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/* Call stacks at program points.
Copyright (C) 2019-2022 Free Software Foundation, Inc.
Contributed by David Malcolm <>.
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
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
<>. */
namespace ana {
class supergraph;
class supernode;
class call_superedge;
class return_superedge;
/* A string of return_superedge pointers, representing a call stack
at a program point.
This is used to ensure that we generate interprocedurally valid paths
i.e. that we return to the same callsite that called us.
The class stores returning calls ( which may be represented by a
returning superedge ). We do so because this is what we need to compare
Instances of call_string are consolidated by the region_model_manager,
which effectively owns them: it owns the root/empty call_string, and each
call_string instance tracks its children, lazily creating them on demand,
so that the call_string instances form a tree-like hierarchy in memory. */
class call_string
/* A struct representing an element in the call_string.
Each element represents a path from m_callee to m_caller which represents
returning from function. */
struct element_t
element_t (const supernode *caller, const supernode *callee)
: m_caller (caller), m_callee (callee)
bool operator== (const element_t &other) const;
bool operator!= (const element_t &other) const;
/* Accessors */
function *get_caller_function () const;
function *get_callee_function () const;
const supernode *m_caller;
const supernode *m_callee;
void print (pretty_printer *pp) const;
json::value *to_json () const;
bool empty_p () const { return m_elements.is_empty (); }
const call_string *push_call (const supergraph &sg,
const call_superedge *sedge) const;
const call_string *push_call (const supernode *src,
const supernode *dest) const;
const call_string *get_parent () const { return m_parent; }
int calc_recursion_depth () const;
static int cmp (const call_string &a,
const call_string &b);
static int cmp_ptr_ptr (const void *, const void *);
/* Accessors */
const supernode *get_callee_node () const;
const supernode *get_caller_node () const;
unsigned length () const { return m_elements.length (); }
element_t operator[] (unsigned idx) const
return m_elements[idx];
const element_t &get_top_of_stack () const
gcc_assert (m_elements.length () > 0);
return m_elements[m_elements.length () - 1];
int count_occurrences_of_function (function *) const;
void validate () const;
struct hashmap_traits_t
typedef element_t key_type;
typedef const call_string *value_type;
static const bool maybe_mx = false;
static inline hashval_t hash (const key_type &k)
inchash::hash hstate;
hstate.add_ptr (k.m_caller);
hstate.add_ptr (k.m_callee);
return hstate.end ();
static inline bool equal_keys (const key_type &k1, const key_type &k2)
return k1 == k2;
template <typename T> static inline void remove (T &entry)
entry.m_key = element_t (NULL, NULL);
static const bool empty_zero_p = true;
template <typename T> static inline bool is_empty (const T &entry)
return entry.m_key.m_caller == NULL;
template <typename T> static inline bool is_deleted (const T &entry)
return entry.m_key.m_caller == reinterpret_cast<const supernode *> (1);
template <typename T> static inline void mark_empty (T &entry)
entry.m_key = element_t (NULL, NULL);
entry.m_value = NULL;
template <typename T> static inline void mark_deleted (T &entry)
entry.m_key.m_caller = reinterpret_cast<const supernode *> (1);
friend class region_model_manager;
call_string ();
call_string (const call_string &parent, const element_t &to_push);
~call_string ();
void recursive_log (logger *logger) const;
const call_string *m_parent;
auto_vec<element_t> m_elements;
mutable hash_map<element_t, const call_string *, hashmap_traits_t> m_children;
} // namespace ana