#include "config.h"#include "system.h"#include "coretypes.h"#include "backend.h"#include "rtl.h"#include "tree.h"#include "gimple.h"#include "alloc-pool.h"#include "tree-pass.h"#include "ssa.h"#include "cgraph.h"#include "gimple-pretty-print.h"#include "gimple-ssa-warn-access.h"#include "gimple-ssa-warn-restrict.h"#include "fold-const.h"#include "stor-layout.h"#include "gimple-iterator.h"#include "gimple-fold.h"#include "tree-eh.h"#include "gimplify.h"#include "gimplify-me.h"#include "expr.h"#include "tree-cfg.h"#include "tree-dfa.h"#include "domwalk.h"#include "tree-ssa-alias.h"#include "tree-ssa-propagate.h"#include "tree-ssa-strlen.h"#include "tree-hash-traits.h"#include "builtins.h"#include "pointer-query.h"#include "target.h"#include "diagnostic-core.h"#include "diagnostic.h"#include "intl.h"#include "attribs.h"#include "calls.h"#include "cfgloop.h"#include "tree-ssa-loop.h"#include "tree-scalar-evolution.h"#include "vr-values.h"#include "gimple-range.h"#include "tree-ssa.h"
Data Structures | |
| struct | strinfo |
| struct | stridxlist |
| struct | decl_stridxlist_map |
| struct | laststmt_struct |
| class | strlen_pass |
Typedefs | |
| typedef hash_map< tree_decl_hash, stridxlist > | decl_to_stridxlist_htab_t |
| typedef std::pair< int, location_t > | stridx_strlenloc |
Variables | |
| static vec< int > | ssa_ver_to_stridx |
| static int | max_stridx |
| static bool | strlen_optimize |
| static object_allocator< strinfo > | strinfo_pool ("strinfo pool") |
| static vec< strinfo *, va_heap, vl_embed > * | stridx_to_strinfo |
| static decl_to_stridxlist_htab_t * | decl_to_stridxlist_htab |
| static hash_map< tree, stridx_strlenloc > * | strlen_to_stridx |
| static struct obstack | stridx_obstack |
| struct laststmt_struct | laststmt |
Typedef Documentation
◆ decl_to_stridxlist_htab_t
Hash table for mapping decls to a chained list of offset -> idx mappings.
◆ stridx_strlenloc
| typedef std::pair<int, location_t> stridx_strlenloc |
Hash table mapping strlen (or strnlen with constant bound and return smaller than bound) calls to stridx instances describing the calls' arguments. Non-null only when warn_stringop_truncation is non-zero.
Function Documentation
◆ addr_stridxptr()
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static |
Attempt to create a string index for exp, ADDR_EXPR's operand. Return a pointer to the location where the string index can be stored (if 0) or is stored, or NULL if this can't be tracked.
References DECL_P, decl_to_stridxlist_htab, exp(), gcc_obstack_init, get_addr_base_and_unit_offset(), hash_map< KeyId, Value, Traits >::get_or_insert(), i, stridxlist::idx, poly_int< N, C >::is_constant(), stridxlist::next, NULL, NULL_TREE, stridxlist::offset, and stridx_obstack.
Referenced by find_equal_ptrs(), get_stridx_plus_constant(), new_addr_stridx(), and new_stridx().
◆ adjust_related_strinfos()
For strinfo ORIGSI whose length has been just updated, adjust other related strinfos so that they match the new ORIGSI. This involves: - adding ADJ to the nonzero_chars fields - copying full_string_p from the new ORIGSI.
References fold_build2_loc(), fold_convert_loc(), strinfo::full_string_p, gcc_assert, get_next_strinfo(), NULL, NULL_TREE, si, TREE_TYPE, unshare_strinfo(), and verify_related_strinfos().
Referenced by strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_strlen(), and strlen_pass::handle_store().
◆ compare_nonzero_chars() [1/2]
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static |
Same as above but suitable also for strings with non-constant lengths. Uses RVALS to determine length range.
References wi::cmp(), compare_tree_int(), irange::lower_bound(), range_query::range_of_expr(), si, irange::singleton_p(), TREE_CODE, irange::type(), TYPE_PRECISION, TYPE_SIGN, wi::uhwi(), vrange::undefined_p(), and vrange::varying_p().
◆ compare_nonzero_chars() [2/2]
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static |
Return:
* +1 if SI is known to start with more than OFF nonzero characters.
* 0 if SI is known to start with exactly OFF nonzero characters.
* -1 if SI either does not start with OFF nonzero characters
or the relationship between the number of leading nonzero
characters in SI and OFF is unknown.
References compare_tree_int(), si, and TREE_CODE.
Referenced by get_addr_stridx(), get_stridx(), get_stridx_plus_constant(), and strlen_pass::handle_store().
◆ do_invalidate()
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static |
Recursively call maybe_invalidate on stmts that might be executed in between dombb and current bb and that contain a vdef. Stop when *count stmts are inspected, or if the whole strinfo vector has been invalidated.
References bitmap_set_bit, CDI_DOMINATORS, count, do_invalidate(), dominated_by_p(), gimple_bb(), gimple_phi_arg_def(), gimple_phi_num_args(), gimple_vuse(), i, basic_block_def::index, maybe_invalidate(), NULL, SSA_NAME_DEF_STMT, laststmt_struct::stmt, and visited.
Referenced by strlen_pass::before_dom_children(), and do_invalidate().
◆ dump_strlen_info()
| DEBUG_FUNCTION void dump_strlen_info | ( | FILE * | fp, |
| gimple * | stmt, | ||
| range_query * | rvals ) |
Dump strlen data to FP for statement STMT. When non-null, RVALS points to the valuation engine used to calculate ranges, and is used to dump strlen range for non-constant results.
References hash_map< KeyId, Value, Traits >::begin(), cfun, decl_to_stridxlist_htab, vrange::dump(), hash_map< KeyId, Value, Traits >::end(), fputc(), get_next_strinfo(), get_range_query(), i, stridxlist::idx, laststmt, laststmt_struct::len, max_stridx, stridxlist::next, stridxlist::offset, print_generic_expr(), print_gimple_expr(), path_range_query::range_of_expr(), range_query::range_of_expr(), si, ssa_ver_to_stridx, laststmt_struct::stmt, laststmt_struct::stridx, stridx_to_strinfo, TDF_LINENO, and TREE_CODE.
◆ find_equal_ptrs()
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static |
Find if there are other SSA_NAME pointers equal to PTR for which we don't track their string lengths yet. If so, use IDX for them.
References addr_stridxptr(), CASE_CONVERT, gimple_assign_rhs1(), gimple_assign_rhs_code(), stridxlist::idx, is_gimple_assign(), NULL, num_ssa_names, POINTER_TYPE_P, SSA_NAME_DEF_STMT, SSA_NAME_VERSION, ssa_ver_to_stridx, TREE_CODE, TREE_OPERAND, and TREE_TYPE.
Referenced by strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_memset(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), and strlen_pass::handle_builtin_strlen().
◆ fold_strstr_to_strncmp()
Try to fold strstr (s, t) eq/ne s to strncmp (s, t, strlen (t)) eq/ne 0.
References as_a(), build_int_cst(), build_zero_cst(), builtin_decl_explicit(), g, get_stridx(), get_strinfo(), get_string_length(), gimple_assign_rhs1(), gimple_assign_rhs_code(), gimple_assign_set_rhs1(), gimple_assign_set_rhs2(), gimple_build_assign(), gimple_build_call(), gimple_call_arg(), gimple_call_builtin_p(), gimple_call_set_lhs(), gimple_cond_set_lhs(), gimple_cond_set_rhs(), gimple_set_vuse(), gimple_vuse(), gsi_for_stmt(), gsi_insert_before(), gsi_remove(), GSI_SAME_STMT, has_single_use(), integer_type_node, is_gimple_assign(), is_gimple_val(), make_ssa_name(), NULL, NULL_TREE, si, size_type_node, SSA_NAME_DEF_STMT, laststmt_struct::stmt, TREE_CODE, TREE_OPERAND, TREE_TYPE, and update_stmt().
Referenced by strlen_pass::check_and_optimize_stmt(), and strlen_pass::handle_integral_assign().
◆ free_strinfo()
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inlinestatic |
Decrease strinfo refcount and free it if not referenced anymore.
References si, and strinfo_pool.
Referenced by strlen_pass::after_dom_children(), strlen_pass::before_dom_children(), maybe_invalidate(), and unshare_strinfo().
◆ get_addr_stridx()
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static |
Helper function for get_stridx. Return the strinfo index of the address of EXP, which is available in PTR if nonnull. If OFFSET_OUT, it is OK to return the index for some X <= &EXP and store &EXP - X in *OFFSET_OUT. When RVALS is nonnull uses it to determine range information.
References compare_nonzero_chars(), DECL_P, decl_to_stridxlist_htab, exp(), hash_map< KeyId, Value, Traits >::get(), get_addr_base_and_unit_offset(), get_stridx_plus_constant(), get_strinfo(), stridxlist::idx, poly_int< N, C >::is_constant(), last, stridxlist::next, NULL, stridxlist::offset, and si.
Referenced by get_stridx(), strlen_pass::handle_integral_assign(), and strlen_pass::handle_store().
◆ get_maxbound()
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static |
Return the maximum possible length of the string PTR that's less than MAXLEN given the size of the object of subobject it points to at the given STMT. MAXLEN is the maximum length of the string determined so far. Return null when no such maximum can be determined.
References DECL_SIZE_UNIT, field_at_offset(), wi::fits_shwi_p(), pointer_query::get_ref(), NULL_TREE, access_ref::offrng, RECORD_OR_UNION_TYPE_P, access_ref::ref, access_ref::size_remaining(), size_type_node, wi::to_offset(), TREE_TYPE, and wide_int_to_tree().
Referenced by get_range_strlen_dynamic().
◆ get_next_strinfo()
Get the next strinfo in the chain after SI, or null if none.
References strinfo::first, get_strinfo(), NULL, strinfo::prev, and si.
Referenced by strlen_pass::adjust_last_stmt(), adjust_related_strinfos(), dump_strlen_info(), get_stridx_plus_constant(), get_string_length(), and zero_length_string().
◆ get_range()
| tree get_range | ( | tree | val, |
| gimple * | stmt, | ||
| wide_int | minmax[2], | ||
| range_query * | rvals ) |
Sets MINMAX to either the constant value or the range VAL is in and returns either the constant value or VAL on success or null when the range couldn't be determined. Uses RVALS or CFUN for range info, whichever is nonnull.
References cfun, get_legacy_range(), get_range_query(), NULL_TREE, range_query::range_of_expr(), wi::to_wide(), TREE_TYPE, and VR_RANGE.
Referenced by get_offset_range(), get_stridx(), known_lower(), and strlen_pass::maybe_warn_overflow().
◆ get_range_strlen_dynamic() [1/2]
| void get_range_strlen_dynamic | ( | tree | src, |
| gimple * | stmt, | ||
| c_strlen_data * | pdata, | ||
| pointer_query & | ptr_qry ) |
Analogous to get_range_strlen but for dynamically created strings, i.e., those created by calls to strcpy as opposed to just string constants. Try to obtain the range of the lengths of the string(s) referenced by SRC, or the size of the largest array SRC refers to if the range of lengths cannot be determined, and store all in *PDATA. RVALS points to the valuation engine used to calculate ranges.
References build_all_ones_cst(), get_range_strlen_dynamic(), c_strlen_data::maxbound, c_strlen_data::maxlen, c_strlen_data::minlen, size_type_node, ssize_int, and visited.
◆ get_range_strlen_dynamic() [2/2]
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static |
Attempt to determine the length of the string SRC. On success, store the length in *PDATA and return true. Otherwise, return false. VISITED is a bitmap of visited PHI nodes. RVALS points to the valuation engine used to calculate ranges. PSSA_DEF_MAX to an SSA_NAME assignment limit used to prevent runaway recursion.
References build_all_ones_cst(), build_int_cst(), build_zero_cst(), DECL_P, dyn_cast(), fold_build2, get_addr_base_and_unit_offset(), get_maxbound(), get_range_strlen(), get_range_strlen_phi(), get_stridx(), get_strinfo(), get_string_length(), stridxlist::idx, poly_int< N, C >::is_constant(), irange::lower_bound(), c_strlen_data::maxbound, c_strlen_data::maxlen, c_strlen_data::minlen, range_query::range_of_expr(), pointer_query::rvals, si, SIGNED, size_type_node, SSA_NAME_DEF_STMT, TREE_CODE, tree_int_cst_lt(), TREE_OPERAND, TREE_TYPE, irange::type(), TYPE_SIZE_UNIT, vrange::undefined_p(), irange::upper_bound(), vrange::varying_p(), visited, and wide_int_to_tree().
Referenced by strlen_pass::get_len_or_size(), get_range_strlen_dynamic(), and get_range_strlen_phi().
◆ get_range_strlen_phi()
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static |
Helper of get_range_strlen_dynamic(). See below.
References bitmap_set_bit, build_all_ones_cst(), c_strlen_data::decl, get_range_strlen_dynamic(), gimple_phi_arg_def(), gimple_phi_num_args(), gimple_phi_result(), i, integer_all_onesp(), integer_zerop(), c_strlen_data::maxbound, c_strlen_data::maxlen, c_strlen_data::minlen, size_type_node, SSA_NAME_VERSION, TREE_CODE, tree_int_cst_lt(), and visited.
Referenced by get_range_strlen_dynamic().
◆ get_stridx()
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static |
Returns string index for EXP. When EXP is an SSA_NAME that refers to a known strinfo with an offset and OFFRNG is non-null, sets both elements of the OFFRNG array to the range of the offset and returns the index of the known strinfo. In this case the result must not be used in for functions that modify the string. When nonnull, uses RVALS to determine range information.
References c_getstr(), compare_nonzero_chars(), exp(), fold_build2, fold_convert, get_addr_stridx(), get_range(), get_stridx_plus_constant(), get_strinfo(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), i, stridxlist::idx, integer_onep(), integer_zero_node, is_gimple_assign(), NULL, offset, ptrdiff_type_node, wi::shwi(), si, sizetype, SSA_NAME_DEF_STMT, SSA_NAME_VERSION, ssa_ver_to_stridx, ssizetype, wi::to_wide(), TREE_CODE, tree_fits_shwi_p(), TREE_OPERAND, tree_to_shwi(), TREE_TYPE, TYPE_MAX_VALUE, TYPE_PRECISION, TYPE_SIZE_UNIT, and wi::zero().
Referenced by strlen_pass::before_dom_children(), strlen_pass::check_and_optimize_stmt(), strlen_pass::count_nonzero_bytes_addr(), fold_strstr_to_strncmp(), get_range_strlen_dynamic(), strlen_pass::handle_alloc_call(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_memset(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_string_cmp(), strlen_pass::handle_builtin_strlen(), strlen_pass::handle_builtin_stxncpy_strncat(), strlen_pass::handle_integral_assign(), strlen_pass::handle_pointer_plus(), strlen_pass::handle_store(), and maybe_diag_stxncpy_trunc().
◆ get_stridx_plus_constant()
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static |
Attempt to create a new strinfo for BASESI + OFF, or find existing strinfo if there is any. Return it's idx, or 0 if no strinfo has been created.
References addr_stridxptr(), build_int_cst(), compare_nonzero_chars(), compare_tree_int(), strinfo::full_string_p, gcc_checking_assert, get_next_strinfo(), get_strinfo(), stridxlist::idx, new_stridx(), new_strinfo(), strinfo::nonzero_chars, NULL, NULL_TREE, num_ssa_names, r, set_strinfo(), si, size_type_node, SSA_NAME_OCCURS_IN_ABNORMAL_PHI, SSA_NAME_VERSION, ssa_ver_to_stridx, TREE_CODE, tree_fits_uhwi_p(), TREE_OPERAND, tree_to_uhwi(), unshare_strinfo(), verify_related_strinfos(), and zero_length_string_p().
Referenced by get_addr_stridx(), and get_stridx().
◆ get_strinfo()
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inlinestatic |
Return strinfo vector entry IDX.
References NULL, stridx_to_strinfo, and vec_safe_length().
Referenced by strlen_pass::adjust_last_stmt(), strlen_pass::count_nonzero_bytes_addr(), fold_strstr_to_strncmp(), get_addr_stridx(), strlen_pass::get_len_or_size(), get_next_strinfo(), get_range_strlen_dynamic(), get_stridx(), get_stridx_plus_constant(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_memset(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_strlen(), strlen_pass::handle_builtin_stxncpy_strncat(), strlen_pass::handle_integral_assign(), strlen_pass::handle_pointer_plus(), strlen_pass::handle_store(), maybe_diag_stxncpy_trunc(), and verify_related_strinfos().
◆ get_string_length()
Return the string length, or NULL if it can't be computed. The length may but need not be constant. Instead, it might be the result of a strlen() call.
References BUILT_IN_NORMAL, builtin_decl_explicit(), builtin_decl_implicit(), builtin_decl_implicit_p(), convert_to_ptrofftype, DECL_FUNCTION_CODE(), dump_file, dump_flags, fndecl_built_in_p(), force_gimple_operand_gsi(), gcc_assert, gcc_unreachable, get_next_strinfo(), gimple_assign_lhs(), gimple_build_assign(), gimple_build_call(), gimple_call_arg(), gimple_call_fndecl(), gimple_call_lhs(), gimple_call_num_args(), gimple_call_set_arg(), gimple_call_set_fndecl(), gimple_call_set_lhs(), gimple_location(), gimple_set_vuse(), gimple_vuse(), gsi_for_stmt(), gsi_insert_before(), GSI_SAME_STMT, is_gimple_call(), make_ssa_name(), NULL, NULL_TREE, print_gimple_stmt(), ptrofftype_p(), set_endptr_and_length(), si, TDF_DETAILS, TDF_SLIM, TREE_TYPE, unshare_expr(), update_stmt(), and verify_related_strinfos().
Referenced by fold_strstr_to_strncmp(), get_range_strlen_dynamic(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), and strlen_pass::handle_builtin_strlen().
◆ is_char_type()
Return true if TYPE corresponds to a narrow character type.
References char_type_node, TREE_CODE, TYPE_MODE, and TYPE_PRECISION.
Referenced by strlen_pass::handle_assign().
◆ is_strlen_related_p()
Return true if LEN depends on a call to strlen(SRC) in an interesting way. LEN can either be an integer expression, or a pointer (to char). When it is the latter (such as in recursive calls to self) it is assumed to be the argument in some call to strlen() whose relationship to SRC is being ascertained.
References BUILT_IN_NORMAL, DECL_FUNCTION_CODE(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_call_arg(), gimple_call_builtin_p(), gimple_call_fndecl(), INTEGRAL_TYPE_P, is_gimple_assign(), is_gimple_call(), is_strlen_related_p(), laststmt_struct::len, operand_equal_p(), SSA_NAME_DEF_STMT, TREE_CODE, TREE_TYPE, and valid_builtin_call().
Referenced by strlen_pass::handle_builtin_stxncpy_strncat(), is_strlen_related_p(), maybe_diag_stxncpy_trunc(), maybe_warn_nonstring_arg(), and strlen_pass::maybe_warn_overflow().
◆ make_pass_strlen()
| gimple_opt_pass * make_pass_strlen | ( | gcc::context * | ctxt | ) |
◆ make_pass_warn_printf()
| gimple_opt_pass * make_pass_warn_printf | ( | gcc::context * | ctxt | ) |
◆ maybe_diag_stxncpy_trunc()
| bool maybe_diag_stxncpy_trunc | ( | gimple_stmt_iterator | gsi, |
| tree | src, | ||
| tree | cnt, | ||
| pointer_query * | ptr_qry ) |
Called by handle_builtin_stxncpy_strncat and by
gimple_fold_builtin_strncpy in gimple-fold.cc.
Check to see if the specified bound is a) equal to the size of
the destination DST and if so, b) if it's immediately followed by
DST[CNT - 1] = '\0'. If a) holds and b) does not, warn. Otherwise,
do nothing. Return true if diagnostic has been issued.
The purpose is to diagnose calls to strncpy and stpncpy that do
not nul-terminate the copy while allowing for the idiom where
such a call is immediately followed by setting the last element
to nul, as in:
char a[32];
strncpy (a, s, sizeof a);
a[sizeof a - 1] = '\0';
References cfun, compute_objsize(), DECL_FUNCTION_CODE(), EDGE_SUCC, get_addr_base_and_unit_offset(), get_attr_nonstring_decl(), get_legacy_range(), get_range_query(), get_range_strlen(), get_stridx(), get_strinfo(), wi::geu_p(), gimple_assign_lhs(), gimple_bb(), gimple_call_arg(), gimple_call_fndecl(), gimple_call_lhs(), gimple_or_expr_nonartificial_location(), gsi_next_nondebug(), gsi_start_bb(), gsi_stmt(), wi::gtu_p(), integer_all_onesp(), is_gimple_assign(), is_gimple_debug(), is_strlen_related_p(), known_eq, wi::leu_p(), wi::ltu_p(), c_strlen_data::maxbound, c_strlen_data::maxlen, c_strlen_data::minlen, wi::neg_p(), NULL, NULL_TREE, operand_equal_p(), ptrdiff_type_node, r, wi::shwi(), single_succ_p(), ssa_ver_to_stridx, laststmt_struct::stmt, wi::to_wide(), TREE_CODE, TREE_OPERAND, TREE_TYPE, TYPE_MAX_VALUE, TYPE_PRECISION, VR_ANTI_RANGE, warning_at(), warning_n(), warning_suppressed_p(), and wi::zero().
Referenced by gimple_fold_builtin_strncpy(), and strlen_pass::handle_builtin_stxncpy_strncat().
◆ maybe_invalidate()
Invalidate string length information for strings whose length might change due to stores in STMT, except those marked DONT_INVALIDATE. For string-modifying statements, ZERO_WRITE is set when the statement wrote only zeros. Returns true if any STRIDX_TO_STRINFO entries were considered for invalidation.
References ao_ref_init_from_ptr_and_size(), DECL_FUNCTION_CODE(), dump_file, dump_flags, fputc(), free_strinfo(), gimple_call_fndecl(), HOST_WIDE_INT_MAX, HOST_WIDE_INT_PRINT_UNSIGNED, i, is_gimple_call(), known_le, NULL, NULL_TREE, POINTER_TYPE_P, print_generic_expr(), print_gimple_stmt(), r, set_strinfo(), si, stmt_may_clobber_ref_p_1(), stridx_to_strinfo, TDF_DETAILS, TDF_LINENO, tree_fits_uhwi_p(), tree_to_uhwi(), TREE_TYPE, and vec_safe_iterate().
Referenced by strlen_pass::check_and_optimize_stmt(), and do_invalidate().
◆ maybe_set_strlen_range()
For an LHS that is an SSA_NAME and for strlen() or strnlen() argument SRC, set LHS range info to [0, min (N, BOUND)] if SRC refers to a character array A[N] with unknown length bounded by N, and for strnlen(), by min (N, BOUND).
References array_ref_flexible_size_p(), DECL_SIZE_UNIT, get_base_address(), gimple_assign_rhs1(), gimple_assign_rhs_code(), integer_zerop(), INTEGRAL_TYPE_P, is_gimple_assign(), NULL_TREE, ptrdiff_type_node, set_strlen_range(), SSA_NAME_DEF_STMT, wi::to_wide(), TREE_CODE, TREE_OPERAND, TREE_TYPE, TYPE_MAX_VALUE, TYPE_SIZE_UNIT, VAR_P, and wi::zero().
Referenced by strlen_pass::handle_builtin_strlen().
◆ maybe_warn_pointless_strcmp()
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static |
Diagnose pointless calls to strcmp or strncmp STMT with string arguments of lengths LEN or size SIZ and (for strncmp) BOUND, whose result is used in equality expressions that evaluate to a constant due to one argument being longer than the size of the other.
References G_, gimple_call_fndecl(), gimple_call_lhs(), gimple_location(), gimple_or_expr_nonartificial_location(), HOST_WIDE_INT_MAX, inform(), laststmt_struct::len, LOCATION_LINE, MIN, laststmt_struct::stmt, use_in_zero_equality(), and warning_at().
Referenced by strlen_pass::handle_builtin_string_cmp().
◆ new_addr_stridx()
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static |
Like new_stridx, but for ADDR_EXPR's operand instead.
References addr_stridxptr(), exp(), gcc_assert, max_stridx, and NULL.
Referenced by strlen_pass::handle_store().
◆ new_stridx()
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static |
Create a new string index, or return 0 if reached limit.
References addr_stridxptr(), exp(), gcc_assert, stridxlist::idx, max_stridx, NULL, SSA_NAME_OCCURS_IN_ABNORMAL_PHI, SSA_NAME_VERSION, ssa_ver_to_stridx, TREE_CODE, and TREE_OPERAND.
Referenced by get_stridx_plus_constant(), strlen_pass::handle_alloc_call(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_memset(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_strlen(), strlen_pass::handle_integral_assign(), strlen_pass::handle_store(), and zero_length_string().
◆ new_strinfo()
Create a new strinfo.
References stridxlist::idx, strinfo::nonzero_chars, NULL, NULL_TREE, si, strinfo_pool, and STRIP_USELESS_TYPE_CONVERSION.
Referenced by get_stridx_plus_constant(), strlen_pass::handle_alloc_call(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_memset(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_strlen(), strlen_pass::handle_integral_assign(), strlen_pass::handle_store(), unshare_strinfo(), and zero_length_string().
◆ nonzero_bytes_for_type()
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static |
Set LENRANGE to the number of nonzero bytes for a store of TYPE and clear all flags. Return true on success and false on failure.
References tree_fits_uhwi_p(), tree_to_uhwi(), TYPE_SIZE_UNIT, and UINT_MAX.
Referenced by strlen_pass::count_nonzero_bytes(), and strlen_pass::count_nonzero_bytes().
◆ set_endptr_and_length()
Set SI's endptr to ENDPTR and compute its length based on SI->ptr. Use LOC for folding.
References strinfo::endptr, fold_build2_loc(), fold_convert_loc(), NULL, si, and size_type_node.
Referenced by get_string_length().
◆ set_strinfo()
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Set strinfo in the vector entry IDX to SI.
References stridxlist::idx, si, stridx_to_strinfo, unshare_strinfo_vec(), vec_safe_grow_cleared(), and vec_safe_length().
Referenced by get_stridx_plus_constant(), strlen_pass::handle_alloc_call(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_memset(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_strlen(), strlen_pass::handle_integral_assign(), strlen_pass::handle_store(), maybe_invalidate(), unshare_strinfo(), and zero_length_string().
◆ set_strlen_range()
For an LHS that is an SSA_NAME that is the result of a strlen() call, or when BOUND is non-null, of a strnlen() call, set LHS range info to [0, min (MAX, BOUND)] when the range includes more than one value and return LHS. Otherwise, when the range [MIN, MAX] is such that MIN == MAX, return the tree representation of (MIN). The latter allows callers to fold suitable strnlen() calls to constants.
References cfun, wi::cmpu(), get_range_query(), INTEGRAL_TYPE_P, wi::ltu_p(), wi::ne_p(), NULL_TREE, r, path_range_query::range_of_expr(), set_range_info(), size_type_node, wi::to_wide(), TREE_CODE, TREE_TYPE, and wide_int_to_tree().
Referenced by gimple_fold_builtin_strlen(), strlen_pass::handle_builtin_strlen(), and maybe_set_strlen_range().
◆ strinfo_shared()
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Return true if strinfo vector is shared with the immediate dominator.
References NULL, stridx_to_strinfo, and vec_safe_length().
Referenced by strlen_pass::before_dom_children(), unshare_strinfo(), and unshare_strinfo_vec().
◆ unshare_strinfo()
Unshare strinfo record SI, if it has refcount > 1 or if stridx_to_strinfo vector is shared with some other bbs.
References strinfo::alloc, strinfo::endptr, strinfo::first, free_strinfo(), new_strinfo(), strinfo::next, strinfo::prev, set_strinfo(), si, strinfo::stmt, strinfo_shared(), and strinfo::writable.
Referenced by adjust_related_strinfos(), get_stridx_plus_constant(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_strcat(), strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_builtin_strlen(), strlen_pass::handle_store(), and zero_length_string().
◆ unshare_strinfo_vec()
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Unshare strinfo vector that is shared with the immediate dominator.
References gcc_assert, i, NULL, si, stridx_to_strinfo, strinfo_shared(), vec_safe_copy(), and vec_safe_iterate().
Referenced by set_strinfo().
◆ use_in_zero_equality()
Return first such statement if RES is used in statements testing its equality to zero, and null otherwise. If EXCLUSIVE is true, return nonnull if and only RES is used in such expressions exclusively and in none other.
References FOR_EACH_IMM_USE_FAST, gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_cond_code(), gimple_cond_rhs(), integer_zerop(), is_gimple_debug(), NULL, TREE_CODE, TREE_OPERAND, and USE_STMT.
Referenced by strlen_pass::handle_builtin_memcmp(), strlen_pass::handle_builtin_string_cmp(), maybe_warn_pointless_strcmp(), and simplify_builtin_call().
◆ valid_builtin_call()
Return true if STMT is a call to a builtin function with the right arguments and attributes that should be considered for optimization by this pass.
References BUILT_IN_NORMAL, DECL_FUNCTION_CODE(), gimple_call_builtin_p(), gimple_call_fndecl(), gimple_vdef(), gimple_vuse(), and NULL_TREE.
Referenced by strlen_pass::adjust_last_stmt(), strlen_pass::check_and_optimize_call(), strlen_pass::handle_builtin_memset(), and is_strlen_related_p().
◆ verify_related_strinfos()
Return the first strinfo in the related strinfo chain if all strinfos in between belong to the chain, otherwise NULL.
References strinfo::first, get_strinfo(), NULL, and si.
Referenced by strlen_pass::adjust_last_stmt(), adjust_related_strinfos(), get_stridx_plus_constant(), get_string_length(), strlen_pass::handle_builtin_strcpy(), and zero_length_string().
◆ zero_length_string()
Note that PTR, a pointer SSA_NAME initialized in the current stmt, points to a zero-length string and if possible chain it to a related strinfo chain whose part is or might be CHAINSI.
References build_int_cst(), strinfo::endptr, strinfo::first, strinfo::full_string_p, gcc_assert, gcc_checking_assert, get_next_strinfo(), stridxlist::idx, strinfo::idx, new_stridx(), new_strinfo(), strinfo::next, NULL, NULL_TREE, num_ssa_names, strinfo::prev, set_strinfo(), si, size_type_node, SSA_NAME_OCCURS_IN_ABNORMAL_PHI, SSA_NAME_VERSION, ssa_ver_to_stridx, TREE_CODE, unshare_strinfo(), verify_related_strinfos(), strinfo::writable, and zero_length_string_p().
Referenced by strlen_pass::handle_builtin_strchr(), strlen_pass::handle_builtin_strcpy(), and strlen_pass::handle_pointer_plus().
◆ zero_length_string_p()
Return true if SI is known to be a zero-length string.
References integer_zerop(), and si.
Referenced by strlen_pass::adjust_last_stmt(), get_stridx_plus_constant(), and zero_length_string().
Variable Documentation
◆ decl_to_stridxlist_htab
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Referenced by addr_stridxptr(), dump_strlen_info(), and get_addr_stridx().
◆ laststmt
| struct laststmt_struct laststmt |
◆ max_stridx
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Number of currently active string indexes plus one.
Referenced by dump_strlen_info(), new_addr_stridx(), and new_stridx().
◆ ssa_ver_to_stridx
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String length optimization Copyright (C) 2011-2024 Free Software Foundation, Inc. Contributed by Jakub Jelinek <jakub@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/>.
A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value is an index into strinfo vector, negative value stands for string length of a string literal (~strlen).
Referenced by strlen_pass::before_dom_children(), strlen_pass::check_and_optimize_stmt(), dump_strlen_info(), find_equal_ptrs(), get_stridx(), get_stridx_plus_constant(), strlen_pass::handle_builtin_memcpy(), strlen_pass::handle_builtin_strcpy(), strlen_pass::handle_pointer_plus(), maybe_diag_stxncpy_trunc(), new_stridx(), and zero_length_string().
◆ stridx_obstack
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Obstack for struct stridxlist and struct decl_stridxlist_map.
Referenced by addr_stridxptr().
◆ stridx_to_strinfo
Vector mapping positive string indexes to strinfo, for the current basic block. The first pointer in the vector is special, it is either NULL, meaning the vector isn't shared, or it is a basic block pointer to the owner basic_block if shared. If some other bb wants to modify the vector, the vector needs to be unshared first, and only the owner bb is supposed to free it.
Referenced by strlen_pass::after_dom_children(), strlen_pass::before_dom_children(), dump_strlen_info(), get_strinfo(), maybe_invalidate(), set_strinfo(), strinfo_shared(), and unshare_strinfo_vec().
◆ strinfo_pool
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Pool for allocating strinfo_struct entries.
Referenced by free_strinfo(), and new_strinfo().
◆ strlen_optimize
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Set to true to optimize, false when just checking.
Referenced by strlen_pass::check_and_optimize_call(), and strlen_pass::check_and_optimize_stmt().
◆ strlen_to_stridx
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