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> you should only attempt to be “smart” and search for that type of thing if you really need it — why use any search logic at all, if it can be avoided. vcvars

> you should only attempt to be “smart” and search for that type of thing if you really need it — why use any search logic at all, if it can be avoided. vcvars and its modern incarnations exist to facilitate this. But that's the standard for how to do things on Windows. That's how it works. Sure you might not like it, but personally I don't like the implicit assumption that everything is configured and "there" that your scripts and the OPs scripts assume. Here's the alternative in cmake though: cmake_minimum_required(VERSION 3.10) project(hello_world) add_executable(app main.cpp) All of a sudden you have support for all major platforms, the workflow is the same (meaning you don't have platform dependent scripts like build_win and build_linux), it works out of the box with all major IDEs/editors, supportd optimised and stripped builds easily, and abstracts that away across platforms (-O2 Vs /O2, /Z7 instead of objcopy +strip). These are problems that have been solved for 30 years, and makeshift bash/batch scripts only make it harder for people to understand what's going on.

dundarious 4y ago
It’s fine if you want searching, but I disagree that it’s implicitly wrong not to do it because searching is supposedly standard and how everyone else is doing it. Never mind that there exists plenty of software (with far more specific requirements than “give me an object file/dll/executable, compiler version/ABI/options be damned”) that doesn’t use such an approach. For example, try to tell CMake how to create a freestanding executable (one that doesn’t link to the system C library). You end up fighting against the abstractions inherent in its design. Which is to say, depending on what you want to do, it might not be a good fit, and you may be better off just writing out your compiler options yourself. Here’s part of the powershell version of a build script I have used, where I had fewer build variants, so I didn’t even bother to make a `build` function, I just copy paste the `out=... ; if { ... }` block and change the value of `$out` and which compiler and options are called. Note that you can accomplish this with far fewer variables if you don’t want quite as many build variants as this script supports — it was written as an illustration of how flexible you can make things, rather than how simple things can be, so it supports clang, clang-cl, cl, zig cc, with variants for asan, freestanding, for architectures x86, x64, aarch64: $ml = @("-nologo","-c","-Zd","-WX","-W3") ... $clstd = @("-volatile:iso","-permissive-") $clangcl = @("-nologo","-diagnostics:column","-Z7","-Zo","-FC") + $clstd $cl = $clangcl + @("-WL","-Gm-","-utf-8") # -Wall > -W4 but includes very silly things like "function not inlined" for snprintf $clwx = @("-WX","-W4","-wd4100","-wd4127") ... $clfree = @("-D","EXAMPLE_FREESTANDING","-Zl","-GS-","-sdl-","-Gs9999999") $clfreedebug = $clwx + $clodebug + $cldd + $clfree + $clnortti + $clhash + $cllink + $link + $linkfree ... $out = "./x86_64-windows-free-cl-debug" if ("all" -in $targets -or (split-path -path $out -leaf) -in $targets) { new-item -itemtype directory -force $out | out-null try { push-location $out $buildcount++ write-host (split-path -path $out -leaf) ml64 @ml $src/example-x64.asm cl "-Fm./example.map" "-Tc$src/example.c" ./example-x64.obj @cl @clfreedebug } finally { pop-location ; } } If you have an issue, you can easily change compiler options. It will always work and won’t suddenly break if you install a second set of compilers for another project, whereas CMake will have to choose which one and might pick wrong. Likewise, there is no potential for an upgrade to CMake to decide to use different compiler options that interfere with the freestanding stuff. You lose CMake’s abstractions, but like I said, that may be a good thing, depending on what your requirements are, assuming you have detailed knowledge of the compiler (which I’d rather accumulate than detailed knowledge of CMake, and I would know, I have both).
- maccard 4y ago
  > For example, try to tell CMake how to create a freestanding executable (one that doesn’t link to the system C library). You end up fighting against the abstractions inherent in its design. What's wrong with target_link_options(foo PRIVATE -static-libgcc -static-libstdc++) I don't understand how that particular powrshell block is more flexible than cmake from what I can see it does less (it's windows specific - mine works on Linux, Mac, windows, and also works with cross compilation toolchains out of the box). If I want to add specific warnings I can use target_compile_options to get exactly the same behaviour. > won’t suddenly break if you install a second set of compilers for another project, I'm genuinely curious - have you used cmake? Cmake has sensible defaults but is completely customizable. Cmake uses platform standards - if you overwrite the CC variable it will use that toolchain instead. Cmake has its warts, for sure, but lack of flexibility is definitely not one of them.
  - dundarious 4y ago
    I have extensively used CMake since years before it supported the target_ options, and years afterwards. So I was using it before, during, and after the breath of fresh air that was the shift to what is now called “modern CMake”, i.e., bjam/b2 style (define targets with private/public/interface dependencies/options). As you can guess, I’ve also used bjam/b2 extensively. I’ve also used meson to a more limited extent. And when I say “used”, I mean where I’ve written many build files from scratch myself, in a professional capacity. I’m always the “build system expert” on my team because of how much experience I have. If working on a team where people know the compilers, and where build times are kept reasonable (so not using lots of templates in C++), then on a practical level I recommend not using a build system at all, and just writing a super simple shell script (unity builds are easier there too). I still recommend CMake sometimes though — especially if the main requirement is just “gimme some machine code, who cares how, and who cares about using ASAN, etc.”, and the second most important requirement is to ship the code to the open source community. BTW, I mean freestanding as in “does not link to any C library”, rather than “statically links to the C library”. declare -a free=(-std=gnu99 -DEXAMPLE_FREESTANDING -nostartfiles -nostdlib -nodefaultlibs -ffreestanding -fno-stack-protector)

dundarious 4y ago

It’s fine if you want searching, but I disagree that it’s implicitly wrong not to do it because searching is supposedly standard and how everyone else is doing it. Never mind that there exists plenty of software (with far more specific requirements than “give me an object file/dll/executable, compiler version/ABI/options be damned”) that doesn’t use such an approach. For example, try to tell CMake how to create a freestanding executable (one that doesn’t link to the system C library). You end up fighting against the abstractions inherent in its design. Which is to say, depending on what you want to do, it might not be a good fit, and you may be better off just writing out your compiler options yourself. Here’s part of the powershell version of a build script I have used, where I had fewer build variants, so I didn’t even bother to make a `build` function, I just copy paste the `out=... ; if { ... }` block and change the value of `$out` and which compiler and options are called. Note that you can accomplish this with far fewer variables if you don’t want quite as many build variants as this script supports — it was written as an illustration of how flexible you can make things, rather than how simple things can be, so it supports clang, clang-cl, cl, zig cc, with variants for asan, freestanding, for architectures x86, x64, aarch64: $ml = @("-nologo","-c","-Zd","-WX","-W3") ... $clstd = @("-volatile:iso","-permissive-") $clangcl = @("-nologo","-diagnostics:column","-Z7","-Zo","-FC") + $clstd $cl = $clangcl + @("-WL","-Gm-","-utf-8") # -Wall > -W4 but includes very silly things like "function not inlined" for snprintf $clwx = @("-WX","-W4","-wd4100","-wd4127") ... $clfree = @("-D","EXAMPLE_FREESTANDING","-Zl","-GS-","-sdl-","-Gs9999999") $clfreedebug = $clwx + $clodebug + $cldd + $clfree + $clnortti + $clhash + $cllink + $link + $linkfree ... $out = "./x86_64-windows-free-cl-debug" if ("all" -in $targets -or (split-path -path $out -leaf) -in $targets) { new-item -itemtype directory -force $out | out-null try { push-location $out $buildcount++ write-host (split-path -path $out -leaf) ml64 @ml $src/example-x64.asm cl "-Fm./example.map" "-Tc$src/example.c" ./example-x64.obj @cl @clfreedebug } finally { pop-location ; } } If you have an issue, you can easily change compiler options. It will always work and won’t suddenly break if you install a second set of compilers for another project, whereas CMake will have to choose which one and might pick wrong. Likewise, there is no potential for an upgrade to CMake to decide to use different compiler options that interfere with the freestanding stuff. You lose CMake’s abstractions, but like I said, that may be a good thing, depending on what your requirements are, assuming you have detailed knowledge of the compiler (which I’d rather accumulate than detailed knowledge of CMake, and I would know, I have both).

maccard 4y ago
> For example, try to tell CMake how to create a freestanding executable (one that doesn’t link to the system C library). You end up fighting against the abstractions inherent in its design. What's wrong with target_link_options(foo PRIVATE -static-libgcc -static-libstdc++) I don't understand how that particular powrshell block is more flexible than cmake from what I can see it does less (it's windows specific - mine works on Linux, Mac, windows, and also works with cross compilation toolchains out of the box). If I want to add specific warnings I can use target_compile_options to get exactly the same behaviour. > won’t suddenly break if you install a second set of compilers for another project, I'm genuinely curious - have you used cmake? Cmake has sensible defaults but is completely customizable. Cmake uses platform standards - if you overwrite the CC variable it will use that toolchain instead. Cmake has its warts, for sure, but lack of flexibility is definitely not one of them.
- dundarious 4y ago
  I have extensively used CMake since years before it supported the target_ options, and years afterwards. So I was using it before, during, and after the breath of fresh air that was the shift to what is now called “modern CMake”, i.e., bjam/b2 style (define targets with private/public/interface dependencies/options). As you can guess, I’ve also used bjam/b2 extensively. I’ve also used meson to a more limited extent. And when I say “used”, I mean where I’ve written many build files from scratch myself, in a professional capacity. I’m always the “build system expert” on my team because of how much experience I have. If working on a team where people know the compilers, and where build times are kept reasonable (so not using lots of templates in C++), then on a practical level I recommend not using a build system at all, and just writing a super simple shell script (unity builds are easier there too). I still recommend CMake sometimes though — especially if the main requirement is just “gimme some machine code, who cares how, and who cares about using ASAN, etc.”, and the second most important requirement is to ship the code to the open source community. BTW, I mean freestanding as in “does not link to any C library”, rather than “statically links to the C library”. declare -a free=(-std=gnu99 -DEXAMPLE_FREESTANDING -nostartfiles -nostdlib -nodefaultlibs -ffreestanding -fno-stack-protector)