From 8c12c6939aab9106db14ec2d11d983bc5b29fb2c Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 7 Jul 2019 21:33:44 +0100 Subject: Switch to modules --- vendor/golang.org/x/sys/unix/README.md | 173 --------------------------------- 1 file changed, 173 deletions(-) delete mode 100644 vendor/golang.org/x/sys/unix/README.md (limited to 'vendor/golang.org/x/sys/unix/README.md') diff --git a/vendor/golang.org/x/sys/unix/README.md b/vendor/golang.org/x/sys/unix/README.md deleted file mode 100644 index bc6f603..0000000 --- a/vendor/golang.org/x/sys/unix/README.md +++ /dev/null @@ -1,173 +0,0 @@ -# Building `sys/unix` - -The sys/unix package provides access to the raw system call interface of the -underlying operating system. See: https://godoc.org/golang.org/x/sys/unix - -Porting Go to a new architecture/OS combination or adding syscalls, types, or -constants to an existing architecture/OS pair requires some manual effort; -however, there are tools that automate much of the process. - -## Build Systems - -There are currently two ways we generate the necessary files. We are currently -migrating the build system to use containers so the builds are reproducible. -This is being done on an OS-by-OS basis. Please update this documentation as -components of the build system change. - -### Old Build System (currently for `GOOS != "Linux" || GOARCH == "sparc64"`) - -The old build system generates the Go files based on the C header files -present on your system. This means that files -for a given GOOS/GOARCH pair must be generated on a system with that OS and -architecture. This also means that the generated code can differ from system -to system, based on differences in the header files. - -To avoid this, if you are using the old build system, only generate the Go -files on an installation with unmodified header files. It is also important to -keep track of which version of the OS the files were generated from (ex. -Darwin 14 vs Darwin 15). This makes it easier to track the progress of changes -and have each OS upgrade correspond to a single change. - -To build the files for your current OS and architecture, make sure GOOS and -GOARCH are set correctly and run `mkall.sh`. This will generate the files for -your specific system. Running `mkall.sh -n` shows the commands that will be run. - -Requirements: bash, perl, go - -### New Build System (currently for `GOOS == "Linux" && GOARCH != "sparc64"`) - -The new build system uses a Docker container to generate the go files directly -from source checkouts of the kernel and various system libraries. This means -that on any platform that supports Docker, all the files using the new build -system can be generated at once, and generated files will not change based on -what the person running the scripts has installed on their computer. - -The OS specific files for the new build system are located in the `${GOOS}` -directory, and the build is coordinated by the `${GOOS}/mkall.go` program. When -the kernel or system library updates, modify the Dockerfile at -`${GOOS}/Dockerfile` to checkout the new release of the source. - -To build all the files under the new build system, you must be on an amd64/Linux -system and have your GOOS and GOARCH set accordingly. Running `mkall.sh` will -then generate all of the files for all of the GOOS/GOARCH pairs in the new build -system. Running `mkall.sh -n` shows the commands that will be run. - -Requirements: bash, perl, go, docker - -## Component files - -This section describes the various files used in the code generation process. -It also contains instructions on how to modify these files to add a new -architecture/OS or to add additional syscalls, types, or constants. Note that -if you are using the new build system, the scripts cannot be called normally. -They must be called from within the docker container. - -### asm files - -The hand-written assembly file at `asm_${GOOS}_${GOARCH}.s` implements system -call dispatch. There are three entry points: -``` - func Syscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) - func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr) - func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr) -``` -The first and second are the standard ones; they differ only in how many -arguments can be passed to the kernel. The third is for low-level use by the -ForkExec wrapper. Unlike the first two, it does not call into the scheduler to -let it know that a system call is running. - -When porting Go to an new architecture/OS, this file must be implemented for -each GOOS/GOARCH pair. - -### mksysnum - -Mksysnum is a script located at `${GOOS}/mksysnum.pl` (or `mksysnum_${GOOS}.pl` -for the old system). This script takes in a list of header files containing the -syscall number declarations and parses them to produce the corresponding list of -Go numeric constants. See `zsysnum_${GOOS}_${GOARCH}.go` for the generated -constants. - -Adding new syscall numbers is mostly done by running the build on a sufficiently -new installation of the target OS (or updating the source checkouts for the -new build system). However, depending on the OS, you make need to update the -parsing in mksysnum. - -### mksyscall.pl - -The `syscall.go`, `syscall_${GOOS}.go`, `syscall_${GOOS}_${GOARCH}.go` are -hand-written Go files which implement system calls (for unix, the specific OS, -or the specific OS/Architecture pair respectively) that need special handling -and list `//sys` comments giving prototypes for ones that can be generated. - -The mksyscall.pl script takes the `//sys` and `//sysnb` comments and converts -them into syscalls. This requires the name of the prototype in the comment to -match a syscall number in the `zsysnum_${GOOS}_${GOARCH}.go` file. The function -prototype can be exported (capitalized) or not. - -Adding a new syscall often just requires adding a new `//sys` function prototype -with the desired arguments and a capitalized name so it is exported. However, if -you want the interface to the syscall to be different, often one will make an -unexported `//sys` prototype, an then write a custom wrapper in -`syscall_${GOOS}.go`. - -### types files - -For each OS, there is a hand-written Go file at `${GOOS}/types.go` (or -`types_${GOOS}.go` on the old system). This file includes standard C headers and -creates Go type aliases to the corresponding C types. The file is then fed -through godef to get the Go compatible definitions. Finally, the generated code -is fed though mkpost.go to format the code correctly and remove any hidden or -private identifiers. This cleaned-up code is written to -`ztypes_${GOOS}_${GOARCH}.go`. - -The hardest part about preparing this file is figuring out which headers to -include and which symbols need to be `#define`d to get the actual data -structures that pass through to the kernel system calls. Some C libraries -preset alternate versions for binary compatibility and translate them on the -way in and out of system calls, but there is almost always a `#define` that can -get the real ones. -See `types_darwin.go` and `linux/types.go` for examples. - -To add a new type, add in the necessary include statement at the top of the -file (if it is not already there) and add in a type alias line. Note that if -your type is significantly different on different architectures, you may need -some `#if/#elif` macros in your include statements. - -### mkerrors.sh - -This script is used to generate the system's various constants. This doesn't -just include the error numbers and error strings, but also the signal numbers -an a wide variety of miscellaneous constants. The constants come from the list -of include files in the `includes_${uname}` variable. A regex then picks out -the desired `#define` statements, and generates the corresponding Go constants. -The error numbers and strings are generated from `#include `, and the -signal numbers and strings are generated from `#include `. All of -these constants are written to `zerrors_${GOOS}_${GOARCH}.go` via a C program, -`_errors.c`, which prints out all the constants. - -To add a constant, add the header that includes it to the appropriate variable. -Then, edit the regex (if necessary) to match the desired constant. Avoid making -the regex too broad to avoid matching unintended constants. - - -## Generated files - -### `zerror_${GOOS}_${GOARCH}.go` - -A file containing all of the system's generated error numbers, error strings, -signal numbers, and constants. Generated by `mkerrors.sh` (see above). - -### `zsyscall_${GOOS}_${GOARCH}.go` - -A file containing all the generated syscalls for a specific GOOS and GOARCH. -Generated by `mksyscall.pl` (see above). - -### `zsysnum_${GOOS}_${GOARCH}.go` - -A list of numeric constants for all the syscall number of the specific GOOS -and GOARCH. Generated by mksysnum (see above). - -### `ztypes_${GOOS}_${GOARCH}.go` - -A file containing Go types for passing into (or returning from) syscalls. -Generated by godefs and the types file (see above). -- cgit v1.2.3