Allow specifiying path to use for stdin error messages (#24595)

Implements #24569

Adds `--stdinfile` flag for specifying the file to use in place of
`stdinfile.nim` in error messages. Will enable easier integration of
tooling with nim check

(cherry picked from commit 0cba752c8a)

compiler/commands.nim

@@ -459,7 +459,7 @@ template handleStdinOrCmdInput =
     conf.outDir = getNimcacheDir(conf)
 
 proc handleStdinInput*(conf: ConfigRef) =
-  conf.projectName = "stdinfile"
+  conf.projectName = conf.stdinFile.string
   conf.projectIsStdin = true
   handleStdinOrCmdInput()
 
@@ -935,6 +935,10 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     var value: int = 0
     discard parseSaturatedNatural(arg, value)
     conf.errorMax = if value == 0: high(int) else: value
+  of "stdinfile":
+    expectArg(conf, switch, arg, pass, info)
+    conf.stdinFile = if os.isAbsolute(arg): AbsoluteFile(arg)
+                     else: AbsoluteFile(getCurrentDir() / arg)
   of "verbosity":
     expectArg(conf, switch, arg, pass, info)
     let verbosity = parseInt(arg)

compiler/options.nim

@@ -404,6 +404,7 @@ type
     projectPath*: AbsoluteDir # holds a path like /home/alice/projects/nim/compiler/
     projectFull*: AbsoluteFile # projectPath/projectName
     projectIsStdin*: bool # whether we're compiling from stdin
+    stdinFile*: AbsoluteFile # Filename to use in messages for stdin
     lastMsgWasDot*: set[StdOrrKind] # the last compiler message was a single '.'
     projectMainIdx*: FileIndex # the canonical path id of the main module
     projectMainIdx2*: FileIndex # consider merging with projectMainIdx
@@ -580,6 +581,7 @@ proc newConfigRef*(): ConfigRef =
     projectPath: AbsoluteDir"", # holds a path like /home/alice/projects/nim/compiler/
     projectFull: AbsoluteFile"", # projectPath/projectName
     projectIsStdin: false, # whether we're compiling from stdin
+    stdinFile: AbsoluteFile"stdinfile",
     projectMainIdx: FileIndex(0'i32), # the canonical path id of the main module
     command: "", # the main command (e.g. cc, check, scan, etc)
     commandArgs: @[], # any arguments after the main command

compiler/pipelines.nim

@@ -234,7 +234,8 @@ proc compilePipelineModule*(graph: ModuleGraph; fileIdx: FileIndex; flags: TSymF
     result = moduleFromRodFile(graph, fileIdx, cachedModules)
     let path = toFullPath(graph.config, fileIdx)
     let filename = AbsoluteFile path
-    if fileExists(filename): # it could be a stdinfile
+    # it could be a stdinfile/cmdfile
+    if fileExists(filename) and not graph.config.projectIsStdin:
       graph.cachedFiles[path] = $secureHashFile(path)
     if result == nil:
       result = newModule(graph, fileIdx)