nimbus.nim: use custom jsonscript executor

Work around https://github.com/nim-lang/Nim/issues/21741

.reuse/dep5

@@ -3,8 +3,6 @@ Upstream-Name: nimbus
 Upstream-Contact: Anna <cyber@sysrq.in>
 Source: https://nimbus.sysrq.in
 
-# Sample paragraph, commented out:
-#
-# Files: src/*
-# Copyright: $YEAR $NAME <$CONTACT>
-# License: ...
+Files: ChangeLog
+Copyright: Nimbus contributors
+License: CC0-1.0

src/nimbs/builderscript.nim

@@ -22,48 +22,64 @@ const
 
 type
   Options = object
+    genScript: bool
     target: string
+    targetName: string
     inFile: string
     outFile: string
     paths: seq[string]
 
-proc build(options: Options) =
+proc genScript(options: Options) =
   var paths = ""
   if options.paths.len != 0:
     paths = "-p:" & options.paths.join(" -p:")
 
-  let targetName = options.target.extractFilename
-  let nimCache = nimCacheBaseDir / targetName
+  let nimCache = nimCacheBaseDir / options.targetName
   exec fmt"{nimBin} {nimFlags} c --genScript:on --nimcache:{nimCache.quoteShell}" &
        fmt" -o:{options.outFile.quoteShell} {paths} {options.inFile.quoteShell}"
 
   let txt2deps = findExe("txt2deps")
   if txt2deps.len != 0:
-    let nimDepsFile = nimCache / targetName.addFileExt("deps")
+    let nimDepsFile = nimCache / options.targetName.addFileExt("deps")
     let gccDepsFile = options.target.addFileExt("d")
     exec fmt"{txt2deps} -T:{options.target.quoteShell}" &
          fmt" -i:{nimDepsFile.quoteShell} -o:{gccDepsFile.quoteShell}"
 
+proc execScript(options: Options) =
+  let nimCache = nimCacheBaseDir / options.targetName
+  withDir nimCache:
+    exec fmt"{nimBin} {nimFlags} jsonscript --nimcache:{nimCache.quoteShell}" &
+         fmt" -o:{options.outFile.quoteShell} {options.inFile.quoteShell}"
+
 proc parseCmdLine(): Options =
+  result.genScript = true
   for kind, key, val in getOpt():
     case kind
     of cmdArgument:
       result.inFile = key
-    of cmdShortOption:
+    of cmdLongOption, cmdShortOption:
       case key.normalize()
       of "t":
         # full path!
         result.target = val
+        result.targetName = val.extractFilename
         result.outFile = val.addFileExt(ExeExt)
       of "p":
         result.paths.add(val)
+      of "genscript":
+        result.genScript = true
+      of "jsonscript":
+        result.genScript = false
       else:
         discard
-    of cmdEnd, cmdLongOption:
+    of cmdEnd:
       discard
 
 let opts = parseCmdLine()
-build(opts)
+if opts.genScript:
+  genScript(opts)
+else:
+  execScript(opts)
 """ % [options.getNimBin().tripleQuoted,
        options.getNimFlags().tripleQuoted,
        options.getNimCacheBaseDir().tripleQuoted])

src/nimbus.nim

@@ -34,18 +34,20 @@ proc processDependencies(requires: seq[string], options: Options): seq[string] =
     else:
       result.add(dep.getPath(options).quoteShell)
 
-proc application(ninja: File, input, target: string;
+proc application(ninja: File, input, targetName: string;
                  paths: seq[string], options: Options) =
-  debug(fmt"[build.ninja] Generating target for application '{target}'")
+  debug(fmt"[build.ninja] Generating target for application '{targetName}'")
 
   var vars = newStringTable()
-  vars["target"] = "$builddir" / target.escape(body = true)
+  vars["targetname"] = targetName
+  vars["target"] = "$builddir" / targetName.escape(body = true)
   vars["sourcefile"] = input.escape(body = true)
-  vars["nimcache"] = options.getNimCacheBaseDir() / target
+  vars["nimcache"] = escape(options.getNimCacheBaseDir() / targetName,
+                            body = true)
   if paths.len != 0:
     vars["paths"] = escape("-p:" & paths.join(" -p:"), body = true)
 
-  let jsonScript = "$nimcache" / target.addFileExt("json").escape
+  let jsonScript = "$nimcache" / targetName.addFileExt("json").escape
   ninja.build([jsonScript],
     rule = "genscript",
     inputs = [input.escape, "$builder"],
@@ -53,9 +55,9 @@ proc application(ninja: File, input, target: string;
   )
   ninja.newline()
 
-  ninja.build([target.addFileExt(ExeExt).escape],
+  ninja.build([vars["target"].addFileExt(ExeExt)],
     rule = "jsonscript",
-    inputs = [input.escape],
+    inputs = [input.escape, "$builder"],
     implicit = [jsonScript],
     variables = vars
   )
@@ -144,6 +146,7 @@ proc setup(options: Options) =
   ninja.newline()
 
   debug("[build.ninja] Writing variables")
+  ninja.variable("builddir", options.getBuildDir().escape(body = true))
   ninja.variable("nim", options.getNimBin().escape(body = true))
   ninja.variable("nimbus", getAppFilename().escape(body = true))
   ninja.variable("cmdline", options.getCmdLine().escape(body = true))
@@ -168,8 +171,9 @@ proc setup(options: Options) =
   if pkgInfo.bin.len != 0:
     debug("[build.ninja] Generating 'genscript' rule")
     ninja.rule("genscript",
-      command = "$nim --hints:off e $builder -T:$target $paths $sourcefile",
-      description = "Generating build script for Nim application $out",
+      command = "$nim --hints:off e $builder" &
+                " --genscript -T:$target $paths $sourcefile",
+      description = "Generating build script for Nim application $targetname",
       depfile = "$target".addFileExt("d"),
       deps = "gcc",
       pool = "console")
@@ -177,8 +181,9 @@ proc setup(options: Options) =
 
     debug("[build.ninja] Generating 'jsonscript' rule")
     ninja.rule("jsonscript",
-      command = "$nim jsonscript --nimcache:$nimcache -o:$out $sourcefile",
-      description = "Compiling Nim application $out",
+      command = "$nim --hints:off e $builder" &
+                " --jsonscript -T:$target $sourcefile",
+      description = "Compiling Nim application $targetname",
       depfile = "$target".addFileExt("d"),
       deps = "gcc",
       pool = "console")
@@ -216,13 +221,16 @@ proc setup(options: Options) =
 
   for bin in pkgInfo.bin:
     let input = pkgInfo.getSourceDir(options) / bin.addFileExt("nim")
-    let target = bin.lastPathPart
-    ninja.application(input, target, depPaths, options)
+    let targetName = bin.lastPathPart
+    ninja.application(input, targetName, depPaths, options)
 
   debug("[build.ninja] Generating 'all' target")
   ninja.build(["all"],
     rule = "phony",
-    inputs = pkgInfo.bin.mapIt(it.lastPathPart.addFileExt(ExeExt).escape))
+    inputs = pkgInfo.bin.mapIt(
+      "$builddir" / it.lastPathPart.addFileExt(ExeExt).escape
+    )
+  )
   ninja.default(["all"])
   ninja.newline()