[libc][NFC] Couple of small warning fixes

[mikhailramalho]

This patch fixes a couple of warning when compiling with gcc 13:

• CPP/type_traits_test.cpp: 'apply' overrides a member function but is not marked 'override'

• UnitTest/LibcTest.cpp:98: control reaches end of non-void function

• MPFRWrapper/MPFRUtils.cpp:75: control reaches end of non-void function

• smoke/FrexpTest.h:92: backslash-newline at end of file

[llvmbot]

@llvm/pr-subscribers-libc

Changes

This patch fixes a couple of warning when compiling with gcc 13:

• CPP/type_traits_test.cpp: 'apply' overrides a member function but is not marked 'override'

• UnitTest/LibcTest.cpp:98: control reaches end of non-void function

• MPFRWrapper/MPFRUtils.cpp:75: control reaches end of non-void function

• smoke/FrexpTest.h:92: backslash-newline at end of file

---

Full diff: https://github.com/llvm/llvm-project/pull/67847.diff

4 Files Affected:

• (modified) libc/test/UnitTest/LibcTest.cpp (+1)
• (modified) libc/test/src/__support/CPP/type_traits_test.cpp (+1-1)
• (modified) libc/test/src/math/smoke/FrexpTest.h (+1-1)
• (modified) libc/utils/MPFRWrapper/MPFRUtils.cpp (+1)

diff --git a/libc/test/UnitTest/LibcTest.cpp b/libc/test/UnitTest/LibcTest.cpp
index 2f18d5778e71d84..b01f40f0526461f 100644
--- a/libc/test/UnitTest/LibcTest.cpp
+++ b/libc/test/UnitTest/LibcTest.cpp
@@ -95,6 +95,7 @@ bool test(RunContext *Ctx, TestCond Cond, ValType LHS, ValType RHS,
   case TestCond::GE:
     return ExplainDifference(LHS >= RHS, "greater than or equal to");
   }
+  __builtin_unreachable();
 }
 
 } // namespace internal
diff --git a/libc/test/src/__support/CPP/type_traits_test.cpp b/libc/test/src/__support/CPP/type_traits_test.cpp
index 0e5f4a1f738b7aa..a2051f380275326 100644
--- a/libc/test/src/__support/CPP/type_traits_test.cpp
+++ b/libc/test/src/__support/CPP/type_traits_test.cpp
@@ -157,7 +157,7 @@ struct A {
 
 struct B : public A {
   virtual ~B() {}
-  virtual void apply() { state = B_APPLY_CALLED; }
+  virtual void apply() override { state = B_APPLY_CALLED; }
 };
 
 void free_function() {}
diff --git a/libc/test/src/math/smoke/FrexpTest.h b/libc/test/src/math/smoke/FrexpTest.h
index 1740770fd6c4787..3ff169091cc9a38 100644
--- a/libc/test/src/math/smoke/FrexpTest.h
+++ b/libc/test/src/math/smoke/FrexpTest.h
@@ -93,4 +93,4 @@ template <typename T> class FrexpTest : public LIBC_NAMESPACE::testing::Test {
   using LlvmLibcFrexpTest = FrexpTest<T>;                                      \
   TEST_F(LlvmLibcFrexpTest, SpecialNumbers) { testSpecialNumbers(&func); }     \
   TEST_F(LlvmLibcFrexpTest, PowersOfTwo) { testPowersOfTwo(&func); }           \
-  TEST_F(LlvmLibcFrexpTest, SomeIntegers) { testSomeIntegers(&func); }\
+  TEST_F(LlvmLibcFrexpTest, SomeIntegers) { testSomeIntegers(&func); }
diff --git a/libc/utils/MPFRWrapper/MPFRUtils.cpp b/libc/utils/MPFRWrapper/MPFRUtils.cpp
index e23a3c2034cb283..0818955f14de7d3 100644
--- a/libc/utils/MPFRWrapper/MPFRUtils.cpp
+++ b/libc/utils/MPFRWrapper/MPFRUtils.cpp
@@ -72,6 +72,7 @@ static inline mpfr_rnd_t get_mpfr_rounding_mode(RoundingMode mode) {
     return MPFR_RNDN;
     break;
   }
+  __builtin_unreachable();
 }
 
 class MPFRNumber {

[michaelrj-google]

LGTM with one fix

[michaelrj-google]

LGTM