From b094d6c4bf572654a031ecc4afe675154c886dc5 Mon Sep 17 00:00:00 2001 From: Jing Yu Date: Thu, 22 Jul 2010 14:03:48 -0700 Subject: commit gcc-4.4.3 which is used to build gcc-4.4.3 Android toolchain in master. The source is based on fsf gcc-4.4.3 and contains local patches which are recorded in gcc-4.4.3/README.google. Change-Id: Id8c6d6927df274ae9749196a1cc24dbd9abc9887 --- gcc-4.4.3/gcc/varpool.c | 488 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 488 insertions(+) create mode 100644 gcc-4.4.3/gcc/varpool.c (limited to 'gcc-4.4.3/gcc/varpool.c') diff --git a/gcc-4.4.3/gcc/varpool.c b/gcc-4.4.3/gcc/varpool.c new file mode 100644 index 000000000..54ca343a2 --- /dev/null +++ b/gcc-4.4.3/gcc/varpool.c @@ -0,0 +1,488 @@ +/* Callgraph handling code. + Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 + Free Software Foundation, Inc. + Contributed by Jan Hubicka + +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 +. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "cgraph.h" +#include "langhooks.h" +#include "diagnostic.h" +#include "hashtab.h" +#include "ggc.h" +#include "timevar.h" +#include "debug.h" +#include "target.h" +#include "output.h" +#include "gimple.h" +#include "tree-flow.h" +#include "toplev.h" + +/* This file contains basic routines manipulating variable pool. + + Varpool acts as interface in between the front-end and middle-end + and drives the decision process on what variables and when are + going to be compiled. + + The varpool nodes are allocated lazily for declarations + either by frontend or at callgraph construction time. + All variables supposed to be output into final file needs to be + explicitly marked by frontend via VARPOOL_FINALIZE_DECL function. */ + +/* Hash table used to convert declarations into nodes. */ +static GTY((param_is (struct varpool_node))) htab_t varpool_hash; + +/* The linked list of cgraph varpool nodes. + Linked via node->next pointer. */ +struct varpool_node *varpool_nodes; + +/* Queue of cgraph nodes scheduled to be lowered and output. + The queue is maintained via mark_needed_node, linked via node->next_needed + pointer. + + LAST_NEEDED_NODE points to the end of queue, so it can be + maintained in forward order. GTY is needed to make it friendly to + PCH. + + During compilation we construct the queue of needed variables + twice: first time it is during cgraph construction, second time it is at the + end of compilation in VARPOOL_REMOVE_UNREFERENCED_DECLS so we can avoid + optimized out variables being output. + + Each variable is thus first analyzed and then later possibly output. + FIRST_UNANALYZED_NODE points to first node in queue that was not analyzed + yet and is moved via VARPOOL_ANALYZE_PENDING_DECLS. */ + +struct varpool_node *varpool_nodes_queue; +static GTY(()) struct varpool_node *varpool_last_needed_node; +static GTY(()) struct varpool_node *varpool_first_unanalyzed_node; + +/* Lists all assembled variables to be sent to debugger output later on. */ +static GTY(()) struct varpool_node *varpool_assembled_nodes_queue; + +/* Return name of the node used in debug output. */ +static const char * +varpool_node_name (struct varpool_node *node) +{ + return lang_hooks.decl_printable_name (node->decl, 2); +} + +/* Returns a hash code for P. */ +static hashval_t +hash_varpool_node (const void *p) +{ + const struct varpool_node *n = (const struct varpool_node *) p; + return (hashval_t) DECL_UID (n->decl); +} + +/* Returns nonzero if P1 and P2 are equal. */ +static int +eq_varpool_node (const void *p1, const void *p2) +{ + const struct varpool_node *n1 = + (const struct varpool_node *) p1; + const struct varpool_node *n2 = + (const struct varpool_node *) p2; + return DECL_UID (n1->decl) == DECL_UID (n2->decl); +} + +/* Return varpool node assigned to DECL. Create new one when needed. */ +struct varpool_node * +varpool_node (tree decl) +{ + struct varpool_node key, *node, **slot; + + gcc_assert (DECL_P (decl) && TREE_CODE (decl) != FUNCTION_DECL); + + if (!varpool_hash) + varpool_hash = htab_create_ggc (10, hash_varpool_node, + eq_varpool_node, NULL); + key.decl = decl; + slot = (struct varpool_node **) + htab_find_slot (varpool_hash, &key, INSERT); + if (*slot) + return *slot; + node = GGC_CNEW (struct varpool_node); + node->decl = decl; + node->order = cgraph_order++; + node->next = varpool_nodes; + varpool_nodes = node; + node->module_id = current_module_id; + *slot = node; + return node; +} + +/* Dump given cgraph node. */ +void +dump_varpool_node (FILE *f, struct varpool_node *node) +{ + fprintf (f, "%s:", varpool_node_name (node)); + fprintf (f, " availability:%s", + cgraph_function_flags_ready + ? cgraph_availability_names[cgraph_variable_initializer_availability (node)] + : "not-ready"); + if (DECL_INITIAL (node->decl)) + fprintf (f, " initialized"); + if (node->needed) + fprintf (f, " needed"); + if (node->analyzed) + fprintf (f, " analyzed"); + if (node->finalized) + fprintf (f, " finalized"); + if (node->output) + fprintf (f, " output"); + if (node->externally_visible) + fprintf (f, " externally_visible"); + fprintf (f, "\n"); +} + +/* Dump the variable pool. */ +void +dump_varpool (FILE *f) +{ + struct varpool_node *node; + + fprintf (f, "variable pool:\n\n"); + for (node = varpool_nodes; node; node = node->next) + dump_varpool_node (f, node); +} + +/* Given an assembler name, look up the node. */ + +struct varpool_node * +varpool_node_for_asm (tree asmname) +{ + struct varpool_node *node; + + for (node = varpool_nodes; node ; node = node->next) + if (decl_assembler_name_equal (node->decl, asmname)) + return node; + + return NULL; +} + +/* Helper function for finalization code - add node into lists so it will + be analyzed and compiled. */ + +static void +varpool_enqueue_needed_node (struct varpool_node *node) +{ + if (varpool_last_needed_node) + varpool_last_needed_node->next_needed = node; + varpool_last_needed_node = node; + node->next_needed = NULL; + if (!varpool_nodes_queue) + varpool_nodes_queue = node; + if (!varpool_first_unanalyzed_node) + varpool_first_unanalyzed_node = node; + notice_global_symbol (node->decl); +} + +/* Notify finalize_compilation_unit that given node is reachable + or needed. */ + +void +varpool_mark_needed_node (struct varpool_node *node) +{ + if (!node->needed && node->finalized + && !TREE_ASM_WRITTEN (node->decl)) + varpool_enqueue_needed_node (node); + node->needed = 1; +} + +/* Reset the queue of needed nodes. */ +void +varpool_reset_queue (void) +{ + varpool_last_needed_node = NULL; + varpool_nodes_queue = NULL; + varpool_first_unanalyzed_node = NULL; +} + +/* Determine if variable DECL is needed. That is, visible to something + either outside this translation unit, something magic in the system + configury */ +bool +decide_is_variable_needed (struct varpool_node *node, tree decl) +{ + /* If the user told us it is used, then it must be so. */ + if (node->externally_visible || node->force_output) + return true; + + /* ??? If the assembler name is set by hand, it is possible to assemble + the name later after finalizing the function and the fact is noticed + in assemble_name then. This is arguably a bug. */ + if (DECL_ASSEMBLER_NAME_SET_P (decl) + && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))) + return true; + + /* If we decided it was needed before, but at the time we didn't have + the definition available, then it's still needed. */ + if (node->needed) + return true; + + /* Externally visible variables must be output. The exception is + COMDAT variables that must be output only when they are needed. */ + if (TREE_PUBLIC (decl) && !flag_whole_program && !DECL_COMDAT (decl) + && !DECL_EXTERNAL (decl)) + return true; + + /* When emulating tls, we actually see references to the control + variable, rather than the user-level variable. */ + if (!targetm.have_tls + && TREE_CODE (decl) == VAR_DECL + && DECL_THREAD_LOCAL_P (decl)) + { + tree control = emutls_decl (decl); + if (decide_is_variable_needed (varpool_node (control), control)) + return true; + } + + /* When not reordering top level variables, we have to assume that + we are going to keep everything. */ + if (flag_toplevel_reorder) + return false; + + /* We want to emit COMDAT variables only when absolutely necessary. */ + if (DECL_COMDAT (decl)) + return false; + return true; +} + +/* Mark DECL as finalized. By finalizing the declaration, frontend instruct the + middle end to output the variable to asm file, if needed or externally + visible. */ +void +varpool_finalize_decl (tree decl) +{ + struct varpool_node *node = varpool_node (decl); + + /* The first declaration of a variable that comes through this function + decides whether it is global (in C, has external linkage) + or local (in C, has internal linkage). So do nothing more + if this function has already run. */ + if (node->finalized) + { + if (cgraph_global_info_ready) + varpool_assemble_pending_decls (); + return; + } + if (node->needed) + varpool_enqueue_needed_node (node); + node->finalized = true; + + if (decide_is_variable_needed (node, decl)) + varpool_mark_needed_node (node); + /* Since we reclaim unreachable nodes at the end of every language + level unit, we need to be conservative about possible entry points + there. */ + else if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl)) + varpool_mark_needed_node (node); + if (cgraph_global_info_ready) + varpool_assemble_pending_decls (); +} + +/* Return variable availability. See cgraph.h for description of individual + return values. */ +enum availability +cgraph_variable_initializer_availability (struct varpool_node *node) +{ + gcc_assert (cgraph_function_flags_ready); + if (!node->finalized) + return AVAIL_NOT_AVAILABLE; + if (!TREE_PUBLIC (node->decl)) + return AVAIL_AVAILABLE; + /* If the variable can be overwritten, return OVERWRITABLE. Takes + care of at least two notable extensions - the COMDAT variables + used to share template instantiations in C++. */ + if (!(*targetm.binds_local_p) (node->decl) && !DECL_COMDAT (node->decl)) + return AVAIL_OVERWRITABLE; + return AVAIL_AVAILABLE; +} + +/* Walk the decls we marked as necessary and see if they reference new + variables or functions and add them into the worklists. */ +bool +varpool_analyze_pending_decls (void) +{ + bool changed = false; + timevar_push (TV_CGRAPH); + + while (varpool_first_unanalyzed_node) + { + tree decl = varpool_first_unanalyzed_node->decl; + + varpool_first_unanalyzed_node->analyzed = true; + + varpool_first_unanalyzed_node = varpool_first_unanalyzed_node->next_needed; + + /* Compute the alignment early so function body expanders are + already informed about increased alignment. */ + align_variable (decl, 0); + + if (DECL_INITIAL (decl)) + record_references_in_initializer (decl); + changed = true; + } + timevar_pop (TV_CGRAPH); + return changed; +} + +/* Output one variable, if necessary. Return whether we output it. */ +bool +varpool_assemble_decl (struct varpool_node *node) +{ + tree decl = node->decl; + + if (!TREE_ASM_WRITTEN (decl) + && !node->alias + && !DECL_EXTERNAL (decl) + && (TREE_CODE (decl) != VAR_DECL || !DECL_HAS_VALUE_EXPR_P (decl))) + { + assemble_variable (decl, 0, 1, 0); + if (TREE_ASM_WRITTEN (decl)) + { + node->next_needed = varpool_assembled_nodes_queue; + varpool_assembled_nodes_queue = node; + node->finalized = 1; + return true; + } + } + + return false; +} + +/* Optimization of function bodies might've rendered some variables as + unnecessary so we want to avoid these from being compiled. + + This is done by pruning the queue and keeping only the variables that + really appear needed (ie they are either externally visible or referenced + by compiled function). Re-doing the reachability analysis on variables + brings back the remaining variables referenced by these. */ +void +varpool_remove_unreferenced_decls (void) +{ + struct varpool_node *next, *node = varpool_nodes_queue; + + varpool_reset_queue (); + + if (errorcount || sorrycount) + return; + + while (node) + { + tree decl = node->decl; + next = node->next_needed; + node->needed = 0; + + if (node->finalized + && (decide_is_variable_needed (node, decl) + /* ??? Cgraph does not yet rule the world with an iron hand, + and does not control the emission of debug information. + After a variable has its DECL_RTL set, we must assume that + it may be referenced by the debug information, and we can + no longer elide it. */ + || DECL_RTL_SET_P (decl))) + varpool_mark_needed_node (node); + + node = next; + } + /* Make sure we mark alias targets as used targets. */ + finish_aliases_1 (); + varpool_analyze_pending_decls (); +} + +/* Output all variables enqueued to be assembled. */ +bool +varpool_assemble_pending_decls (void) +{ + bool changed = false; + + if (errorcount || sorrycount) + return false; + + /* EH might mark decls as needed during expansion. This should be safe since + we don't create references to new function, but it should not be used + elsewhere. */ + varpool_analyze_pending_decls (); + + while (varpool_nodes_queue) + { + struct varpool_node *node = varpool_nodes_queue; + + varpool_nodes_queue = varpool_nodes_queue->next_needed; + if (varpool_assemble_decl (node)) + changed = true; + else + node->next_needed = NULL; + } + /* varpool_nodes_queue is now empty, clear the pointer to the last element + in the queue. */ + varpool_last_needed_node = NULL; + return changed; +} + +/* Remove all elements from the queue so we can re-use it for debug output. */ +void +varpool_empty_needed_queue (void) +{ + /* EH might mark decls as needed during expansion. This should be safe since + we don't create references to new function, but it should not be used + elsewhere. */ + varpool_analyze_pending_decls (); + + while (varpool_nodes_queue) + { + struct varpool_node *node = varpool_nodes_queue; + varpool_nodes_queue = varpool_nodes_queue->next_needed; + node->next_needed = NULL; + } + /* varpool_nodes_queue is now empty, clear the pointer to the last element + in the queue. */ + varpool_last_needed_node = NULL; +} + +/* Create a new global variable of type TYPE. */ +tree +add_new_static_var (tree type) +{ + tree new_decl; + struct varpool_node *new_node; + + new_decl = create_tmp_var (type, NULL); + DECL_NAME (new_decl) = create_tmp_var_name (NULL); + TREE_READONLY (new_decl) = 0; + TREE_STATIC (new_decl) = 1; + TREE_USED (new_decl) = 1; + DECL_CONTEXT (new_decl) = NULL_TREE; + DECL_ABSTRACT (new_decl) = 0; + lang_hooks.dup_lang_specific_decl (new_decl); + create_var_ann (new_decl); + new_node = varpool_node (new_decl); + varpool_mark_needed_node (new_node); + add_referenced_var (new_decl); + varpool_finalize_decl (new_decl); + + return new_node->decl; +} + +#include "gt-varpool.h" -- cgit v1.2.3