[Sanitizer] Move OS-specific code for MemoryMappingLayout into separate source files.

llvm-svn: 198003

1 files changed, 165 insertions, 0 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc
new file mode 100644
index 00000000000..26e882b8ef3
--- /dev/null
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_mac.cc
@@ -0,0 +1,165 @@
+//===-- sanitizer_procmaps_mac.cc -----------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Information about the process mappings (Mac-specific parts).
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_MAC
+#include "sanitizer_common.h"
+#include "sanitizer_procmaps.h"
+
+#include <mach-o/dyld.h>
+#include <mach-o/loader.h>
+
+namespace __sanitizer {
+
+MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
+  Reset();
+}
+
+MemoryMappingLayout::~MemoryMappingLayout() {
+}
+
+// More information about Mach-O headers can be found in mach-o/loader.h
+// Each Mach-O image has a header (mach_header or mach_header_64) starting with
+// a magic number, and a list of linker load commands directly following the
+// header.
+// A load command is at least two 32-bit words: the command type and the
+// command size in bytes. We're interested only in segment load commands
+// (LC_SEGMENT and LC_SEGMENT_64), which tell that a part of the file is mapped
+// into the task's address space.
+// The |vmaddr|, |vmsize| and |fileoff| fields of segment_command or
+// segment_command_64 correspond to the memory address, memory size and the
+// file offset of the current memory segment.
+// Because these fields are taken from the images as is, one needs to add
+// _dyld_get_image_vmaddr_slide() to get the actual addresses at runtime.
+
+void MemoryMappingLayout::Reset() {
+  // Count down from the top.
+  // TODO(glider): as per man 3 dyld, iterating over the headers with
+  // _dyld_image_count is thread-unsafe. We need to register callbacks for
+  // adding and removing images which will invalidate the MemoryMappingLayout
+  // state.
+  current_image_ = _dyld_image_count();
+  current_load_cmd_count_ = -1;
+  current_load_cmd_addr_ = 0;
+  current_magic_ = 0;
+  current_filetype_ = 0;
+}
+
+// static
+void MemoryMappingLayout::CacheMemoryMappings() {
+  // No-op on Mac for now.
+}
+
+void MemoryMappingLayout::LoadFromCache() {
+  // No-op on Mac for now.
+}
+
+// Next and NextSegmentLoad were inspired by base/sysinfo.cc in
+// Google Perftools, http://code.google.com/p/google-perftools.
+
+// NextSegmentLoad scans the current image for the next segment load command
+// and returns the start and end addresses and file offset of the corresponding
+// segment.
+// Note that the segment addresses are not necessarily sorted.
+template<u32 kLCSegment, typename SegmentCommand>
+bool MemoryMappingLayout::NextSegmentLoad(
+    uptr *start, uptr *end, uptr *offset,
+    char filename[], uptr filename_size, uptr *protection) {
+  if (protection)
+    UNIMPLEMENTED();
+  const char* lc = current_load_cmd_addr_;
+  current_load_cmd_addr_ += ((const load_command *)lc)->cmdsize;
+  if (((const load_command *)lc)->cmd == kLCSegment) {
+    const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
+    const SegmentCommand* sc = (const SegmentCommand *)lc;
+    if (start) *start = sc->vmaddr + dlloff;
+    if (end) *end = sc->vmaddr + sc->vmsize + dlloff;
+    if (offset) {
+      if (current_filetype_ == /*MH_EXECUTE*/ 0x2) {
+        *offset = sc->vmaddr;
+      } else {
+        *offset = sc->fileoff;
+      }
+    }
+    if (filename) {
+      internal_strncpy(filename, _dyld_get_image_name(current_image_),
+                       filename_size);
+    }
+    return true;
+  }
+  return false;
+}
+
+bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
+                               char filename[], uptr filename_size,
+                               uptr *protection) {
+  for (; current_image_ >= 0; current_image_--) {
+    const mach_header* hdr = _dyld_get_image_header(current_image_);
+    if (!hdr) continue;
+    if (current_load_cmd_count_ < 0) {
+      // Set up for this image;
+      current_load_cmd_count_ = hdr->ncmds;
+      current_magic_ = hdr->magic;
+      current_filetype_ = hdr->filetype;
+      switch (current_magic_) {
+#ifdef MH_MAGIC_64
+        case MH_MAGIC_64: {
+          current_load_cmd_addr_ = (char*)hdr + sizeof(mach_header_64);
+          break;
+        }
+#endif
+        case MH_MAGIC: {
+          current_load_cmd_addr_ = (char*)hdr + sizeof(mach_header);
+          break;
+        }
+        default: {
+          continue;
+        }
+      }
+    }
+
+    for (; current_load_cmd_count_ >= 0; current_load_cmd_count_--) {
+      switch (current_magic_) {
+        // current_magic_ may be only one of MH_MAGIC, MH_MAGIC_64.
+#ifdef MH_MAGIC_64
+        case MH_MAGIC_64: {
+          if (NextSegmentLoad<LC_SEGMENT_64, struct segment_command_64>(
+                  start, end, offset, filename, filename_size, protection))
+            return true;
+          break;
+        }
+#endif
+        case MH_MAGIC: {
+          if (NextSegmentLoad<LC_SEGMENT, struct segment_command>(
+                  start, end, offset, filename, filename_size, protection))
+            return true;
+          break;
+        }
+      }
+    }
+    // If we get here, no more load_cmd's in this image talk about
+    // segments.  Go on to the next image.
+  }
+  return false;
+}
+
+bool MemoryMappingLayout::GetObjectNameAndOffset(uptr addr, uptr *offset,
+                                                 char filename[],
+                                                 uptr filename_size,
+                                                 uptr *protection) {
+  return IterateForObjectNameAndOffset(addr, offset, filename, filename_size,
+                                       protection);
+}
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_MAC