Hi, > However, with the current implementation, only one version of the library > actually exists within a single build process.
What does "only one version of the library" mean here? Only shared version or only static version? If we use -DARROW_BUILD_SHARED=ON and -DARROW_BUILD_STATIC=ON, we can build both of shared version and static version in the same build process. Am I missing something? Thanks, -- kou In <cahgae5exol+9ohtujp+-n3vpssrgeajbxn1do0dlegbqsz6...@mail.gmail.com> "Re: [C++] Static/Shared Linkage in CMakeLists.txt" on Tue, 3 Jun 2025 16:37:42 +0800, Eddie Chang <kalcifer7...@gmail.com> wrote: > Hi Kou, > > Building both shared and static versions of the library simultaneously is > certainly possible. My current focus is on the fact that we have multiple > build targets linking against the same library, and each time we do so, we > repeat the same if-else logic to decide which version to link. > > However, with the current implementation, only one version of the library > actually exists within a single build process. So we only need to determine > whether to build the static or shared version once―when building the > library itself―instead of repeating the same check every time a build > target links against the same library. > > If you'd like to support both versions, I suppose you already need to build > twice (with different build options) with the current implementation? > Thanks, > Eddie > > Sutou Kouhei <k...@clear-code.com> 於 2025年6月3日 週二 下午3:10寫道： > >> Hi, >> >> How to support a use case that wants both of shared library >> and static library with your suggested approach? Do you >> build Apache Arrow C++ twice for shared library and static >> library? >> >> If so, what CMake package name is used for them? >> "ArrowShared" and "ArrowStatic"? >> >> >> Thanks, >> -- >> kou >> >> In <cahgae5er0+vbomjv7w8_dt068yhabclqdkkigo_qp8lz4vr...@mail.gmail.com> >> "RE: Re: [C++] Static/Shared Linkage in CMakeLists.txt" on Tue, 3 Jun >> 2025 14:49:02 +0800, >> Eddie Chang <kalcifer7...@gmail.com> wrote: >> >> > Just to clarify, my suggestion was assuming that each build only produces >> > either static or shared libraries, not both. >> > >> > Given that assumption, wouldn't it be better to define targets using a >> > single name (without `_static` or `_shared` suffix), and decide in one >> > place whether that target is defined as STATIC or SHARED depending on the >> > `ARROW_BUILD_SHARED`? >> > >> > That way, we wouldn't need to switch on `ARROW_BUILD_SHARED` repeatedly >> to >> > determine which target name to link. >> > >> > On 2025/06/03 06:05:45 Sutou Kouhei wrote: >> >> Hi, >> >> >> >> Do you want a CMake target that can be used for shared >> >> linking and static linking? For example, you want to use >> >> Parquet::parquet for shared linking and static linking, >> >> right? >> >> >> >> In my understanding, we can't do it with CMake. We need to >> >> specify "SHARED" or "STATIC" when create a CMake target by >> >> add_library(). >> >> See also: >> >> https://cmake.org/cmake/help/latest/command/add_library.html#normal >> >> >> >> Thanks, >> >> -- >> >> kou >> >> >> >> In <ca...@mail.gmail.com> >> >> "[C++] Static/Shared Linkage in CMakeLists.txt" on Tue, 3 Jun 2025 >> > 13:45:36 +0800, >> >> Eddie Chang <ka...@gmail.com> wrote: >> >> >> >> > Hello everyone, I've noticed that in our CMakeLists.txt files, we have >> >> > multiple instances where we conditionally select either the static or >> >> > shared version of a linked target based on a cache variable such as >> >> > ARROW_BUILD_SHARED. For example, the following pattern appears in >> > several >> >> > places: >> >> > >> >> > if(ARROW_BUILD_SHARED) >> >> > set(PARQUET_EXAMPLE_LINK_LIBS parquet_shared) >> >> > else() >> >> > set(PARQUET_EXAMPLE_LINK_LIBS parquet_static) >> >> > endif() >> >> > >> >> > I’m wondering if there is a specific reason we don’t set the >> > static/shared >> >> > property of the libraries in a single location, and instead continue >> >> > duplicating this kind of logic throughout the codebase? >> >> >>
