WIP: 'feature' pragma

doc/tags.md

@@ -211,6 +211,7 @@
 | `(assume X)` | NimonyPragma, NimonyStmt | `assume` pragma |
 | `(assert X)` | NimonyPragma, NimonyStmt | `assert` pragma |
 | `(build X)`; `(build STR STR STR)` | NimonyPragma, NifIndexKind | `build` pragma |
+| `(feature STR)` | NimonyPragma | `feature` pragma |
 | `(string)` | NimonyPragma | `string` pragma |
 | `(view)` | NimonyPragma | `view` pragma |
 | `(quoted X+)` | NimonyExpr, NiflerKind | name in backticks |

src/hexer/nifcgen.nim

@@ -783,7 +783,7 @@ proc parsePragmas(c: var EContext; n: var Cursor): CollectedPragmas =
           inc n
         of RequiresP, EnsuresP, StringP, RaisesP, ErrorP, AssumeP, AssertP, ReportP,
            TagsP, DeprecatedP, SideEffectP, KeepOverflowFlagP, SemanticsP,
-           BaseP, FinalP, PragmaP, CursorP, PassiveP, PluginP:
+           BaseP, FinalP, PragmaP, CursorP, PassiveP, PluginP, FeatureP:
           skip n
           continue
         of BuildP, EmitP, PushP, PopP, PassLP:

src/models/nimony_tags.nim

@@ -310,6 +310,7 @@ type
     AssumeP = (ord(AssumeTagId), "assume")  ## `assume` pragma
     AssertP = (ord(AssertTagId), "assert")  ## `assert` pragma
     BuildP = (ord(BuildTagId), "build")  ## `build` pragma
+    FeatureP = (ord(FeatureTagId), "feature")  ## `feature` pragma
     StringP = (ord(StringTagId), "string")  ## `string` pragma
     ViewP = (ord(ViewTagId), "view")  ## `view` pragma
     InjectP = (ord(InjectTagId), "inject")  ## `inject` pragma
@@ -333,7 +334,7 @@ type
     PassLP = (ord(PassLTagId), "passL")  ## `passL` pragma adds options to the backend linker
 
 proc rawTagIsNimonyPragma*(raw: TagEnum): bool {.inline.} =
-  raw in {CursorTagId, EmitTagId, UnionTagId, InlineTagId, NoinlineTagId, ClosureTagId, VarargsTagId, SelectanyTagId, AlignTagId, BitsTagId, NodeclTagId, RaisesTagId, UntypedTagId, MagicTagId, ImportcTagId, ImportcppTagId, DynlibTagId, ExportcTagId, HeaderTagId, ThreadvarTagId, GlobalTagId, DiscardableTagId, NoreturnTagId, BorrowTagId, NoSideEffectTagId, NodestroyTagId, PluginTagId, BycopyTagId, ByrefTagId, NoinitTagId, RequiresTagId, EnsuresTagId, AssumeTagId, AssertTagId, BuildTagId, StringTagId, ViewTagId, InjectTagId, GensymTagId, ErrorTagId, ReportTagId, TagsTagId, DeprecatedTagId, SideEffectTagId, KeepOverflowFlagTagId, SemanticsTagId, InheritableTagId, BaseTagId, PureTagId, FinalTagId, PragmaTagId, PackedTagId, PassiveTagId, PushTagId, PopTagId, PassLTagId}
+  raw in {CursorTagId, EmitTagId, UnionTagId, InlineTagId, NoinlineTagId, ClosureTagId, VarargsTagId, SelectanyTagId, AlignTagId, BitsTagId, NodeclTagId, RaisesTagId, UntypedTagId, MagicTagId, ImportcTagId, ImportcppTagId, DynlibTagId, ExportcTagId, HeaderTagId, ThreadvarTagId, GlobalTagId, DiscardableTagId, NoreturnTagId, BorrowTagId, NoSideEffectTagId, NodestroyTagId, PluginTagId, BycopyTagId, ByrefTagId, NoinitTagId, RequiresTagId, EnsuresTagId, AssumeTagId, AssertTagId, BuildTagId, FeatureTagId, StringTagId, ViewTagId, InjectTagId, GensymTagId, ErrorTagId, ReportTagId, TagsTagId, DeprecatedTagId, SideEffectTagId, KeepOverflowFlagTagId, SemanticsTagId, InheritableTagId, BaseTagId, PureTagId, FinalTagId, PragmaTagId, PackedTagId, PassiveTagId, PushTagId, PopTagId, PassLTagId}
 
 type
   NimonySym* = enum

src/models/tags.nim

@@ -214,6 +214,7 @@ type
     AssumeTagId
     AssertTagId
     BuildTagId
+    FeatureTagId
     StringTagId
     ViewTagId
     QuotedTagId
@@ -520,96 +521,97 @@ const
     ("assume", 209),
     ("assert", 210),
     ("build", 211),
-    ("string", 212),
-    ("view", 213),
-    ("quoted", 214),
-    ("hderef", 215),
-    ("ddot", 216),
-    ("haddr", 217),
-    ("newref", 218),
-    ("newobj", 219),
-    ("tup", 220),
-    ("tupconstr", 221),
-    ("setconstr", 222),
-    ("tabconstr", 223),
-    ("ashr", 224),
-    ("baseobj", 225),
-    ("hconv", 226),
-    ("dconv", 227),
-    ("callstrlit", 228),
-    ("infix", 229),
-    ("prefix", 230),
-    ("hcall", 231),
-    ("compiles", 232),
-    ("declared", 233),
-    ("defined", 234),
-    ("astToStr", 235),
-    ("instanceof", 236),
-    ("proccall", 237),
-    ("high", 238),
-    ("low", 239),
-    ("typeof", 240),
-    ("unpack", 241),
-    ("fields", 242),
-    ("fieldpairs", 243),
-    ("enumtostr", 244),
-    ("ismainmodule", 245),
-    ("defaultobj", 246),
-    ("defaulttup", 247),
-    ("defaultdistinct", 248),
-    ("delay", 249),
-    ("expr", 250),
-    ("do", 251),
-    ("arrat", 252),
-    ("tupat", 253),
-    ("plusset", 254),
-    ("minusset", 255),
-    ("mulset", 256),
-    ("xorset", 257),
-    ("eqset", 258),
-    ("leset", 259),
-    ("ltset", 260),
-    ("inset", 261),
-    ("card", 262),
-    ("emove", 263),
-    ("destroy", 264),
-    ("dup", 265),
-    ("copy", 266),
-    ("wasmoved", 267),
-    ("sinkh", 268),
-    ("trace", 269),
-    ("errv", 270),
-    ("staticstmt", 271),
-    ("bind", 272),
-    ("mixin", 273),
-    ("using", 274),
-    ("asm", 275),
-    ("defer", 276),
-    ("index", 277),
-    ("public", 278),
-    ("private", 279),
-    ("inject", 280),
-    ("gensym", 281),
-    ("error", 282),
-    ("report", 283),
-    ("tags", 284),
-    ("deprecated", 285),
-    ("sideEffect", 286),
-    ("keepOverflowFlag", 287),
-    ("semantics", 288),
-    ("inheritable", 289),
-    ("base", 290),
-    ("pure", 291),
-    ("final", 292),
-    ("pragma", 293),
-    ("internalTypeName", 294),
-    ("internalFieldPairs", 295),
-    ("failed", 296),
-    ("is", 297),
-    ("envp", 298),
-    ("packed", 299),
-    ("passive", 300),
-    ("push", 301),
-    ("pop", 302),
-    ("passL", 303)
+    ("feature", 212),
+    ("string", 213),
+    ("view", 214),
+    ("quoted", 215),
+    ("hderef", 216),
+    ("ddot", 217),
+    ("haddr", 218),
+    ("newref", 219),
+    ("newobj", 220),
+    ("tup", 221),
+    ("tupconstr", 222),
+    ("setconstr", 223),
+    ("tabconstr", 224),
+    ("ashr", 225),
+    ("baseobj", 226),
+    ("hconv", 227),
+    ("dconv", 228),
+    ("callstrlit", 229),
+    ("infix", 230),
+    ("prefix", 231),
+    ("hcall", 232),
+    ("compiles", 233),
+    ("declared", 234),
+    ("defined", 235),
+    ("astToStr", 236),
+    ("instanceof", 237),
+    ("proccall", 238),
+    ("high", 239),
+    ("low", 240),
+    ("typeof", 241),
+    ("unpack", 242),
+    ("fields", 243),
+    ("fieldpairs", 244),
+    ("enumtostr", 245),
+    ("ismainmodule", 246),
+    ("defaultobj", 247),
+    ("defaulttup", 248),
+    ("defaultdistinct", 249),
+    ("delay", 250),
+    ("expr", 251),
+    ("do", 252),
+    ("arrat", 253),
+    ("tupat", 254),
+    ("plusset", 255),
+    ("minusset", 256),
+    ("mulset", 257),
+    ("xorset", 258),
+    ("eqset", 259),
+    ("leset", 260),
+    ("ltset", 261),
+    ("inset", 262),
+    ("card", 263),
+    ("emove", 264),
+    ("destroy", 265),
+    ("dup", 266),
+    ("copy", 267),
+    ("wasmoved", 268),
+    ("sinkh", 269),
+    ("trace", 270),
+    ("errv", 271),
+    ("staticstmt", 272),
+    ("bind", 273),
+    ("mixin", 274),
+    ("using", 275),
+    ("asm", 276),
+    ("defer", 277),
+    ("index", 278),
+    ("public", 279),
+    ("private", 280),
+    ("inject", 281),
+    ("gensym", 282),
+    ("error", 283),
+    ("report", 284),
+    ("tags", 285),
+    ("deprecated", 286),
+    ("sideEffect", 287),
+    ("keepOverflowFlag", 288),
+    ("semantics", 289),
+    ("inheritable", 290),
+    ("base", 291),
+    ("pure", 292),
+    ("final", 293),
+    ("pragma", 294),
+    ("internalTypeName", 295),
+    ("internalFieldPairs", 296),
+    ("failed", 297),
+    ("is", 298),
+    ("envp", 299),
+    ("packed", 300),
+    ("passive", 301),
+    ("push", 302),
+    ("pop", 303),
+    ("passL", 304)
   ]

src/nimony/features.nim

@@ -0,0 +1,19 @@
+#       Nimony
+# (c) Copyright 2024 Andreas Rumpf
+#
+# See the file "license.txt", included in this
+# distribution, for details about the copyright.
+
+
+type
+  Feature* = enum ## A feature is a language mode that is purely frontend-related.
+                  ## A `CheckMode` is something Hexer needs to know about too.
+    InvalidFeature
+    NotnilFeature
+
+proc parseFeature*(s: string): Feature =
+  case s
+  of "notnil": NotnilFeature
+  else: InvalidFeature
+
+

src/nimony/sem.nim

@@ -13,7 +13,7 @@ from std/os import changeFileExt, getCurrentDir
 include nifprelude
 import nimony_model, symtabs, builtintypes, decls, symparser, asthelpers,
   programs, sigmatch, magics, reporters, nifconfig, nifindexes,
-  intervals, xints, typeprops,
+  intervals, xints, typeprops, features,
   semdata, sembasics, semos, expreval, semborrow, enumtostr, derefs, sizeof, renderer,
   semuntyped, contracts, vtables_frontend, module_plugins, deferstmts, pragmacanon
 
@@ -1333,6 +1333,21 @@ proc semPragma(c: var SemContext; n: var Cursor; crucial: var CrucialPragma; kin
     else:
       buildErr c, n.info, "`magic` pragma takes a string literal"
     c.dest.addParRi()
+  of FeatureP:
+    c.dest.add parLeToken(FeatureP, n.info)
+    inc n
+    if hasParRi and n.kind in {StringLit, Ident}:
+      let feature = parseFeature(pool.strings[n.litId])
+      if feature == InvalidFeature:
+        buildErr c, n.info, "unknown `feature`"
+      else:
+        c.features.incl feature
+      takeToken c, n
+    elif n.exprKind == ErrX:
+      c.dest.addSubtree n
+    else:
+      buildErr c, n.info, "`feature` pragma takes a string literal"
+    c.dest.addParRi()
   of ErrorP, ReportP, DeprecatedP:
     crucial.flags.incl pk
     c.dest.add parLeToken(pk, n.info)

src/nimony/semdata.nim

@@ -6,10 +6,10 @@
 
 ## Types required by semantic checking.
 
 import std / [tables, sets, os, syncio, formatfloat, assertions]
 include nifprelude
 import nimony_model, symtabs, builtintypes, decls, symparser,
-  programs, magics, reporters, nifconfig, nifindexes
+  programs, magics, reporters, nifconfig, nifindexes, features
 
 import ".." / gear2 / modnames
 
@@ -92,6 +92,7 @@
     instantiatedProcs*: Table[(SymId, string), SymId]
     thisModuleSuffix*: string
     moduleFlags*: set[ModuleFlag]
+    features*: set[Feature]
     processedModules*: Table[string, SymId] # suffix to sym
     usedTypevars*: int
     phase*: SemPhase