[gcc r11-9316] d: fix ASAN in option processing

[Martin Liska <marxin@gcc.gnu.org>]

https://gcc.gnu.org/g:f2255d28538e81cff7a8f5822f9489625fb88e70

commit r11-9316-gf2255d28538e81cff7a8f5822f9489625fb88e70
Author: Martin Liska <mliska@suse.cz>
Date:   Thu Nov 25 14:41:50 2021 +0100

    d: fix ASAN in option processing
    
    Fixes:
    
    ==129444==ERROR: AddressSanitizer: global-buffer-overflow on address 0x00000666ca5c at pc 0x000000ef094b bp 0x7fffffff8180 sp 0x7fffffff8178
    READ of size 4 at 0x00000666ca5c thread T0
        #0 0xef094a in parse_optimize_options ../../gcc/d/d-attribs.cc:855
        #1 0xef0d36 in d_handle_optimize_attribute ../../gcc/d/d-attribs.cc:916
        #2 0xef107e in d_handle_optimize_attribute ../../gcc/d/d-attribs.cc:887
        #3 0xff85b1 in decl_attributes(tree_node**, tree_node*, int, tree_node*) ../../gcc/attribs.c:829
        #4 0xef2a91 in apply_user_attributes(Dsymbol*, tree_node*) ../../gcc/d/d-attribs.cc:427
        #5 0xf7b7f3 in get_symbol_decl(Declaration*) ../../gcc/d/decl.cc:1346
        #6 0xf87bc7 in get_symbol_decl(Declaration*) ../../gcc/d/decl.cc:967
        #7 0xf87bc7 in DeclVisitor::visit(FuncDeclaration*) ../../gcc/d/decl.cc:808
        #8 0xf83db5 in DeclVisitor::build_dsymbol(Dsymbol*) ../../gcc/d/decl.cc:146
    
    for the following test-case: gcc/testsuite/gdc.dg/attr_optimize1.d.
    
    gcc/d/ChangeLog:
    
            * d-attribs.cc (parse_optimize_options): Check index before
            accessing cl_options.

Diff:
---
 gcc/d/d-attribs.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/d/d-attribs.cc b/gcc/d/d-attribs.cc
index 070866020a2..13c7341fdcd 100644
--- a/gcc/d/d-attribs.cc
+++ b/gcc/d/d-attribs.cc
@@ -852,7 +852,9 @@ parse_optimize_options (tree args)
   unsigned j = 1;
   for (unsigned i = 1; i < decoded_options_count; ++i)
     {
-      if (! (cl_options[decoded_options[i].opt_index].flags & CL_OPTIMIZATION))
+      unsigned opt_index = decoded_options[i].opt_index;
+      if (opt_index >= cl_options_count
+	  && ! (cl_options[opt_index].flags & CL_OPTIMIZATION))
 	{
 	  ret = false;
 	  warning (OPT_Wattributes,