| /* Tree lowering pass. This pass gimplifies the tree representation built |
| by the C-based front ends. The structure of gimplified, or |
| language-independent, trees is dictated by the grammar described in this |
| file. |
| Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
| Lowering of expressions contributed by Sebastian Pop <s.pop@laposte.net> |
| Re-written to support lowering of whole function trees, documentation |
| and miscellaneous cleanups by Diego Novillo <dnovillo@redhat.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 2, 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 COPYING. If not, write to the Free |
| Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301, USA. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "tm.h" |
| #include "tree.h" |
| #include "varray.h" |
| #include "c-tree.h" |
| #include "c-common.h" |
| #include "tree-gimple.h" |
| #include "hard-reg-set.h" |
| #include "basic-block.h" |
| #include "tree-flow.h" |
| #include "tree-inline.h" |
| #include "diagnostic.h" |
| #include "langhooks.h" |
| #include "langhooks-def.h" |
| #include "flags.h" |
| #include "rtl.h" |
| #include "toplev.h" |
| #include "tree-dump.h" |
| #include "c-pretty-print.h" |
| #include "cgraph.h" |
| |
| |
| /* The gimplification pass converts the language-dependent trees |
| (ld-trees) emitted by the parser into language-independent trees |
| (li-trees) that are the target of SSA analysis and transformations. |
| |
| Language-independent trees are based on the SIMPLE intermediate |
| representation used in the McCAT compiler framework: |
| |
| "Designing the McCAT Compiler Based on a Family of Structured |
| Intermediate Representations," |
| L. Hendren, C. Donawa, M. Emami, G. Gao, Justiani, and B. Sridharan, |
| Proceedings of the 5th International Workshop on Languages and |
| Compilers for Parallel Computing, no. 757 in Lecture Notes in |
| Computer Science, New Haven, Connecticut, pp. 406-420, |
| Springer-Verlag, August 3-5, 1992. |
| |
| http://www-acaps.cs.mcgill.ca/info/McCAT/McCAT.html |
| |
| Basically, we walk down gimplifying the nodes that we encounter. As we |
| walk back up, we check that they fit our constraints, and copy them |
| into temporaries if not. */ |
| |
| /* Gimplification of statement trees. */ |
| |
| /* Convert the tree representation of FNDECL from C frontend trees to |
| GENERIC. */ |
| |
| void |
| c_genericize (tree fndecl) |
| { |
| FILE *dump_orig; |
| int local_dump_flags; |
| struct cgraph_node *cgn; |
| |
| /* Dump the C-specific tree IR. */ |
| dump_orig = dump_begin (TDI_original, &local_dump_flags); |
| if (dump_orig) |
| { |
| fprintf (dump_orig, "\n;; Function %s", |
| lang_hooks.decl_printable_name (fndecl, 2)); |
| fprintf (dump_orig, " (%s)\n", |
| IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl))); |
| fprintf (dump_orig, ";; enabled by -%s\n", dump_flag_name (TDI_original)); |
| fprintf (dump_orig, "\n"); |
| |
| if (local_dump_flags & TDF_RAW) |
| dump_node (DECL_SAVED_TREE (fndecl), |
| TDF_SLIM | local_dump_flags, dump_orig); |
| else |
| print_c_tree (dump_orig, DECL_SAVED_TREE (fndecl)); |
| fprintf (dump_orig, "\n"); |
| |
| dump_end (TDI_original, dump_orig); |
| } |
| |
| /* Go ahead and gimplify for now. */ |
| gimplify_function_tree (fndecl); |
| |
| /* Dump the genericized tree IR. */ |
| dump_function (TDI_generic, fndecl); |
| |
| /* Genericize all nested functions now. We do things in this order so |
| that items like VLA sizes are expanded properly in the context of |
| the correct function. */ |
| cgn = cgraph_node (fndecl); |
| for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) |
| c_genericize (cgn->decl); |
| } |
| |
| static void |
| add_block_to_enclosing (tree block) |
| { |
| tree enclosing; |
| |
| for (enclosing = gimple_current_bind_expr (); |
| enclosing; enclosing = TREE_CHAIN (enclosing)) |
| if (BIND_EXPR_BLOCK (enclosing)) |
| break; |
| |
| enclosing = BIND_EXPR_BLOCK (enclosing); |
| BLOCK_SUBBLOCKS (enclosing) = chainon (BLOCK_SUBBLOCKS (enclosing), block); |
| } |
| |
| /* Genericize a scope by creating a new BIND_EXPR. |
| BLOCK is either a BLOCK representing the scope or a chain of _DECLs. |
| In the latter case, we need to create a new BLOCK and add it to the |
| BLOCK_SUBBLOCKS of the enclosing block. |
| BODY is a chain of C _STMT nodes for the contents of the scope, to be |
| genericized. */ |
| |
| tree |
| c_build_bind_expr (tree block, tree body) |
| { |
| tree decls, bind; |
| |
| if (block == NULL_TREE) |
| decls = NULL_TREE; |
| else if (TREE_CODE (block) == BLOCK) |
| decls = BLOCK_VARS (block); |
| else |
| { |
| decls = block; |
| if (DECL_ARTIFICIAL (decls)) |
| block = NULL_TREE; |
| else |
| { |
| block = make_node (BLOCK); |
| BLOCK_VARS (block) = decls; |
| add_block_to_enclosing (block); |
| } |
| } |
| |
| if (!body) |
| body = build_empty_stmt (); |
| if (decls || block) |
| { |
| bind = build3 (BIND_EXPR, void_type_node, decls, body, block); |
| TREE_SIDE_EFFECTS (bind) = 1; |
| } |
| else |
| bind = body; |
| |
| return bind; |
| } |
| |
| /* Gimplification of expression trees. */ |
| |
| /* Gimplify a C99 compound literal expression. This just means adding |
| the DECL_EXPR before the current statement and using its anonymous |
| decl instead. */ |
| |
| static enum gimplify_status |
| gimplify_compound_literal_expr (tree *expr_p, tree *pre_p) |
| { |
| tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (*expr_p); |
| tree decl = DECL_EXPR_DECL (decl_s); |
| |
| /* This decl isn't mentioned in the enclosing block, so add it to the |
| list of temps. FIXME it seems a bit of a kludge to say that |
| anonymous artificial vars aren't pushed, but everything else is. */ |
| if (DECL_NAME (decl) == NULL_TREE && !DECL_SEEN_IN_BIND_EXPR_P (decl)) |
| gimple_add_tmp_var (decl); |
| |
| gimplify_and_add (decl_s, pre_p); |
| *expr_p = decl; |
| return GS_OK; |
| } |
| |
| /* Do C-specific gimplification. Args are as for gimplify_expr. */ |
| |
| int |
| c_gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p ATTRIBUTE_UNUSED) |
| { |
| enum tree_code code = TREE_CODE (*expr_p); |
| |
| switch (code) |
| { |
| case DECL_EXPR: |
| /* This is handled mostly by gimplify.c, but we have to deal with |
| not warning about int x = x; as it is a GCC extension to turn off |
| this warning but only if warn_init_self is zero. */ |
| if (TREE_CODE (DECL_EXPR_DECL (*expr_p)) == VAR_DECL |
| && !DECL_EXTERNAL (DECL_EXPR_DECL (*expr_p)) |
| && !TREE_STATIC (DECL_EXPR_DECL (*expr_p)) |
| && (DECL_INITIAL (DECL_EXPR_DECL (*expr_p)) |
| == DECL_EXPR_DECL (*expr_p)) |
| && !warn_init_self) |
| TREE_NO_WARNING (DECL_EXPR_DECL (*expr_p)) = 1; |
| return GS_UNHANDLED; |
| |
| case COMPOUND_LITERAL_EXPR: |
| return gimplify_compound_literal_expr (expr_p, pre_p); |
| |
| default: |
| return GS_UNHANDLED; |
| } |
| } |