Fix libutils_binder_sdk build warnings

-Wclass-memaccess
-Winvalid-offsetof
-Wsequence-point
-Wzero-as-null-pointer-constant (turned on in ag/4503295)

Bug: 285204695
Test: m libutils_binder_sdk
Change-Id: I5b988f498cb8e0cf04617a4f7fd41ba9970d321d

libutils/binder/Android.bp

@@ -22,6 +22,12 @@ cc_defaults {
         "VectorImpl.cpp",
     ],
 
+    cflags: [
+        "-Winvalid-offsetof",
+        "-Wsequence-point",
+        "-Wzero-as-null-pointer-constant",
+    ],
+
     apex_available: [
         "//apex_available:anyapex",
         "//apex_available:platform",

libutils/binder/SharedBuffer.cpp

@@ -75,7 +75,7 @@ SharedBuffer* SharedBuffer::editResize(size_t newSize) const
         LOG_ALWAYS_FATAL_IF((newSize >= (SIZE_MAX - sizeof(SharedBuffer))),
                             "Invalid buffer size %zu", newSize);
 
-        buf = (SharedBuffer*)realloc(buf, sizeof(SharedBuffer) + newSize);
+        buf = (SharedBuffer*)realloc(reinterpret_cast<void*>(buf), sizeof(SharedBuffer) + newSize);
         if (buf != nullptr) {
             buf->mSize = newSize;
             return buf;

libutils/binder/String16.cpp

@@ -22,6 +22,19 @@
 
 #include "SharedBuffer.h"
 
+#define LIBUTILS_PRAGMA(arg) _Pragma(#arg)
+#if defined(__clang__)
+#define LIBUTILS_PRAGMA_FOR_COMPILER(arg) LIBUTILS_PRAGMA(clang arg)
+#elif defined(__GNUC__)
+#define LIBUTILS_PRAGMA_FOR_COMPILER(arg) LIBUTILS_PRAGMA(GCC arg)
+#else
+#define LIBUTILS_PRAGMA_FOR_COMPILER(arg)
+#endif
+#define LIBUTILS_IGNORE(warning_flag)             \
+    LIBUTILS_PRAGMA_FOR_COMPILER(diagnostic push) \
+    LIBUTILS_PRAGMA_FOR_COMPILER(diagnostic ignored warning_flag)
+#define LIBUTILS_IGNORE_END() LIBUTILS_PRAGMA_FOR_COMPILER(diagnostic pop)
+
 namespace android {
 
 static const StaticString16 emptyString(u"");
@@ -347,7 +360,9 @@ void String16::release()
 bool String16::isStaticString() const {
     // See String16.h for notes on the memory layout of String16::StaticData and
     // SharedBuffer.
+    LIBUTILS_IGNORE("-Winvalid-offsetof")
     static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
+    LIBUTILS_IGNORE_END()
     const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
     return (*(p - 1) & kIsSharedBufferAllocated) == 0;
 }
@@ -355,7 +370,9 @@ bool String16::isStaticString() const {
 size_t String16::staticStringSize() const {
     // See String16.h for notes on the memory layout of String16::StaticData and
     // SharedBuffer.
+    LIBUTILS_IGNORE("-Winvalid-offsetof")
     static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
+    LIBUTILS_IGNORE_END()
     const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
     return static_cast<size_t>(*(p - 1));
 }

libutils/binder/include/utils/RefBase.h

@@ -555,7 +555,7 @@ template<typename T>
 wp<T>::wp(T* other)
     : m_ptr(other)
 {
-    m_refs = other ? m_refs = other->createWeak(this) : nullptr;
+    m_refs = other ? other->createWeak(this) : nullptr;
 }
 
 template <typename T>
@@ -662,8 +662,7 @@ wp<T>& wp<T>::operator = (const wp<U>& other)
 template<typename T> template<typename U>
 wp<T>& wp<T>::operator = (const sp<U>& other)
 {
-    weakref_type* newRefs =
-        other != nullptr ? other->createWeak(this) : 0;
+    weakref_type* newRefs = other != nullptr ? other->createWeak(this) : nullptr;
     U* otherPtr(other.m_ptr);
     if (m_ptr) m_refs->decWeak(this);
     m_ptr = otherPtr;
@@ -695,8 +694,8 @@ void wp<T>::clear()
 {
     if (m_ptr) {
         m_refs->decWeak(this);
-        m_refs = 0;
-        m_ptr = 0;
+        m_refs = nullptr;
+        m_ptr = nullptr;
     }
 }
 

libutils/binder/include/utils/TypeHelpers.h

@@ -200,7 +200,7 @@ template<typename TYPE>
 typename std::enable_if<use_trivial_move<TYPE>::value>::type
 inline
 move_forward_type(TYPE* d, const TYPE* s, size_t n = 1) {
-    memmove(d, s, n*sizeof(TYPE));
+    memmove(reinterpret_cast<void*>(d), s, n * sizeof(TYPE));
 }
 
 template<typename TYPE>
@@ -227,7 +227,7 @@ template<typename TYPE>
 typename std::enable_if<use_trivial_move<TYPE>::value>::type
 inline
 move_backward_type(TYPE* d, const TYPE* s, size_t n = 1) {
-    memmove(d, s, n*sizeof(TYPE));
+    memmove(reinterpret_cast<void*>(d), s, n * sizeof(TYPE));
 }
 
 template<typename TYPE>