ld64-123.2.tar.gz

[apple/ld64.git] / src / ld / passes / dylibs.cpp

diff --git a/src/ld/passes/dylibs.cpp b/src/ld/passes/dylibs.cpp
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+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2010 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+#include <stdint.h>
+#include <math.h>
+#include <unistd.h>
+#include <dlfcn.h>
+#include <mach/machine.h>
+
+#include <vector>
+
+#include "ld.hpp"
+#include "dylibs.h"
+
+namespace ld {
+namespace passes {
+namespace dylibs {
+
+
+class WillBeUsed
+{
+public:
+       bool operator()(ld::dylib::File* dylib) const {
+               return dylib->willRemoved();
+       }
+};
+
+
+void doPass(const Options& opts, ld::Internal& state)
+{
+//     const bool log = false;
+       
+       // only optimize dylibs in final linked images
+       if ( opts.outputKind() == Options::kObjectFile )
+               return;
+
+       // clear "willRemoved" bit on all dylibs
+       for (std::vector<ld::dylib::File*>::iterator it = state.dylibs.begin(); it != state.dylibs.end(); ++it) {
+               ld::dylib::File* aDylib = *it;
+               aDylib->setWillBeRemoved(false);
+       }
+       for (std::vector<ld::dylib::File*>::iterator it = state.dylibs.begin(); it != state.dylibs.end(); ++it) {
+               ld::dylib::File* aDylib = *it;
+               // set "willRemoved" bit on implicit dylibs that did not provide any exports
+               if ( aDylib->implicitlyLinked() && !aDylib->explicitlyLinked() && !aDylib->providedExportAtom() )
+                       aDylib->setWillBeRemoved(true);
+               // set "willRemoved" bit on dead strippable explicit dylibs that did not provide any exports
+               if ( aDylib->explicitlyLinked() && aDylib->deadStrippable() && !aDylib->providedExportAtom() )
+                       aDylib->setWillBeRemoved(true);
+               // set "willRemoved" bit on any unused explicit when -dead_strip_dylibs is used
+               if ( opts.deadStripDylibs() && !aDylib->providedExportAtom() )
+                       aDylib->setWillBeRemoved(true);
+       }
+       
+       
+       // remove unused dylibs
+       state.dylibs.erase(std::remove_if(state.dylibs.begin(), state.dylibs.end(), WillBeUsed()), state.dylibs.end());
+       
+}
+
+
+} // namespace dylibs
+} // namespace passes 
+} // namespace ld