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

llvm-svn: 307688

1 files changed, 10 insertions, 9 deletions

diff --git a/compiler-rt/lib/esan/working_set.cpp b/compiler-rt/lib/esan/working_set.cpp
index f39111993c3..e56902c8f32 100644
--- a/compiler-rt/lib/esan/working_set.cpp
+++ b/compiler-rt/lib/esan/working_set.cpp
@@ -160,15 +160,16 @@ static u32 countAndClearShadowValues(u32 BitIdx, uptr ShadowStart,
 static u32 computeWorkingSizeAndReset(u32 BitIdx) {
   u32 WorkingSetSize = 0;
   MemoryMappingLayout MemIter(true/*cache*/);
-  uptr Start, End, Prot;
-  while (MemIter.Next(&Start, &End, nullptr/*offs*/, nullptr/*file*/,
-                      0/*file size*/, &Prot)) {
-    VPrintf(4, "%s: considering %p-%p app=%d shadow=%d prot=%u\n",
-            __FUNCTION__, Start, End, Prot, isAppMem(Start),
-            isShadowMem(Start));
-    if (isShadowMem(Start) && (Prot & MemoryMappingLayout::kProtectionWrite)) {
-      VPrintf(3, "%s: walking %p-%p\n", __FUNCTION__, Start, End);
-      WorkingSetSize += countAndClearShadowValues(BitIdx, Start, End);
+  MemoryMappedSegment Segment;
+  while (MemIter.Next(&Segment)) {
+    VPrintf(4, "%s: considering %p-%p app=%d shadow=%d prot=%u\n", __FUNCTION__,
+            Segment.start, Segment.end, Segment.protection,
+            isAppMem(Segment.start), isShadowMem(Segment.start));
+    if (isShadowMem(Segment.start) && Segment.IsWritable()) {
+      VPrintf(3, "%s: walking %p-%p\n", __FUNCTION__, Segment.start,
+              Segment.end);
+      WorkingSetSize +=
+          countAndClearShadowValues(BitIdx, Segment.start, Segment.end);
     }
   }
   return WorkingSetSize;