On February 5, 2015 4:42:50 PM CET, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>On the following testcase we fail -fcompare-debug, because in .LASAN0
>initializer we get a NOP_EXPR optimized away only in one of the cases.
>The reason is that cgraph* is looking at DECL_ABSTRACT_P flag of
>__PRETTY_FUNCTION__ and that flag is different between -g and -g0.
>The DECL_ABSTRACT_P is normally set by the FE on some decls (common to
>-g
>and -g0), but then dwarf2out_abstract_function can set/reset it in a
>weird
>way, leaving it in different state from what it has been in initially.
>
>The dwarf2out.c code pretty much assumes that if some decl is
>DECL_ABSTRACT_P, then all the blocks in it and all the VAR_DECLs in
>BLOCK_VARS and parameters etc. will necessarily be equal to that, but
>that
>is usually not the case.
>
>So, this patch changes it, so that it always reverts it to the original
>state (temporarily it is set as before).
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, additionally
>I've
>checked the debug info of cc1* and various *.so* libraries created
>during
>gcc bootstrap and the patch doesn't result in any debug info
>differences.
>Ok for trunk?
Looks good to me. I wonder if this will also help Aldyh...
I also wonder what it takes to make dwarf2out use DECL_ABSTRACT_P ||
force_abstract with maintaining that new state and whether that would be both
cheaper and cleaner?
Thanks,
Richard.
>2015-02-05 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/64937
> * dwarf2out.c (set_block_abstract_flags, set_decl_abstract_flags):
> Replace setting argument with abstract_vec, always set BLOCK_ABSTRACT
> or DECL_ABSTRACT_P flags to 1 rather than to setting, and if it wasn't
> 1 before, push it to abstract_vec.
> (dwarf2out_abstract_function): Adjust caller. Don't call
> set_decl_abstract_flags second time, instead clear BLOCK_ABSTRACT or
> DECL_ABSTRACT_P flags for all abstract_vec elts.
>
> * g++.dg/asan/pr64937.C: New test.
>
>--- gcc/dwarf2out.c.jj 2015-02-04 23:36:33.000000000 +0100
>+++ gcc/dwarf2out.c 2015-02-05 13:19:41.401748148 +0100
>@@ -18062,7 +18062,7 @@ gen_type_die_for_member (tree type, tree
>/* Forward declare these functions, because they are mutually recursive
> with their set_block_* pairing functions. */
> static void set_decl_origin_self (tree);
>-static void set_decl_abstract_flags (tree, int);
>+static void set_decl_abstract_flags (tree, vec<tree> &);
>
>/* Given a pointer to some BLOCK node, if the BLOCK_ABSTRACT_ORIGIN for
>the
>given BLOCK node is NULL, set the BLOCK_ABSTRACT_ORIGIN for the node so
>@@ -18135,59 +18135,72 @@ set_decl_origin_self (tree decl)
> }
> }
> >
>-/* Given a pointer to some BLOCK node, and a boolean value to set the
>- "abstract" flags to, set that value into the BLOCK_ABSTRACT flag
>for
>- the given block, and for all local decls and all local sub-blocks
>- (recursively) which are contained therein. */
>+/* Given a pointer to some BLOCK node, set the BLOCK_ABSTRACT flag to
>1
>+ and if it wasn't 1 before, push it to abstract_vec vector.
>+ For all local decls and all local sub-blocks (recursively) do it
>+ too. */
>
> static void
>-set_block_abstract_flags (tree stmt, int setting)
>+set_block_abstract_flags (tree stmt, vec<tree> &abstract_vec)
> {
> tree local_decl;
> tree subblock;
> unsigned int i;
>
>- BLOCK_ABSTRACT (stmt) = setting;
>+ if (!BLOCK_ABSTRACT (stmt))
>+ {
>+ abstract_vec.safe_push (stmt);
>+ BLOCK_ABSTRACT (stmt) = 1;
>+ }
>
> for (local_decl = BLOCK_VARS (stmt);
> local_decl != NULL_TREE;
> local_decl = DECL_CHAIN (local_decl))
> if (! DECL_EXTERNAL (local_decl))
>- set_decl_abstract_flags (local_decl, setting);
>+ set_decl_abstract_flags (local_decl, abstract_vec);
>
> for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (stmt); i++)
> {
> local_decl = BLOCK_NONLOCALIZED_VAR (stmt, i);
> if ((TREE_CODE (local_decl) == VAR_DECL && !TREE_STATIC (local_decl))
> || TREE_CODE (local_decl) == PARM_DECL)
>- set_decl_abstract_flags (local_decl, setting);
>+ set_decl_abstract_flags (local_decl, abstract_vec);
> }
>
> for (subblock = BLOCK_SUBBLOCKS (stmt);
> subblock != NULL_TREE;
> subblock = BLOCK_CHAIN (subblock))
>- set_block_abstract_flags (subblock, setting);
>+ set_block_abstract_flags (subblock, abstract_vec);
> }
>
>-/* Given a pointer to some ..._DECL node, and a boolean value to set
>the
>- "abstract" flags to, set that value into the DECL_ABSTRACT_P flag
>for the
>- given decl, and (in the case where the decl is a FUNCTION_DECL)
>also
>- set the abstract flags for all of the parameters, local vars, local
>- blocks and sub-blocks (recursively) to the same setting. */
>+/* Given a pointer to some ..._DECL node, set DECL_ABSTRACT_P flag on
>it
>+ to 1 and if it wasn't 1 before, push to abstract_vec vector.
>+ In the case where the decl is a FUNCTION_DECL also set the abstract
>+ flags for all of the parameters, local vars, local
>+ blocks and sub-blocks (recursively). */
>
> static void
>-set_decl_abstract_flags (tree decl, int setting)
>+set_decl_abstract_flags (tree decl, vec<tree> &abstract_vec)
> {
>- DECL_ABSTRACT_P (decl) = setting;
>+ if (!DECL_ABSTRACT_P (decl))
>+ {
>+ abstract_vec.safe_push (decl);
>+ DECL_ABSTRACT_P (decl) = 1;
>+ }
>+
> if (TREE_CODE (decl) == FUNCTION_DECL)
> {
> tree arg;
>
> for (arg = DECL_ARGUMENTS (decl); arg; arg = DECL_CHAIN (arg))
>- DECL_ABSTRACT_P (arg) = setting;
>+ if (!DECL_ABSTRACT_P (arg))
>+ {
>+ abstract_vec.safe_push (arg);
>+ DECL_ABSTRACT_P (arg) = 1;
>+ }
> if (DECL_INITIAL (decl) != NULL_TREE
> && DECL_INITIAL (decl) != error_mark_node)
>- set_block_abstract_flags (DECL_INITIAL (decl), setting);
>+ set_block_abstract_flags (DECL_INITIAL (decl), abstract_vec);
> }
> }
>
>@@ -18200,7 +18213,6 @@ dwarf2out_abstract_function (tree decl)
> dw_die_ref old_die;
> tree save_fn;
> tree context;
>- int was_abstract;
> hash_table<decl_loc_hasher> *old_decl_loc_table;
> hash_table<dw_loc_list_hasher> *old_cached_dw_loc_list_table;
> int old_call_site_count, old_tail_call_site_count;
>@@ -18242,11 +18254,16 @@ dwarf2out_abstract_function (tree decl)
> save_fn = current_function_decl;
> current_function_decl = decl;
>
>- was_abstract = DECL_ABSTRACT_P (decl);
>- set_decl_abstract_flags (decl, 1);
>+ auto_vec<tree, 64> abstract_vec;
>+ set_decl_abstract_flags (decl, abstract_vec);
> dwarf2out_decl (decl);
>- if (! was_abstract)
>- set_decl_abstract_flags (decl, 0);
>+ unsigned int i;
>+ tree t;
>+ FOR_EACH_VEC_ELT (abstract_vec, i, t)
>+ if (TREE_CODE (t) == BLOCK)
>+ BLOCK_ABSTRACT (t) = 0;
>+ else
>+ DECL_ABSTRACT_P (t) = 0;
>
> current_function_decl = save_fn;
> decl_loc_table = old_decl_loc_table;
>--- gcc/testsuite/g++.dg/asan/pr64937.C.jj 2015-02-05
>13:22:04.510353994 +0100
>+++ gcc/testsuite/g++.dg/asan/pr64937.C 2015-02-05 13:21:44.000000000
>+0100
>@@ -0,0 +1,30 @@
>+// PR middle-end/64937
>+// { dg-do compile }
>+// { dg-options "-fsanitize=address -fcompare-debug" }
>+
>+namespace foo_aux {
>+ struct BarParser { };
>+}
>+extern "C" {
>+ extern void __assert_fail (__const char *__assertion, __const char
>*__file,
>+ unsigned int __line, __const char
>*__function);
>+}
>+namespace foo {
>+ class BarBox {
>+ public:
>+ BarBox (int xl = 0, int yl = 0) { }
>+ };
>+ class BarFoo {
>+ public:
>+ explicit BarFoo (BarBox box) {
>+ ((_orig_mask) ? static_cast < void >(0) :
>+ __assert_fail ("_orig_mask", "foo.h", 159,
>__PRETTY_FUNCTION__));
>+ }
>+ BarBox *_orig_mask;
>+ };
>+}
>+static void
>+ProcessOp (foo_aux::BarParser * p, int xl, int yr)
>+{
>+ foo::BarFoo tiles (foo::BarBox (xl, yr));
>+}
>
> Jakub
