From 9a27acc30a34b7854db32eac562306cebac6fa1e Mon Sep 17 00:00:00 2001
From: Martin Sebor <msebor@redhat.com>
Date: Tue, 26 Oct 2021 14:38:11 -0600
Subject: Make full use of context-sensitive ranges in access warnings.

gcc/ChangeLog:

	* builtins.c (check_strncat_sizes): Pass access_data ctor additional
	arguments.
	(expand_builtin_memcmp): Move code to gimple-ssa-warn-access.cc.
	(expand_builtin_fork_or_exec): Same.
	* gimple-array-bounds.cc (array_bounds_checker::check_mem_ref): Pass
	compute_objsize additional arguments.
	(inbounds_memaccess_p): Same.
	(array_bounds_checker::check_array_bounds): Add an assert.  Stash
	statement in a member.
	(check_array_bounds_dom_walker::before_dom_children): Same.
	* gimple-array-bounds.h (array_bounds_checker::m_stmt): New member.
	* gimple-ssa-sprintf.c (get_destination_size): Add an argument.
	(handle_printf_call): Pass a new argument.
	* gimple-ssa-warn-access.cc (get_size_range): Add an argument.
	(check_access): Add an argument and pass it along to callees.
	(check_read_access): Make a member function.
	(pass_waccess::check_strcat): Pass access_data ctor additional
	arguments.
	(pass_waccess::check_strncat): Same.
	(pass_waccess::check_stxcpy): Same.
	(pass_waccess::check_stxncpy): Same.
	(pass_waccess::check_strncmp): Same.
	(pass_waccess::check_read_access): Same.
	(pass_waccess::check_builtin): Same.
	(pass_waccess::maybe_check_access_sizes): Same.
	(pass_waccess::maybe_check_dealloc_call): Same.
	* gimple-ssa-warn-access.h (check_read_access): Declare a new
	member function.
	* pointer-query.cc (compute_objsize_r): Add an argument.
	(gimple_call_return_array): Same.
	(gimple_call_alloc_size): Same.
	(access_ref::access_ref): Same.
	(access_ref::get_ref): Same.
	(pointer_query::get_ref): Same.
	(handle_min_max_size): Pass an arguments to callees.
	(handle_array_ref): Add an argument.
	(handle_mem_ref): Same.
	(compute_objsize): Same.
	* pointer-query.h (struct access_ref): Adjust signatures.
	(struct access_data): Same.
	(gimple_call_alloc_size): Add an argument.
	(gimple_parm_array_size): Same.
	(compute_objsize): Same.
	* tree-ssa-strlen.c (strlen_pass::adjust_last_stmt): Pass an additional
	argument to compute_objsize.
	(strlen_pass::maybe_warn_overflow): Same.
	(maybe_diag_stxncpy_trunc): Same.

gcc/testsuite/ChangeLog:

	* gcc.dg/Wstringop-overflow-22.c: Correct typos.
	* gcc.dg/Wstringop-overflow-81.c: New test.

libstdc++-v3/ChangeLog:

	* testsuite/21_strings/basic_string/capacity/1.cc: Also suppress
	-Wstringop-overread.
	* testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc: Same.
---
 gcc/tree-ssa-strlen.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'gcc/tree-ssa-strlen.c')

diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c
index 8c39869..2de7cb1 100644
--- a/gcc/tree-ssa-strlen.c
+++ b/gcc/tree-ssa-strlen.c
@@ -1833,7 +1833,7 @@ strlen_pass::adjust_last_stmt (strinfo *si, gimple *stmt, bool is_strcat)
       tree dst = gimple_call_arg (last.stmt, 0);
 
       access_ref aref;
-      tree size = compute_objsize (dst, 1, &aref, &ptr_qry);
+      tree size = compute_objsize (dst, stmt, 1, &aref, &ptr_qry);
       if (size && tree_int_cst_lt (size, len))
 	return;
     }
@@ -2035,7 +2035,7 @@ strlen_pass::maybe_warn_overflow (gimple *stmt, bool call_lhs, tree len,
   access_ref aref;
   /* The size of the destination region (which is smaller than
      the destination object for stores at a non-zero offset).  */
-  tree destsize = compute_objsize (dest, ostype, &aref, &ptr_qry);
+  tree destsize = compute_objsize (dest, stmt, ostype, &aref, &ptr_qry);
 
   if (!destsize)
     {
@@ -3115,7 +3115,7 @@ maybe_diag_stxncpy_trunc (gimple_stmt_iterator gsi, tree src, tree cnt,
     }
 
   access_ref aref;
-  if (tree dstsize = compute_objsize (dst, 1, &aref, ptr_qry))
+  if (tree dstsize = compute_objsize (dst, stmt, 1, &aref, ptr_qry))
     {
       /* The source length is unknown.  Try to determine the destination
 	 size and see if it matches the specified bound.  If not, bail.
@@ -3130,7 +3130,7 @@ maybe_diag_stxncpy_trunc (gimple_stmt_iterator gsi, tree src, tree cnt,
       /* Avoid warning for strncpy(a, b, N) calls where the following
 	 equalities hold:
 	   N == sizeof a && N == sizeof b */
-      if (tree srcsize = compute_objsize (src, 1, &aref, ptr_qry))
+      if (tree srcsize = compute_objsize (src, stmt, 1, &aref, ptr_qry))
 	if (wi::to_wide (srcsize) == cntrange[1])
 	  return false;
 
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