[sanitizer] Allow BackgroundThread to not depend on StackDepot

Summary:
Still pursuing the ultimate goal of splitting the Symbolizer code from
RTSanitizerCommon core, allow `BackgroundThread` to work even when not linked
with `sanitizer_stackdepot.cc`. There is no reason this function should pull in
the whole `StackDepot` if symbolization is not supported.

Currently this has no functional change as the depot is always linked anyway.

Reviewers: alekseyshl

Reviewed By: alekseyshl

Subscribers: kubamracek, delcypher, llvm-commits, #sanitizers

Differential Revision: https://reviews.llvm.org/D45296

llvm-svn: 329595

1 files changed, 14 insertions, 10 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_libcdep.cc b/compiler-rt/lib/sanitizer_common/sanitizer_common_libcdep.cc
index 9c24c30749c..48d1749b210 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_libcdep.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_libcdep.cc
@@ -18,7 +18,6 @@
 #include "sanitizer_flags.h"
 #include "sanitizer_procmaps.h"
 #include "sanitizer_report_decorator.h"
-#include "sanitizer_stackdepot.h"
 #include "sanitizer_stacktrace.h"
 #include "sanitizer_symbolizer.h"
 
@@ -113,6 +112,9 @@ void SetSoftRssLimitExceededCallback(void (*Callback)(bool exceeded)) {
 }
 
 #if SANITIZER_LINUX && !SANITIZER_GO
+// Weak definition for when sanitizer_stackdepot is not linked in.
+SANITIZER_WEAK_ATTRIBUTE StackDepotStats *StackDepotGetStats();
+
 void BackgroundThread(void *arg) {
   uptr hard_rss_limit_mb = common_flags()->hard_rss_limit_mb;
   uptr soft_rss_limit_mb = common_flags()->soft_rss_limit_mb;
@@ -130,15 +132,17 @@ void BackgroundThread(void *arg) {
         Printf("%s: RSS: %zdMb\n", SanitizerToolName, current_rss_mb);
         prev_reported_rss = current_rss_mb;
       }
-      // If stack depot has grown 10% since last time, print it too.
-      StackDepotStats *stack_depot_stats = StackDepotGetStats();
-      if (prev_reported_stack_depot_size * 11 / 10 <
-          stack_depot_stats->allocated) {
-        Printf("%s: StackDepot: %zd ids; %zdM allocated\n",
-               SanitizerToolName,
-               stack_depot_stats->n_uniq_ids,
-               stack_depot_stats->allocated >> 20);
-        prev_reported_stack_depot_size = stack_depot_stats->allocated;
+      if (&StackDepotGetStats) {
+        // If stack depot has grown 10% since last time, print it too.
+        StackDepotStats *stack_depot_stats = StackDepotGetStats();
+        if (prev_reported_stack_depot_size * 11 / 10 <
+            stack_depot_stats->allocated) {
+          Printf("%s: StackDepot: %zd ids; %zdM allocated\n",
+                 SanitizerToolName,
+                 stack_depot_stats->n_uniq_ids,
+                 stack_depot_stats->allocated >> 20);
+          prev_reported_stack_depot_size = stack_depot_stats->allocated;
+        }
       }
     }
     // Check RSS against the limit.