On Thu, Jul 4, 2019 at 10:29 AM Alexandre Oliva <ol...@adacore.com> wrote:
>
> On Jul 2, 2019, Richard Biener <richard.guent...@gmail.com> wrote:
>
> > Yeah, it's on trunk. The parser is ontop of the C frontend and resides
> > in gcc/c/gimple-parser.c while testcases are in gcc.dg/gimplefe-*.c
>
> > The parsing is incomplete, there's no support for parsing try/catch/finally
>
> I'm afraid I haven't got very far, but I tried. It didn't recognize try
> and finally as keywords, and since the parser is integrated with the C
> parser IIUC, I wasn't sure how to enable the keywords only within gimple
> functions.
Yeah. For other stuff we're simply looking at CPP_NAME and
string-matching, see c_parser_gimple_compound_statement
where you'd probably hook this into.
> As mentioned in another message, I chose try/finally/else as the
> notation for TRY_FINALLY_EXPR <..., EH_ELSE_EXPR <..., ...> >, to avoid
> introducing yet another keyword such as eh_finally.
>
> I also considered try/noexcept/finally, or try/noexcept finally/finally,
> but... else seems to be a lot more closely related with EH_ELSE_EXPR,
> and at least in gimple it's non-ambiguous.
>
>
> introduce try/finally/else in gimplefe (WIP FTR)
>
> From: Alexandre Oliva <ol...@adacore.com>
>
>
> ---
> gcc/c/gimple-parser.c | 49
> ++++++++++++++++++++++++++++++++++++
> gcc/testsuite/gcc.dg/gimplefe-43.c | 13 ++++++++++
> 2 files changed, 62 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/gimplefe-43.c
>
> diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c
> index b2b364cc41a3..91f2499bb1cc 100644
> --- a/gcc/c/gimple-parser.c
> +++ b/gcc/c/gimple-parser.c
> @@ -115,6 +115,7 @@ static struct c_expr
> c_parser_gimple_postfix_expression_after_primary
> static void c_parser_gimple_declaration (gimple_parser &);
> static void c_parser_gimple_goto_stmt (gimple_parser &, location_t,
> tree, gimple_seq *);
> +static void c_parser_gimple_try_stmt (gimple_parser &, gimple_seq *);
> static void c_parser_gimple_if_stmt (gimple_parser &, gimple_seq *);
> static void c_parser_gimple_switch_stmt (gimple_parser &, gimple_seq *);
> static void c_parser_gimple_return_stmt (gimple_parser &, gimple_seq *);
> @@ -405,6 +406,9 @@ c_parser_gimple_compound_statement (gimple_parser
> &parser, gimple_seq *seq)
> case CPP_KEYWORD:
> switch (c_parser_peek_token (parser)->keyword)
> {
> + case RID_AT_TRY:
> + c_parser_gimple_try_stmt (parser, seq);
> + break;
> case RID_IF:
> c_parser_gimple_if_stmt (parser, seq);
> break;
> @@ -2088,6 +2092,51 @@ c_parser_gimple_paren_condition (gimple_parser &parser)
> return cond;
> }
>
> +/* Parse gimple try statement.
> +
> + try-statement:
> + try { ... } finally { ... }
> + try { ... } finally { ... } else { ... }
> +
> + This could support try/catch as well, but it's not implemented yet.
> + */
> +
> +static void
> +c_parser_gimple_try_stmt (gimple_parser &parser, gimple_seq *seq)
> +{
> + gimple_seq tryseq = NULL;
> + c_parser_consume_token (parser);
> + c_parser_gimple_compound_statement (parser, &tryseq);
> +
> + if (c_parser_next_token_is (parser, CPP_KEYWORD)
> + && c_parser_peek_token (parser)->keyword == RID_AT_FINALLY)
> + {
> + gimple_seq finseq = NULL;
> + c_parser_consume_token (parser);
> + c_parser_gimple_compound_statement (parser, &finseq);
> +
> + if (c_parser_next_token_is (parser, CPP_KEYWORD)
> + && c_parser_peek_token (parser)->keyword == RID_ELSE)
> + {
> + gimple_seq elsseq = NULL;
> + c_parser_consume_token (parser);
> + c_parser_gimple_compound_statement (parser, &finseq);
> +
> + geh_else *stmt = gimple_build_eh_else (finseq, elsseq);
> + finseq = NULL;
> + gimple_seq_add_stmt_without_update (&finseq, stmt);
> + }
> +
> + gtry *stmt = gimple_build_try (tryseq, finseq, GIMPLE_TRY_FINALLY);
> + gimple_seq_add_stmt_without_update (seq, stmt);
> + }
> + else if (c_parser_next_token_is (parser, CPP_KEYWORD)
> + && c_parser_peek_token (parser)->keyword == RID_AT_CATCH)
> + c_parser_error (parser, "%<catch%> is not supported");
> + else
> + c_parser_error (parser, "expected %<finally%> or %<catch%>");
> +}
> +
> /* Parse gimple if-else statement.
>
> if-statement:
> diff --git a/gcc/testsuite/gcc.dg/gimplefe-43.c
> b/gcc/testsuite/gcc.dg/gimplefe-43.c
> new file mode 100644
> index 000000000000..c740e06a78e1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/gimplefe-43.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-options "-fgimple" } */
> +
> +void __GIMPLE foo()
> +{
> + try {
> + ;
> + } finally {
> + ;
> + } else {
> + ;
> + }
> +}
>
>
> --
> Alexandre Oliva, freedom fighter he/him https://FSFLA.org/blogs/lxo
> Be the change, be Free! FSF Latin America board member
> GNU Toolchain Engineer Free Software Evangelist
> Hay que enGNUrecerse, pero sin perder la terGNUra jamás - Che GNUevara
