diff --git a/eng/native/configurecompiler.cmake b/eng/native/configurecompiler.cmake
index c22469f567b72..502d432f17bb3 100644
--- a/eng/native/configurecompiler.cmake
+++ b/eng/native/configurecompiler.cmake
@@ -340,15 +340,17 @@ if (CLR_CMAKE_HOST_UNIX)
   #These seem to indicate real issues
   add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-Wno-invalid-offsetof>)
 
-  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wno-unused-but-set-variable)
+
+  if (CMAKE_C_COMPILER_ID MATCHES "Clang")
+    add_compile_options(-Wno-unknown-warning-option)
+
     # The -ferror-limit is helpful during the porting, it makes sure the compiler doesn't stop
     # after hitting just about 20 errors.
     add_compile_options(-ferror-limit=4096)
 
     # Disabled warnings
     add_compile_options(-Wno-unused-private-field)
-    # Explicit constructor calls are not supported by clang (this->ClassName::ClassName())
-    add_compile_options(-Wno-microsoft)
     # There are constants of type BOOL used in a condition. But BOOL is defined as int
     # and so the compiler thinks that there is a mistake.
     add_compile_options(-Wno-constant-logical-operand)
@@ -363,8 +365,9 @@ if (CLR_CMAKE_HOST_UNIX)
     # to a struct or a class that has virtual members or a base class. In that case, clang
     # may not generate the same object layout as MSVC.
     add_compile_options(-Wno-incompatible-ms-struct)
+
+    add_compile_options(-Wno-reserved-identifier)
   else()
-    add_compile_options(-Wno-unused-but-set-variable)
     add_compile_options(-Wno-unknown-pragmas)
     add_compile_options(-Wno-uninitialized)
     add_compile_options(-Wno-strict-aliasing)
diff --git a/src/coreclr/inc/corhlpr.h b/src/coreclr/inc/corhlpr.h
index 450514da95c18..427e8cdc0ff5c 100644
--- a/src/coreclr/inc/corhlpr.h
+++ b/src/coreclr/inc/corhlpr.h
@@ -336,7 +336,7 @@ struct COR_ILMETHOD_SECT
     const COR_ILMETHOD_SECT* Next() const
     {
         if (!More()) return(0);
-        return ((COR_ILMETHOD_SECT*)(((BYTE *)this) + DataSize()))->Align();
+        return ((COR_ILMETHOD_SECT*)Align(((BYTE *)this) + DataSize()));
     }
 
     const BYTE* Data() const
@@ -374,9 +374,9 @@ struct COR_ILMETHOD_SECT
         return((AsSmall()->Kind & CorILMethod_Sect_FatFormat) != 0);
     }
 
-    const COR_ILMETHOD_SECT* Align() const
+    static const void* Align(const void* p)
     {
-        return((COR_ILMETHOD_SECT*) ((((UINT_PTR) this) + 3) & ~3));
+        return((void*) ((((UINT_PTR) p) + 3) & ~3));
     }
 
 protected:
@@ -579,7 +579,7 @@ typedef struct tagCOR_ILMETHOD_FAT : IMAGE_COR_ILMETHOD_FAT
 
     const COR_ILMETHOD_SECT* GetSect() const {
         if (!More()) return (0);
-        return(((COR_ILMETHOD_SECT*) (GetCode() + GetCodeSize()))->Align());
+        return(((COR_ILMETHOD_SECT*) COR_ILMETHOD_SECT::Align(GetCode() + GetCodeSize())));
     }
 } COR_ILMETHOD_FAT;
 
diff --git a/src/coreclr/jit/bitsetasshortlong.h b/src/coreclr/jit/bitsetasshortlong.h
index dce54d6a5ca3a..365cf346a10ac 100644
--- a/src/coreclr/jit/bitsetasshortlong.h
+++ b/src/coreclr/jit/bitsetasshortlong.h
@@ -345,7 +345,7 @@ class BitSetOps</*BitSetType*/ BitSetShortLongRep,
     {
         if (IsShort(env))
         {
-            (size_t&)out = (size_t)out & ((size_t)gen | (size_t)in);
+            out = (BitSetShortLongRep)((size_t)out & ((size_t)gen | (size_t)in));
         }
         else
         {
@@ -361,7 +361,7 @@ class BitSetOps</*BitSetType*/ BitSetShortLongRep,
     {
         if (IsShort(env))
         {
-            (size_t&)in = (size_t)use | ((size_t)out & ~(size_t)def);
+            in = (BitSetShortLongRep)((size_t)use | ((size_t)out & ~(size_t)def));
         }
         else
         {
diff --git a/src/coreclr/jit/inlinepolicy.h b/src/coreclr/jit/inlinepolicy.h
index 466e17fe0e112..e604fd57a36ed 100644
--- a/src/coreclr/jit/inlinepolicy.h
+++ b/src/coreclr/jit/inlinepolicy.h
@@ -185,7 +185,7 @@ class DefaultPolicy : public LegalPolicy
 class ExtendedDefaultPolicy : public DefaultPolicy
 {
 public:
-    ExtendedDefaultPolicy::ExtendedDefaultPolicy(Compiler* compiler, bool isPrejitRoot)
+    ExtendedDefaultPolicy(Compiler* compiler, bool isPrejitRoot)
         : DefaultPolicy(compiler, isPrejitRoot)
         , m_ProfileFrequency(0.0)
         , m_BinaryExprWithCns(0)
diff --git a/src/libraries/Native/Unix/CMakeLists.txt b/src/libraries/Native/Unix/CMakeLists.txt
index 31cea57a62938..6fae902369c0e 100644
--- a/src/libraries/Native/Unix/CMakeLists.txt
+++ b/src/libraries/Native/Unix/CMakeLists.txt
@@ -36,6 +36,8 @@ add_compile_options(-Wno-cast-align)
 add_compile_options(-Wno-typedef-redefinition)
 add_compile_options(-Wno-c11-extensions)
 add_compile_options(-Wno-unknown-pragmas)
+add_compile_options(-Wno-unknown-warning-option)
+add_compile_options(-Wno-unused-but-set-variable)
 
 check_c_compiler_flag(-Wimplicit-fallthrough COMPILER_SUPPORTS_W_IMPLICIT_FALLTHROUGH)
 if (COMPILER_SUPPORTS_W_IMPLICIT_FALLTHROUGH)
@@ -48,6 +50,7 @@ add_compile_options(-g)
 if(CMAKE_C_COMPILER_ID STREQUAL Clang)
     add_compile_options(-Wthread-safety)
     add_compile_options(-Wno-thread-safety-analysis)
+    add_compile_options(-Wno-reserved-identifier)
 elseif(CMAKE_C_COMPILER_ID STREQUAL GNU)
     add_compile_options(-Wno-stringop-truncation)
 endif()
diff --git a/src/libraries/Native/Unix/System.Native/pal_process.c b/src/libraries/Native/Unix/System.Native/pal_process.c
index 5e97d958f74d1..fabdfae76187c 100644
--- a/src/libraries/Native/Unix/System.Native/pal_process.c
+++ b/src/libraries/Native/Unix/System.Native/pal_process.c
@@ -191,6 +191,24 @@ static int SetGroups(uint32_t* userGroups, int32_t userGroupsLength, uint32_t* p
     return rv;
 }
 
+typedef void (*VoidIntFn)(int);
+
+static
+VoidIntFn
+handler_from_sigaction (struct sigaction *sa)
+{
+    if (((unsigned int)sa->sa_flags) & SA_SIGINFO)
+    {
+        // work around -Wcast-function-type
+        void (*tmp)(void) = (void (*)(void))sa->sa_sigaction;
+        return (void (*)(int))tmp;
+    }
+    else
+    {
+        return sa->sa_handler;
+    }
+}
+
 int32_t SystemNative_ForkAndExecProcess(const char* filename,
                                       char* const argv[],
                                       char* const envp[],
@@ -371,7 +389,7 @@ int32_t SystemNative_ForkAndExecProcess(const char* filename,
             }
             if (!sigaction(sig, NULL, &sa_old))
             {
-                void (*oldhandler)(int) = (((unsigned int)sa_old.sa_flags) & SA_SIGINFO) ? (void (*)(int))sa_old.sa_sigaction : sa_old.sa_handler;
+                void (*oldhandler)(int) = handler_from_sigaction (&sa_old);
                 if (oldhandler != SIG_IGN && oldhandler != SIG_DFL)
                 {
                     // It has a custom handler, put the default handler back.