Codegen is a cimgui-go-featured GO code generator.
Cod is generated basing on several JSON config files and refers to a shared library compiled from C source.
[codegen (0) ]$ go run . --help
Usage: codegen [FLAG]...
Flags:
-lg, --log-generated Log about functions that was generated. (type: bool; default: false)
-lng, --log-not-generated Log about functions that was NOT generated. (type: bool; default: false)
-d, --definitions definitions.json file path (type: string)
-e, --enums structs_and_enums.json file path (type: string)
-t, --typedefs typedefs_dict.json file path (type: string)
-re, --ref-enums structs_and_enums.json file path for reference package (see README.md). (type: string)
-rt, --ref-typedefs typedefs_dict.json file path for reference package (see README.md). (type: string)
-p, --preset Preset of custom (manual) generator rules. See go doc github.com/AllenDang/cimgui-go/cmd/codegen.Preset for more details. (in form of json file) (type: string)
-rp, --ref-pkg name for refTypedefs package name (type: string; default: imgui)
-pkg, --package name for current package (type: string)
-i, --include Include header file (source project's header) (type: string)
-h, --help show help (type: bool)[codegen (0) ]$ go doc Preset
type Preset struct {
// SkipFuncs functions (from definitions.json) to be skipped
// e.g. they are temporarily hard-coded
SkipFuncs map[CIdentifier]bool
// SkipStructs allows to specify struct names that will be skipped.
SkipStructs map[CIdentifier]bool
// SkipMethods struct names from structs_and_enums.json.
// structures that's METHODS should be skipped
SkipMethods map[CIdentifier]bool
// SkipTypedefs typedefs from typedefs_dict.json to be skipped
// e.g. for hardcoded typedefs or typedefs which are obvious (e.g. ImU16 becomes uint16 without extra type information)
SkipTypedefs map[CIdentifier]bool
// TypedefsPoolSize sets a default size for callbacks pool.
// Rembmber to set this as it defaults to 0 and you'll get no callbacks!
TypedefsPoolSize int
// TypedefsCustomPoolSizes allows to override TypedefsPoolSize for certain types.
TypedefsCustomPoolSizes map[CIdentifier]int
// Replace is a map for C -> Go names conversion.
// It allows you to force-rename anything (including functions and enums)
Replace map[CIdentifier]GoIdentifier
// TrimPrefix allows to remove unwanted prefixes from everything during C->Go renaming.
// NOTE: order sensitive!
// NOTE: Case sensitive
TrimPrefix []string
// OriginReplace allows to force-replace function name with some other name.
// Introduced to replace TextEditor_GetText -> TextEditor_GetText_alloc
// but could be re-used to force use of another function than json tells us to use.
//
// It differs from Replace - Replace renames an identifier in general (changes its name but refers to the same function).
// This allows to absolutely abandon the source C function and use some OTHER C function.
OriginReplace map[CIdentifier]CIdentifier
// DefaultArgReplace is used in C-side default args generation (gencpp.go).
// cimgui-go uses this to change FLT_MIN with igGet_FLT_MIN()
// NOTE: Iterated randomly!
DefaultArgReplace map[CIdentifier]CIdentifier
// DefaultArgArbitraryValue is similar to the above DefaultArgReplace, but
// associates default arg name with any arbitrary value.
// cimgui-go uses this to set text_end to 0
DefaultArgArbitraryValue map[CIdentifier]CIdentifier
// ExtraCGOPreamble allows to specify additional C code elements in Go files.
// For example could be used to Include extra files.
// For ease of use, its in form of []string. These lines will be merged and prefixed (if appliable) with '//'
ExtraCGOPreamble []string
// InternalFiles allows to specify files that are considered Internal.
// If an identifier is found in such a file, it will be generated but its
// name will be prefixed with InternalPrefix
InternalFiles []string
// InternalPrefix is a prefix for identifiers from InternalFiles.
InternalPrefix string
// PackagePath is an import path of the package.
// This is base path. flags.PackageName will be added.
// Example:
// "github.com/AllenDang/cimgui-go"
// If enerated with -pkg imgui, import path
// is supposed to be "github.com/AllenDang/cimgui-go/imgui"
PackagePath string
// SimpleTypes are used for simple (go-convertable) custom types (wrappers will be generated by simpleW/simpleR).
// Example:
// ImS16 is defined as short in C code, so Go can easily convert it via int16()
// Expected format is:
// "ImS16": ["int16", "C.ImS16", "pkgname"]
// where:
// - ImS16 is a C type name
// - int16 is a Go-friendly type name
// - C.ImS16 is a cgo compatible type name
// - pkgname is a source package for the type (in this case int16 is a builtin so it should be empty)
// See also: simpleW
SimpleTypes map[CIdentifier][3]GoIdentifier
// SimplePtrTypes are just like SimpleTypes but for pointer types.
// Example:
// "ImS16": ["int16", "C.ImS16", "pkgname"]
SimplePtrTypes map[CIdentifier][3]GoIdentifier
// WrappableTypes are types that implement a special interface
// github.com/AllenDang/cimgui-go/internal.WrappableType[CTYPE, SELF]
// In short they are supposed to have 2 methods:
// - ToC() CTYPE which returns SELF converted to CTYPE
// - FromC(CTYPE) SELF which restores SELF from CTYPE.
//
// Key is a C type name, value is a list:
// - Go name
// - C name
// - package where the type is defined
// Example syntax:
// "ImVec2": ["Vec2", "C.ImVec2", "imgui"]
WrappableTypes map[CIdentifier][3]GoIdentifier
}
Preset is a set of rules iperative to XXX_templates/ json files. They are
used to manually set some properties of the generator.Assume you have a C project which exports its public API in a header (.h) file.
What this module does not cover is the first step:
- You need JSON files describing functions in your C project. This is at the moment done by https://github.com/cimgui lua cpp2ffi.lua script which however is highly single-purpose and you probably will not be able to use it for your project. You need to handle this yourself for now. Let us know if you find/create an universal solution for that. For specification of the JSON files see here
- Then you need a another JSON file called "preset" (see here) which will tell the generator more about your project. e.g. its github path, ids you want to exclude (if you're need for some reason - we do for imgui), prefixes to remove, etc.
- Execute codegen. Do
codegen -lng --preset your_preset.json -e structs_and_enums.json -t typedefs_dict.json -d definitions.json -i your_header.h -pkg your_package_name. This will create several files in your current directory that should contain operational code.
Sometimes you may want to generate one package basing on another package wrapped by this
(I mean imgui plugin for example).
Example:
header.h contains symbol A. Then you have header2.h with a function using this symbol A.
On go sied you have package1.A and you want to generate header2.h in package2 and
use package1.A in it. This is where --ref* flags comes in. You specify header1's json files as reference files
and package1 as reference package. Then you generate package2 and it will use package1's symbols.
The minimalistic working configuration is present in here review it yourself.