Add stdin read support to nimscrit #3983 (#10292)

compiler/scriptconfig.nim

@@ -42,15 +42,18 @@ proc setupVM*(module: PSym; cache: IdentCache; scriptName: string;
       proc (a: VmArgs) =
         body
 
-  template cbos(name, body) {.dirty.} =
+  template cbexc(name, exc, body) {.dirty.} =
     result.registerCallback "stdlib.system." & astToStr(name),
       proc (a: VmArgs) =
         errorMsg = ""
         try:
           body
-        except OSError:
+        except exc:
           errorMsg = getCurrentExceptionMsg()
 
+  template cbos(name, body) {.dirty.} =
+    cbexc(name, OSError, body)
+
   # Idea: Treat link to file as a file, but ignore link to directory to prevent
   # endless recursions out of the box.
   cbos listFiles:
@@ -64,7 +67,7 @@ proc setupVM*(module: PSym; cache: IdentCache; scriptName: string;
   cbos createDir:
     os.createDir getString(a, 0)
 
-  result.registerCallback "stdlib.system.getOsError",
+  result.registerCallback "stdlib.system.getError",
     proc (a: VmArgs) = setResult(a, errorMsg)
 
   cbos setCurrentDir:
@@ -157,6 +160,12 @@ proc setupVM*(module: PSym; cache: IdentCache; scriptName: string;
     setResult(a, os.getAppFilename())
   cbconf cppDefine:
     options.cppDefine(conf, a.getString(0))
+  cbexc stdinReadLine, EOFError:
+    setResult(a, "")
+    setResult(a, stdin.readLine())
+  cbexc stdinReadAll, EOFError:
+    setResult(a, "")
+    setResult(a, stdin.readAll())
 
 proc runNimScript*(cache: IdentCache; scriptName: AbsoluteFile;
                    freshDefines=true; conf: ConfigRef) =

lib/system/nimscript.nim

@@ -46,7 +46,7 @@ proc copyDir(src, dest: string) {.
   tags: [ReadIOEffect, WriteIOEffect], raises: [OSError].} = builtin
 proc createDir(dir: string) {.tags: [WriteIOEffect], raises: [OSError].} =
   builtin
-proc getOsError: string = builtin
+proc getError: string = builtin
 proc setCurrentDir(dir: string) = builtin
 proc getCurrentDir*(): string =
   ## Retrieves the current working directory.
@@ -178,9 +178,12 @@ var
   mode*: ScriptMode ## Set this to influence how mkDir, rmDir, rmFile etc.
                     ## behave
 
+template checkError(exc: untyped): untyped =
+  let err = getError()
+  if err.len > 0: raise newException(exc, err)
+
 template checkOsError =
-  let err = getOsError()
-  if err.len > 0: raise newException(OSError, err)
+  checkError(OSError)
 
 template log(msg: string, body: untyped) =
   if mode in {ScriptMode.Verbose, ScriptMode.Whatif}:
@@ -332,6 +335,26 @@ proc cppDefine*(define: string) =
   ## needs to be mangled.
   builtin
 
+proc stdinReadLine(): TaintedString {.
+  tags: [ReadIOEffect], raises: [IOError].} =
+  builtin
+
+proc stdinReadAll(): TaintedString {.
+  tags: [ReadIOEffect], raises: [IOError].} =
+  builtin
+
+proc readLineFromStdin*(): TaintedString {.raises: [IOError].} =
+  ## Reads a line of data from stdin - blocks until \n or EOF which happens when stdin is closed
+  log "readLineFromStdin":
+    result = stdinReadLine()
+    checkError(EOFError)
+
+proc readAllFromStdin*(): TaintedString {.raises: [IOError].} =
+  ## Reads all data from stdin - blocks until EOF which happens when stdin is closed
+  log "readAllFromStdin":
+    result = stdinReadAll()
+    checkError(EOFError)
+
 when not defined(nimble):
   template `==?`(a, b: string): bool = cmpIgnoreStyle(a, b) == 0
   template task*(name: untyped; description: string; body: untyped): untyped =