/gcc/analyzer/analyzer.cc
C++ | 449 lines | 279 code | 72 blank | 98 comment | 63 complexity | 86097836c7e35fcf638d49cfab39a89c MD5 | raw file
- /* Utility functions for the analyzer.
- Copyright (C) 2019-2022 Free Software Foundation, Inc.
- Contributed by David Malcolm <dmalcolm@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 "tree.h"
- #include "function.h"
- #include "basic-block.h"
- #include "gimple.h"
- #include "diagnostic.h"
- #include "intl.h"
- #include "function.h"
- #include "analyzer/analyzer.h"
- #if ENABLE_ANALYZER
- namespace ana {
- /* Workaround for missing location information for some stmts,
- which ultimately should be solved by fixing the frontends
- to provide the locations (TODO). */
- location_t
- get_stmt_location (const gimple *stmt, function *fun)
- {
- if (get_pure_location (stmt->location) == UNKNOWN_LOCATION)
- {
- /* Workaround for missing location information for clobber
- stmts, which seem to lack location information in the C frontend
- at least. Created by gimplify_bind_expr, which uses the
- BLOCK_SOURCE_END_LOCATION (BIND_EXPR_BLOCK (bind_expr))
- but this is never set up when the block is created in
- c_end_compound_stmt's pop_scope.
- TODO: fix this missing location information.
- For now, as a hackish workaround, use the location of the end of
- the function. */
- if (gimple_clobber_p (stmt) && fun)
- return fun->function_end_locus;
- }
- return stmt->location;
- }
- static tree
- fixup_tree_for_diagnostic_1 (tree expr, hash_set<tree> *visited);
- /* Attemp to generate a tree for the LHS of ASSIGN_STMT.
- VISITED must be non-NULL; it is used to ensure termination. */
- static tree
- get_diagnostic_tree_for_gassign_1 (const gassign *assign_stmt,
- hash_set<tree> *visited)
- {
- enum tree_code code = gimple_assign_rhs_code (assign_stmt);
- /* Reverse the effect of extract_ops_from_tree during
- gimplification. */
- switch (get_gimple_rhs_class (code))
- {
- default:
- case GIMPLE_INVALID_RHS:
- gcc_unreachable ();
- case GIMPLE_TERNARY_RHS:
- case GIMPLE_BINARY_RHS:
- case GIMPLE_UNARY_RHS:
- {
- tree t = make_node (code);
- TREE_TYPE (t) = TREE_TYPE (gimple_assign_lhs (assign_stmt));
- unsigned num_rhs_args = gimple_num_ops (assign_stmt) - 1;
- for (unsigned i = 0; i < num_rhs_args; i++)
- {
- tree op = gimple_op (assign_stmt, i + 1);
- if (op)
- {
- op = fixup_tree_for_diagnostic_1 (op, visited);
- if (op == NULL_TREE)
- return NULL_TREE;
- }
- TREE_OPERAND (t, i) = op;
- }
- return t;
- }
- case GIMPLE_SINGLE_RHS:
- {
- tree op = gimple_op (assign_stmt, 1);
- op = fixup_tree_for_diagnostic_1 (op, visited);
- return op;
- }
- }
- }
- /* Subroutine of fixup_tree_for_diagnostic_1, called on SSA names.
- Attempt to reconstruct a tree expression for SSA_NAME
- based on its def-stmt.
- SSA_NAME must be non-NULL.
- VISITED must be non-NULL; it is used to ensure termination.
- Return NULL_TREE if there is a problem. */
- static tree
- maybe_reconstruct_from_def_stmt (tree ssa_name,
- hash_set<tree> *visited)
- {
- /* Ensure termination. */
- if (visited->contains (ssa_name))
- return NULL_TREE;
- visited->add (ssa_name);
- gimple *def_stmt = SSA_NAME_DEF_STMT (ssa_name);
- switch (gimple_code (def_stmt))
- {
- default:
- gcc_unreachable ();
- case GIMPLE_ASM:
- case GIMPLE_NOP:
- case GIMPLE_PHI:
- /* Can't handle these. */
- return NULL_TREE;
- case GIMPLE_ASSIGN:
- return get_diagnostic_tree_for_gassign_1
- (as_a <const gassign *> (def_stmt), visited);
- case GIMPLE_CALL:
- {
- gcall *call_stmt = as_a <gcall *> (def_stmt);
- tree return_type = gimple_call_return_type (call_stmt);
- tree fn = fixup_tree_for_diagnostic_1 (gimple_call_fn (call_stmt),
- visited);
- if (fn == NULL_TREE)
- return NULL_TREE;
- unsigned num_args = gimple_call_num_args (call_stmt);
- auto_vec<tree> args (num_args);
- for (unsigned i = 0; i < num_args; i++)
- {
- tree arg = gimple_call_arg (call_stmt, i);
- arg = fixup_tree_for_diagnostic_1 (arg, visited);
- if (arg == NULL_TREE)
- return NULL_TREE;
- args.quick_push (arg);
- }
- gcc_assert (fn);
- return build_call_array_loc (gimple_location (call_stmt),
- return_type, fn,
- num_args, args.address ());
- }
- break;
- }
- }
- /* Subroutine of fixup_tree_for_diagnostic: attempt to fixup EXPR,
- which can be NULL.
- VISITED must be non-NULL; it is used to ensure termination. */
- static tree
- fixup_tree_for_diagnostic_1 (tree expr, hash_set<tree> *visited)
- {
- if (expr
- && TREE_CODE (expr) == SSA_NAME
- && (SSA_NAME_VAR (expr) == NULL_TREE
- || DECL_ARTIFICIAL (SSA_NAME_VAR (expr))))
- {
- if (tree var = SSA_NAME_VAR (expr))
- if (VAR_P (var) && DECL_HAS_DEBUG_EXPR_P (var))
- return DECL_DEBUG_EXPR (var);
- if (tree expr2 = maybe_reconstruct_from_def_stmt (expr, visited))
- return expr2;
- }
- return expr;
- }
- /* We don't want to print '<unknown>' in our diagnostics (PR analyzer/99771),
- but sometimes we generate diagnostics involving an ssa name for a
- temporary.
- Work around this by attempting to reconstruct a tree expression for
- such temporaries based on their def-stmts.
- Otherwise return EXPR.
- EXPR can be NULL. */
- tree
- fixup_tree_for_diagnostic (tree expr)
- {
- hash_set<tree> visited;
- return fixup_tree_for_diagnostic_1 (expr, &visited);
- }
- /* Attempt to generate a tree for the LHS of ASSIGN_STMT. */
- tree
- get_diagnostic_tree_for_gassign (const gassign *assign_stmt)
- {
- hash_set<tree> visited;
- return get_diagnostic_tree_for_gassign_1 (assign_stmt, &visited);
- }
- } // namespace ana
- /* Helper function for checkers. Is the CALL to the given function name,
- and with the given number of arguments?
- This doesn't resolve function pointers via the region model;
- is_named_call_p should be used instead, using a fndecl from
- get_fndecl_for_call; this function should only be used for special cases
- where it's not practical to get at the region model, or for special
- analyzer functions such as __analyzer_dump. */
- bool
- is_special_named_call_p (const gcall *call, const char *funcname,
- unsigned int num_args)
- {
- gcc_assert (funcname);
- tree fndecl = gimple_call_fndecl (call);
- if (!fndecl)
- return false;
- return is_named_call_p (fndecl, funcname, call, num_args);
- }
- /* Helper function for checkers. Is FNDECL an extern fndecl at file scope
- that has the given FUNCNAME?
- Compare with special_function_p in calls.cc. */
- bool
- is_named_call_p (const_tree fndecl, const char *funcname)
- {
- gcc_assert (fndecl);
- gcc_assert (funcname);
- if (!maybe_special_function_p (fndecl))
- return false;
- tree identifier = DECL_NAME (fndecl);
- const char *name = IDENTIFIER_POINTER (identifier);
- const char *tname = name;
- /* Potentially disregard prefix _ or __ in FNDECL's name, but not if
- FUNCNAME itself has leading underscores (e.g. when looking for
- "__analyzer_eval"). */
- if (funcname[0] != '_' && name[0] == '_')
- {
- if (name[1] == '_')
- tname += 2;
- else
- tname += 1;
- }
- return 0 == strcmp (tname, funcname);
- }
- /* Return true if FNDECL is within the namespace "std".
- Compare with cp/typeck.cc: decl_in_std_namespace_p, but this doesn't
- rely on being the C++ FE (or handle inline namespaces inside of std). */
- static inline bool
- is_std_function_p (const_tree fndecl)
- {
- tree name_decl = DECL_NAME (fndecl);
- if (!name_decl)
- return false;
- if (!DECL_CONTEXT (fndecl))
- return false;
- if (TREE_CODE (DECL_CONTEXT (fndecl)) != NAMESPACE_DECL)
- return false;
- tree ns = DECL_CONTEXT (fndecl);
- if (!(DECL_CONTEXT (ns) == NULL_TREE
- || TREE_CODE (DECL_CONTEXT (ns)) == TRANSLATION_UNIT_DECL))
- return false;
- if (!DECL_NAME (ns))
- return false;
- return id_equal ("std", DECL_NAME (ns));
- }
- /* Like is_named_call_p, but look for std::FUNCNAME. */
- bool
- is_std_named_call_p (const_tree fndecl, const char *funcname)
- {
- gcc_assert (fndecl);
- gcc_assert (funcname);
- if (!is_std_function_p (fndecl))
- return false;
- tree identifier = DECL_NAME (fndecl);
- const char *name = IDENTIFIER_POINTER (identifier);
- const char *tname = name;
- /* Don't disregard prefix _ or __ in FNDECL's name. */
- return 0 == strcmp (tname, funcname);
- }
- /* Helper function for checkers. Is FNDECL an extern fndecl at file scope
- that has the given FUNCNAME, and does CALL have the given number of
- arguments? */
- bool
- is_named_call_p (const_tree fndecl, const char *funcname,
- const gcall *call, unsigned int num_args)
- {
- gcc_assert (fndecl);
- gcc_assert (funcname);
- if (!is_named_call_p (fndecl, funcname))
- return false;
- if (gimple_call_num_args (call) != num_args)
- return false;
- return true;
- }
- /* Like is_named_call_p, but check for std::FUNCNAME. */
- bool
- is_std_named_call_p (const_tree fndecl, const char *funcname,
- const gcall *call, unsigned int num_args)
- {
- gcc_assert (fndecl);
- gcc_assert (funcname);
- if (!is_std_named_call_p (fndecl, funcname))
- return false;
- if (gimple_call_num_args (call) != num_args)
- return false;
- return true;
- }
- /* Return true if stmt is a setjmp or sigsetjmp call. */
- bool
- is_setjmp_call_p (const gcall *call)
- {
- if (is_special_named_call_p (call, "setjmp", 1)
- || is_special_named_call_p (call, "sigsetjmp", 2))
- /* region_model::on_setjmp requires a pointer. */
- if (POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0))))
- return true;
- return false;
- }
- /* Return true if stmt is a longjmp or siglongjmp call. */
- bool
- is_longjmp_call_p (const gcall *call)
- {
- if (is_special_named_call_p (call, "longjmp", 2)
- || is_special_named_call_p (call, "siglongjmp", 2))
- /* exploded_node::on_longjmp requires a pointer for the initial
- argument. */
- if (POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0))))
- return true;
- return false;
- }
- /* For a CALL that matched is_special_named_call_p or is_named_call_p for
- some name, return a name for the called function suitable for use in
- diagnostics (stripping the leading underscores). */
- const char *
- get_user_facing_name (const gcall *call)
- {
- tree fndecl = gimple_call_fndecl (call);
- gcc_assert (fndecl);
- tree identifier = DECL_NAME (fndecl);
- gcc_assert (identifier);
- const char *name = IDENTIFIER_POINTER (identifier);
- /* Strip prefix _ or __ in FNDECL's name. */
- if (name[0] == '_')
- {
- if (name[1] == '_')
- return name + 2;
- else
- return name + 1;
- }
- return name;
- }
- /* Generate a label_text instance by formatting FMT, using a
- temporary clone of the global_dc's printer (thus using its
- formatting callbacks).
- Colorize if the global_dc supports colorization and CAN_COLORIZE is
- true. */
- label_text
- make_label_text (bool can_colorize, const char *fmt, ...)
- {
- pretty_printer *pp = global_dc->printer->clone ();
- pp_clear_output_area (pp);
- if (!can_colorize)
- pp_show_color (pp) = false;
- text_info ti;
- rich_location rich_loc (line_table, UNKNOWN_LOCATION);
- va_list ap;
- va_start (ap, fmt);
- ti.format_spec = _(fmt);
- ti.args_ptr = ≈
- ti.err_no = 0;
- ti.x_data = NULL;
- ti.m_richloc = &rich_loc;
- pp_format (pp, &ti);
- pp_output_formatted_text (pp);
- va_end (ap);
- label_text result = label_text::take (xstrdup (pp_formatted_text (pp)));
- delete pp;
- return result;
- }
- #endif /* #if ENABLE_ANALYZER */