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/gimple-ssa-sprintf.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'gcc/gimple-ssa-sprintf.c')

diff --git a/gcc/gimple-ssa-sprintf.c b/gcc/gimple-ssa-sprintf.c
index 8e90b7c..8f42cb5 100644
--- a/gcc/gimple-ssa-sprintf.c
+++ b/gcc/gimple-ssa-sprintf.c
@@ -4030,11 +4030,11 @@ compute_format_length (call_info &info, format_result *res, range_query *query)
   return success;
 }
 
-/* Return the size of the object referenced by the expression DEST if
-   available, or the maximum possible size otherwise.  */
+/* Return the size of the object referenced by the expression DEST in
+   statement STMT, if available, or the maximum possible size otherwise.  */
 
 static unsigned HOST_WIDE_INT
-get_destination_size (tree dest, pointer_query &ptr_qry)
+get_destination_size (tree dest, gimple *stmt, pointer_query &ptr_qry)
 {
   /* When there is no destination return the maximum.  */
   if (!dest)
@@ -4042,7 +4042,7 @@ get_destination_size (tree dest, pointer_query &ptr_qry)
 
   /* Use compute_objsize to determine the size of the destination object.  */
   access_ref aref;
-  if (!ptr_qry.get_ref (dest, &aref))
+  if (!ptr_qry.get_ref (dest, stmt, &aref))
     return HOST_WIDE_INT_MAX;
 
   offset_int remsize = aref.size_remaining ();
@@ -4516,7 +4516,7 @@ handle_printf_call (gimple_stmt_iterator *gsi, pointer_query &ptr_qry)
       /* For non-bounded functions like sprintf, determine the size
 	 of the destination from the object or pointer passed to it
 	 as the first argument.  */
-      dstsize = get_destination_size (dstptr, ptr_qry);
+      dstsize = get_destination_size (dstptr, info.callstmt, ptr_qry);
     }
   else if (tree size = gimple_call_arg (info.callstmt, idx_dstsize))
     {
-- 
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