[compiler-rt] r352567 - [libFuzzer] revert an accidental commit

[Kostya Serebryany via llvm-commits]

Author: kcc
Date: Tue Jan 29 15:41:50 2019
New Revision: 352567

URL: http://llvm.org/viewvc/llvm-project?rev=352567&view=rev
Log:
[libFuzzer] revert an accidental commit

Modified:
    compiler-rt/trunk/lib/fuzzer/FuzzerTracePC.cpp

Modified: compiler-rt/trunk/lib/fuzzer/FuzzerTracePC.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/fuzzer/FuzzerTracePC.cpp?rev=352567&r1=352566&r2=352567&view=diff
==============================================================================
--- compiler-rt/trunk/lib/fuzzer/FuzzerTracePC.cpp (original)
+++ compiler-rt/trunk/lib/fuzzer/FuzzerTracePC.cpp Tue Jan 29 15:41:50 2019
@@ -23,6 +23,15 @@
 #include "FuzzerValueBitMap.h"
 #include <set>
 
+// The coverage counters and PCs.
+// These are declared as global variables named "__sancov_*" to simplify
+// experiments with inlined instrumentation.
+alignas(64) ATTRIBUTE_INTERFACE
+uint8_t __sancov_trace_pc_guard_8bit_counters[fuzzer::TracePC::kNumPCs];
+
+ATTRIBUTE_INTERFACE
+uintptr_t __sancov_trace_pc_pcs[fuzzer::TracePC::kNumPCs];
+
 // Used by -fsanitize-coverage=stack-depth to track stack depth
 ATTRIBUTES_INTERFACE_TLS_INITIAL_EXEC uintptr_t __sancov_lowest_stack;
 
@@ -30,9 +39,13 @@ namespace fuzzer {
 
 TracePC TPC;
 
-/// ZZZ uint8_t *TracePC::Counters() const {
+uint8_t *TracePC::Counters() const {
+  return __sancov_trace_pc_guard_8bit_counters;
+}
 
-/// ZZZ uintptr_t *TracePC::PCs() const {
+uintptr_t *TracePC::PCs() const {
+  return __sancov_trace_pc_pcs;
+}
 
 size_t TracePC::GetTotalPCCoverage() {
   if (ObservedPCs.size())
@@ -83,6 +96,13 @@ void TracePC::HandleInit(uint32_t *Start
 }
 
 void TracePC::PrintModuleInfo() {
+  if (NumGuards) {
+    Printf("INFO: Loaded %zd modules   (%zd guards): ", NumModules, NumGuards);
+    for (size_t i = 0; i < NumModules; i++)
+      Printf("%zd [%p, %p), ", Modules[i].Stop - Modules[i].Start,
+             Modules[i].Start, Modules[i].Stop);
+    Printf("\n");
+  }
   if (NumModulesWithInline8bitCounters) {
     Printf("INFO: Loaded %zd modules   (%zd inline 8-bit counters): ",
            NumModulesWithInline8bitCounters, NumInline8bitCounters);
@@ -100,7 +120,8 @@ void TracePC::PrintModuleInfo() {
     }
     Printf("\n");
 
-    if (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables) {
+    if ((NumGuards && NumGuards != NumPCsInPCTables) ||
+        (NumInline8bitCounters && NumInline8bitCounters != NumPCsInPCTables)) {
       Printf("ERROR: The size of coverage PC tables does not match the\n"
              "number of instrumented PCs. This might be a compiler bug,\n"
              "please contact the libFuzzer developers.\n"
@@ -179,6 +200,17 @@ void TracePC::UpdateObservedPCs() {
           if (Beg[j])
             Observe(ModulePCTable[i].Start[j]);
       }
+    } else if (NumGuards == NumPCsInPCTables) {
+      size_t GuardIdx = 1;
+      for (size_t i = 0; i < NumModules; i++) {
+        uint32_t *Beg = Modules[i].Start;
+        size_t Size = Modules[i].Stop - Beg;
+        assert(Size ==
+               (size_t)(ModulePCTable[i].Stop - ModulePCTable[i].Start));
+        for (size_t j = 0; j < Size; j++, GuardIdx++)
+          if (Counters()[GuardIdx])
+            Observe(ModulePCTable[i].Start[j]);
+      }
     }
   }