ld64-123.2.tar.gz

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

diff --git a/src/ld/passes/huge.cpp b/src/ld/passes/huge.cpp
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+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2009 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 "huge.h"
+
+namespace ld {
+namespace passes {
+namespace huge {
+
+class NullAtom
+{
+public:
+       bool operator()(const ld::Atom* atom) const {
+               return (atom == NULL);
+       }
+};
+
+void doPass(const Options& opts, ld::Internal& state)
+{
+       const bool log = false;
+       
+       // only make make __huge section in final linked images
+       if ( opts.outputKind() == Options::kObjectFile )
+               return;
+
+       // only make make __huge section for x86_64
+       if ( opts.architecture() != CPU_TYPE_X86_64 )
+               return;
+
+       // only needed if some (non-linkedit) atoms have an addresss >2GB from base address 
+       state.usingHugeSections = false;
+       uint64_t address = 0;
+       for (std::vector<ld::Internal::FinalSection*>::iterator sit=state.sections.begin(); sit != state.sections.end(); ++sit) {
+               ld::Internal::FinalSection* sect = *sit;
+               if ( sect->type() == ld::Section::typePageZero )
+                       continue;
+               if ( sect->type() == ld::Section::typeStack )
+                       continue;
+               for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+                       const ld::Atom* atom = *ait;
+                       if ( (address > 0x7FFFFFFFLL) && !sect->isSectionHidden() ) {
+                               state.usingHugeSections = true;
+                               if (log) fprintf(stderr, "atom: %s is >2GB (0x%09llX), so enabling huge mode\n", atom->name(), address);
+                               break;
+                       }
+                       address += atom->size();
+               }
+               if ( state.usingHugeSections )
+                       break;
+       }
+       if ( !state.usingHugeSections )
+               return;
+
+       // move all zero fill atoms that >1MB in size to a new __huge section
+       ld::Internal::FinalSection* hugeSection = state.getFinalSection(ld::Section("__DATA", "__huge", ld::Section::typeZeroFill));
+       for (std::vector<ld::Internal::FinalSection*>::iterator sit=state.sections.begin(); sit != state.sections.end(); ++sit) {
+               ld::Internal::FinalSection* sect = *sit;
+               if ( sect == hugeSection )
+                       continue;
+               if ( sect->type() == ld::Section::typeZeroFill ) {
+                       bool movedSome = false;
+                       for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+                               const ld::Atom* atom = *ait;
+                               if ( atom->size() > 1024*1024 ) {
+                                       hugeSection->atoms.push_back(atom);
+                                       if (log) fprintf(stderr, "moved to __huge: %s, size=%llu\n", atom->name(), atom->size());
+                                       *ait = NULL;  // change atom to NULL for later bulk removal
+                                       movedSome = true;
+                               }
+                       }
+                       if ( movedSome ) 
+                               sect->atoms.erase(std::remove_if(sect->atoms.begin(), sect->atoms.end(), NullAtom()), sect->atoms.end());
+               }
+       }
+
+       
+}
+
+
+} // namespace huge
+} // namespace passes 
+} // namespace ld