[compiler-rt][scudo] Fix sign-compare warnings

[jsji]

Summary

Fix buildbot failure
https://lab.llvm.org/buildbot/#/builders/57/builds/6542/steps/6/logs/stdio

/llvm-project/llvm/utils/unittest/googletest/include/gtest/gtest.h:1629:28:
error: comparison of integers of different signs: 'const unsigned long'
and 'const int' [-Werror,-Wsign-compare]
GTEST_IMPL_CMP_HELPER_(GT, >);
~~~~~~~~~~~~~~~~~~~~~~~~~~^~
/llvm-project/llvm/utils/unittest/googletest/include/gtest/gtest.h:1609:12:
note: expanded from macro 'GTEST_IMPL_CMP_HELPER_'

if (val1 op val2) {\
    ~~~~ ^  ~~~~

/llvm-project/compiler-rt/lib/scudo/standalone/tests/common_test.cpp:30:3:
note: in instantiation of function template specialization
'testing::internal::CmpHelperGT<unsigned long, int>' requested here

EXPECT_GT(OnStart, 0);
^

[vitalybuka]

Thanks

compiler-rt/lib/scudo/standalone/tests/common_test.cpp

42

could you change to reinterpret cast?
or maybe N to size_t?

[jsji]

compiler-rt/lib/scudo/standalone/tests/common_test.cpp

42

Do you mean ptrdiff_t? size_t is also unsigned, while std::count is returning signed int.

[jsji]

Update type of N to size_t.

compiler-rt/lib/scudo/standalone/tests/common_test.cpp

static uptr getResidentMemorySize() {
   IFS >> Size;
   IFS >> Resident;
   return Resident * getPageSizeCached();
 }
 
 // Fuchsia needs getResidentMemorySize implementation.
 TEST(ScudoCommonTest, SKIP_ON_FUCHSIA(ResidentMemorySize)) {
   uptr OnStart = getResidentMemorySize();
-  EXPECT_GT(OnStart, 0);
+  EXPECT_GT(OnStart, 0UL);
 
   const uptr Size = 1ull << 30;
   const uptr Threshold = Size >> 3;
 
   MapPlatformData Data = {};
   uptr *P = reinterpret_cast<uptr *>(
       map(nullptr, Size, "ResidentMemorySize", 0, &Data));
-  const uptr N = Size / sizeof(*P);
+  const size_t N = Size / sizeof(*P);
   ASSERT_NE(nullptr, P);
-  EXPECT_EQ(std::count(P, P + N, 0), N);
+  EXPECT_EQ((size_t)std::count(P, P + N, 0), N);
   EXPECT_LT(getResidentMemorySize() - OnStart, Threshold);
 
   memset(P, 1, Size);
   EXPECT_EQ(std::count(P, P + N, 0), 0);
   EXPECT_LT(getResidentMemorySize() - Size, Threshold);
 
   releasePagesToOS((uptr)P, 0, Size, &Data);
-  EXPECT_EQ(std::count(P, P + N, 0), N);
+  EXPECT_EQ((size_t)std::count(P, P + N, 0), N);
   // FIXME: does not work with QEMU-user.
   // EXPECT_LT(getResidentMemorySize() - OnStart, Threshold);
 
   memset(P, 1, Size);
   EXPECT_EQ(std::count(P, P + N, 0), 0);
   EXPECT_LT(getResidentMemorySize() - Size, Threshold);
 }
 
 } // namespace scudo