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2014-04-16 18:03 GMT+04:00 Ilya Enkovich <enkovich....@gmail.com>:
> Hi,
>
> This patch introduces changes in call graph for Pointer Bounds Checker.
>
> New fields instrumented_version, instrumentation_clone and orig_decl are
> added for cgraph_node:
> - instrumentation_clone field is 1 for nodes created for instrumented
> version of functions
> - instrumented_version points to instrumented/original node
> - orig_decl holds original function declaration for instrumented nodes in
> case original node is removed
>
> IPA_REF_CHKP reference type is introduced for nodes to reference instrumented
> function versions from originals. It is used to have proper reachability
> analysis.
>
> When original function bodies are not needed anymore, functions are
> transformed into thunks having call edge to the instrumented function.
> Therefore new field appeared in cgraph_thunk_info to mark such thunks.
>
> Does it look OK?
>
> Bootstrapped and tested on linux-x86_64.
>
> Thanks,
> Ilya
> --
> gcc/
>
> 2014-04-16 Ilya Enkovich <ilya.enkov...@intel.com>
>
> * cgraph.h (cgraph_thunk_info): Add add_pointer_bounds_args
> field.
> (cgraph_node): Add instrumented_version, orig_decl and
> instrumentation_clone fields.
> (symtab_alias_target): Allow IPA_REF_CHKP reference.
> * cgraph.c (cgraph_remove_node): Fix instrumented_version
> of the referenced node if any.
> (dump_cgraph_node): Dump instrumentation_clone and
> instrumented_version fields.
> (verify_cgraph_node): Check correctness of IPA_REF_CHKP
> references and instrumentation thunks.
> * cgraphbuild.c (rebuild_cgraph_edges): Rebuild IPA_REF_CHKP
> reference.
> (cgraph_rebuild_references): Likewise.
> * cgraphunit.c (assemble_thunks_and_aliases): Skip thunks
> calling instrumneted function version.
> * ipa-ref.h (ipa_ref_use): Add IPA_REF_CHKP.
> (ipa_ref): increase size of use field.
> * ipa-ref.c (ipa_ref_use_name): Add element for IPA_REF_CHKP.
> * lto-cgraph.c (lto_output_node): Output instrumentation_clone,
> thunk.add_pointer_bounds_args and orig_decl field.
> (lto_output_ref): Adjust to new ipa_ref::use field size.
> (input_overwrite_node): Read instrumentation_clone field.
> (input_node): Read thunk.add_pointer_bounds_args and orig_decl
> fields.
> (input_ref): Adjust to new ipa_ref::use field size.
> (input_cgraph_1): Compute instrumented_version fields and restore
> IDENTIFIER_TRANSPARENT_ALIAS chains.
> * lto-streamer.h (LTO_minor_version): Change minor version from
> 0 to 1.
> * ipa.c (symtab_remove_unreachable_nodes): Consider instrumented
> clone as address taken if the original one is address taken.
> (cgraph_externally_visible_p): Mark instrumented 'main' as
> externally visible.
> (function_and_variable_visibility): Filter instrumentation
> thunks.
>
>
> diff --git a/gcc/cgraph.c b/gcc/cgraph.c
> index be3661a..6210c68 100644
> --- a/gcc/cgraph.c
> +++ b/gcc/cgraph.c
> @@ -1828,6 +1828,12 @@ cgraph_remove_node (struct cgraph_node *node)
> }
> cgraph_n_nodes--;
>
> + if (node->instrumented_version)
> + {
> + node->instrumented_version->instrumented_version = NULL;
> + node->instrumented_version = NULL;
> + }
> +
> /* Clear out the node to NULL all pointers and add the node to the free
> list. */
> memset (node, 0, sizeof (*node));
> @@ -2070,6 +2076,11 @@ dump_cgraph_node (FILE *f, struct cgraph_node *node)
> if (indirect_calls_count)
> fprintf (f, " Has %i outgoing edges for indirect calls.\n",
> indirect_calls_count);
> +
> + if (node->instrumentation_clone)
> + fprintf (f, " Is instrumented version.\n");
> + else if (node->instrumented_version)
> + fprintf (f, " Has instrumented version.\n");
> }
>
>
> @@ -2850,7 +2861,9 @@ verify_cgraph_node (struct cgraph_node *node)
> }
> for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list,
> i, ref); i++)
> - if (ref->use != IPA_REF_ALIAS)
> + if (ref->use == IPA_REF_CHKP)
> + ;
> + else if (ref->use != IPA_REF_ALIAS)
> {
> error ("Alias has non-alias reference");
> error_found = true;
> @@ -2868,6 +2881,35 @@ verify_cgraph_node (struct cgraph_node *node)
> error_found = true;
> }
> }
> +
> + /* Check all nodes reference their instrumented versions. */
> + if (node->analyzed
> + && node->instrumented_version
> + && !node->instrumentation_clone)
> + {
> + bool ref_found = false;
> + int i;
> + struct ipa_ref *ref;
> +
> + for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list,
> + i, ref); i++)
> + if (ref->use == IPA_REF_CHKP)
> + {
> + if (ref_found)
> + {
> + error ("Node has more than one chkp reference");
> + error_found = true;
> + }
> + ref_found = true;
> + }
> +
> + if (!ref_found)
> + {
> + error ("Analyzed node has no reference to instrumented version");
> + error_found = true;
> + }
> + }
> +
> if (node->analyzed && node->thunk.thunk_p)
> {
> if (!node->callees)
> @@ -2885,6 +2927,12 @@ verify_cgraph_node (struct cgraph_node *node)
> error ("Thunk is not supposed to have body");
> error_found = true;
> }
> + if (node->thunk.add_pointer_bounds_args
> + && node->callees->callee != node->instrumented_version)
> + {
> + error ("Instrumentation thunk has wrong edge callee");
> + error_found = true;
> + }
> }
> else if (node->analyzed && gimple_has_body_p (node->decl)
> && !TREE_ASM_WRITTEN (node->decl)
> diff --git a/gcc/cgraph.h b/gcc/cgraph.h
> index a6a51cf..5e702a7 100644
> --- a/gcc/cgraph.h
> +++ b/gcc/cgraph.h
> @@ -191,6 +191,7 @@ struct GTY(()) cgraph_thunk_info {
> tree alias;
> bool this_adjusting;
> bool virtual_offset_p;
> + bool add_pointer_bounds_args;
> /* Set to true when alias node is thunk. */
> bool thunk_p;
> };
> @@ -373,6 +374,13 @@ public:
> struct cgraph_node *prev_sibling_clone;
> struct cgraph_node *clones;
> struct cgraph_node *clone_of;
> + /* If instrumentation_clone is 1 then instrumented_version points
> + to the original function used to make instrumented version.
> + Otherwise points to instrumented version of the function. */
> + struct cgraph_node *instrumented_version;
> + /* If instrumentation_clone is 1 then orig_decl is the original
> + function declaration. */
> + tree orig_decl;
> /* For functions with many calls sites it holds map from call expression
> to the edge to speed up cgraph_edge function. */
> htab_t GTY((param_is (struct cgraph_edge))) call_site_hash;
> @@ -433,6 +441,9 @@ public:
> /* True if this decl calls a COMDAT-local function. This is set up in
> compute_inline_parameters and inline_call. */
> unsigned calls_comdat_local : 1;
> + /* True when function is clone created for Pointer Bounds Checker
> + instrumentation. */
> + unsigned instrumentation_clone : 1;
> };
>
>
> @@ -1412,6 +1423,8 @@ symtab_alias_target (symtab_node *n)
> {
> struct ipa_ref *ref;
> ipa_ref_list_reference_iterate (&n->ref_list, 0, ref);
> + if (ref->use == IPA_REF_CHKP)
> + ipa_ref_list_reference_iterate (&n->ref_list, 1, ref);
> gcc_checking_assert (ref->use == IPA_REF_ALIAS);
> return ref->referred;
> }
> diff --git a/gcc/cgraphbuild.c b/gcc/cgraphbuild.c
> index 19961e2..a2b2106 100644
> --- a/gcc/cgraphbuild.c
> +++ b/gcc/cgraphbuild.c
> @@ -481,6 +481,10 @@ rebuild_cgraph_edges (void)
> record_eh_tables (node, cfun);
> gcc_assert (!node->global.inlined_to);
>
> + if (node->instrumented_version
> + && !node->instrumentation_clone)
> + ipa_record_reference (node, node->instrumented_version, IPA_REF_CHKP,
> NULL);
> +
> return 0;
> }
>
> @@ -513,6 +517,11 @@ cgraph_rebuild_references (void)
> ipa_record_stmt_references (node, gsi_stmt (gsi));
> }
> record_eh_tables (node, cfun);
> +
> +
> + if (node->instrumented_version
> + && !node->instrumentation_clone)
> + ipa_record_reference (node, node->instrumented_version, IPA_REF_CHKP,
> NULL);
> }
>
> namespace {
> diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
> index 06283fc..ceb4060 100644
> --- a/gcc/cgraphunit.c
> +++ b/gcc/cgraphunit.c
> @@ -1702,7 +1702,8 @@ assemble_thunks_and_aliases (struct cgraph_node *node)
> struct ipa_ref *ref;
>
> for (e = node->callers; e;)
> - if (e->caller->thunk.thunk_p)
> + if (e->caller->thunk.thunk_p
> + && !e->caller->thunk.add_pointer_bounds_args)
> {
> struct cgraph_node *thunk = e->caller;
>
> diff --git a/gcc/ipa-ref.c b/gcc/ipa-ref.c
> index 6aa41e6..3a055d9 100644
> --- a/gcc/ipa-ref.c
> +++ b/gcc/ipa-ref.c
> @@ -27,7 +27,7 @@ along with GCC; see the file COPYING3. If not see
> #include "cgraph.h"
> #include "ipa-utils.h"
>
> -static const char *ipa_ref_use_name[] = {"read","write","addr","alias"};
> +static const char *ipa_ref_use_name[] =
> {"read","write","addr","alias","chkp"};
>
> /* Return ipa reference from REFERING_NODE or REFERING_VARPOOL_NODE
> to REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
> diff --git a/gcc/ipa-ref.h b/gcc/ipa-ref.h
> index 4ce5f8d..d0df0bf 100644
> --- a/gcc/ipa-ref.h
> +++ b/gcc/ipa-ref.h
> @@ -29,7 +29,8 @@ enum GTY(()) ipa_ref_use
> IPA_REF_LOAD,
> IPA_REF_STORE,
> IPA_REF_ADDR,
> - IPA_REF_ALIAS
> + IPA_REF_ALIAS,
> + IPA_REF_CHKP
> };
>
> /* Record of reference in callgraph or varpool. */
> @@ -40,7 +41,7 @@ struct GTY(()) ipa_ref
> gimple stmt;
> unsigned int lto_stmt_uid;
> unsigned int referred_index;
> - ENUM_BITFIELD (ipa_ref_use) use:2;
> + ENUM_BITFIELD (ipa_ref_use) use:3;
> unsigned int speculative:1;
> };
>
> diff --git a/gcc/ipa.c b/gcc/ipa.c
> index 5ab3aed..1d7fa35 100644
> --- a/gcc/ipa.c
> +++ b/gcc/ipa.c
> @@ -508,6 +508,12 @@ symtab_remove_unreachable_nodes (bool before_inlining_p,
> FILE *file)
> cgraph_node_remove_callees (node);
> ipa_remove_all_references (&node->ref_list);
> changed = true;
> + if (node->thunk.thunk_p
> + && node->thunk.add_pointer_bounds_args)
> + {
> + node->thunk.thunk_p = false;
> + node->thunk.add_pointer_bounds_args = false;
> + }
> }
> }
> else
> @@ -583,7 +589,10 @@ symtab_remove_unreachable_nodes (bool before_inlining_p,
> FILE *file)
> if (node->address_taken
> && !node->used_from_other_partition)
> {
> - if (!cgraph_for_node_and_aliases (node, has_addr_references_p, NULL,
> true))
> + if (!cgraph_for_node_and_aliases (node, has_addr_references_p, NULL,
> true)
> + && (!node->instrumentation_clone
> + || !node->instrumented_version
> + || !node->instrumented_version->address_taken))
> {
> if (file)
> fprintf (file, " %s", node->name ());
> @@ -814,6 +823,10 @@ cgraph_externally_visible_p (struct cgraph_node *node,
> if (MAIN_NAME_P (DECL_NAME (node->decl)))
> return true;
>
> + if (node->instrumentation_clone
> + && MAIN_NAME_P (DECL_NAME (node->orig_decl)))
> + return true;
> +
> return false;
> }
>
> @@ -1016,6 +1029,7 @@ function_and_variable_visibility (bool whole_program)
> }
>
> if (node->thunk.thunk_p
> + && !node->thunk.add_pointer_bounds_args
> && TREE_PUBLIC (node->decl))
> {
> struct cgraph_node *decl_node = node;
> diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
> index 999ce3d..58105f0 100644
> --- a/gcc/lto-cgraph.c
> +++ b/gcc/lto-cgraph.c
> @@ -526,6 +526,7 @@ lto_output_node (struct lto_simple_output_block *ob,
> struct cgraph_node *node,
> bp_pack_value (&bp, node->thunk.thunk_p && !boundary_p, 1);
> bp_pack_enum (&bp, ld_plugin_symbol_resolution,
> LDPR_NUM_KNOWN, node->resolution);
> + bp_pack_value (&bp, node->instrumentation_clone, 1);
> streamer_write_bitpack (&bp);
>
> if (node->thunk.thunk_p && !boundary_p)
> @@ -533,11 +534,15 @@ lto_output_node (struct lto_simple_output_block *ob,
> struct cgraph_node *node,
> streamer_write_uhwi_stream
> (ob->main_stream,
> 1 + (node->thunk.this_adjusting != 0) * 2
> - + (node->thunk.virtual_offset_p != 0) * 4);
> + + (node->thunk.virtual_offset_p != 0) * 4
> + + (node->thunk.add_pointer_bounds_args != 0) * 8);
> streamer_write_uhwi_stream (ob->main_stream, node->thunk.fixed_offset);
> streamer_write_uhwi_stream (ob->main_stream,
> node->thunk.virtual_value);
> }
> streamer_write_hwi_stream (ob->main_stream, node->profile_id);
> +
> + if (node->instrumentation_clone)
> + lto_output_fn_decl_index (ob->decl_state, ob->main_stream,
> node->orig_decl);
> }
>
> /* Output the varpool NODE to OB.
> @@ -613,7 +618,7 @@ lto_output_ref (struct lto_simple_output_block *ob,
> struct ipa_ref *ref,
> struct cgraph_node *node;
>
> bp = bitpack_create (ob->main_stream);
> - bp_pack_value (&bp, ref->use, 2);
> + bp_pack_value (&bp, ref->use, 3);
> bp_pack_value (&bp, ref->speculative, 1);
> streamer_write_bitpack (&bp);
> nref = lto_symtab_encoder_lookup (encoder, ref->referred);
> @@ -1002,6 +1007,7 @@ input_overwrite_node (struct lto_file_decl_data
> *file_data,
> node->thunk.thunk_p = bp_unpack_value (bp, 1);
> node->resolution = bp_unpack_enum (bp, ld_plugin_symbol_resolution,
> LDPR_NUM_KNOWN);
> + node->instrumentation_clone = bp_unpack_value (bp, 1);
> gcc_assert (flag_ltrans
> || (!node->in_other_partition
> && !node->used_from_other_partition));
> @@ -1112,10 +1118,19 @@ input_node (struct lto_file_decl_data *file_data,
> node->thunk.this_adjusting = (type & 2);
> node->thunk.virtual_value = virtual_value;
> node->thunk.virtual_offset_p = (type & 4);
> + node->thunk.add_pointer_bounds_args = (type & 8);
> }
> if (node->alias && !node->analyzed && node->weakref)
> node->alias_target = get_alias_symbol (node->decl);
> node->profile_id = streamer_read_hwi (ib);
> +
> + if (node->instrumentation_clone)
> + {
> + decl_index = streamer_read_uhwi (ib);
> + fn_decl = lto_file_decl_data_get_fn_decl (file_data, decl_index);
> + node->orig_decl = fn_decl;
> + }
> +
> return node;
> }
>
> @@ -1196,7 +1211,7 @@ input_ref (struct lto_input_block *ib,
> struct ipa_ref *ref;
>
> bp = streamer_read_bitpack (ib);
> - use = (enum ipa_ref_use) bp_unpack_value (&bp, 2);
> + use = (enum ipa_ref_use) bp_unpack_value (&bp, 3);
> speculative = (enum ipa_ref_use) bp_unpack_value (&bp, 1);
> node = nodes[streamer_read_hwi (ib)];
> ref = ipa_record_reference (referring_node, node, use, NULL);
> @@ -1337,6 +1352,22 @@ input_cgraph_1 (struct lto_file_decl_data *file_data,
> cgraph (node)->global.inlined_to = cgraph (nodes[ref]);
> else
> cnode->global.inlined_to = NULL;
> +
> + /* Compute instrumented_version. */
> + if (cnode->instrumentation_clone)
> + {
> + gcc_assert (cnode->orig_decl);
> +
> + cnode->instrumented_version = cgraph_get_node
> (cnode->orig_decl);
> + if (cnode->instrumented_version)
> + cnode->instrumented_version->instrumented_version = cnode;
> +
> + /* Restore decl names reference. */
> + if (IDENTIFIER_TRANSPARENT_ALIAS (DECL_ASSEMBLER_NAME
> (cnode->decl))
> + && !TREE_CHAIN (DECL_ASSEMBLER_NAME (cnode->decl)))
> + TREE_CHAIN (DECL_ASSEMBLER_NAME (cnode->decl))
> + = DECL_ASSEMBLER_NAME (cnode->orig_decl);
> + }
> }
>
> ref = (int) (intptr_t) node->same_comdat_group;
> diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h
> index 51b1903..62a5fe0 100644
> --- a/gcc/lto-streamer.h
> +++ b/gcc/lto-streamer.h
> @@ -141,7 +141,7 @@ along with GCC; see the file COPYING3. If not see
> #define LTO_SECTION_NAME_PREFIX ".gnu.lto_"
>
> #define LTO_major_version 3
> -#define LTO_minor_version 0
> +#define LTO_minor_version 1
>
> typedef unsigned char lto_decl_flags_t;
>
