This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: [gimplefe] Parsing __GIMPLE function body
- From: Prasad Ghangal <prasad dot ghangal at gmail dot com>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: gcc Mailing List <gcc at gcc dot gnu dot org>, David Malcolm <dmalcolm at redhat dot com>, Prathamesh Kulkarni <prathamesh dot kulkarni at linaro dot org>
- Date: Mon, 6 Jun 2016 14:57:44 +0530
- Subject: Re: [gimplefe] Parsing __GIMPLE function body
- Authentication-results: sourceware.org; auth=none
- References: <CAE+uiWYTNOnK-MWB8qicpVU9aO-ZX0praDmTyzO4ipv=UqBrwA at mail dot gmail dot com> <CAFiYyc1CLrDu+C88s+MjSq9Zgq8SAEdcn5ayijPn5DEf6FqpLA at mail dot gmail dot com>
Hi,
This patch parses simple assignment statement
int a;
void __GIMPLE foo()
{
a = 1;
}
but it does not produce gimple dump. In debugging I found that
cfun->gimple_body is not NULL and it contains GIMPLE_ASSIGN statement.
Am I missing something ?
Thanks,
Prasad Ghangal
On 31 May 2016 at 15:57, Richard Biener <richard.guenther@gmail.com> wrote:
> On Mon, May 30, 2016 at 5:15 PM, Prasad Ghangal
> <prasad.ghangal@gmail.com> wrote:
>> Hi,
>>
>> As David suggested in his rtlfe patch,
>> this patch recognizes __GIMPLE keyword and switches to
>> c_parser_parse_gimple_body by providing -fgimple option.
>>
>>
>> diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
>> index 4568cf6..41a8f05 100644
>> --- a/gcc/c-family/c-common.c
>> +++ b/gcc/c-family/c-common.c
>> @@ -511,6 +511,7 @@ const struct c_common_resword c_common_reswords[] =
>> { "__underlying_type", RID_UNDERLYING_TYPE, D_CXXONLY },
>> { "__volatile", RID_VOLATILE, 0 },
>> { "__volatile__", RID_VOLATILE, 0 },
>> + { "__GIMPLE", RID_GIMPLE, 0 },
>
> I think we need a D_GIMPLE_ONLY flag which disables this reserved word
> when -fgimple is not
> in effect. That's something to put on a list of TODOs once everything
> else works fine (it's not
> high priority but a requirement to merge to trunk). For now you can
> at least put D_CONLY there
> (as -fgimple is a C only flag).
>
>> { "alignas", RID_ALIGNAS, D_CXXONLY | D_CXX11 | D_CXXWARN },
>> { "alignof", RID_ALIGNOF, D_CXXONLY | D_CXX11 | D_CXXWARN },
>> { "asm", RID_ASM, D_ASM },
>> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
>> index 0295532..23a401d 100644
>> --- a/gcc/c-family/c-common.h
>> +++ b/gcc/c-family/c-common.h
>> @@ -104,6 +104,9 @@ enum rid
>> RID_DFLOAT32, RID_DFLOAT64, RID_DFLOAT128,
>> RID_FRACT, RID_ACCUM, RID_AUTO_TYPE, RID_BUILTIN_CALL_WITH_STATIC_CHAIN,
>>
>> + /* "__GIMPLE", for the GIMPLE-parsing extension to the C frontend. */
>> + RID_GIMPLE,
>> +
>> /* C11 */
>> RID_ALIGNAS, RID_GENERIC,
>>
>> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
>> index 918df16..8ab56af 100644
>> --- a/gcc/c-family/c.opt
>> +++ b/gcc/c-family/c.opt
>> @@ -200,6 +200,10 @@ F
>> Driver C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path
>> after %qs)
>> -F <dir> Add <dir> to the end of the main framework include path.
>>
>> +fgimple
>> +C Var(flag_gimple) Init(0)
>> +Enable parsing GIMPLE
>> +
>> H
>> C ObjC C++ ObjC++
>> Print the name of header files as they are used.
>> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
>> index 1cf4fb4..c5a4d3f 100644
>> --- a/gcc/c/c-parser.c
>> +++ b/gcc/c/c-parser.c
>> @@ -1396,6 +1396,7 @@ static bool c_parser_cilk_verify_simd (c_parser
>> *, enum pragma_context);
>> static tree c_parser_array_notation (location_t, c_parser *, tree, tree);
>> static tree c_parser_cilk_clause_vectorlength (c_parser *, tree, bool);
>> static void c_parser_cilk_grainsize (c_parser *, bool *);
>> +static void c_parser_parse_gimple_body (c_parser *parser);
>>
>> /* Parse a translation unit (C90 6.7, C99 6.9).
>>
>> @@ -1638,6 +1639,7 @@ c_parser_declaration_or_fndef (c_parser *parser,
>> bool fndef_ok,
>> tree all_prefix_attrs;
>> bool diagnosed_no_specs = false;
>> location_t here = c_parser_peek_token (parser)->location;
>> + bool gimple_body_p = false;
>>
>> if (static_assert_ok
>> && c_parser_next_token_is_keyword (parser, RID_STATIC_ASSERT))
>> @@ -1687,6 +1689,17 @@ c_parser_declaration_or_fndef (c_parser
>> *parser, bool fndef_ok,
>> c_parser_skip_to_end_of_block_or_statement (parser);
>> return;
>> }
>> +
>> + if (c_parser_next_token_is (parser, CPP_KEYWORD))
>> + {
>> + c_token *kw_token = c_parser_peek_token (parser);
>> + if (kw_token->keyword == RID_GIMPLE)
>> + {
>> + gimple_body_p = true;
>> + c_parser_consume_token (parser);
>> + }
>> + }
>> +
>> finish_declspecs (specs);
>> bool auto_type_p = specs->typespec_word == cts_auto_type;
>> if (c_parser_next_token_is (parser, CPP_SEMICOLON))
>> @@ -2102,6 +2115,14 @@ c_parser_declaration_or_fndef (c_parser
>> *parser, bool fndef_ok,
>> oacc_routine_clauses, false, first, true);
>> DECL_STRUCT_FUNCTION (current_function_decl)->function_start_locus
>> = c_parser_peek_token (parser)->location;
>> +
>> + if (gimple_body_p && flag_gimple)
>> + {
>> + c_parser_parse_gimple_body (parser);
>> + finish_function ();
>> + return;
>> + }
>> +
>> fnbody = c_parser_compound_statement (parser);
>> if (flag_cilkplus && contains_array_notation_expr (fnbody))
>> fnbody = expand_array_notation_exprs (fnbody);
>> @@ -2123,7 +2144,7 @@ c_parser_declaration_or_fndef (c_parser *parser,
>> bool fndef_ok,
>> add_stmt (fnbody);
>> finish_function ();
>> }
>> -
>> +
>> timevar_pop (tv);
>> break;
>> }
>
> Always avoid stay changes like this.
>
>> @@ -18055,4 +18076,23 @@ c_parser_array_notation (location_t loc,
>> c_parser *parser, tree initial_index,
>> return value_tree;
>> }
>>
>> +/* Parse the body of a function declaration marked with "__GIMPLE". */
>> +
>> +void
>> +c_parser_parse_gimple_body (c_parser *parser)
>> +{
>> + if (!c_parser_require (parser, CPP_OPEN_BRACE, "expected %<{%>"))
>> + return;
>> +
>> + location_t loc1 = c_parser_peek_token (parser)->location;
>> + inform (loc1, "start of GIMPLE");
>> +
>> + while (c_parser_next_token_is_not (parser, CPP_CLOSE_BRACE))
>> + {
>> + c_parser_consume_token (parser);
>> + }
>> +
>> + c_parser_consume_token (parser);
>> +}
>> +
>> #include "gt-c-c-parser.h"
>>
>>
>>
>>
>> GIMPLE function body consists of GIMPLE statements. For parsing GIMPLE
>> function body, we need to populate gimple body with gimple statements
>> which will emit GIMPLE as it is.
>>
>> I would like to hear suggestions about how can I emit GIMPLE directly from FE.
>
> You should be able to use gimple_build_* functions declared in gimple.h, for
> example
>
> stmt = gimple_build_assign (res, PLUS_EXPR, op0, op1);
>
> will build an assignment to res computing op0 + op1. res, op0 and op1 can be
> most easily parsed using the appropriate C parsing functions for identifiers.
>
> You'll need to queue stmts you built in a gimple_seq and attach that to the
> function via gimple_set_body (fndecl, sequence).
>
> I suggest you try with a "simple" example like
>
> int a;
>
> __GIMPLE void foo (void)
> {
> a = 1;
> }
>
> going forward with handling a = 1 + 2; and then, sth you'll need very quickly,
> handle local declarations like
>
> int a;
> __GIMPLE int foo (void)
> {
> int b;
> b = a;
> b = b + 1;
> a = b;
> }
>
> this is sth C code like int foo (void) { a = a + 1; } is gimplified to.
>
> Richard.
>
>>
>>
>> Thanks,
>> Prasad Ghangal
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 4568cf6..f2e62ca 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -511,6 +511,7 @@ const struct c_common_resword c_common_reswords[] =
{ "__underlying_type", RID_UNDERLYING_TYPE, D_CXXONLY },
{ "__volatile", RID_VOLATILE, 0 },
{ "__volatile__", RID_VOLATILE, 0 },
+ { "__GIMPLE", RID_GIMPLE, D_CONLY },
{ "alignas", RID_ALIGNAS, D_CXXONLY | D_CXX11 | D_CXXWARN },
{ "alignof", RID_ALIGNOF, D_CXXONLY | D_CXX11 | D_CXXWARN },
{ "asm", RID_ASM, D_ASM },
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 0295532..23a401d 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -104,6 +104,9 @@ enum rid
RID_DFLOAT32, RID_DFLOAT64, RID_DFLOAT128,
RID_FRACT, RID_ACCUM, RID_AUTO_TYPE, RID_BUILTIN_CALL_WITH_STATIC_CHAIN,
+ /* "__GIMPLE", for the GIMPLE-parsing extension to the C frontend. */
+ RID_GIMPLE,
+
/* C11 */
RID_ALIGNAS, RID_GENERIC,
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 918df16..8ab56af 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -200,6 +200,10 @@ F
Driver C ObjC C++ ObjC++ Joined Separate MissingArgError(missing path after %qs)
-F <dir> Add <dir> to the end of the main framework include path.
+fgimple
+C Var(flag_gimple) Init(0)
+Enable parsing GIMPLE
+
H
C ObjC C++ ObjC++
Print the name of header files as they are used.
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index bca8653..f2f5b5a 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -58,6 +58,7 @@ along with GCC; see the file COPYING3. If not see
#include "c-family/c-indentation.h"
#include "gimple-expr.h"
#include "context.h"
+#include "tree-pass.h"
/* We need to walk over decls with incomplete struct/union/enum types
after parsing the whole translation unit.
@@ -1396,6 +1397,11 @@ static bool c_parser_cilk_verify_simd (c_parser *, enum pragma_context);
static tree c_parser_array_notation (location_t, c_parser *, tree, tree);
static tree c_parser_cilk_clause_vectorlength (c_parser *, tree, bool);
static void c_parser_cilk_grainsize (c_parser *, bool *);
+static void c_parser_parse_gimple_body (c_parser *);
+static void c_parser_gimple_compound_statement (c_parser *, gimple_seq *);
+static void c_finish_gimple_expr_stmt (tree, gimple_seq *);
+extern gimple *gimple_build_assign (tree, tree CXX_MEM_STAT_INFO);
+extern void gimple_seq_add_stmt (gimple_seq *, gimple *);
/* Parse a translation unit (C90 6.7, C99 6.9).
@@ -1638,6 +1644,7 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok,
tree all_prefix_attrs;
bool diagnosed_no_specs = false;
location_t here = c_parser_peek_token (parser)->location;
+ bool gimple_body_p = false;
if (static_assert_ok
&& c_parser_next_token_is_keyword (parser, RID_STATIC_ASSERT))
@@ -1687,6 +1694,17 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok,
c_parser_skip_to_end_of_block_or_statement (parser);
return;
}
+
+ if (c_parser_next_token_is (parser, CPP_KEYWORD))
+ {
+ c_token *kw_token = c_parser_peek_token (parser);
+ if (kw_token->keyword == RID_GIMPLE)
+ {
+ gimple_body_p = true;
+ c_parser_consume_token (parser);
+ }
+ }
+
finish_declspecs (specs);
bool auto_type_p = specs->typespec_word == cts_auto_type;
if (c_parser_next_token_is (parser, CPP_SEMICOLON))
@@ -2102,6 +2120,15 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok,
oacc_routine_clauses, false, first, true);
DECL_STRUCT_FUNCTION (current_function_decl)->function_start_locus
= c_parser_peek_token (parser)->location;
+
+ if (gimple_body_p && flag_gimple)
+ {
+ c_parser_parse_gimple_body (parser);
+ finish_function ();
+ timevar_pop (tv);
+ return;
+ }
+
fnbody = c_parser_compound_statement (parser);
if (flag_cilkplus && contains_array_notation_expr (fnbody))
fnbody = expand_array_notation_exprs (fnbody);
@@ -18070,4 +18097,97 @@ c_parser_array_notation (location_t loc, c_parser *parser, tree initial_index,
return value_tree;
}
+/* Parse the body of a function declaration marked with "__GIMPLE". */
+
+void
+c_parser_parse_gimple_body (c_parser *parser)
+{
+ gimple_seq seq;
+ location_t loc1 = c_parser_peek_token (parser)->location;
+ inform (loc1, "start of GIMPLE");
+ seq = NULL;
+ c_parser_gimple_compound_statement (parser, &seq);
+ gimple_set_body (current_function_decl, seq);
+ cfun->curr_properties = PROP_gimple_any;
+ return;
+}
+
+/* Parser a compound statement in gimple function body */
+
+static void
+c_parser_gimple_compound_statement (c_parser *parser, gimple_seq *seq)
+{
+ location_t brace_loc;
+ brace_loc = c_parser_peek_token (parser)->location;
+ if (!c_parser_require (parser, CPP_OPEN_BRACE, "expected %<{%>"))
+ {
+ return;
+ }
+ if (c_parser_next_token_is (parser, CPP_CLOSE_BRACE))
+ {
+ c_parser_consume_token (parser);
+ goto out;
+ }
+
+ /* We must now have at least one statement, label or declaration. */
+
+ if (c_parser_next_token_is (parser, CPP_CLOSE_BRACE))
+ {
+ c_parser_error (parser, "expected declaration or statement");
+ c_parser_consume_token (parser);
+ goto out;
+ }
+ while (c_parser_next_token_is_not (parser, CPP_CLOSE_BRACE))
+ {
+ if (c_parser_next_token_is (parser, CPP_EOF))
+ {
+ c_parser_error (parser, "expected declaration or statement");
+ goto out;
+ }
+ else
+ {
+ switch (c_parser_peek_token (parser)->type)
+ {
+ case CPP_KEYWORD:
+ switch (c_parser_peek_token (parser)->keyword)
+ {
+ default:
+ goto expr_stmt;
+ }
+ break;
+ case CPP_SEMICOLON:
+ c_parser_consume_token (parser);
+ break;
+ default:
+ expr_stmt:
+ c_finish_gimple_expr_stmt (c_parser_expression_conv (parser).value, seq);
+ c_parser_skip_until_found (parser, CPP_SEMICOLON, "expected %<;%>");
+ break;
+ }
+ }
+ parser->error = false;
+ }
+ c_parser_consume_token (parser);
+
+ out:
+ return;
+}
+
+/* Emit an expression as a statement. */
+
+static void
+c_finish_gimple_expr_stmt (tree expr, gimple_seq *seq)
+{
+ tree lhs, rhs;
+ gimple *stmt;
+ if (expr)
+ {
+ lhs = TREE_OPERAND (expr, 0);
+ rhs = TREE_OPERAND (expr, 1);
+ stmt = gimple_build_assign (lhs, rhs);
+ gimple_seq_add_stmt (seq, stmt);
+ return;
+ }
+}
+
#include "gt-c-c-parser.h"
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 8316bb8..dd6b04e 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -11678,7 +11678,10 @@ gimplify_function_tree (tree fndecl)
&& !needs_to_live_in_memory (ret))
DECL_GIMPLE_REG_P (ret) = 1;
- bind = gimplify_body (fndecl, true);
+ if (!cfun->gimple_body)
+ bind = gimplify_body (fndecl, true);
+ else
+ bind = NULL;
/* The tree body of the function is no longer needed, replace it
with the new GIMPLE body. */