[tsan] Allow symbolizers that don't obtain global symbol sizes

[kubamracek]

Summary

The default symbolizer, llvm-symbolizer provides sizes for global symbols. On OS X, we want to also allow using atos (because it's available everywhere and users don't need to copy/install it) and dladdr (it's the only available option when running in a sandbox). However, these symbolizers do not supply the symbol sizes, only names and starting addresses. This patch changes the reporting functions to hide the size of the symbol when this value is unavailable, and modifies tests to make this part of the report "optional".

compiler-rt/trunk/lib/tsan/rtl/tsan_report.cc

 
 static void PrintLocation(const ReportLocation *loc) {
   Decorator d;
   char thrbuf[kThreadBufSize];
   bool print_stack = false;
   Printf("%s", d.Location());
   if (loc->type == ReportLocationGlobal) {
     const DataInfo &global = loc->global;
+    if (global.size != 0)
       Printf("  Location is global '%s' of size %zu at %p (%s+%p)\n\n",
              global.name, global.size, global.start,
              StripModuleName(global.module), global.module_offset);
+    else
+      Printf("  Location is global '%s' at %p (%s+%p)\n\n", global.name,
+             global.start, StripModuleName(global.module),
+             global.module_offset);
   } else if (loc->type == ReportLocationHeap) {
     char thrbuf[kThreadBufSize];
     Printf("  Location is heap block of size %zu at %p allocated by %s:\n",
            loc->heap_chunk_size, loc->heap_chunk_start,
            thread_name(thrbuf, loc->tid));
     print_stack = true;
   } else if (loc->type == ReportLocationStack) {
     Printf("  Location is stack of %s.\n\n", thread_name(thrbuf, loc->tid));

compiler-rt/trunk/test/tsan/global_race.cc

int main() {
   pthread_create(&t, 0, Thread, 0);
   GlobalData[2] = 43;
   barrier_wait(&barrier);
   pthread_join(t, 0);
 }
 
 // CHECK: addr=[[ADDR:0x[0-9,a-f]+]]
 // CHECK: WARNING: ThreadSanitizer: data race
-// CHECK: Location is global 'GlobalData' of size 40 at [[ADDR]] (global_race.cc.exe+0x{{[0-9,a-f]+}})
+// CHECK: Location is global 'GlobalData' {{(of size 40 )?}}at [[ADDR]] (global_race.cc.exe+0x{{[0-9,a-f]+}})
 

compiler-rt/trunk/test/tsan/global_race2.cc

int main() {
   pthread_create(&t, 0, Thread, 0);
   x = 0;
   barrier_wait(&barrier);
   pthread_join(t, 0);
 }
 
 // CHECK: addr2=[[ADDR2:0x[0-9,a-f]+]]
 // CHECK: WARNING: ThreadSanitizer: data race
-// CHECK: Location is global 'x' of size 4 at [[ADDR2]] ({{.*}}+0x{{[0-9,a-f]+}})
+// CHECK: Location is global 'x' {{(of size 4 )?}}at [[ADDR2]] ({{.*}}+0x{{[0-9,a-f]+}})
 

compiler-rt/trunk/test/tsan/global_race3.cc

int main() {
   pthread_create(&t, 0, Thread, 0);
   XXX::YYY::ZZZ[0] = 0;
   barrier_wait(&barrier);
   pthread_join(t, 0);
 }
 
 // CHECK: addr3=[[ADDR3:0x[0-9,a-f]+]]
 // CHECK: WARNING: ThreadSanitizer: data race
-// CHECK: Location is global 'XXX::YYY::ZZZ' of size 40 at [[ADDR3]] ({{.*}}+0x{{[0-9,a-f]+}})
+// CHECK: Location is global 'XXX::YYY::ZZZ' {{(of size 40 )?}}at [[ADDR3]] ({{.*}}+0x{{[0-9,a-f]+}})