1 /* Tree lowering pass. This pass gimplifies the tree representation built
2 by the C-based front ends. The structure of gimplified, or
3 language-independent, trees is dictated by the grammar described in this
5 Copyright (C) 2002-2013 Free Software Foundation, Inc.
6 Lowering of expressions contributed by Sebastian Pop <s.pop@laposte.net>
7 Re-written to support lowering of whole function trees, documentation
8 and miscellaneous cleanups by Diego Novillo <dnovillo@redhat.com>
10 This file is part of GCC.
12 GCC is free software; you can redistribute it and/or modify it under
13 the terms of the GNU General Public License as published by the Free
14 Software Foundation; either version 3, or (at your option) any later
17 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
18 WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 You should have received a copy of the GNU General Public License
23 along with GCC; see the file COPYING3. If not see
24 <http://www.gnu.org/licenses/>. */
28 #include "coretypes.h"
33 #include "tree-inline.h"
34 #include "diagnostic-core.h"
35 #include "langhooks.h"
36 #include "langhooks-def.h"
39 #include "c-pretty-print.h"
43 /* The gimplification pass converts the language-dependent trees
44 (ld-trees) emitted by the parser into language-independent trees
45 (li-trees) that are the target of SSA analysis and transformations.
47 Language-independent trees are based on the SIMPLE intermediate
48 representation used in the McCAT compiler framework:
50 "Designing the McCAT Compiler Based on a Family of Structured
51 Intermediate Representations,"
52 L. Hendren, C. Donawa, M. Emami, G. Gao, Justiani, and B. Sridharan,
53 Proceedings of the 5th International Workshop on Languages and
54 Compilers for Parallel Computing, no. 757 in Lecture Notes in
55 Computer Science, New Haven, Connecticut, pp. 406-420,
56 Springer-Verlag, August 3-5, 1992.
58 http://www-acaps.cs.mcgill.ca/info/McCAT/McCAT.html
60 Basically, we walk down gimplifying the nodes that we encounter. As we
61 walk back up, we check that they fit our constraints, and copy them
62 into temporaries if not. */
64 /* Gimplification of statement trees. */
66 /* Convert the tree representation of FNDECL from C frontend trees to
70 c_genericize (tree fndecl
)
74 struct cgraph_node
*cgn
;
76 /* Dump the C-specific tree IR. */
77 dump_orig
= dump_begin (TDI_original
, &local_dump_flags
);
80 fprintf (dump_orig
, "\n;; Function %s",
81 lang_hooks
.decl_printable_name (fndecl
, 2));
82 fprintf (dump_orig
, " (%s)\n",
83 (!DECL_ASSEMBLER_NAME_SET_P (fndecl
) ? "null"
84 : IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl
))));
85 fprintf (dump_orig
, ";; enabled by -%s\n", dump_flag_name (TDI_original
));
86 fprintf (dump_orig
, "\n");
88 if (local_dump_flags
& TDF_RAW
)
89 dump_node (DECL_SAVED_TREE (fndecl
),
90 TDF_SLIM
| local_dump_flags
, dump_orig
);
92 print_c_tree (dump_orig
, DECL_SAVED_TREE (fndecl
));
93 fprintf (dump_orig
, "\n");
95 dump_end (TDI_original
, dump_orig
);
98 /* Dump all nested functions now. */
99 cgn
= cgraph_get_create_node (fndecl
);
100 for (cgn
= cgn
->nested
; cgn
; cgn
= cgn
->next_nested
)
101 c_genericize (cgn
->symbol
.decl
);
105 add_block_to_enclosing (tree block
)
110 vec
<gimple
> stack
= gimple_bind_expr_stack ();
112 FOR_EACH_VEC_ELT (stack
, i
, bind
)
113 if (gimple_bind_block (bind
))
116 enclosing
= gimple_bind_block (bind
);
117 BLOCK_SUBBLOCKS (enclosing
) = chainon (BLOCK_SUBBLOCKS (enclosing
), block
);
120 /* Genericize a scope by creating a new BIND_EXPR.
121 BLOCK is either a BLOCK representing the scope or a chain of _DECLs.
122 In the latter case, we need to create a new BLOCK and add it to the
123 BLOCK_SUBBLOCKS of the enclosing block.
124 BODY is a chain of C _STMT nodes for the contents of the scope, to be
128 c_build_bind_expr (location_t loc
, tree block
, tree body
)
132 if (block
== NULL_TREE
)
134 else if (TREE_CODE (block
) == BLOCK
)
135 decls
= BLOCK_VARS (block
);
139 if (DECL_ARTIFICIAL (decls
))
143 block
= make_node (BLOCK
);
144 BLOCK_VARS (block
) = decls
;
145 add_block_to_enclosing (block
);
150 body
= build_empty_stmt (loc
);
153 bind
= build3 (BIND_EXPR
, void_type_node
, decls
, body
, block
);
154 TREE_SIDE_EFFECTS (bind
) = 1;
155 SET_EXPR_LOCATION (bind
, loc
);
163 /* Gimplification of expression trees. */
165 /* Do C-specific gimplification on *EXPR_P. PRE_P and POST_P are as in
169 c_gimplify_expr (tree
*expr_p
, gimple_seq
*pre_p ATTRIBUTE_UNUSED
,
170 gimple_seq
*post_p ATTRIBUTE_UNUSED
)
172 enum tree_code code
= TREE_CODE (*expr_p
);
177 /* This is handled mostly by gimplify.c, but we have to deal with
178 not warning about int x = x; as it is a GCC extension to turn off
179 this warning but only if warn_init_self is zero. */
180 if (TREE_CODE (DECL_EXPR_DECL (*expr_p
)) == VAR_DECL
181 && !DECL_EXTERNAL (DECL_EXPR_DECL (*expr_p
))
182 && !TREE_STATIC (DECL_EXPR_DECL (*expr_p
))
183 && (DECL_INITIAL (DECL_EXPR_DECL (*expr_p
)) == DECL_EXPR_DECL (*expr_p
))
185 TREE_NO_WARNING (DECL_EXPR_DECL (*expr_p
)) = 1;
188 case PREINCREMENT_EXPR
:
189 case PREDECREMENT_EXPR
:
190 case POSTINCREMENT_EXPR
:
191 case POSTDECREMENT_EXPR
:
193 tree type
= TREE_TYPE (TREE_OPERAND (*expr_p
, 0));
194 if (INTEGRAL_TYPE_P (type
) && c_promoting_integer_type_p (type
))
196 if (TYPE_OVERFLOW_UNDEFINED (type
))
197 type
= unsigned_type_for (type
);
198 return gimplify_self_mod_expr (expr_p
, pre_p
, post_p
, 1, type
);