Changeset 74172 in webkit

Timestamp:

Dec 15, 2010 8:35:13 PM (13 years ago)

Author:

cwzwarich@webkit.org

Message:

Reviewed by Darin Adler.

Clang -Wcast-align gives an error in WebBasePluginPackage.mm
​https://bugs.webkit.org/show_bug.cgi?id=51144

Fix an alignment issue. OSSwapInt32 takes data that is 32-bit aligned on ARM, but
we were calling it on a byte array 32 bits at a time. While this is okay in practice,
since TCMalloc won't give us a non-32-bit aligned block array of bytes and Vector's
inline storage is at the beginning of the Vector, it is still better to fix this
and silence the warning.

• Plugins/WebBasePluginPackage.mm:

(swapIntsInHeader):
(-[WebBasePluginPackage isNativeLibraryData:]):

Location:

trunk/WebKit/mac

Files:

• ChangeLog (modified) (1 diff)
• Plugins/WebBasePluginPackage.mm (modified) (4 diffs)

trunk/WebKit/mac/ChangeLog

@@ +1 @@
+2010-12-15  Cameron Zwarich  <zwarich@apple.com>
+
+        Reviewed by Darin Adler.
+
+        Clang -Wcast-align gives an error in WebBasePluginPackage.mm
+        https://bugs.webkit.org/show_bug.cgi?id=51144
+
+        Fix an alignment issue. OSSwapInt32 takes data that is 32-bit aligned on ARM, but
+        we were calling it on a byte array 32 bits at a time. While this is okay in practice,
+        since TCMalloc won't give us a non-32-bit aligned block array of bytes and Vector's
+        inline storage is at the beginning of the Vector, it is still better to fix this
+        and silence the warning.
+
+        * Plugins/WebBasePluginPackage.mm:
+        (swapIntsInHeader):
+        (-[WebBasePluginPackage isNativeLibraryData:]):
+
 2010-12-14  Mark Rowe  <mrowe@apple.com>
 

trunk/WebKit/mac/Plugins/WebBasePluginPackage.mm

@@ -344 +344 @@
 }
 
-static inline void swapIntsInHeader(uint8_t* bytes, unsigned length)
-{
-    for (unsigned i = 0; i < length; i += 4) 
-        *(uint32_t*)(bytes + i) = OSSwapInt32(*(uint32_t *)(bytes + i));
+static inline void swapIntsInHeader(uint32_t* rawData, size_t length)
+{
+    for (size_t i = 0; i < length; ++i) 
+        rawData[i] = OSSwapInt32(rawData[i]);
 }
 
 - (BOOL)isNativeLibraryData:(NSData *)data
 {
-    Vector<uint8_t, 512> bytes([data length]);
-    memcpy(bytes.data(), [data bytes], bytes.size());
+    NSUInteger sizeInBytes = [data length];
+    Vector<uint32_t, 128> rawData((sizeInBytes - 1) / 4 + 1);
+    memcpy(rawData.data(), [data bytes], sizeInBytes);
     
     unsigned numArchs = 0;
@@ -359 +360 @@
     struct fat_arch* archs = 0;
        
-    if (bytes.size() >= sizeof(struct mach_header_64)) {
-        uint32_t magic = *reinterpret_cast<uint32_t*>(bytes.data());
+    if (sizeInBytes >= sizeof(struct mach_header_64)) {
+        uint32_t magic = *rawData.data();
         
         if (magic == MH_MAGIC || magic == MH_CIGAM) {
             // We have a 32-bit thin binary
-            struct mach_header* header = (struct mach_header*)bytes.data();
+            struct mach_header* header = (struct mach_header*)rawData.data();
 
             // Check if we need to swap the bytes
             if (magic == MH_CIGAM)
-                swapIntsInHeader(bytes.data(), bytes.size());
+                swapIntsInHeader(rawData.data(), rawData.size());
     
             singleArch.cputype = header->cputype;
@@ -377 +378 @@
         } else if (magic == MH_MAGIC_64 || magic == MH_CIGAM_64) {
             // We have a 64-bit thin binary
-            struct mach_header_64* header = (struct mach_header_64*)bytes.data();
+            struct mach_header_64* header = (struct mach_header_64*)rawData.data();
 
             // Check if we need to swap the bytes
             if (magic == MH_CIGAM_64)
-                swapIntsInHeader(bytes.data(), bytes.size());
+                swapIntsInHeader(rawData.data(), rawData.size());
             
             singleArch.cputype = header->cputype;
@@ -393 +394 @@
             // Check if we need to swap the bytes
             if (magic == FAT_CIGAM)
-                swapIntsInHeader(bytes.data(), bytes.size());
+                swapIntsInHeader(rawData.data(), rawData.size());
             
-            archs = (struct fat_arch*)(bytes.data() + sizeof(struct fat_header));            
-            numArchs = ((struct fat_header *)bytes.data())->nfat_arch;
+            archs = (struct fat_arch*)(rawData.data() + sizeof(struct fat_header));            
+            numArchs = ((struct fat_header *)rawData.data())->nfat_arch;
             
-            unsigned maxArchs = (bytes.size() - sizeof(struct fat_header)) / sizeof(struct fat_arch);
+            unsigned maxArchs = (sizeInBytes - sizeof(struct fat_header)) / sizeof(struct fat_arch);
             if (numArchs > maxArchs)
                 numArchs = maxArchs;