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| -rw-r--r-- | docs/boost.md | 119 |
1 files changed, 61 insertions, 58 deletions
diff --git a/docs/boost.md b/docs/boost.md index ead2103..37ff3bb 100644 --- a/docs/boost.md +++ b/docs/boost.md @@ -1,20 +1,23 @@ Library naming -------------- -The way Boost names library files by default is insane. It's absolutely not compatible between -OSs, compilers, Boost versions, etc. On Linux, for example, it would create -stage/lib/libboost_filesystem.a, while on Windows it would become something insane like -stage\lib\libboost_filesystem-vc142-mt-s-x64-1_72.lib. More than that, older Boost versions -wouldn't include architecture information (the "x64" part) in the file name, so you couldn't -store libraries for both x86 and x64 in the same directory. On Linux, on the other hand, you -can't even store debug/release binaries in the same directory. What's worse is that older CMake -versions don't support the architecture suffix, choking on the Windows example above. - -With all of that in mind, I decided to bring some uniformity by sacrificing some flexibility. -b2 is called with --layout=system, and libraries are put to stage/\<platform\>/\<configuration\>/lib, -where \<platform\> is x86/x64 and \<configuration\> is CMake's CMAKE_BUILD_TYPE. That means that I -can't have libraries with different runtime-link values in the same directory, but I don't really -care. +The way Boost names library files by default is insane. It's absolutely not +compatible between OSs, compilers, Boost versions, etc. On Linux, for example, +it would create stage/lib/libboost_filesystem.a, while on Windows it would +become something insane like stage\lib\libboost_filesystem-vc142-mt-s-x64-1_72.lib. +More than that, older Boost versions wouldn't include architecture information +(the "x64" part) in the file name, so you couldn't store libraries for both x86 +and x64 in the same directory. On Linux, on the other hand, you can't even +store debug/release binaries in the same directory. What's worse is that older +CMake versions don't support the architecture suffix, choking on the Windows +example above. + +With all of that in mind, I decided to bring some uniformity by sacrificing +some flexibility. b2 is called with `--layout=system`, and libraries are put to +stage/\<platform\>/\<configuration\>/lib, where \<platform\> is x86/x64 and +\<configuration\> is CMake's CMAKE_BUILD_TYPE. That means that I can't have +libraries with different runtime-link values in the same directory, but I don't +really care. Hate speech ----------- @@ -22,27 +25,27 @@ Hate speech Is there a person who doesn't hate Boost.Build? I'm not sure, I'm definitely _not_ one of these people. Maybe it's the lack of adoption (meaning that learning it is useless outside of Boost), maybe it's the incomprehensible -syntax. Maybe it's the absolutely insane compiler-specific configuration -files (tools/build/src/tools/*.jam), which are impossible to figure out. -Maybe it's the fact that the implementation switched from C to C++ while some -half-baked Python implementation has been there since at least 2015 (see the -marvelous memo "Status: mostly ported." at the top of tools/build/src/build_system.py). +syntax. Maybe it's the absolutely insane compiler-specific configuration files +(tools/build/src/tools/*.jam), which are impossible to figure out. Maybe it's +the fact that the implementation switched from C to C++ while some half-baked +Python implementation has been there since at least 2015 (see the marvelous +memo "Status: mostly ported." at the top of tools/build/src/build_system.py). What I hate the most though is how its various subtle, implicit and invisible -decision-making heuristics changed thoughout the release history of Boost. -You have a config and a compiler that will happily build version 1.65.0? -Great! Want to use the same config and the same compiler to build version -1.72.0? Well, too fucking bad, it doesn't work anymore. This I really do -hate the most. +decision-making heuristics changed thoughout the release history of Boost. You +have a config and a compiler that will happily build version 1.65.0? Great! +Want to use the same config and the same compiler to build version 1.72.0? +Well, too fucking bad, it doesn't work anymore. This I really do hate the +most. Three kinds of toolsets ----------------------- -b2 accepts the toolset= parameter. What about building b2 itself though? +b2 accepts the `toolset=` parameter. What about building b2 itself though? Well, this is what the bootstrap.{sh,bat} scripts do. They also accept a -toolset argument, but it is _completely_ different to that of b2. That's -sort of OK, since e.g. cross-compiling b2 is something we rarely want to do -(and hence there must typically be a native toolset available). +toolset argument, but it is _completely_ different to that of b2. That's sort +of OK, since e.g. cross-compiling b2 is something we rarely want to do (and +hence there must typically be a native toolset available). bootstrap.sh and bootstrap.bat are completely different (of course!), and accept different arguments for their toolset parameters. @@ -51,27 +54,27 @@ Config file insanity -------------------- Say, we're building Boost on Windows using the GCC from a MinGW-w64 -distribution. We can pass toolset=gcc and all the required flags on the -command line no problem. What if we want to make a user configuration file -so that 1) the command line is less polluted, and 2) it can possibly be -shared? Well, if we put +distribution. We can pass `toolset=gcc` and all the required flags on the +command line no problem. What if we want to make a user configuration file so +that 1) the command line is less polluted, and 2) it can possibly be shared? +Well, if we put using gcc : : : <name>value... ; there, Boost 1.65.0 will happily build everything, while Boost 1.72.0 will -complain about "duplicate initialization of gcc". This is because when we -ran `bootstrap.bat gcc` earlier, it wrote `using gcc ;` in project-config.jam. -And while Boost 1.65.0 detects that toolset=gcc means we're going to use the -MinGW GCC, and magically turns toolset=gcc to toolset=gcc-mingw, Boost 1.72.0 -does no such thing, and chokes on the "duplicate" GCC declaration. +complain about "duplicate initialization of gcc". This is because when we ran +`bootstrap.bat gcc` earlier, it wrote `using gcc ;` in project-config.jam. And +while Boost 1.65.0 detects that `toolset=gcc` means we're going to use the +MinGW GCC, and magically turns `toolset=gcc` to `toolset=gcc-mingw`, Boost +1.72.0 does no such thing, and chokes on the "duplicate" GCC declaration. We also cannot put using gcc : custom : : <options> ; without the executable path, since Boost insists that `g++ -dumpversion` must -equal to "custom" (which makes total sense, lol). So we have to force it, -and do provide the path. +equal to "custom" (which makes total sense, lol). So we have to force it, and +do provide the path. Windows & Clang --------------- @@ -84,19 +87,19 @@ three main ways to install the native Clang toolchain on Windows: * install it as part of a MSYS2 installation (`pacman -S mingw-w64-x86_64-clang`), * install as part of a Visual Studio installation. -Using the latter method, you can switch a project to use the LLVM toolset -using Visual Studio, but that's stupid. The former two, on the other hand, -give us the the required clang/clang++/clang-cl executables, so everything -seems to be fine. +Using the latter method, you can switch a project to use the LLVM toolset using +Visual Studio, but that's stupid. The former two, on the other hand, give us +the the required clang/clang++/clang-cl executables, so everything seems to be +fine. Except it's not fine. Let's start with the fact that prior to 1.66.0, -toolset=clang is completely broken on Windows. It's just an alias for +`toolset=clang` is completely broken on Windows. It's just an alias for clang-linux, and it's hardcoded to require the ar & ranlib executables to create static libraries. Which is fine on Linux, since, and I'm quoting the source, "ar is always available". But it's not fine on Windows, since -ar/ranlib are not, in fact, available there by default. Sure, you can -install some kind of MinGW toolchain, and it might even work, but what the -hell, honestly? +ar/ranlib are not, in fact, available there by default. Sure, you can install +some kind of MinGW toolchain, and it might even work, but what the hell, +honestly? Luckily, both the upstream distribution and the MSYS2 mingw-w64-x86_64-llvm package come with the llvm-ar and llvm-ranlib utilities. So we can put @@ -108,21 +111,21 @@ and later call b2 toolset=clang-custom --user-config=path/to/config.jam ... -But, as I mentioned, prior to 1.66.0, toolset=clang is _hardcoded_ to use ar -& ranlib, these exact utility names. So either get them as part of some -MinGW distribution or build Boost using another toolset. +But, as I mentioned, prior to 1.66.0, `toolset=clang` is _hardcoded_ to use ar +& ranlib, these exact utility names. So either get them as part of some MinGW +distribution or build Boost using another toolset. Now, it's all fine, but building stuff on Windows adds another thing into the equation: debug runtimes. When you build Boost using MSVC, for example, it -picks one of the appropriate /MT[d] or /MD[d] flags to build the Boost -libraries with. Emulating these flags with toolset=clang is complicated and +picks one of the appropriate `/MT[d]` or `/MD[d]` flags to build the Boost +libraries with. Emulating these flags with `toolset=clang` is complicated and inconvenient. Luckily, there's the clang-cl.exe executable, which aims to provide command line interface compatible with that of cl.exe. -Boost.Build even supports toolset=clang-win, which should use clang-cl.exe. -But alas, it's completely broken prior to 1.69.0. It just doesn't work at -all. So, if you want to build w/ clang-cl.exe, either use Boost 1.69.0 or -later, or build using another toolset. +Boost.Build even supports `toolset=clang-win`, which should use clang-cl.exe. +But alas, it's completely broken prior to 1.69.0. It just doesn't work at all. +So, if you want to build w/ clang-cl.exe, either use Boost 1.69.0 or later, or +build using another toolset. Cygwin & Clang -------------- @@ -138,8 +141,8 @@ the following error: ^ GCC doesn't emit an error here because /usr/include is in a pre-configured -"system" include directories list, and the declaration there take precedence, -I guess? The root of the problem BTW is that sizeof(unsigned long) is +"system" include directories list, and the declaration there take precedence, I +guess? The root of the problem BTW is that sizeof(unsigned long) is * 4 for MSVC and MinGW-born GCCs, * 8 for Clang (and, strangely, Cygwin GCC; why don't we get runtime |