[llvm] r289310 - [libFuzzer] use __sanitizer_get_module_and_offset_for_pc to get the module name while printing the coverage

[Kostya Serebryany via llvm-commits]

Author: kcc
Date: Fri Dec  9 19:19:35 2016
New Revision: 289310

URL: http://llvm.org/viewvc/llvm-project?rev=289310&view=rev
Log:
[libFuzzer] use __sanitizer_get_module_and_offset_for_pc to get the module name while printing the coverage

Modified:
    llvm/trunk/lib/Fuzzer/FuzzerExtFunctions.def
    llvm/trunk/lib/Fuzzer/FuzzerTracePC.cpp

Modified: llvm/trunk/lib/Fuzzer/FuzzerExtFunctions.def
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerExtFunctions.def?rev=289310&r1=289309&r2=289310&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerExtFunctions.def (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerExtFunctions.def Fri Dec  9 19:19:35 2016
@@ -40,6 +40,9 @@ EXT_FUNC(__sanitizer_print_memory_profil
 EXT_FUNC(__sanitizer_print_stack_trace, void, (), true);
 EXT_FUNC(__sanitizer_symbolize_pc, void,
          (void *, const char *fmt, char *out_buf, size_t out_buf_size), false);
+EXT_FUNC(__sanitizer_get_module_and_offset_for_pc, int,
+         (void *pc, char *module_path,
+         size_t module_path_len,void **pc_offset), false);
 EXT_FUNC(__sanitizer_reset_coverage, void, (), true);
 EXT_FUNC(__sanitizer_set_death_callback, void, (void (*)(void)), true);
 EXT_FUNC(__sanitizer_set_report_fd, void, (void*), false);

Modified: llvm/trunk/lib/Fuzzer/FuzzerTracePC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/FuzzerTracePC.cpp?rev=289310&r1=289309&r2=289310&view=diff
==============================================================================
--- llvm/trunk/lib/Fuzzer/FuzzerTracePC.cpp (original)
+++ llvm/trunk/lib/Fuzzer/FuzzerTracePC.cpp Fri Dec  9 19:19:35 2016
@@ -89,8 +89,10 @@ void TracePC::PrintNewPCs() {
 }
 
 void TracePC::PrintCoverage() {
-  if (!EF->__sanitizer_symbolize_pc) {
-    Printf("INFO: __sanitizer_symbolize_pc is not available,"
+  if (!EF->__sanitizer_symbolize_pc ||
+      !EF->__sanitizer_get_module_and_offset_for_pc) {
+    Printf("INFO: __sanitizer_symbolize_pc or "
+           "__sanitizer_get_module_and_offset_for_pc is not available,"
            " not printing coverage\n");
     return;
   }
@@ -106,12 +108,15 @@ void TracePC::PrintCoverage() {
     std::string FixedPCStr = DescribePC("%p", PCs[i]);
     std::string FunctionStr = DescribePC("%F", PCs[i]);
     std::string LineStr = DescribePC("%l", PCs[i]);
-    // TODO(kcc): get the module using some other way since this
-    // does not work with ASAN_OPTIONS=strip_path_prefix=something.
-    std::string Module = DescribePC("%m", PCs[i]);
-    std::string OffsetStr = DescribePC("%o", PCs[i]);
+    char ModulePathRaw[4096] = "";  // What's PATH_MAX in portable C++?
+    void *OffsetRaw = nullptr;
+    if (!EF->__sanitizer_get_module_and_offset_for_pc(
+            reinterpret_cast<void *>(PCs[i]), ModulePathRaw,
+            sizeof(ModulePathRaw), &OffsetRaw))
+      continue;
+    std::string Module = ModulePathRaw;
     uintptr_t FixedPC = std::stol(FixedPCStr, 0, 16);
-    uintptr_t PcOffset = std::stol(OffsetStr, 0, 16);
+    uintptr_t PcOffset = reinterpret_cast<uintptr_t>(OffsetRaw);
     ModuleOffsets[Module] = FixedPC - PcOffset;
     CoveredPCsPerModule[Module].push_back(PcOffset);
     CoveredFunctions.insert(FunctionStr);