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Run-time check for floating point byte order rather than CMake check.

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It's safer not to use an unofficial CMake script.
This commit is contained in:
Tsuda Kageyu 2015-07-31 12:46:43 +09:00
parent 13dab99af0
commit 44d9f2bf25
6 changed files with 17 additions and 122 deletions
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12
ConfigureChecks.cmake
View File

@ -2,7 +2,6 @@ include(CheckLibraryExists)
include(CheckTypeSize)
include(CheckCXXSourceCompiles)
include(TestBigEndian)
include(TestFloatFormat)
# Check if the size of numeric types are suitable.
@ -46,17 +45,6 @@ else()
set(SYSTEM_BYTEORDER 2)
endif()
# Check if the format of floating point types are suitable.
test_float_format(FP_IEEE754)
if(${FP_IEEE754} EQUAL 1)
set(FLOAT_BYTEORDER 1)
elseif(${FP_IEEE754} EQUAL 2)
set(FLOAT_BYTEORDER 2)
else()
message(FATAL_ERROR "TagLib requires that floating point types are IEEE754 compliant.")
endif()
# Determine which kind of atomic operations your compiler supports.
check_cxx_source_compiles("

17
cmake/TestFloatFormat.c
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@ -1,17 +0,0 @@
int main(int argc, char **argv)
{
int ret = 0;
double bin1[] = {
// "*TAGLIB*" encoded as a little-endian floating-point number
(double)3.9865557444897601e-105, (double)0.0
};
float bin2[] = {
// "*TL*" encoded as a little-endian floating-point number
(float)1.81480400e-013, (float)0.0
};
ret += ((int*)bin1)[argc];
ret += ((int*)bin2)[argc];
return ret;
}

61
cmake/modules/TestFloatFormat.cmake
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@ -1,61 +0,0 @@
# Returns 1 if IEEE754 little-endian, 2 if IEEE754 big-endian, otherwise 0.
MACRO(TEST_FLOAT_FORMAT FP_IEEE754)
IF(NOT FP_IEEE754)
TRY_COMPILE(HAVE_FLOAT_FORMAT_BIN
"${CMAKE_BINARY_DIR}" "${CMAKE_CURRENT_SOURCE_DIR}/cmake/TestFloatFormat.c"
COPY_FILE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestFloatFormat.bin")
SET(FP_IEEE754 0)
IF(HAVE_FLOAT_FORMAT_BIN)
# dont match first/last letter because of string rounding errors :-)
FILE(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestFloatFormat.bin"
DOUBLE_IEEE754_LE LIMIT_COUNT 1 REGEX "TAGLIB")
FILE(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestFloatFormat.bin"
DOUBLE_IEEE754_BE LIMIT_COUNT 1 REGEX "BILGAT")
FILE(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestFloatFormat.bin"
FLOAT_IEEE754_LE LIMIT_COUNT 1 REGEX "TL")
FILE(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestFloatFormat.bin"
FLOAT_IEEE754_BE LIMIT_COUNT 1 REGEX "LT")
IF(DOUBLE_IEEE754_LE AND FLOAT_IEEE754_LE)
SET(FP_IEEE754_LE 1)
ENDIF()
IF(DOUBLE_IEEE754_BE AND FLOAT_IEEE754_BE)
SET(FP_IEEE754_BE 1)
ENDIF()
# OS X Universal binaries will contain both strings, set it to the host
IF(FP_IEEE754_LE AND FP_IEEE754_BE)
IF(CMAKE_SYSTEM_PROCESSOR MATCHES powerpc)
SET(FP_IEEE754_LE FALSE)
SET(FP_IEEE754_BE TRUE)
ELSE()
SET(FP_IEEE754_LE TRUE)
SET(FP_IEEE754_BE FALSE)
ENDIF()
ENDIF()
IF(FP_IEEE754_LE)
SET(FP_IEEE754 1)
ELSEIF(FP_IEEE754_BE)
SET(FP_IEEE754 2)
ENDIF()
ENDIF()
# just some informational output for the user
IF(FP_IEEE754_LE)
MESSAGE(STATUS "Checking the floating point format - IEEE754 (LittleEndian)")
ELSEIF(FP_IEEE754_BE)
MESSAGE(STATUS "Checking the floating point format - IEEE754 (BigEndian)")
ELSE()
MESSAGE(STATUS "Checking the floating point format - Not IEEE754 or failed to detect.")
ENDIF()
SET(FP_IEEE754 "${${FP_IEEE754}}" CACHE INTERNAL "Result of TEST_FLOAT_FORMAT" FORCE)
ENDIF()
ENDMACRO(TEST_FLOAT_FORMAT FP_IEEE754)

4
config.h.cmake
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@ -4,10 +4,6 @@
/* 1 if little-endian, 2 if big-endian. */
#cmakedefine SYSTEM_BYTEORDER ${SYSTEM_BYTEORDER}
/* IEEE754 byte order of your target system. */
/* 1 if little-endian, 2 if big-endian. */
#cmakedefine FLOAT_BYTEORDER ${FLOAT_BYTEORDER}
/* Defined if your compiler supports some byte swap functions */
#cmakedefine HAVE_GCC_BYTESWAP_16 1
#cmakedefine HAVE_GCC_BYTESWAP_32 1

4
taglib/toolkit/tbytevector.cpp
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@ -251,7 +251,7 @@ TFloat toFloat(const ByteVector &v, size_t offset)
} tmp;
::memcpy(&tmp, v.data() + offset, sizeof(TInt));
if(ENDIAN != Utils::FloatByteOrder)
if(ENDIAN != Utils::floatByteOrder())
tmp.i = Utils::byteSwap(tmp.i);
return tmp.f;
@ -266,7 +266,7 @@ ByteVector fromFloat(TFloat value)
} tmp;
tmp.f = value;
if(ENDIAN != Utils::FloatByteOrder)
if(ENDIAN != Utils::floatByteOrder())
tmp.i = Utils::byteSwap(tmp.i);
return ByteVector(reinterpret_cast<char *>(&tmp), sizeof(TInt));

41
taglib/toolkit/tutils.h
View File

@ -248,37 +248,26 @@ namespace TagLib
#endif
#ifdef FLOAT_BYTEORDER
# if FLOAT_BYTEORDER == 1
const ByteOrder FloatByteOrder = LittleEndian;
# else
const ByteOrder FloatByteOrder = BigEndian;
# endif
#else
/*!
* Returns the IEEE754 byte order of the system.
*/
inline ByteOrder floatByteOrder()
{
double bin[] = {
// "*TAGLIB*" encoded as a little-endian floating-point number
(double) 3.9865557444897601e-105, (double) 0.0
};
union {
double d;
char c;
} u;
char *str = (char*)&bin[0];
if(strncmp(&str[1], "TAGLIB", 6) == 0)
return LittleEndian;
else
return BigEndian;
// 1.0 is stored in memory like 0x3FF0000000000000 in canonical form.
// So the first byte is zero if little endian.
u.d = 1.0;
if(u.c == 0)
return LittleEndian;
else
return BigEndian;
}
const ByteOrder FloatByteOrder = floatByteOrder();
#endif
}
}