diff options
| -rw-r--r-- | CMakeLists.txt | 15 | ||||
| -rw-r--r-- | INSTALL | 4 | ||||
| -rw-r--r-- | configure.ac | 31 | ||||
| -rw-r--r-- | src/liblzma/check/crc32_small.c | 7 | ||||
| -rw-r--r-- | src/liblzma/check/crc64_small.c | 5 | ||||
| -rw-r--r-- | src/liblzma/lz/lz_encoder.c | 2 |
6 files changed, 59 insertions, 5 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt index e3af3bf6..11f3a055 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -48,6 +48,7 @@ cmake_minimum_required(VERSION 3.13...3.16 FATAL_ERROR) +include(CMakePushCheckState) include(CheckSymbolExists) include(CheckStructHasMember) include(cmake/tuklib_integer.cmake) @@ -387,6 +388,20 @@ if(NOT TUKLIB_CPUCORES_FOUND OR NOT TUKLIB_PHYSMEM_FOUND) "To build anyway, edit this CMakeLists.txt to ignore this error.") endif() +# Check for __attribute__((__constructor__)) support. +# This needs -Werror because some compilers just warn +# about this being unsupported. +cmake_push_check_state() +set(CMAKE_REQUIRED_FLAGS "-Werror") +check_c_source_compiles(" + __attribute__((__constructor__)) + static void my_constructor_func(void) { return; } + int main(void) { return 0; } + " + HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR) +cmake_pop_check_state() +tuklib_add_definition_if(liblzma HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR) + # immintrin.h: include(CheckIncludeFile) check_include_file(immintrin.h HAVE_IMMINTRIN_H) @@ -456,7 +456,9 @@ XZ Utils Installation no Disable threading support. This is the same as using --disable-threads. - NOTE: If combined with --enable-small, the + NOTE: If combined with --enable-small + and the compiler doesn't support + __attribute__((__constructor__)), the resulting liblzma won't be thread safe, that is, if a multi-threaded application calls any liblzma functions from more than diff --git a/configure.ac b/configure.ac index 15b4ba4c..cf226b29 100644 --- a/configure.ac +++ b/configure.ac @@ -768,6 +768,29 @@ AC_CHECK_MEMBERS([ AC_SYS_LARGEFILE AC_C_BIGENDIAN +# __attribute__((__constructor__)) can be used for one-time initializations. +# Use -Werror because some compilers accept unknown attributes and just +# give a warning. If it works this should give no warnings, even +# clang -Weverything should be fine. +# dnl This doesn't need AC_LANG_SOURCE, minimal code is enough. +AC_MSG_CHECKING([if __attribute__((__constructor__)) can be used]) +have_func_attribute_constructor=no +OLD_CFLAGS="$CFLAGS" +CFLAGS="$CFLAGS -Werror" +AC_COMPILE_IFELSE([ + __attribute__((__constructor__)) + static void my_constructor_func(void) { return; } +], [ + AC_DEFINE([HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR], [1], + [Define to 1 if __attribute__((__constructor__)) + is supported for functions.]) + have_func_attribute_constructor=yes + AC_MSG_RESULT([yes]) +], [ + AC_MSG_RESULT([no]) +]) +CFLAGS="$OLD_CFLAGS" + ############################################################################### # Checks for library functions. @@ -1005,9 +1028,11 @@ if test x$tuklib_cv_cpucores_method = xunknown; then echo "No supported method to detect the number of CPU cores." fi -if test "x$enable_threads$enable_small" = xnoyes; then +if test "x$enable_threads$enable_small$have_func_attribute_constructor" \ + = xnoyesno; then echo echo "NOTE:" - echo "liblzma will be thread unsafe due the combination" - echo "of --disable-threads --enable-small." + echo "liblzma will be thread-unsafe due to the combination" + echo "of --disable-threads --enable-small when using a compiler" + echo "that doesn't support __attribute__((__constructor__))." fi diff --git a/src/liblzma/check/crc32_small.c b/src/liblzma/check/crc32_small.c index 5f8a3286..186966e9 100644 --- a/src/liblzma/check/crc32_small.c +++ b/src/liblzma/check/crc32_small.c @@ -16,6 +16,9 @@ uint32_t lzma_crc32_table[1][256]; +#ifdef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR +__attribute__((__constructor__)) +#endif static void crc32_init(void) { @@ -37,18 +40,22 @@ crc32_init(void) } +#ifndef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR extern void lzma_crc32_init(void) { mythread_once(crc32_init); return; } +#endif extern LZMA_API(uint32_t) lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc) { +#ifndef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR lzma_crc32_init(); +#endif crc = ~crc; diff --git a/src/liblzma/check/crc64_small.c b/src/liblzma/check/crc64_small.c index 55d72316..420f7cfb 100644 --- a/src/liblzma/check/crc64_small.c +++ b/src/liblzma/check/crc64_small.c @@ -16,6 +16,9 @@ static uint64_t crc64_table[256]; +#ifdef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR +__attribute__((__constructor__)) +#endif static void crc64_init(void) { @@ -40,7 +43,9 @@ crc64_init(void) extern LZMA_API(uint64_t) lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc) { +#ifndef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR mythread_once(crc64_init); +#endif crc = ~crc; diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c index 890d1bc4..2dad7e5f 100644 --- a/src/liblzma/lz/lz_encoder.c +++ b/src/liblzma/lz/lz_encoder.c @@ -543,7 +543,7 @@ lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, const lzma_allocator *allocator, const void *options, lzma_lz_options *lz_options)) { -#ifdef HAVE_SMALL +#if defined(HAVE_SMALL) && !defined(HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR) // We need that the CRC32 table has been initialized. lzma_crc32_init(); #endif |