Refactor MemoryMappingLayout::Next to use a single struct instead of output parameters. NFC.

Summary:
This is the first in a series of patches to refactor sanitizer_procmaps
to allow MachO section information to be exposed on darwin.

In addition, grouping all segment information in a single struct is
cleaner than passing it through a large set of output parameters, and
avoids the need for annotations of NULL parameters for unneeded
information.

The filename string is optional and must be managed and supplied by the
calling function. This is to allow the MemoryMappedSegment struct to be
stored on the stack without causing overly large stack sizes.

Reviewers: alekseyshl, kubamracek, glider

Subscribers: emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D35135

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@307688 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 8 deletions

diff --git a/lib/sanitizer_common/sanitizer_procmaps_common.cc b/lib/sanitizer_common/sanitizer_procmaps_common.cc
index c583f42f2..b95f301a4 100644
--- a/lib/sanitizer_common/sanitizer_procmaps_common.cc
+++ b/lib/sanitizer_common/sanitizer_procmaps_common.cc
@@ -119,12 +119,10 @@ void MemoryMappingLayout::LoadFromCache() {
 void MemoryMappingLayout::DumpListOfModules(
     InternalMmapVector<LoadedModule> *modules) {
   Reset();
-  uptr cur_beg, cur_end, cur_offset, prot;
   InternalScopedString module_name(kMaxPathLength);
-  for (uptr i = 0; Next(&cur_beg, &cur_end, &cur_offset, module_name.data(),
-                        module_name.size(), &prot);
-       i++) {
-    const char *cur_name = module_name.data();
+  MemoryMappedSegment segment(module_name.data(), module_name.size());
+  for (uptr i = 0; Next(&segment); i++) {
+    const char *cur_name = segment.filename;
     if (cur_name[0] == '\0')
       continue;
     // Don't subtract 'cur_beg' from the first entry:
@@ -138,11 +136,11 @@ void MemoryMappingLayout::DumpListOfModules(
     //   mapped high at address space (in particular, higher than
     //   shadow memory of the tool), so the module can't be the
     //   first entry.
-    uptr base_address = (i ? cur_beg : 0) - cur_offset;
+    uptr base_address = (i ? segment.start : 0) - segment.offset;
     LoadedModule cur_module;
     cur_module.set(cur_name, base_address);
-    cur_module.addAddressRange(cur_beg, cur_end, prot & kProtectionExecute,
-                               prot & kProtectionWrite);
+    cur_module.addAddressRange(segment.start, segment.end,
+                               segment.IsExecutable(), segment.IsWritable());
     modules->push_back(cur_module);
   }
 }