Re: [Tarantool-patches] [PATCH luajit 2/2] test: fix LuaJIT-tests for old libc version

[Sergey Bronnikov via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Hi, Sergey,

thanks for the patch!


On 16:42 Thu 05 Dec , Sergey Kaplun wrote:
>The `strtod parsing` subtest in the <lib/base/tonumber_scan.lua> checks
>the results yielded by the `strtod()` via FFI call. In versions before

s/versions/GLibc versions/

>2.19 it returns an incorrect result for "0x1p-2075" [1]. This patch
>skips this test for a smaller version of the libc installed.
>
>[1]: https://sourceware.org/bugzilla/show_bug.cgi?id=16151
>---
> test/CMakeLists.txt                          |  1 +
> test/LuaJIT-tests/CMakeLists.txt             |  9 +++++
> test/LuaJIT-tests/lib/base/tonumber_scan.lua |  4 ++-
> test/cmake/GetLibCVersion.cmake              | 35 ++++++++++++++++++++
> 4 files changed, 48 insertions(+), 1 deletion(-)
> create mode 100644 test/cmake/GetLibCVersion.cmake
>
>diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
>index 0db2dd8b..be02d2e4 100644
>--- a/test/CMakeLists.txt
>+++ b/test/CMakeLists.txt
>@@ -73,6 +73,7 @@ separate_arguments(LUAJIT_TEST_COMMAND)
>
> set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
> include(AddTestLib)
>+include(GetLibCVersion)
> include(LibRealPath)
>
> # CTEST_FLAGS is used by CMake targets in test suites.
>diff --git a/test/LuaJIT-tests/CMakeLists.txt b/test/LuaJIT-tests/CMakeLists.txt
>index 019762e0..d0771e14 100644
>--- a/test/LuaJIT-tests/CMakeLists.txt
>+++ b/test/LuaJIT-tests/CMakeLists.txt
>@@ -62,6 +62,15 @@ if(CMAKE_C_FLAGS MATCHES "-march=skylake-avx512")
>   list(APPEND LUAJIT_TEST_TAGS_EXTRA +avx512)
> endif()
>
>+if(NOT CMAKE_SYSTEM_NAME STREQUAL "Darwin")
>+  GetLibCVersion(LIBC_VERSION)
>+  # XXX: <tonumber_scan.lua> uses `strtod()`, old versions of
>+  # which have the bug [1] for "0x1p-2075" parsing. Add the skip
>+  # check for it.
>+  # [1]: https://sourceware.org/bugzilla/show_bug.cgi?id=16151
>+  list(APPEND LUAJIT_TEST_TAGS_EXTRA +libc=${LIBC_VERSION})
>+endif()
>+
> set(TEST_SUITE_NAME "LuaJIT-tests")
>
> # XXX: The call produces both test and target <LuaJIT-tests-deps>
>diff --git a/test/LuaJIT-tests/lib/base/tonumber_scan.lua b/test/LuaJIT-tests/lib/base/tonumber_scan.lua
>index e2dcd4d0..ac7d68a4 100644
>--- a/test/LuaJIT-tests/lib/base/tonumber_scan.lua
>+++ b/test/LuaJIT-tests/lib/base/tonumber_scan.lua
>@@ -186,7 +186,9 @@ do --- tonumber parsing
>   test_conv(tonumber)
> end
>
>-do --- strtod parsing
>+-- Skip for the old libc version with the bug in the `strtod()`.
>+-- See also https://sourceware.org/bugzilla/show_bug.cgi?id=16151.
>+do --- strtod parsing -libc<2.19
>   test_conv(function(s)
>     local d = ffi.C.strtod(s, e)
>     return (e[0][0] == 0 and #s ~= 0) and d or nil
>diff --git a/test/cmake/GetLibCVersion.cmake b/test/cmake/GetLibCVersion.cmake
>new file mode 100644
>index 00000000..fd05fa6d
>--- /dev/null
>+++ b/test/cmake/GetLibCVersion.cmake
>@@ -0,0 +1,35 @@
>+# Get the libc version installed in the system.
>+# XXX: uses `LibRealPath`, so unsupported for OSX.
>+macro(GetLibCVersion output)
>+  LibRealPath(libcpath "libc.so.6")

I don't get why shared lib filename is hardcoded.
Version (6) can be changed and our test will fail.

We can use gcc:

[1] ~/sources/MRG/tarantool/third_party/luajit $ gcc -Wl,--trace main.c  | grep libc
/usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libc.so
/lib/x86_64-linux-gnu/libc.so.6
/usr/lib/x86_64-linux-gnu/libc_nonshared.a
/usr/lib/x86_64-linux-gnu/libc_nonshared.a

or ldd:

[1] ~/sources/MRG/tarantool/third_party/luajit $ ldd build/src/luajit
         linux-vdso.so.1 (0x00007ffd161fd000)
         libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f272b6ac000)
         libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f272b68c000)
         libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f272b400000)
         /lib64/ld-linux-x86-64.so.2 (0x00007f272b88a000)

>+
>+  # Get the version from the library name.
>+  if(libcpath MATCHES "libc-([0-9]+\.[0-9]+)\.so")
>+    set(${output} ${CMAKE_MATCH_1})
>+  else()
>+    # Try to directly run the library and parse the version from
>+    # the output message.
>+    execute_process(
>+      COMMAND ${libcpath}
>+      OUTPUT_VARIABLE LIB_C_INFO
>+      ERROR_VARIABLE ERROR_MSG
>+      OUTPUT_STRIP_TRAILING_WHITESPACE
>+      RESULT_VARIABLE RES
>+    )
>+
>+    if(NOT RES EQUAL 0)
>+      message(FATAL_ERROR "Executing '${libcpath}' has failed: '${ERROR_MSG}'")
>+    endif()
>+
>+    if(LIB_C_INFO MATCHES "^.*stable release version ([0-9]+\.[0-9]+)")
>+      set(${output} ${CMAKE_MATCH_1})
>+    else()
>+      message(FATAL_ERROR "Can't determine libc version")
>+    endif()
>+
>+    unset(RES)
>+    unset(ERROR_MSG)
>+    unset(LIB_C_INFO)
>+  endif()
>+  unset(CMAKE_MATCH_1)
>+endmacro()
>-- 
>2.47.0
>

-- 
sergeyb@