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.

1 files changed, 1 insertions, 28 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index f1c3fea..7d0f61f 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -3600,7 +3600,7 @@ check_strncat_sizes (tree exp, tree objsize)
   /* Try to verify that the destination is big enough for the shortest
      string.  */
 
-  access_data data (exp, access_read_write, maxread, true);
+  access_data data (nullptr, exp, access_read_write, maxread, true);
   if (!objsize && warn_stringop_overflow)
     {
       /* If it hasn't been provided by __strncat_chk, try to determine
@@ -4260,12 +4260,6 @@ expand_builtin_memcmp (tree exp, rtx target, bool result_eq)
   tree arg2 = CALL_EXPR_ARG (exp, 1);
   tree len = CALL_EXPR_ARG (exp, 2);
 
-  /* Diagnose calls where the specified length exceeds the size of either
-     object.  */
-  if (!check_read_access (exp, arg1, len, 0)
-      || !check_read_access (exp, arg2, len, 0))
-    return NULL_RTX;
-
   /* Due to the performance benefit, always inline the calls first
      when result_eq is false.  */
   rtx result = NULL_RTX;
@@ -5486,27 +5480,6 @@ expand_builtin_fork_or_exec (tree fn, tree exp, rtx target, int ignore)
   tree id, decl;
   tree call;
 
-  if (DECL_FUNCTION_CODE (fn) != BUILT_IN_FORK)
-    {
-      tree path = CALL_EXPR_ARG (exp, 0);
-      /* Detect unterminated path.  */
-      if (!check_read_access (exp, path))
-	return NULL_RTX;
-
-      /* Also detect unterminated first argument.  */
-      switch (DECL_FUNCTION_CODE (fn))
-	{
-	case BUILT_IN_EXECL:
-	case BUILT_IN_EXECLE:
-	case BUILT_IN_EXECLP:
-	  if (!check_read_access (exp, path))
-	    return NULL_RTX;
-	default:
-	  break;
-	}
-    }
-
-
   /* If we are not profiling, just call the function.  */
   if (!profile_arc_flag)
     return NULL_RTX;