[PATCH 28/73] inline: Duplicate generic expressions instead of evaluating them

[Bart Van Assche <bvanassche@acm.org>]

Duplicate the EXPR_GENERIC expression, its control expression, its
default expression, and each type-expression map entry during function
inlining instead of evaluating the generic selection prematurely.

Prevent copy_symbol() from traversing already-evaluated expressions
where compound literals (such as &(size_t){ 0 }) produce anonymous local
symbols without replacement symbols and trigger false 'unreplaced symbol
<noident>' warnings.

Allow evaluate_statement() to evaluate the selected branch of the copied
generic expression when the expanded inlined function body is evaluated,
and add validation/inline-generic.c.

Fixes: eb6779f6f621 ("generic: fix missing inlining of generic expression")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 inline.c                    | 18 ++++++++++++++----
 validation/inline-generic.c | 25 +++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/inline.c b/inline.c
index 1948bea52ffb..d94fba807d19 100644
--- a/inline.c
+++ b/inline.c
@@ -345,13 +345,23 @@ static struct expression * copy_expression(struct expression *expr)
 		}
 		break;
 	}
-	case EXPR_GENERIC:
+	case EXPR_GENERIC: {
+		struct type_expression *map, **p;
 		expr = dup_expression(expr);
 		expr->control = copy_expression(expr->control);
-		if (!evaluate_expression(expr))
-			return NULL;
-		expr = copy_expression(expr);
+		expr->def = copy_expression(expr->def);
+		p = &expr->map;
+		for (map = expr->map; map; map = map->next) {
+			struct type_expression *new_map = __alloc_type_expression(0);
+			*new_map = *map;
+			new_map->type = copy_type(map->type);
+			new_map->expr = copy_expression(map->expr);
+			*p = new_map;
+			p = &new_map->next;
+		}
+		*p = NULL;
 		break;
+	}
 
 	default:
 		warning(expr->pos, "trying to copy expression type %d", expr->type);
diff --git a/validation/inline-generic.c b/validation/inline-generic.c
index 1f05c07904b5..3bf97eb69c53 100644
--- a/validation/inline-generic.c
+++ b/validation/inline-generic.c
@@ -5,6 +5,31 @@ inline unsigned f(void) { return e(_Generic(b, int: c())); }
 static int g(void) { return f(); }
 static int h(void) { return f(); }
 
+inline void *cl(void)
+{
+	return _Generic((void *)0,
+			void *: &(int){ 0 },
+			default: (void *)0);
+}
+
+static void test_cl(void)
+{
+	cl();
+}
+
+static inline int inl_gen_vla(int n, void *p)
+{
+	return _Generic((int (*)[n])p,
+			int (*)[n]: (int)sizeof(int [n]),
+			default: 0);
+}
+
+static int test_gen_vla(int x, int y, void *p)
+{
+	return inl_gen_vla(x, p) + inl_gen_vla(y, p);
+}
+
 /*
  * check-name: inline-generic
+ * check-command: sparse -Wno-vla $file
  */