diff options
| -rw-r--r-- | config/CMakeLists.txt | 56 | ||||
| -rw-r--r-- | src/nvim/shada.c | 3 |
2 files changed, 41 insertions, 18 deletions
diff --git a/config/CMakeLists.txt b/config/CMakeLists.txt index 9334691e2a..b780291264 100644 --- a/config/CMakeLists.txt +++ b/config/CMakeLists.txt @@ -3,6 +3,7 @@ include(CheckSymbolExists) include(CheckFunctionExists) include(CheckIncludeFiles) include(CheckCSourceRuns) +include(CheckCSourceCompiles) check_type_size("int" SIZEOF_INT) check_type_size("long" SIZEOF_LONG) @@ -75,31 +76,50 @@ endif() set(SI "#include <stdint.h>\n") set(MS "int main(int argc,char**argv)\n{\n uint64_t i=0x0102030405060708ULL;") set(ME "}") -check_c_source_runs(" - ${SI} - ${MS} - char *s = (char *) &i; - return ( - s[0] == 0x01 - && s[1] == 0x02 - && s[2] == 0x03 - && s[3] == 0x04 - && s[4] == 0x05 - && s[5] == 0x06 - && s[6] == 0x07 - && s[7] == 0x08) ? 0 : 1; - ${ME}" - ORDER_BIG_ENDIAN) -check_c_source_runs(" +check_c_source_compiles(" #define _BSD_SOURCE 1 #define _DEFAULT_SOURCE 1 ${SI} #include <endian.h> + #ifndef be64toh + # error No be64toh macros + #endif ${MS} uint64_t j = be64toh(i); - return (j == 0); // Must not be zero + return (j == 0); // j must not be zero ${ME}" - HAVE_BE64TOH) + HAVE_BE64TOH_MACROS) +if(NOT "${HAVE_BE64TOH_MACROS}") + check_function_exists(be64toh HAVE_BE64TOH_FUNC) +endif() +if("${HAVE_BE64TOH_MACROS}" OR "${HAVE_BE64TOH_FUNC}") + set(HAVE_BE64TOH 1) +endif() +if (NOT "${HAVE_BE64TOH}") + if (NOT "${CMAKE_CROSSCOMPILING}") + # It is safe to make ORDER_BIG_ENDIAN not defined if + # - HAVE_BE64TOH is true. In this case be64toh will be used unconditionally in + # any case and ORDER_BIG_ENDIAN will not be examined. + # - CMAKE_CROSSCOMPILING *and* HAVE_BE64TOH are both false. In this case + # be64toh function which uses cycle and arithmetic operations is used which + # will work regardless of endianess. Function is sub-optimal though. + check_c_source_runs(" + ${SI} + ${MS} + char *s = (char *) &i; + return ( + s[0] == 0x01 + && s[1] == 0x02 + && s[2] == 0x03 + && s[3] == 0x04 + && s[4] == 0x05 + && s[5] == 0x06 + && s[6] == 0x07 + && s[7] == 0x08) ? 0 : 1; + ${ME}" + ORDER_BIG_ENDIAN) + endif() +endif() # generate configuration header and update include directories configure_file ( diff --git a/src/nvim/shada.c b/src/nvim/shada.c index 6de3d8b20e..1d4b486823 100644 --- a/src/nvim/shada.c +++ b/src/nvim/shada.c @@ -3141,6 +3141,9 @@ static inline uint64_t be64toh(uint64_t big_endian_64_bits) #ifdef ORDER_BIG_ENDIAN return big_endian_64_bits; #else + // It may appear that when !defined(ORDER_BIG_ENDIAN) actual order is big + // endian. This variant is suboptimal, but it works regardless of actual + // order. uint8_t *buf = (uint8_t *) &big_endian_64_bits; uint64_t ret = 0; for (size_t i = 8; i; i--) { |