Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/used_vars.cpp

@@ -0,0 +1,113 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    used_vars.cpp
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Leonardo de Moura (leonardo) 2008-01-14.
+
+Revision History:
+
+--*/
+
+#include"used_vars.h"
+
+void used_vars::process(expr * n, unsigned delta) {
+    unsigned j, idx;
+
+    m_cache.reset();
+    m_todo.reset();
+    m_todo.push_back(expr_delta_pair(n, delta));
+
+    while (!m_todo.empty()) {
+        expr_delta_pair const & p = m_todo.back();
+
+        n     = p.m_node;
+
+        if (n->get_ref_count() > 1 && m_cache.contains(p)) {
+            m_todo.pop_back();
+            continue;
+        }
+        
+        if (n->get_ref_count() > 1) {
+            // cache only shared and non-constant nodes
+            m_cache.insert(p);
+        }
+
+        delta = p.m_delta;
+        m_todo.pop_back();
+        
+        switch (n->get_kind()) {
+        case AST_APP:
+            j = to_app(n)->get_num_args();
+            while (j > 0) {
+                --j;
+                expr * arg = to_app(n)->get_arg(j);
+                m_todo.push_back(expr_delta_pair(arg, delta));
+            }
+            break;
+        case AST_VAR:
+            idx = to_var(n)->get_idx();
+            if (idx >= delta) {
+                idx = idx - delta;
+                if (idx >= m_found_vars.size())
+                    m_found_vars.resize(idx + 1, 0);
+                m_found_vars[idx] = to_var(n)->get_sort();
+            }
+            break;
+        case AST_QUANTIFIER:
+            // recurse so that memoization is correct with respect to 'delta'.
+            delta += to_quantifier(n)->get_num_decls();
+            j      = to_quantifier(n)->get_num_patterns();
+            while (j > 0) {
+                --j;
+                m_todo.push_back(expr_delta_pair(to_quantifier(n)->get_pattern(j), delta));
+            }
+            j      = to_quantifier(n)->get_num_no_patterns();
+            while (j > 0) {
+                --j;
+                m_todo.push_back(expr_delta_pair(to_quantifier(n)->get_no_pattern(j), delta));
+            }
+            m_todo.push_back(expr_delta_pair(to_quantifier(n)->get_expr(), delta));
+            break;
+        default:
+            break;
+        }
+    }
+}
+
+bool used_vars::uses_all_vars(unsigned num_decls) const {
+    if (num_decls > m_found_vars.size())
+        return false;
+    for (unsigned i = 0; i < num_decls; i++) {
+        if (!m_found_vars[i])
+            return false;
+    }
+    return true;
+}
+
+bool used_vars::uses_a_var(unsigned num_decls) const {
+    num_decls = std::min(num_decls, m_found_vars.size());
+    for (unsigned i = 0; i < num_decls; i++) {
+        if (m_found_vars[i])
+            return true;
+    }
+    return false;
+}
+
+unsigned used_vars::get_num_vars() const {
+    unsigned r   = 0;
+    unsigned num = m_found_vars.size();
+    for (unsigned i = 0; i < num; i++) {
+        if (m_found_vars[i])
+            return r++;
+    }
+    return r;
+}