nimbus.nim: add depfile support

ChangeLog

@@ -6,7 +6,8 @@
 
 	* nimbleexecutor.nim (toJsonString): query variables in bulk
 
-	* nimbus.nim: add debug output
+	* nimbus.nim: support patched Nim compilers with --depfile option; add
+	debug output
 
 	* options.nim (initLogger): set default log level to NOTICE
 

nimbus.1

@@ -14,6 +14,7 @@
 .Op Fl Fl nimbleDir : Ns Ar path
 .Op Fl Fl nim : Ns Ar path
 .Op Fl Fl url : Ns Ar url
+.Op Fl Fl useDepfile
 .Op nim opts...
 .Ar sourceDir
 .Op Ar buildDir
@@ -45,14 +46,18 @@ Set the executable directory, where project's binaries will be installed.
 .It Fl Fl debug
 Show debugging information.
 .
-.It Fl Fl nim : Ns Ar path
-Set the Nim executable.
-.
 .It Fl Fl nimbleDir : Ns Ar path
 Set the Nimble directory, where project's sources will be installed.
 .
+.It Fl Fl nim : Ns Ar path
+Set the Nim executable.
+.
 .It Fl Fl url : Ns Ar url
 If this options is set,
+.
+.It Fl Fl useDepfile
+Tell the Nim compiler to make a depfile.
+Only available with patched Nim.
 .Nm
 will generate and install a
 .Pa nimblemeta.json

src/nimbs/options.nim

@@ -10,6 +10,7 @@ type
   Options* = object
     showHelp*: bool
     debug*: bool
+    useDepfile*: bool
     nimbleDir*: string
     binDir*: string
     nim*: string # Nim compiler location
@@ -22,8 +23,8 @@ type
 
 const
   help* = """
-Usage: nimbus [-h] [--debug] [--nimbleDir:path] [--binDir:path] [--nim:path]
-              [--url:url] [nim opts...] sourceDir [buildDir]
+Usage: nimbus [-h] [--debug] [--useDepfile] [--nimbleDir:path] [--binDir:path]
+              [--nim:path] [--url:url] [nim opts...] sourceDir [buildDir]
 
 positional arguments:
   sourceDir
@@ -32,6 +33,7 @@ positional arguments:
 optional arguments:
   -h, --help          show this help message and exit
   --debug             Show debugging information.
+  --useDepfile        Tell Nim compiler to make a depfile.
   --nimbleDir:path    Nimble directory (default: $1).
   --binDir:path       Executable directory (default: $2).
   --nim:path          Nim compiler (default: nim).
@@ -158,6 +160,7 @@ func parseFlag(flag, val: string, result: var Options, kind = cmdLongOption) =
   case f
   of "help", "h": result.showHelp = true
   of "debug": result.debug = true
+  of "usedepfile": result.useDepfile = true
   of "nimbledir": result.nimbleDir = val
   of "bindir": result.binDir = val
   of "nim": result.nim = val
@@ -177,6 +180,7 @@ proc parseCmdLine*(): Options =
   # set default values here
   result.debug = false
   result.showHelp = false
+  result.useDepfile = false
 
   var argc = 0
   for kind, key, val in getOpt():

src/nimbus.nim

@@ -21,17 +21,22 @@ proc processDependencies(requires: seq[string], options: Options): seq[string] =
     else:
       result.add(dep.getPath(options).quoteShell)
 
-proc application(ninja: File, input, output: string, paths: seq[string]) =
+proc application(ninja: File, input, output: string, paths: seq[string],
+                 useDepfile: bool) =
   debug(fmt"[build.ninja] Generating target for application '{output}'")
 
   var vars = newStringTable()
   if paths.len != 0:
     vars["paths"] = "-p:" & paths.join(" -p:")
+  if useDepfile:
+    let depfile = quoteShell(output & ".d")
+    vars["depfileopt"] = "--depfile:" & depfile
 
   ninja.build([output],
     rule = "nimc",
     inputs = [input],
-    implicit = ["PHONY"], # FIXME: add depfile support to the Nim compiler
+    implicit = if useDepfile: newSeq[string]()
+               else: @["PHONY"],
     variables = vars
   )
 
@@ -147,9 +152,10 @@ proc setup(options: Options) =
   if pkgInfo.bin.len != 0:
     debug("[build.ninja] Generating 'nimc' rule")
     ninja.rule("nimc",
-      command = "$nim --hints:off $nimflags c --nimcache:$nimcache " &
-                "-o:$out $paths $in",
-      description = "Compiling Nim application $out")
+      command = "$nim --hints:off $nimflags c --nimcache:$nimcache -o:$out " &
+                "$depfileopt $paths $in",
+      description = "Compiling Nim application $out",
+      depfile = "$out.d")
     ninja.newline()
 
   debug("[build.ninja] Generating 'PHONY' target")
@@ -176,7 +182,7 @@ proc setup(options: Options) =
   for bin in pkgInfo.bin:
     let output = bin.lastPathPart.addFileExt(ExeExt)
     let input = pkgInfo.getSourceDir(options) / bin.addFileExt("nim")
-    ninja.application(input, output, depPaths)
+    ninja.application(input, output, depPaths, options.useDepfile)
     ninja.newline()
 
   debug("[build.ninja] Generating 'all' target")