nim-ffi/ffi/internal/ffi_library.nim
Ivan Folgueira Bande da3251aa1a
evolving more
2025-12-10 17:43:26 +01:00

82 lines
2.7 KiB
Nim

import std/[macros, atomics], strformat, chronicles, chronos
macro declareLibrary*(libraryName: static[string]): untyped =
var res = newStmtList()
## Generate {.pragma: exported, exportc, cdecl, raises: [].}
res.add nnkPragma.newTree(
nnkExprColonExpr.newTree(ident"pragma", ident"exported"),
ident"exportc",
ident"cdecl",
nnkExprColonExpr.newTree(ident"raises", nnkBracket.newTree()),
)
## Generate {.pragma: callback, cdecl, raises: [], gcsafe.}
res.add nnkPragma.newTree(
nnkExprColonExpr.newTree(ident"pragma", ident"callback"),
ident"cdecl",
nnkExprColonExpr.newTree(ident"raises", nnkBracket.newTree()),
ident"gcsafe",
)
## Generate {.passc: "-fPIC".}
res.add nnkPragma.newTree(nnkExprColonExpr.newTree(ident"passc", newLit("-fPIC")))
when defined(linux):
## Generates {.passl: "-Wl,-soname,libwaku.so".} (considering libraryName=="waku", for example)
let soName = fmt"-Wl,-soname,lib{libraryName}.so"
res.add(
newNimNode(nnkPragma).add(
nnkExprColonExpr.newTree(ident"passl", newStrLitNode(soName))
)
)
## proc lib{libraryName}NimMain() {.importc.}
let libNimMainName = ident(fmt"lib{libraryName}NimMain")
let importcPragma = nnkPragma.newTree(ident"importc")
let procDef = newProc(
name = libNimMainName,
params = @[ident"void"],
pragmas = importcPragma,
body = newEmptyNode(),
)
res.add(procDef)
# Create: var initialized: Atomic[bool]
let atomicType = nnkBracketExpr.newTree(ident("Atomic"), ident("bool"))
let varStmt = nnkVarSection.newTree(
nnkIdentDefs.newTree(ident("initialized"), atomicType, newEmptyNode())
)
res.add(varStmt)
## Android chronicles redirection
let chroniclesBlock = quote:
when defined(android) and compiles(defaultChroniclesStream.outputs[0].writer):
defaultChroniclesStream.outputs[0].writer = proc(
logLevel: LogLevel, msg: LogOutputStr
) {.raises: [].} =
echo logLevel, msg
result.add(chroniclesBlock)
let procName = ident("initializeLibrary")
let nimMainName = ident("lib" & libraryName & "NimMain")
let initializeLibraryProc = quote:
proc `procName`*() {.exported.} =
if not initialized.exchange(true):
## Every Nim library needs to call `<yourprefix>NimMain` once exactly,
## to initialize the Nim runtime.
## Being `<yourprefix>` the value given in the optional
## compilation flag --nimMainPrefix:yourprefix
`nimMainName`()
when declared(setupForeignThreadGc):
setupForeignThreadGc()
when declared(nimGC_setStackBottom):
var locals {.volatile, noinit.}: pointer
locals = addr(locals)
nimGC_setStackBottom(locals)
res.add(initializeLibraryProc)
return res