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.

2 files changed, 43 insertions, 6 deletions

diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-22.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-22.c
index 8eaaa71..764b199 100644
--- a/gcc/testsuite/gcc.dg/Wstringop-overflow-22.c
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-22.c
@@ -260,13 +260,12 @@ T (puts_unlocked, a);       // { dg-warning "missing terminating nul" "puts_unlo
 
 // Exerise exec functions.
 T (execl, a, s, NULL);      // { dg-warning "missing terminating nul" "execl" }
-T (execl, a, s, NULL);      // { dg-warning "missing terminating nul" "execl" }
-T (execle, a, s, NULL, NULL);   // { dg-warning "missing terminating nul" "execl" }
-T (execlp, a, s, NULL);     // { dg-warning "missing terminating nul" "execl" }
+T (execle, a, s, NULL, NULL);   // { dg-warning "missing terminating nul" "execle" }
+T (execlp, a, s, NULL);     // { dg-warning "missing terminating nul" "execlp" }
 
-T (execv, a, &d);           // { dg-warning "missing terminating nul" "execl" }
-T (execve, a, &d, &d);      // { dg-warning "missing terminating nul" "execl" }
-T (execvp, a, &d);          // { dg-warning "missing terminating nul" "execl" }
+T (execv, a, &d);           // { dg-warning "missing terminating nul" "execv" }
+T (execve, a, &d, &d);      // { dg-warning "missing terminating nul" "execve" }
+T (execvp, a, &d);          // { dg-warning "missing terminating nul" "execvp" }
 
 T (gettext, a);             // { dg-warning "missing terminating nul" "gettext" }
 
diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-81.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-81.c
new file mode 100644
index 0000000..e8bc327
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-81.c
@@ -0,0 +1,38 @@
+/* Verify that -Wstringop-overflow uses context-sensitive range info
+   even at -O0.
+   { dg-do compile }
+   { dg-options "-O0 -Wall" } */
+
+extern void* memset (void*, int, __SIZE_TYPE__);
+
+char a[8];
+
+void warn_offset_range (int i)
+{
+  if (i < 4)
+    i = 4;
+  memset (a + i, 0, 5);       // { dg-warning "writing 5 bytes into a region of size 4 " }
+}
+
+void warn_size_range (int i, int n)
+{
+  if (n < 5)
+    n = 5;
+
+  memset (a + 4, 1, n);      // { dg-warning "writing between 5 and \\d+ bytes into a region of size 4 " }
+}
+
+void warn_offset_and_size_range (int i, int n)
+{
+  if (n < 5)
+    n = 5;
+
+  if (i < 4)
+    {
+      if (n < 9)
+	n = 9;
+      memset (a + i, 1, n);   // { dg-warning "writing between 9 and \\d+ bytes into a region of size 8 " }
+    }
+  else
+    memset (a + i, 0, n);     // { dg-warning "writing between 5 and \\d+ bytes into a region of size 4 " }
+}