all repos — mgba @ bd4dd8de5ca3cd2c62c778c26114f685be6ac729

mGBA Game Boy Advance Emulator

Util: Don't build crc32 if the function already exists
Vicki Pfau vi@endrift.com
Sat, 09 Sep 2017 10:51:40 -0700
commit

bd4dd8de5ca3cd2c62c778c26114f685be6ac729

parent

076ec733fd4f8f220027bcea001f8d6367915a4a

5 files changed, 27 insertions(+), 9 deletions(-)

jump to
M CHANGES → CHANGES 
@@ -45,6 +45,7 @@ - Qt: Redo GameController into multiple classes
  - SDL: Fix 2.0.5 build on macOS under some circumstances
  - Test: Restructure test suite into multiple executables
  - Python: Integrate tests from cinema test suite
+ - Util: Don't build crc32 if the function already exists
 
 0.6.0: (2017-07-16)
 Features:
M CMakeLists.txt → CMakeLists.txt 
@@ -500,6 +500,14 @@ list(APPEND FEATURES ZLIB)
 	include_directories(AFTER ${ZLIB_INCLUDE_DIRS})
 	list(APPEND DEPENDENCY_LIB ${ZLIB_LIBRARIES})
 	set(CPACK_DEBIAN_PACKAGE_DEPENDS "${CPACK_DEBIAN_PACKAGE_DEPENDS},zlib1g")
+	set(HAVE_CRC32 ON)
+else()
+	# zlib pulls in crc32
+	check_function_exists(crc32 HAVE_CRC32)
+endif()
+
+if(HAVE_CRC32)
+	list(APPEND FUNCTION_DEFINES HAVE_CRC32)
 endif()
 
 if(WANT_PNG AND USE_ZLIB AND NOT USE_PNG)
M include/mgba-util/crc32.h → include/mgba-util/crc32.h 
@@ -12,8 +12,13 @@ CXX_GUARD_START
 
 struct VFile;
 
+#ifndef HAVE_CRC32
+uint32_t crc32(uint32_t crc, const void* buf, size_t size);
+#else
+#include <zlib.h>
+#endif
+
 uint32_t doCrc32(const void* buf, size_t size);
-uint32_t updateCrc32(uint32_t crc, const void* buf, size_t size);
 uint32_t fileCrc32(struct VFile* file, size_t endOffset);
 
 CXX_GUARD_END
M src/util/crc32.c → src/util/crc32.c 
@@ -48,6 +48,7 @@ enum {
 	BUFFER_SIZE = 1024
 };
 
+#ifndef HAVE_CRC32
 static uint32_t crc32Table[] = {
 	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
 	0xe963a535, 0x9e6495a3,	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,

@@ -93,12 +94,14 @@ 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
 	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
 	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
 };
+#endif
 
 uint32_t doCrc32(const void* buf, size_t size) {
-	return updateCrc32(0, buf, size);
+	return crc32(0, buf, size);
 }
 
-uint32_t updateCrc32(uint32_t crc, const void* buf, size_t size) {
+#ifndef HAVE_CRC32
+uint32_t crc32(uint32_t crc, const void* buf, size_t size) {
 	const uint8_t* p = buf;
 	
 	crc = ~crc;

@@ -108,9 +111,10 @@ }
 
 	return ~crc;
 }
+#endif
 
 uint32_t fileCrc32(struct VFile* vf, size_t endOffset) {
-	char buffer[BUFFER_SIZE];
+	uint8_t buffer[BUFFER_SIZE];
 	size_t blocksize;
 	size_t alreadyRead = 0;
 	if (vf->seek(vf, 0, SEEK_SET) < 0) {

@@ -124,7 +128,7 @@ toRead = endOffset - alreadyRead;
 		}
 		blocksize = vf->read(vf, buffer, toRead);
 		alreadyRead += blocksize;
-		crc = updateCrc32(crc, buffer, blocksize);
+		crc = crc32(crc, buffer, blocksize);
 		if (blocksize < toRead) {
 			return 0;
 		}
M src/util/patch-ups.c → src/util/patch-ups.c 
@@ -154,7 +154,7 @@ switch (command & 0x3) {
 		case 0x0:
 			// SourceRead
 			memmove(&writeBuffer[writeLocation], &readBuffer[writeLocation], length);
-			outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation], length);
+			outputChecksum = crc32(outputChecksum, &writeBuffer[writeLocation], length);
 			writeLocation += length;
 			break;
 		case 0x1:

@@ -162,7 +162,7 @@ // TargetRead
 			if (patch->vf->read(patch->vf, &writeBuffer[writeLocation], length) != (ssize_t) length) {
 				return false;
 			}
-			outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation], length);
+			outputChecksum = crc32(outputChecksum, &writeBuffer[writeLocation], length);
 			writeLocation += length;
 			break;
 		case 0x2:

@@ -177,7 +177,7 @@ if (readSourceLocation < 0 || readSourceLocation > (ssize_t) inSize) {
 				return false;
 			}
 			memmove(&writeBuffer[writeLocation], &readBuffer[readSourceLocation], length);
-			outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation], length);
+			outputChecksum = crc32(outputChecksum, &writeBuffer[writeLocation], length);
 			writeLocation += length;
 			readSourceLocation += length;
 			break;

@@ -198,7 +198,7 @@ writeBuffer[writeLocation] = writeBuffer[readTargetLocation];
 				++writeLocation;
 				++readTargetLocation;
 			}
-			outputChecksum = updateCrc32(outputChecksum, &writeBuffer[writeLocation - length], length);
+			outputChecksum = crc32(outputChecksum, &writeBuffer[writeLocation - length], length);
 			break;
 		}
 	}