[libFuzzer] add ShrinkValueProfileTest, move code around, NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283286 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Fuzzer/FuzzerTracePC.cpp

@@ -117,6 +117,70 @@ void TracePC::PrintCoverage() {
   }
 }
 
+// Value profile.
+// We keep track of various values that affect control flow.
+// These values are inserted into a bit-set-based hash map.
+// Every new bit in the map is treated as a new coverage.
+//
+// For memcmp/strcmp/etc the interesting value is the length of the common
+// prefix of the parameters.
+// For cmp instructions the interesting value is a XOR of the parameters.
+// The interesting value is mixed up with the PC and is then added to the map.
+
+void TracePC::AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
+                              size_t n) {
+  if (!n) return;
+  size_t Len = std::min(n, (size_t)32);
+  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
+  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
+  size_t I = 0;
+  for (; I < Len; I++)
+    if (A1[I] != A2[I])
+      break;
+  size_t PC = reinterpret_cast<size_t>(caller_pc);
+  size_t Idx = I;
+  // if (I < Len)
+  //  Idx += __builtin_popcountl((A1[I] ^ A2[I])) - 1;
+  TPC.HandleValueProfile((PC & 4095) | (Idx << 12));
+}
+
+void TracePC::AddValueForStrcmp(void *caller_pc, const char *s1, const char *s2,
+                              size_t n) {
+  if (!n) return;
+  size_t Len = std::min(n, (size_t)32);
+  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
+  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
+  size_t I = 0;
+  for (; I < Len; I++)
+    if (A1[I] != A2[I] || A1[I] == 0)
+      break;
+  size_t PC = reinterpret_cast<size_t>(caller_pc);
+  size_t Idx = I;
+  // if (I < Len && A1[I])
+  //  Idx += __builtin_popcountl((A1[I] ^ A2[I])) - 1;
+  TPC.HandleValueProfile((PC & 4095) | (Idx << 12));
+}
+
+ATTRIBUTE_TARGET_POPCNT
+static void AddValueForCmp(void *PCptr, uint64_t Arg1, uint64_t Arg2) {
+  if (Arg1 == Arg2)
+    return;
+  uintptr_t PC = reinterpret_cast<uintptr_t>(PCptr);
+  uint64_t ArgDistance = __builtin_popcountl(Arg1 ^ Arg2) - 1; // [0,63]
+  uintptr_t Idx = (PC & 4095) | (ArgDistance << 12);
+  TPC.HandleValueProfile(Idx);
+}
+
+static void AddValueForSingleVal(void *PCptr, uintptr_t Val) {
+  if (!Val) return;
+  uintptr_t PC = reinterpret_cast<uintptr_t>(PCptr);
+  uint64_t ArgDistance = __builtin_popcountl(Val) - 1; // [0,63]
+  uintptr_t Idx = (PC & 4095) | (ArgDistance << 12);
+  TPC.HandleValueProfile(Idx);
+}
+
+
+
 } // namespace fuzzer
 
 extern "C" {
@@ -136,4 +200,47 @@ void __sanitizer_cov_trace_pc_indir(uintptr_t Callee) {
   uintptr_t PC = (uintptr_t)__builtin_return_address(0);
   fuzzer::TPC.HandleCallerCallee(PC, Callee);
 }
+
+// TODO: this one will not be used with the newest clang. Remove it.
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
+                               uint64_t Arg2) {
+  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
 }
+
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_cmp8(uint64_t Arg1, int64_t Arg2) {
+  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
+}
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_cmp4(uint32_t Arg1, int32_t Arg2) {
+  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
+}
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_cmp2(uint16_t Arg1, int16_t Arg2) {
+  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
+}
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_cmp1(uint8_t Arg1, int8_t Arg2) {
+  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
+}
+
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
+  // TODO(kcc): support value profile here.
+}
+
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_div4(uint32_t Val) {
+  fuzzer::AddValueForSingleVal(__builtin_return_address(0), Val);
+}
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_div8(uint64_t Val) {
+  fuzzer::AddValueForSingleVal(__builtin_return_address(0), Val);
+}
+__attribute__((visibility("default")))
+void __sanitizer_cov_trace_gep(uintptr_t Idx) {
+  fuzzer::AddValueForSingleVal(__builtin_return_address(0), Idx);
+}
+
+}  // extern "C"

lib/Fuzzer/FuzzerTracePC.h

@@ -62,6 +62,11 @@ class TracePC {
 
   bool HasFeature(size_t Idx) { return CounterMap.Get(Idx); }
 
+  void AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
+                         size_t n);
+  void AddValueForStrcmp(void *caller_pc, const char *s1, const char *s2,
+                         size_t n);
+
 private:
   bool UseCounters = false;
   bool UseValueProfile = false;

lib/Fuzzer/FuzzerTraceState.cpp

@@ -251,68 +251,6 @@ static size_t InternalStrnlen(const char *S, size_t MaxLen) {
   return Len;
 }
 
-// Value profile.
-// We keep track of various values that affect control flow.
-// These values are inserted into a bit-set-based hash map.
-// Every new bit in the map is treated as a new coverage.
-//
-// For memcmp/strcmp/etc the interesting value is the length of the common
-// prefix of the parameters.
-// For cmp instructions the interesting value is a XOR of the parameters.
-// The interesting value is mixed up with the PC and is then added to the map.
-
-static void AddValueForMemcmp(void *caller_pc, const void *s1, const void *s2,
-                              size_t n) {
-  if (!n) return;
-  size_t Len = std::min(n, (size_t)32);
-  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
-  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
-  size_t I = 0;
-  for (; I < Len; I++)
-    if (A1[I] != A2[I])
-      break;
-  size_t PC = reinterpret_cast<size_t>(caller_pc);
-  size_t Idx = I;
-  // if (I < Len)
-  //  Idx += __builtin_popcountl((A1[I] ^ A2[I])) - 1;
-  TPC.HandleValueProfile((PC & 4095) | (Idx << 12));
-}
-
-static void AddValueForStrcmp(void *caller_pc, const char *s1, const char *s2,
-                              size_t n) {
-  if (!n) return;
-  size_t Len = std::min(n, (size_t)32);
-  const uint8_t *A1 = reinterpret_cast<const uint8_t *>(s1);
-  const uint8_t *A2 = reinterpret_cast<const uint8_t *>(s2);
-  size_t I = 0;
-  for (; I < Len; I++)
-    if (A1[I] != A2[I] || A1[I] == 0)
-      break;
-  size_t PC = reinterpret_cast<size_t>(caller_pc);
-  size_t Idx = I;
-  // if (I < Len && A1[I])
-  //  Idx += __builtin_popcountl((A1[I] ^ A2[I])) - 1;
-  TPC.HandleValueProfile((PC & 4095) | (Idx << 12));
-}
-
-ATTRIBUTE_TARGET_POPCNT
-static void AddValueForCmp(void *PCptr, uint64_t Arg1, uint64_t Arg2) {
-  if (Arg1 == Arg2)
-    return;
-  uintptr_t PC = reinterpret_cast<uintptr_t>(PCptr);
-  uint64_t ArgDistance = __builtin_popcountl(Arg1 ^ Arg2) - 1; // [0,63]
-  uintptr_t Idx = (PC & 4095) | (ArgDistance << 12);
-  TPC.HandleValueProfile(Idx);
-}
-
-static void AddValueForSingleVal(void *PCptr, uintptr_t Val) {
-  if (!Val) return;
-  uintptr_t PC = reinterpret_cast<uintptr_t>(PCptr);
-  uint64_t ArgDistance = __builtin_popcountl(Val) - 1; // [0,63]
-  uintptr_t Idx = (PC & 4095) | (ArgDistance << 12);
-  TPC.HandleValueProfile(Idx);
-}
-
 }  // namespace fuzzer
 
 using fuzzer::TS;
@@ -328,7 +266,7 @@ extern "C" {
 #if LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
 void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
                                   const void *s2, size_t n, int result) {
-  fuzzer::AddValueForMemcmp(caller_pc, s1, s2, n);
+  fuzzer::TPC.AddValueForMemcmp(caller_pc, s1, s2, n);
   if (!RecordingMemcmp) return;
   if (result == 0) return;  // No reason to mutate.
   if (n <= 1) return;  // Not interesting.
@@ -338,7 +276,7 @@ void __sanitizer_weak_hook_memcmp(void *caller_pc, const void *s1,
 
 void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
                                    const char *s2, size_t n, int result) {
-  fuzzer::AddValueForStrcmp(caller_pc, s1, s2, n);
+  fuzzer::TPC.AddValueForStrcmp(caller_pc, s1, s2, n);
   if (!RecordingMemcmp) return;
   if (result == 0) return;  // No reason to mutate.
   size_t Len1 = fuzzer::InternalStrnlen(s1, n);
@@ -352,7 +290,7 @@ void __sanitizer_weak_hook_strncmp(void *caller_pc, const char *s1,
 
 void __sanitizer_weak_hook_strcmp(void *caller_pc, const char *s1,
                                    const char *s2, int result) {
-  fuzzer::AddValueForStrcmp(caller_pc, s1, s2, 64);
+  fuzzer::TPC.AddValueForStrcmp(caller_pc, s1, s2, 64);
   if (!RecordingMemcmp) return;
   if (result == 0) return;  // No reason to mutate.
   size_t Len1 = strlen(s1);
@@ -386,47 +324,4 @@ void __sanitizer_weak_hook_memmem(void *called_pc, const void *s1, size_t len1,
 }
 
 #endif  // LLVM_FUZZER_DEFINES_SANITIZER_WEAK_HOOOKS
-
-// TODO: this one will not be used with the newest clang. Remove it.
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_cmp(uint64_t SizeAndType, uint64_t Arg1,
-                               uint64_t Arg2) {
-  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
-}
-
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_cmp8(uint64_t Arg1, int64_t Arg2) {
-  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
-}
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_cmp4(uint32_t Arg1, int32_t Arg2) {
-  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
-}
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_cmp2(uint16_t Arg1, int16_t Arg2) {
-  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
-}
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_cmp1(uint8_t Arg1, int8_t Arg2) {
-  fuzzer::AddValueForCmp(__builtin_return_address(0), Arg1, Arg2);
-}
-
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_switch(uint64_t Val, uint64_t *Cases) {
-  // TODO(kcc): support value profile here.
-}
-
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_div4(uint32_t Val) {
-  fuzzer::AddValueForSingleVal(__builtin_return_address(0), Val);
-}
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_div8(uint64_t Val) {
-  fuzzer::AddValueForSingleVal(__builtin_return_address(0), Val);
-}
-__attribute__((visibility("default")))
-void __sanitizer_cov_trace_gep(uintptr_t Idx) {
-  fuzzer::AddValueForSingleVal(__builtin_return_address(0), Idx);
-}
-
 }  // extern "C"

lib/Fuzzer/test/CMakeLists.txt

@@ -80,7 +80,6 @@ set(Tests
   LeakTest
   LeakTimeoutTest
   LoadTest
-  MinimizeCorpusTest
   NullDerefTest
   NullDerefOnEmptyTest
   NthRunCrashTest
@@ -98,6 +97,8 @@ set(Tests
   SingleStrcmpTest
   SingleStrncmpTest
   SpamyTest
+  ShrinkControlFlowTest
+  ShrinkValueProfileTest
   StrcmpTest
   StrncmpTest
   StrstrTest

lib/Fuzzer/test/ShrinkValueProfileTest.cpp

@@ -0,0 +1,21 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Test that we can find the minimal item in the corpus (3 bytes: "FUZ").
+#include <cstdint>
+#include <cstdlib>
+#include <cstddef>
+#include <cstring>
+#include <cstdio>
+
+static volatile uint32_t Sink;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  if (Size < sizeof(uint32_t)) return 0;
+  uint32_t X;
+  size_t Offset = Size < 8 ? 0 : Size / 2;
+  memcpy(&X, Data + Offset, sizeof(uint32_t));
+  Sink = X == 0xAABBCCDD;
+  return 0;
+}
+

lib/Fuzzer/test/fuzzer.test

@@ -54,6 +54,6 @@ DSO: INFO: Loaded 3 modules
 DSO: BINGO
 
 RUN: LLVMFuzzer-SimpleTest-TracePC  -exit_on_src_pos=SimpleTest.cpp:17                 2>&1 | FileCheck %s --check-prefix=EXIT_ON_SRC_POS
-RUN: LLVMFuzzer-MinimizeCorpusTest-TracePC  -exit_on_src_pos=MinimizeCorpusTest.cpp:23 2>&1 | FileCheck %s --check-prefix=EXIT_ON_SRC_POS
+RUN: LLVMFuzzer-ShrinkControlFlowTest-TracePC  -exit_on_src_pos=ShrinkControlFlowTest.cpp:23 2>&1 | FileCheck %s --check-prefix=EXIT_ON_SRC_POS
 EXIT_ON_SRC_POS: INFO: found line matching '{{.*}}', exiting.
 

lib/Fuzzer/test/trace-pc/CMakeLists.txt

@@ -8,7 +8,8 @@ set(TracePCTests
   CounterTest
   CallerCalleeTest
   NullDerefTest
-  MinimizeCorpusTest
+  ShrinkControlFlowTest
+  ShrinkValueProfileTest
   FullCoverageSetTest
   )