opt_pass -{ -public: - pass_warn_recursion (gcc::context *); - -private: - virtual bool gate (function *) { return warn_infinite_recursion; } - - virtual unsigned int execute (function *); - - bool find_function_exit (basic_block); - - /* Recursive calls found in M_FUNC. */ - vec<gimple *> *m_calls; - /* Basic blocks already visited in the current function. */ - bitmap m_visited; - /* The current function. */ - function *m_func; - /* The current function code if it's (also) a built-in. */ - built_in_function m_built_in; - /* True if M_FUNC is a noreturn function. */ - bool noreturn_p; -}; - -/* Initialize the pass and its members. */ - -pass_warn_recursion::pass_warn_recursion (gcc::context *ctxt) - : gimple_opt_pass (warn_recursion_data, ctxt), - m_calls (), m_visited (), m_func (), m_built_in (), noreturn_p () -{ -} - -/* Return true if there is path from BB to M_FUNC exit point along which - there is no (recursive) call to M_FUNC. */ - -bool -pass_warn_recursion::find_function_exit (basic_block bb) -{ - if (!bitmap_set_bit (m_visited, bb->index)) - return false; - - if (bb == EXIT_BLOCK_PTR_FOR_FN (m_func)) - return true; - - /* Iterate over statements in BB, looking for a call to FNDECL. */ - for (auto si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next_nondebug (&si)) - { - gimple *stmt = gsi_stmt (si); - if (!is_gimple_call (stmt)) - continue; - - if (gimple_call_builtin_p (stmt, BUILT_IN_LONGJMP)) - /* A longjmp breaks infinite recursion. */ - return true; - - if (tree fndecl = gimple_call_fndecl (stmt)) - { - /* A throw statement breaks infinite recursion. */ - tree id = DECL_NAME (fndecl); - const char *name = IDENTIFIER_POINTER (id); - if (startswith (name, "__cxa_throw")) - return true; - /* As does a call to POSIX siglongjmp. */ - if (!strcmp (name, "siglongjmp")) - return true; - - if (m_built_in && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL) - && m_built_in == DECL_FUNCTION_CODE (fndecl)) - { - /* The call is being made from the definition of a built-in - (e.g., in a replacement of one) to itself. */ - m_calls->safe_push (stmt); - return false; - } - } - - if (noreturn_p) - { - /* A noreturn call breaks infinite recursion. */ - int flags = gimple_call_flags (stmt); - if (flags & ECF_NORETURN) - return true; - } - - tree callee = gimple_call_fndecl (stmt); - if (!callee || m_func->decl != callee) - continue; - - /* Add the recursive call to the vector and return false. */ - m_calls->safe_push (stmt); - return false; - } - - /* If no call to FNDECL has been found search all BB's successors. */ - edge e; - edge_iterator ei; - FOR_EACH_EDGE (e, ei, bb->succs) - if (find_function_exit (e->dest)) - return true; - - return false; -} - - -/* Search FUNC for unconditionally infinitely recursive calls to self - and issue a warning if it is such a function. */ - -unsigned int -pass_warn_recursion::execute (function *func) -{ - auto_bitmap visited; - auto_vec<gimple *> calls; - - m_visited = visited; - m_calls = &calls; - m_func = func; - - /* Avoid diagnosing an apparently infinitely recursive function that - doesn't return where the infinite recursion might be avoided by - a call to another noreturn function. */ - noreturn_p = lookup_attribute ("noreturn", DECL_ATTRIBUTES (m_func->decl)); - - if (fndecl_built_in_p (m_func->decl, BUILT_IN_NORMAL)) - m_built_in = DECL_FUNCTION_CODE (m_func->decl); - else - m_built_in = BUILT_IN_NONE; - - basic_block entry_bb = ENTRY_BLOCK_PTR_FOR_FN (func); - - if (find_function_exit (entry_bb) || m_calls->length () == 0) - return 0; - - if (warning_at (DECL_SOURCE_LOCATION (func->decl), - OPT_Winfinite_recursion, - "infinite recursion detected")) - for (auto stmt: *m_calls) - { - location_t loc = gimple_location (stmt); - if (loc == UNKNOWN_LOCATION) - continue; - - inform (loc, "recursive call"); - } - - return 0; -} - -} // namespace - -gimple_opt_pass * -make_pass_warn_recursion (gcc::context *ctxt) -{ - return new pass_warn_recursion (ctxt); -} |