From e86cc5df44a995c19ff1ed75145186717ce37cb1 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <sven.verdoolaege@gmail.com>
Date: Thu, 28 Dec 2017 10:07:39 +0100
Subject: [PATCH] add isl_space_add_param_id

This convenience function allows parameters to be added
to a space without having to resort to first adding an unnamed
parameter and then changing its identifier.
Unnamed parameters and changing the names/identifiers of parameters
should in general be discouraged.
This function will also be used in the next commit.

Signed-off-by: Sven Verdoolaege <sven.verdoolaege@gmail.com>
---
 doc/user.pod        | 10 ++++++++++
 include/isl/space.h |  3 +++
 isl_space.c         | 27 +++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/doc/user.pod b/doc/user.pod
index 32d453fd..21bc4eb9 100644
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -1168,6 +1168,16 @@ an C<isl_union_pw_qpolynomial> and
 an C<isl_union_pw_qpolynomial_fold>
 only have parameters.
 
+Additional parameters can be added to a space using the following function.
+
+	#include <isl/space.h>
+	__isl_give isl_space *isl_space_add_param_id(
+		__isl_take isl_space *space,
+		__isl_take isl_id *id);
+
+If a parameter with the given identifier already appears in the space,
+then it is not added again.
+
 The identifiers or names of the individual dimensions of spaces
 may be set or read off using the following functions on spaces
 or objects that live in spaces.
diff --git a/include/isl/space.h b/include/isl/space.h
index 1a477cdf..fa089e22 100644
--- a/include/isl/space.h
+++ b/include/isl/space.h
@@ -44,6 +44,9 @@ isl_bool isl_space_is_params(__isl_keep isl_space *space);
 isl_bool isl_space_is_set(__isl_keep isl_space *space);
 isl_bool isl_space_is_map(__isl_keep isl_space *space);
 
+__isl_give isl_space *isl_space_add_param_id(__isl_take isl_space *space,
+	__isl_take isl_id *id);
+
 __isl_give isl_space *isl_space_set_tuple_name(__isl_take isl_space *dim,
 	enum isl_dim_type type, const char *s);
 isl_bool isl_space_has_tuple_name(__isl_keep isl_space *space,
diff --git a/isl_space.c b/isl_space.c
index ff4b9aaf..c4682a7e 100644
--- a/isl_space.c
+++ b/isl_space.c
@@ -985,6 +985,33 @@ error:
 	return NULL;
 }
 
+/* Add a parameter with identifier "id" to "space", provided
+ * it does not already appear in "space".
+ */
+__isl_give isl_space *isl_space_add_param_id(__isl_take isl_space *space,
+	__isl_take isl_id *id)
+{
+	int pos;
+
+	if (!space || !id)
+		goto error;
+
+	if (isl_space_find_dim_by_id(space, isl_dim_param, id) >= 0) {
+		isl_id_free(id);
+		return space;
+	}
+
+	pos = isl_space_dim(space, isl_dim_param);
+	space = isl_space_add_dims(space, isl_dim_param, 1);
+	space = isl_space_set_dim_id(space, isl_dim_param, pos, id);
+
+	return space;
+error:
+	isl_space_free(space);
+	isl_id_free(id);
+	return NULL;
+}
+
 static int valid_dim_type(enum isl_dim_type type)
 {
 	switch (type) {
-- 
2.11.4.GIT