From 6e55b20a4cba1f68f89f49ef51b4b25b12fbc128 Mon Sep 17 00:00:00 2001
From: Sveinung Kvilhaugsvik <sveinung84@users.sourceforge.net>
Date: Tue, 16 Feb 2021 15:48:59 +0100
Subject: [PATCH] Introduce universals_mean_unfulfilled().
Make it possible to check if the presence of any universal from a list
means that a requirement vector never can be fulfilled.
See osdn #41589
---
common/requirements.c | 28 ++++++++++++++++++++++++++++
common/requirements.h | 3 +++
2 files changed, 31 insertions(+)
diff --git a/common/requirements.c b/common/requirements.c
index 69b1119b90..28080986a5 100644
--- a/common/requirements.c
+++ b/common/requirements.c
@@ -4242,6 +4242,34 @@ bool universal_is_mentioned_by_requirements(
return FALSE;
}
+/**********************************************************************//**
+ Returns TRUE iff the presence of any of the specified universals is
+ enough to guarantee that the specified requirement vector never will be
+ fulfilled.
+ @param reqs the requirement vector that never should be fulfilled
+ @param unis the universals that are present
+ @param n_unis the number of universals in unis
+ @return if the universals blocks fulfillment of the req vector
+**************************************************************************/
+bool universals_mean_unfulfilled(struct requirement_vector *reqs,
+ struct universal *unis,
+ size_t n_unis)
+{
+ int i;
+
+ for (i = 0; i < n_unis; i++) {
+ if (!universal_fulfills_requirements(FALSE, reqs, &unis[i])) {
+ /* This universal makes it impossible to fulfill the specified
+ * requirement vector */
+ return TRUE;
+ }
+ }
+
+ /* No specified universal is known to guarantee that the requirement
+ * vector never will be fulfilled. */
+ return FALSE;
+}
+
/**********************************************************************//**
Will the universal 'source' fulfill this requirement?
**************************************************************************/
diff --git a/common/requirements.h b/common/requirements.h
index 672faa842b..e8b9abadf3 100644
--- a/common/requirements.h
+++ b/common/requirements.h
@@ -280,6 +280,9 @@ bool universal_fulfills_requirements(bool check_necessary,
const struct universal *source);
bool universal_is_relevant_to_requirement(const struct requirement *req,
const struct universal *source);
+bool universals_mean_unfulfilled(struct requirement_vector *reqs,
+ struct universal *unis,
+ size_t n_unis);
#define universals_iterate(_univ_) \
{ \
--
2.20.1