[scudo][standalone] Get statistics in a char buffer

Summary:
Following up on D68471, this CL introduces some `getStats` APIs to
gather statistics in char buffers (`ScopedString` really) instead of
printing them out right away. Ultimately `printStats` will just
output the buffer, but that allows us to potentially do some work
on the intermediate buffer, and can be used for a `mallocz` type
of functionality. This allows us to pretty much get rid of all the
`Printf` calls around, but I am keeping the function in for
debugging purposes.

This changes the existing tests to use the new APIs when required.

I will add new tests as suggested in D68471 in another CL.

Reviewers: morehouse, hctim, vitalybuka, eugenis, cferris

Reviewed By: morehouse

Subscribers: delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D68653

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@374173 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 6 deletions

diff --git a/lib/scudo/standalone/secondary.cpp b/lib/scudo/standalone/secondary.cpp
index d725034ee..db7361d71 100644
--- a/lib/scudo/standalone/secondary.cpp
+++ b/lib/scudo/standalone/secondary.cpp
@@ -123,12 +123,13 @@ void MapAllocator::deallocate(void *Ptr) {
   unmap(Addr, Size, UNMAP_ALL, &Data);
 }
 
-void MapAllocator::printStats() const {
-  Printf("Stats: MapAllocator: allocated %zu times (%zuK), freed %zu times "
-         "(%zuK), remains %zu (%zuK) max %zuM\n",
-         NumberOfAllocs, AllocatedBytes >> 10, NumberOfFrees, FreedBytes >> 10,
-         NumberOfAllocs - NumberOfFrees, (AllocatedBytes - FreedBytes) >> 10,
-         LargestSize >> 20);
+void MapAllocator::getStats(ScopedString *Str) const {
+  Str->append(
+      "Stats: MapAllocator: allocated %zu times (%zuK), freed %zu times "
+      "(%zuK), remains %zu (%zuK) max %zuM\n",
+      NumberOfAllocs, AllocatedBytes >> 10, NumberOfFrees, FreedBytes >> 10,
+      NumberOfAllocs - NumberOfFrees, (AllocatedBytes - FreedBytes) >> 10,
+      LargestSize >> 20);
 }
 
 } // namespace scudo