dissect: support _Generic() a bit more

Commit Message

Oleg Nesterov July 30, 2020, 3:09 p.m. UTC

Change do_expression(EXPR_GENERIC) to inspect expr->control/map/def.
The is the minimal "better than nothing" change, technically incorrect
but still useful for the indexing.

Example:

	void func(void)
	{
		_Generic(a,
			int:		b,
			void:		c,
			default:	d,
		) = e;
	}

output:

   1:6                    def   f func                             void ( ... )
   3:18  func             ---   v a                                bad type
   4:33  func             -w-   v b                                bad type
   5:33  func             -w-   v c                                bad type
   6:33  func             -w-   v d                                bad type
   7:13  func             -r-   v e                                bad type

Signed-off-by: Oleg Nesterov <[e-mail]>
---
 dissect.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Luc Van Oostenryck July 30, 2020, 8:05 p.m. UTC | #1

On Thu, Jul 30, 2020 at 05:09:58PM +0200, Oleg Nesterov wrote:
> Change do_expression(EXPR_GENERIC) to inspect expr->control/map/def.
> The is the minimal "better than nothing" change, technically incorrect
> but still useful for the indexing.

Thanks. Applied & pushed.

-- Luc

Patch

diff --git a/dissect.c b/dissect.c
index a633c8bf..fd09707d 100644
--- a/dissect.c
+++ b/dissect.c
@@ -342,7 +342,6 @@  again:
 	case EXPR_TYPE:		// [struct T]; Why ???
 	case EXPR_VALUE:
 	case EXPR_FVALUE:
-	case EXPR_GENERIC:
 
 	break; case EXPR_LABEL:
 		ret = &label_ctype;
@@ -472,6 +471,17 @@  again:
 		} while ((expr = expr->down));
 	}
 
+	break; case EXPR_GENERIC: {
+		struct type_expression *map;
+
+		do_expression(U_VOID, expr->control);
+
+		for (map = expr->map; map; map = map->next)
+			ret = do_expression(mode, map->expr);
+		if (expr->def)
+			ret = do_expression(mode, expr->def);
+	}
+
 	break; case EXPR_SYMBOL:
 		ret = report_symbol(mode, expr);
 	}