+++ /dev/null
-/* Write and read any fix-up information generated by the WPA mode.
-
- Copyright 2009 Free Software Foundation, Inc.
- Contributed by Doug Kwan <dougkwan@google.com>
-
-This file is part of GCC.
-
-GCC is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 3, or (at your option) any later
-version.
-
-GCC is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY; without even the implied warranty of MERCHANTABILITY or
-FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
-for more details.
-
-You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING3. If not see
-<http://www.gnu.org/licenses/>. */
-
-#include "config.h"
-#include "system.h"
-#include "coretypes.h"
-#include "tm.h"
-#include "toplev.h"
-#include "tree.h"
-#include "expr.h"
-#include "flags.h"
-#include "cgraph.h"
-#include "function.h"
-#include "diagnostic.h"
-#include "vec.h"
-#include "bitmap.h"
-#include "timevar.h"
-#include "tree-flow.h"
-#include "tree-pass.h"
-#include "lto-streamer.h"
-
-/* LTO fix-up.
-
- In WPA mode, LTO cannot access function bodies. Some modifications in
- IR require additional updates in function bodies, which are not possible
- in WPA mode. So we write out information about these modifications for
- LTRANS to fix up the function bodies accordingly. */
-
-/* The vectors records function DECLs having multiple copies with different
- exception throwing attributes. We do not mark a DECL if all copies of it
- have the same exception throwing attribute. */
-static bitmap lto_nothrow_fndecls;
-
-/* We need to fix up GIMPLE bodies due to changes in exception setting.
- Consider this example:
-
- a.h:
- class a {
- public:
- a();
- ~a();
- };
-
- main.cc:
- #include "a.h"
-
- int
- main (int argc, char **argv)
- {
- a x;
- return 0;
- }
-
- a.cc:
- #include "a.h"
- a::a() {}
- a::~a() {}
-
- When main.cc is compiled, gcc only sees the constructor declaration, so
- the constructor and hence the call to it are marked as exception throwing.
- When a.cc is compiled, the body of the constructor is available and is
- obviously not exception throwing. Thus DECL of a::a in a.o has the NOTHROW
- attribute. When LTO runs, two DECLs of a::a with different exception
- attributes are merged. We want the merged DECL to be not exception
- throwing for better generated code. To do that, we need to fix up any
- function calls that have been marked as exception throwing. */
-
-/* Fix up all the call statements whose target fndecls might have changed
- to NOTHROW. Note that this problem is not WPA specific. We can also
- run into this problem in normal LTO with multiple input files. */
-
-void
-lto_fixup_nothrow_decls (void)
-{
- struct cgraph_node *node;
- struct cgraph_edge *edge;
- struct function *caller_function;
- gimple call_stmt;
-
- /* Quit if we are in WPA mode or have not marked any DECLs. */
- if (flag_wpa || !lto_nothrow_fndecls)
- return;
-
- /* For each node that has been marked, go over all call edges to it. */
- for (node = cgraph_nodes; node; node = node->next)
- if (bitmap_bit_p (lto_nothrow_fndecls, DECL_UID (node->decl)))
- {
- gcc_assert (TREE_NOTHROW (node->decl));
- for (edge = node->callers; edge; edge = edge->next_caller)
- {
- caller_function = DECL_STRUCT_FUNCTION (edge->caller->decl);
- call_stmt = edge->call_stmt;
- gcc_assert (call_stmt);
- if (lookup_stmt_eh_lp_fn (caller_function, call_stmt) != 0)
- remove_stmt_from_eh_lp_fn (caller_function, call_stmt);
- }
- }
-}
-
-/* Mark FNDECL as becoming not exception throwing. */
-
-void
-lto_mark_nothrow_fndecl (tree fndecl)
-{
- gcc_assert (TREE_CODE (fndecl) == FUNCTION_DECL);
- if (!lto_nothrow_fndecls)
- lto_nothrow_fndecls = lto_bitmap_alloc ();
-
- bitmap_set_bit (lto_nothrow_fndecls, DECL_UID (fndecl));
-}
-
-/* Write out fix-up information. Currently the only WPA fix-up
- information is the list of DECLs marked as not exception throwing. SET
- is a cgraph node set whose fix-up information is to be written. */
-
-static void
-lto_output_wpa_fixup (cgraph_node_set set)
-{
- struct lto_simple_output_block *ob;
- cgraph_node_set_iterator csi;
- tree fndecl;
- bitmap seen_decls;
- VEC(tree, heap) *decls = NULL;
- unsigned HOST_WIDE_INT i, count;
-
- ob = lto_create_simple_output_block (LTO_section_wpa_fixup);
-
- /* Accumulate the DECLs to be written out. Since we do not want
- duplicates, we need to use a bitmap and a vector to save the
- DECLs we want. Note that we need to check if lto_nothrow_fndecls
- is NULL. This happens when no DECL has been marked. */
- seen_decls = lto_bitmap_alloc ();
- if (lto_nothrow_fndecls)
- for (csi = csi_start (set); !csi_end_p (csi); csi_next (&csi))
- {
- struct cgraph_edge *e;
- struct cgraph_node *n;
-
- n = csi_node (csi);
- fndecl = n->decl;
-
- /* Check if the N's function is in the set of nothrow functions. */
- if (!bitmap_bit_p (seen_decls, DECL_UID (fndecl)))
- {
- bitmap_set_bit (seen_decls, (DECL_UID (fndecl)));
- if (bitmap_bit_p (lto_nothrow_fndecls, DECL_UID (fndecl)))
- VEC_safe_push (tree, heap, decls, fndecl);
- }
-
- /* Now check the callees and also add them if they are nothrow. This
- is needed because node N may end up in a different partition than
- its callees. In which case, when the file holding N is compiled,
- the calls it makes to nothrow functions will not be fixed up,
- causing verification issues. */
- for (e = n->callees; e; e = e->next_callee)
- {
- fndecl = e->callee->decl;
- if (!bitmap_bit_p (seen_decls, DECL_UID (fndecl)))
- {
- bitmap_set_bit (seen_decls, (DECL_UID (fndecl)));
- if (bitmap_bit_p (lto_nothrow_fndecls, DECL_UID (fndecl)))
- VEC_safe_push (tree, heap, decls, fndecl);
- }
- }
- }
-
- /* Write out number of DECLs, followed by the DECLs. */
- count = VEC_length (tree, decls);
- lto_output_uleb128_stream (ob->main_stream, count);
- for (i = 0; i < count; i++)
- {
- fndecl = VEC_index (tree, decls, i);
- lto_output_fn_decl_index (ob->decl_state, ob->main_stream, fndecl);
- }
-
- /* Release resources. */
- lto_destroy_simple_output_block (ob);
- VEC_free(tree, heap, decls);
- lto_bitmap_free (seen_decls);
-}
-
-/* Read in WPA fix-up information from one file. FILE_DATA points to
- DECL information of the file where as IB is the input block for the
- WPA fix-up section. */
-
-static void
-lto_input_wpa_fixup_1 (struct lto_file_decl_data *file_data,
- struct lto_input_block *ib)
-{
- unsigned HOST_WIDE_INT i, count, decl_index;
- tree fndecl;
-
- count = lto_input_uleb128 (ib);
- for (i = 0; i < count; i++)
- {
- decl_index = lto_input_uleb128 (ib);
- fndecl = lto_file_decl_data_get_fn_decl (file_data, decl_index);
- lto_mark_nothrow_fndecl (fndecl);
- }
-}
-
-/* Read in WPA fix-up information. */
-
-static void
-lto_input_wpa_fixup (void)
-{
- struct lto_file_decl_data ** file_data_vec
- = lto_get_file_decl_data ();
- struct lto_file_decl_data * file_data;
- int i = 0;
-
- /* Fix up information is only used in LTRANS mode. */
- if (!flag_ltrans)
- return;
-
- while ((file_data = file_data_vec[i++]))
- {
- const char *data;
- size_t len;
- struct lto_input_block *ib
- = lto_create_simple_input_block (file_data, LTO_section_wpa_fixup,
- &data, &len);
-
- lto_input_wpa_fixup_1 (file_data, ib);
- lto_destroy_simple_input_block (file_data, LTO_section_wpa_fixup, ib,
- data, len);
- }
-}
-
-/* Gate function for all lto streaming passes. */
-
-static bool
-gate_wpa_fixup (void)
-{
- return (flag_wpa || flag_ltrans) && gate_lto_out ();
-}
-
-struct ipa_opt_pass_d pass_ipa_lto_wpa_fixup =
-{
- {
- IPA_PASS,
- "lto_wpa_fixup", /* name */
- gate_wpa_fixup, /* gate */
- NULL, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_WHOPR_WPA_FIXUP, /* tv_id */
- 0, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_dump_func /* todo_flags_finish */
- },
- NULL, /* generate_summary */
- NULL, /* write_summary */
- NULL, /* read_summary */
- lto_output_wpa_fixup, /* write_optimization_summary */
- lto_input_wpa_fixup, /* read_optimization_summary */
- NULL, /* stmt_fixup */
- 0, /* TODOs */
- NULL, /* function_transform */
- NULL /* variable_transform */
-};
-
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