Allow loading Z3 dynamically at runtime.

libsmtutil/Z3Loader.cpp

@@ -0,0 +1,70 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+// SPDX-License-Identifier: GPL-3.0
+
+#include <libsmtutil/Z3Loader.h>
+#include <libsmtutil/Exceptions.h>
+#include <z3.h>
+#include <z3_version.h>
+#include <vector>
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <dlfcn.h>
+
+using namespace std;
+using namespace solidity;
+using namespace solidity::smtutil;
+
+Z3Loader const& Z3Loader::get()
+{
+	static Z3Loader z3;
+	return z3;
+}
+
+void* Z3Loader::loadSymbol(char const* _name) const
+{
+	smtAssert(m_handle, "Attempted to use dynamically loaded Z3, even though it is not available.");
+	void* sym = dlsym(m_handle, _name);
+	smtAssert(sym, string("Symbol \"") + _name + "\" not found in libz3.so");
+	return sym;
+}
+
+bool Z3Loader::available() const
+{
+	if (m_handle == nullptr)
+		return false;
+	unsigned major = 0;
+	unsigned minor = 0;
+	unsigned build = 0;
+	unsigned rev = 0;
+	Z3_get_version(&major, &minor, &build, &rev);
+	return major == Z3_MAJOR_VERSION && minor == Z3_MINOR_VERSION;
+}
+
+Z3Loader::Z3Loader()
+{
+	string libname{"libz3.so." + to_string(Z3_MAJOR_VERSION) + "." + to_string(Z3_MINOR_VERSION)};
+	m_handle = dlmopen(LM_ID_NEWLM, libname.c_str(), RTLD_NOW);
+}
+
+Z3Loader::~Z3Loader()
+{
+	if (m_handle)
+		dlclose(m_handle);
+}