sem, pragmas: fix fatal pragma

compiler/ast/ast_types.nim

@@ -1324,7 +1324,6 @@ type
         adSemAlignRequiresPowerOfTwo,
         adSemNoReturnHasReturn,
         adSemMisplacedDeprecation,
-        adSemFatalError,
         adSemNoUnionForJs,
         adSemBitsizeRequiresPositive,
         adSemExperimentalRequiresToplevel,
@@ -1421,7 +1420,7 @@ type
       externName*: string
     of adSemPragmaRecursiveDependency:
       userPragma*: PSym
-    of adSemCustomUserError:
+    of adSemCustomUserError, adSemFatalError:
       errmsg*: string
     of adSemImplicitPragmaError:
       implicitPragma*: PSym

compiler/front/cli_reporter.nim

@@ -3211,7 +3211,6 @@ func astDiagToLegacyReport(conf: ConfigRef, diag: PAstDiag): Report {.inline.} =
       adSemAlignRequiresPowerOfTwo,
       adSemNoReturnHasReturn,
       adSemMisplacedDeprecation,
-      adSemFatalError,
       adSemNoUnionForJs,
       adSemBitsizeRequiresPositive,
       adSemExperimentalRequiresToplevel,
@@ -3428,6 +3427,13 @@ func astDiagToLegacyReport(conf: ConfigRef, diag: PAstDiag): Report {.inline.} =
         kind: rsemPragmaRecursiveDependency,
         sym: diag.userPragma,
         ast: diag.wrongNode)
+  of adSemFatalError:
+    semRep = SemReport(
+        location: some diag.location,
+        reportInst: diag.instLoc.toReportLineInfo,
+        kind: rsemFatalError,
+        str: diag.errmsg,
+        ast: diag.wrongNode)
   of adSemCustomUserError:
     semRep = SemReport(
         location: some diag.location,

compiler/front/msgs.nim

@@ -36,7 +36,7 @@ from compiler/ast/reports_base_sem import ReportContext, ReportContextKind
 
 # when you have data where it belongs, it's easy to see this stuff... should
 # `msgs` really depend upon `SemReport`?
-from compiler/ast/reports_sem import SemReport
+from compiler/ast/reports_sem import SemReport, severity
 
 export InstantiationInfo
 export TErrorHandling
@@ -294,7 +294,8 @@ proc errorActions(
     eh: TErrorHandling
   ): tuple[action: TErrorHandling, withTrace: bool] =
   result = (doNothing, false)
-  if conf.isCompilerFatal(report):
+  if conf.isCompilerFatal(report) or
+      (report.category == repSem and report.semReport.severity == rsevFatal):
     # Fatal message such as ICE (internal compiler), errFatal,
     result = (doAbort, true)
   elif conf.isCodeError(report):

compiler/sem/pragmas.nim

@@ -1556,7 +1556,12 @@ proc applyStmtPragma(c: PContext, owner: PSym, it: PNode, k: TSpecialWord): PNod
           result = c.config.newError(
             it, PAstDiag(kind: adSemCustomUserError, errmsg: s.strVal))
   of wFatal:
-    result = c.config.newError(it, PAstDiag(kind: adSemFatalError))
+    let (s, err) = strLitToStrOrErr(c, it)
+    result =
+      if err.isNil:
+        c.config.newError(it, PAstDiag(kind: adSemFatalError, errmsg: s))
+      else:
+        err
   of wDefine:
     result = processDefine(c, it)
   of wUndef:

tests/pragmas/tfatal.nim

@@ -0,0 +1,4 @@
+discard """
+  errormsg: "user message"
+"""
+{.fatal:"user message".}