Platform support and auto scripts improvements

[bavshin-f5]

The whole thing now kind of works on Windows¹. Also on NetBSD, OpenBSD and Illumos.
Getting closer to the "Tested OS and platforms" of nginx.

In the course of debugging, examples/config accumulated too many subtle details so I split it into a reusable examples/auto/rust. The idea is to drop the file into your project, copy config.make and write a minimal config.

TODOs:

• Documentation updates
• Copyright header in auto/rust to allow redistribution.
• Decide if it's worth renaming NGX_OBJS to NGINX_BUILD_DIR

Things to address later:

• Detect NGX_ALIGNMENT redefined via --with-cc-opt and add a compile-time assertion for insufficient alignment, Use CFLAGS from the Makefile #118
• Figure out how to disentangle configure/make commands from nginx-sys/build/vendored.rs
• Windows CI?

Footnotes

1. with a couple of patches: nginx#457 and sed -i -e 's/^\(#define _WIN32_WINNT\).*/\1 0x0600/' src/os/win32/ngx_win32_config.h ↩

[xeioex]

Copyright header in auto/rust to allow redistribution.

Sound good.

Decide if it's worth renaming NGX_OBJS to NGINX_BUILD_DIR

I believe we are in the early days of the project. The project is still experimental.

[xeioex]

When building without --with-debug I get

...
objs/ngx_modules.o \                                                                                                                              
-L/media/psf/workspace/nginx/nginScript/quickjs-ng/build -lpthread -lcrypt objs/ngx_rust_examples/ngx-release/examples/libawssig.a -lm objs/ngx_ru
st_examples/ngx-release/examples/libcurl.a objs/ngx_rust_examples/ngx-release/examples/libupstream.a objs/ngx_rust_examples/ngx-release/examples/l
ibhttporigdst.a -lpcre2-8 -lssl -lcrypto -lpthread -lz \                                                                                          
-Wl,-E                                                                                                                                            
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::num::from_str_radix_panic_rt':                                                                                        
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/num/mod.rs:1399: multiple definition of `core::num::from_str_radix_panic_rt'; obj
s/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.rcgu.o):/rus
tc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/num/mod.rs:1399: first defined here                                                  
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `...                                                                                                                         
u.0.rcgu.o.rcgu.o): in function `core::fmt::num::<impl core::fmt::LowerHex for i8>::fmt':                                                         
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::num::<impl core::fmt::UpperHex for i8>::fmt':                                                                    
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: multiple definition of `core::fmt::num::<impl core::fmt::UpperHex
 for u8>::fmt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.
rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: first defined here                                
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::num::imp::<impl core::fmt::Display for u64>::fmt':                                                               
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:313: multiple definition of `core::fmt::num::imp::<impl core::fmt::Dis
play for usize>::fmt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf
-cgu.0.rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:313: first defined here                         
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::Formatter::write_str':                                                                                           
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/mod.rs:1625: multiple definition of `<core::fmt::Formatter as core::fmt::Writ
e>::write_str'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.
rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/mod.rs:1625: first defined here                               
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::num::<impl core::fmt::LowerHex for i64>::fmt':                                                                   
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: multiple definition of `core::fmt::num::<impl core::fmt::LowerHex
 for usize>::fmt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu
.0.rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: first defined here                             
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::num::<impl core::fmt::UpperHex for i64>::fmt':                                                                   
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: multiple definition of `core::fmt::num::<impl core::fmt::UpperHex
 for usize>::fmt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu
.0.rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: first defined here                             
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::num::<impl core::fmt::LowerHex for i64>::fmt':                                                                   
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: multiple definition of `core::fmt::num::<impl core::fmt::LowerHex
 for u64>::fmt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0
.rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: first defined here                               
/usr/bin/ld: objs/ngx_rust_examples/ngx-release/examples/libcurl.a(curl-de3e6fe882b906f0.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.
rcgu.o): in function `core::fmt::num::<impl core::fmt::UpperHex for i64>::fmt':                                                                   
/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: multiple definition of `core::fmt::num::<impl core::fmt::UpperHex
 for u64>::fmt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0
.rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/fmt/num.rs:155: first defined here                               
collect2: error: ld returned 1 exit status                                                                                                        
make[1]: *** [objs/Makefile:310: objs/nginx] Error 1                                                                                              
make[1]: Leaving directory '/media/psf/workspace/nginx/nginx'                                                                                     
make: *** [Makefile:10: build] Error 2                                                                                                            
(747 of 929): multiple definition of `core::num::from_str_radix_panic_rt'; objs/ngx_rust_examples/ngx-release/examples/libawssig.a(awssig-22b3aae1
e52dce40.core-f5a882967048065e.core.ecb3f420ec5f4bcf-cgu.0.rcgu.o.rcgu.o):/rustc/f6e511eec7342f59a25f7c0534f1dbea00d01b14/library/core/src/num/mod
.rs:1399: first defined here   

[xeioex]

Removing lto = "thin" from profile.ngx-release solves the issue.

[xeioex]

Otherwise looks good.

[bavshin-f5]

There are remaining problems with the approach here:

• LTO is not supported
• as we delegate the linking step to the nginx buildsystem, it lacks some useful linker flags.

Combined, this results in a much larger binary and missed optimization opportunities. We could attempt to address these issues by using Rust cdylib target for the shared modules and synthesizing a single staticlib crate for all the static modules. (See also: https://internals.rust-lang.org/t/rust-staticlibs-and-optimizing-for-size/5746)

It's also possible to simplify the target path logic with cargo rustc ... -- --emit=link=objs/ngx_http_example_module.a, passing an explicit (absolute!) path to the build artifacts (there's also -o, but it produces hashed libraries when used with cargo rustc: libawssig-8a15962bafeb450c.a).

But all of the above is not essential and could be fixed later, so I'm going to stop chasing the perfect solution and merge this as is.