* honor --errorMax even for tools (eg drnim, nim doc) (#14546)

* fix a bug that prevented nim doc compiler/nim on windows

compiler/main.nim

@@ -51,7 +51,7 @@ proc commandGenDepend(graph: ModuleGraph) =
       ' ' & changeFileExt(project, "dot").string)
 
 proc commandCheck(graph: ModuleGraph) =
-  graph.config.errorMax = high(int)  # do not stop after first error
+  graph.config.setErrorMaxHighMaybe
   defineSymbol(graph.config.symbols, "nimcheck")
   semanticPasses(graph)  # use an empty backend for semantic checking only
   compileProject(graph)
@@ -59,7 +59,7 @@ proc commandCheck(graph: ModuleGraph) =
 when not defined(leanCompiler):
   proc commandDoc2(graph: ModuleGraph; json: bool) =
     handleDocOutputOptions graph.config
-    graph.config.errorMax = high(int)  # do not stop after first error
+    graph.config.setErrorMaxHighMaybe
     semanticPasses(graph)
     if json: registerPass(graph, docgen2JsonPass)
     else: registerPass(graph, docgen2Pass)
@@ -136,7 +136,7 @@ proc interactivePasses(graph: ModuleGraph) =
   registerPass(graph, evalPass)
 
 proc commandInteractive(graph: ModuleGraph) =
-  graph.config.errorMax = high(int)  # do not stop after first error
+  graph.config.setErrorMaxHighMaybe
   interactivePasses(graph)
   compileSystemModule(graph)
   if graph.config.commandArgs.len > 0:

compiler/nimeval.nim

@@ -137,6 +137,7 @@ proc destroyInterpreter*(i: Interpreter) =
 proc runRepl*(r: TLLRepl;
               searchPaths: openArray[string];
               supportNimscript: bool) =
+  ## deadcode but please don't remove... might be revived
   var conf = newConfigRef()
   var cache = newIdentCache()
   var graph = newModuleGraph(cache, conf)
@@ -146,7 +147,7 @@ proc runRepl*(r: TLLRepl;
     if conf.libpath.isEmpty: conf.libpath = AbsoluteDir p
 
   conf.cmd = cmdInteractive
-  conf.errorMax = high(int)
+  conf.setErrorMaxHighMaybe
   initDefines(conf.symbols)
   defineSymbol(conf.symbols, "nimscript")
   if supportNimscript: defineSymbol(conf.symbols, "nimconfig")

compiler/options.nim

@@ -315,6 +315,14 @@ type
                                 severity: Severity) {.closure, gcsafe.}
     cppCustomNamespace*: string
 
+proc assignIfDefault*[T](result: var T, val: T, def = default(T)) =
+  ## if `result` was already assigned to a value (that wasn't `def`), this is a noop.
+  if result == def: result = val
+
+template setErrorMaxHighMaybe*(conf: ConfigRef) =
+  ## do not stop after first error (but honor --errorMax if provided)
+  assignIfDefault(conf.errorMax, high(int))
+
 proc setNoteDefaults*(conf: ConfigRef, note: TNoteKind, enabled = true) =
   template fun(op) =
     conf.notes.op note

compiler/sem.nim

@@ -325,7 +325,7 @@ proc tryConstExpr(c: PContext, n: PNode): PNode =
   let oldErrorOutputs = c.config.m.errorOutputs
 
   c.config.m.errorOutputs = {}
-  c.config.errorMax = high(int)
+  c.config.errorMax = high(int) # `setErrorMaxHighMaybe` not appropriate here
 
   try:
     result = evalConstExpr(c.module, c.graph, e)

compiler/semexprs.nim

@@ -2074,8 +2074,7 @@ proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
   if c.compilesContextId == 0:
     inc c.compilesContextIdGenerator
     c.compilesContextId = c.compilesContextIdGenerator
-  # do not halt after first error:
-  c.config.errorMax = high(int)
+  c.config.errorMax = high(int) # `setErrorMaxHighMaybe` not appropriate here
 
   # open a scope for temporary symbol inclusions:
   let oldScope = c.currentScope