drnim: tiny progress (#13882)

* drnim: tiny progress
* refactoring complete
* drnim: prove .ensures annotations
* Moved code around to avoid code duplication
* drnim: first implementation of the 'old' property
* drnim: be precise about the assignment statement
* first implementation of --assumeUnique
* progress on forall/exists handling

compiler/ast.nim

@@ -218,7 +218,7 @@ type
     nkEnumFieldDef,       # `ident = expr` in an enumeration
     nkArgList,            # argument list
     nkPattern,            # a special pattern; used for matching
-    nkHiddenTryStmt,      # token used for interpretation
+    nkHiddenTryStmt,      # a hidden try statement
     nkClosure,            # (prc, env)-pair (internally used for code gen)
     nkGotoState,          # used for the state machine (for iterators)
     nkState,              # give a label to a code section (for iterators)

compiler/cmdlinehelper.nim

@@ -11,10 +11,24 @@
 
 import
   options, idents, nimconf, extccomp, commands, msgs,
-  lineinfos, modulegraphs, condsyms, os, pathutils
+  lineinfos, modulegraphs, condsyms, os, pathutils, parseopt
 
 from strutils import normalize
 
+proc prependCurDir*(f: AbsoluteFile): AbsoluteFile =
+  when defined(unix):
+    if os.isAbsolute(f.string): result = f
+    else: result = AbsoluteFile("./" & f.string)
+  else:
+    result = f
+
+proc addCmdPrefix*(result: var string, kind: CmdLineKind) =
+  # consider moving this to std/parseopt
+  case kind
+  of cmdLongOption: result.add "--"
+  of cmdShortOption: result.add "-"
+  of cmdArgument, cmdEnd: discard
+
 type
   NimProg* = ref object
     suggestMode*: bool

compiler/guards.nim

@@ -84,8 +84,8 @@ proc interestingCaseExpr*(m: PNode): bool = isLetLocation(m, true)
 
 type
   Operators* = object
-    opNot, opContains, opLe, opLt, opAnd, opOr, opIsNil, opEq: PSym
-    opAdd, opSub, opMul, opDiv, opLen: PSym
+    opNot*, opContains*, opLe*, opLt*, opAnd*, opOr*, opIsNil*, opEq*: PSym
+    opAdd*, opSub*, opMul*, opDiv*, opLen*: PSym
 
 proc initOperators*(g: ModuleGraph): Operators =
   result.opLe = createMagic(g, "<=", mLeI)
@@ -156,12 +156,12 @@ proc neg(n: PNode; o: Operators): PNode =
     result[0] = newSymNode(o.opNot)
     result[1] = n
 
-proc buildCall(op: PSym; a: PNode): PNode =
+proc buildCall*(op: PSym; a: PNode): PNode =
   result = newNodeI(nkCall, a.info, 2)
   result[0] = newSymNode(op)
   result[1] = a
 
-proc buildCall(op: PSym; a, b: PNode): PNode =
+proc buildCall*(op: PSym; a, b: PNode): PNode =
   result = newNodeI(nkInfix, a.info, 3)
   result[0] = newSymNode(op)
   result[1] = a
@@ -464,7 +464,7 @@ proc hasSubTree(n, x: PNode): bool =
     for i in 0..n.safeLen-1:
       if hasSubTree(n[i], x): return true
 
-proc invalidateFacts*(m: var TModel, n: PNode) =
+proc invalidateFacts*(s: var seq[PNode], n: PNode) =
   # We are able to guard local vars (as opposed to 'let' variables)!
   # 'while p != nil: f(p); p = p.next'
   # This is actually quite easy to do:
@@ -482,8 +482,11 @@ proc invalidateFacts*(m: var TModel, n: PNode) =
   # The same mechanism could be used for more complex data stored on the heap;
   # procs that 'write: []' cannot invalidate 'n.kind' for instance. In fact, we
   # could CSE these expressions then and help C's optimizer.
-  for i in 0..high(m.s):
-    if m.s[i] != nil and m.s[i].hasSubTree(n): m.s[i] = nil
+  for i in 0..high(s):
+    if s[i] != nil and s[i].hasSubTree(n): s[i] = nil
+
+proc invalidateFacts*(m: var TModel, n: PNode) =
+  invalidateFacts(m.s, n)
 
 proc valuesUnequal(a, b: PNode): bool =
   if a.isValue and b.isValue:

compiler/modulegraphs.nim

@@ -72,9 +72,7 @@ type
     onDefinitionResolveForward*: proc (graph: ModuleGraph; s: PSym; info: TLineInfo) {.nimcall.}
     onUsage*: proc (graph: ModuleGraph; s: PSym; info: TLineInfo) {.nimcall.}
     globalDestructors*: seq[PNode]
-    proofEngine*: proc (graph: ModuleGraph; assumptions: seq[PNode]; toProve: PNode): (bool, string) {.nimcall.}
-    requirementsCheck*: proc (graph: ModuleGraph; assumptions: seq[PNode];
-                             call, requirement: PNode): (bool, string) {.nimcall.}
+    strongSemCheck*: proc (graph: ModuleGraph; owner: PSym; body: PNode) {.nimcall.}
     compatibleProps*: proc (graph: ModuleGraph; formal, actual: PType): bool {.nimcall.}
 
   TPassContext* = object of RootObj # the pass's context

compiler/nim.nim

@@ -33,20 +33,6 @@ when defined(profiler) or defined(memProfiler):
   {.hint: "Profiling support is turned on!".}
   import nimprof
 
-proc prependCurDir(f: AbsoluteFile): AbsoluteFile =
-  when defined(unix):
-    if os.isAbsolute(f.string): result = f
-    else: result = AbsoluteFile("./" & f.string)
-  else:
-    result = f
-
-proc addCmdPrefix*(result: var string, kind: CmdLineKind) =
-  # consider moving this to std/parseopt
-  case kind
-  of cmdLongOption: result.add "--"
-  of cmdShortOption: result.add "-"
-  of cmdArgument, cmdEnd: discard
-
 proc processCmdLine(pass: TCmdLinePass, cmd: string; config: ConfigRef) =
   var p = parseopt.initOptParser(cmd)
   var argsCount = 0

compiler/pragmas.nim

@@ -53,7 +53,7 @@ const
     wDeprecated,
     wFloatChecks, wInfChecks, wNanChecks, wPragma, wEmit, wUnroll,
     wLinearScanEnd, wPatterns, wTrMacros, wEffects, wNoForward, wReorder, wComputedGoto,
-    wInjectStmt, wExperimental, wThis, wUsed, wInvariant, wAssume}
+    wInjectStmt, wExperimental, wThis, wUsed, wInvariant, wAssume, wAssert}
   lambdaPragmas* = declPragmas + {FirstCallConv..LastCallConv,
     wNoSideEffect, wSideEffect, wNoreturn, wNosinks, wDynlib, wHeader,
     wThread, wAsmNoStackFrame,

compiler/semmagic.nim

@@ -429,15 +429,29 @@ proc turnFinalizerIntoDestructor(c: PContext; orig: PSym; info: TLineInfo): PSym
   result.typ.addParam newParam
 
 proc semQuantifier(c: PContext; n: PNode): PNode =
-  checkMinSonsLen(n, 2, c.config)
+  checkSonsLen(n, 2, c.config)
   openScope(c)
-  for i in 0..n.len-2:
-    let v = newSymS(skForVar, n[i], c)
-    styleCheckDef(c.config, v)
-    onDef(n.info, v)
-    n[i] = newSymNode(v)
-    addDecl(c, v)
-  n[^1] = forceBool(c, semExprWithType(c, n[^1]))
+  result = newNodeIT(n.kind, n.info, n.typ)
+  result.add n[0]
+  let args = n[1]
+  assert args.kind == nkArgList
+  for i in 0..args.len-2:
+    let it = args[i]
+    var valid = false
+    if it.kind == nkInfix:
+      let op = considerQuotedIdent(c, it[0])
+      if op.id == ord(wIn):
+        let v = newSymS(skForVar, it[1], c)
+        styleCheckDef(c.config, v)
+        onDef(it[1].info, v)
+        let domain = semExprWithType(c, it[2], {efWantIterator})
+        v.typ = domain.typ
+        valid = true
+        addDecl(c, v)
+        result.add newTree(nkInfix, it[0], newSymNode(v), domain)
+    if not valid:
+      localError(c.config, n.info, "<quantifier> 'in' <range> expected")
+  result.add forceBool(c, semExprWithType(c, args[^1]))
   closeScope(c)
 
 proc semOld(c: PContext; n: PNode): PNode =

compiler/semparallel.nim

@@ -25,7 +25,7 @@ import
   ast, astalgo, idents, lowerings, magicsys, guards, sempass2, msgs,
   renderer, types, modulegraphs, options, spawn, lineinfos
 
-from trees import getMagic
+from trees import getMagic, isTrue, getRoot
 from strutils import `%`
 
 discard """

compiler/sempass2.nim

@@ -433,7 +433,8 @@ proc isForwardedProc(n: PNode): bool =
 proc trackPragmaStmt(tracked: PEffects, n: PNode) =
   for i in 0..<n.len:
     var it = n[i]
-    if whichPragma(it) == wEffects:
+    let pragma = whichPragma(it)
+    if pragma == wEffects:
       # list the computed effects up to here:
       listEffects(tracked)
 
@@ -664,10 +665,6 @@ proc trackBlock(tracked: PEffects, n: PNode) =
   else:
     track(tracked, n)
 
-proc isTrue*(n: PNode): bool =
-  n.kind == nkSym and n.sym.kind == skEnumField and n.sym.position != 0 or
-    n.kind == nkIntLit and n.intVal != 0
-
 proc paramType(op: PType, i: int): PType =
   if op != nil and i < op.len: result = op[i]
 
@@ -676,14 +673,6 @@ proc cstringCheck(tracked: PEffects; n: PNode) =
       a.typ.kind == tyString and a.kind notin {nkStrLit..nkTripleStrLit}):
     message(tracked.config, n.info, warnUnsafeCode, renderTree(n))
 
-proc prove(c: PEffects; prop: PNode): bool =
-  if c.graph.proofEngine != nil:
-    let (success, m) = c.graph.proofEngine(c.graph, c.guards.s,
-      canon(prop, c.guards.o))
-    if not success:
-      message(c.config, prop.info, warnStaticIndexCheck, "cannot prove: " & $prop & m)
-    result = success
-
 proc patchResult(c: PEffects; n: PNode) =
   if n.kind == nkSym and n.sym.kind == skResult:
     let fn = c.owner
@@ -695,45 +684,18 @@ proc patchResult(c: PEffects; n: PNode) =
     for i in 0..<safeLen(n):
       patchResult(c, n[i])
 
-when defined(drnim):
-  proc requiresCheck(c: PEffects; call: PNode; op: PType) =
-    assert op.n[0].kind == nkEffectList
-    if requiresEffects < op.n[0].len:
-      let requires = op.n[0][requiresEffects]
-      if requires != nil and requires.kind != nkEmpty:
-        # we need to map the call arguments to the formal parameters used inside
-        # 'requires':
-        let (success, m) = c.graph.requirementsCheck(c.graph, c.guards.s, call, canon(requires, c.guards.o))
-        if not success:
-          message(c.config, call.info, warnStaticIndexCheck, "cannot prove: " & $requires & m)
-
-else:
-  template requiresCheck(c, n, op) = discard
-
 proc checkLe(c: PEffects; a, b: PNode) =
-  if c.graph.proofEngine != nil:
-    var cmpOp = mLeI
-    if a.typ != nil:
-      case a.typ.skipTypes(abstractInst).kind
-      of tyFloat..tyFloat128: cmpOp = mLeF64
-      of tyChar, tyUInt..tyUInt64: cmpOp = mLeU
-      else: discard
-
-    let cmp = newTree(nkInfix, newSymNode createMagic(c.graph, "<=", cmpOp), a, b)
-    cmp.info = a.info
-    discard prove(c, cmp)
-  else:
-    case proveLe(c.guards, a, b)
-    of impUnknown:
-      #for g in c.guards.s:
-      #  if g != nil: echo "I Know ", g
-      message(c.config, a.info, warnStaticIndexCheck,
-        "cannot prove: " & $a & " <= " & $b)
-    of impYes:
-      discard
-    of impNo:
-      message(c.config, a.info, warnStaticIndexCheck,
-        "can prove: " & $a & " > " & $b)
+  case proveLe(c.guards, a, b)
+  of impUnknown:
+    #for g in c.guards.s:
+    #  if g != nil: echo "I Know ", g
+    message(c.config, a.info, warnStaticIndexCheck,
+      "cannot prove: " & $a & " <= " & $b)
+  of impYes:
+    discard
+  of impNo:
+    message(c.config, a.info, warnStaticIndexCheck,
+      "can prove: " & $a & " > " & $b)
 
 proc checkBounds(c: PEffects; arr, idx: PNode) =
   checkLe(c, lowBound(c.config, arr), idx)
@@ -831,7 +793,6 @@ proc track(tracked: PEffects, n: PNode) =
         mergeEffects(tracked, effectList[exceptionEffects], n)
         mergeTags(tracked, effectList[tagEffects], n)
         gcsafeAndSideeffectCheck()
-      requiresCheck(tracked, n, op)
     if a.kind != nkSym or a.sym.magic != mNBindSym:
       for i in 1..<n.len: trackOperand(tracked, n[i], paramType(op, i), a)
     if a.kind == nkSym and a.sym.magic in {mNew, mNewFinalize, mNewSeq}:
@@ -929,7 +890,6 @@ proc track(tracked: PEffects, n: PNode) =
   of nkWhen, nkIfStmt, nkIfExpr: trackIf(tracked, n)
   of nkBlockStmt, nkBlockExpr: trackBlock(tracked, n[1])
   of nkWhileStmt:
-    track(tracked, n[0])
     # 'while true' loop?
     if isTrue(n[0]):
       trackBlock(tracked, n[1])
@@ -938,6 +898,7 @@ proc track(tracked: PEffects, n: PNode) =
       let oldState = tracked.init.len
       let oldFacts = tracked.guards.s.len
       addFact(tracked.guards, n[0])
+      track(tracked, n[0])
       track(tracked, n[1])
       setLen(tracked.init, oldState)
       setLen(tracked.guards.s, oldFacts)
@@ -1027,12 +988,6 @@ proc track(tracked: PEffects, n: PNode) =
         enforcedGcSafety = true
       elif pragma == wNoSideEffect:
         enforceNoSideEffects = true
-      when defined(drnim):
-        if pragma == wAssume:
-          addFact(tracked.guards, pragmaList[i][1])
-        elif pragma == wInvariant or pragma == wAssert:
-          if prove(tracked, pragmaList[i][1]):
-            addFact(tracked.guards, pragmaList[i][1])
 
     if enforcedGcSafety: tracked.inEnforcedGcSafe = true
     if enforceNoSideEffects: tracked.inEnforcedNoSideEffects = true
@@ -1181,7 +1136,10 @@ proc initEffects(g: ModuleGraph; effects: PNode; s: PSym; t: var TEffects; c: PC
   t.init = @[]
   t.guards.s = @[]
   t.guards.o = initOperators(g)
-  t.currOptions = g.config.options + s.options
+  when defined(drnim):
+    t.currOptions = g.config.options + s.options - {optStaticBoundsCheck}
+  else:
+    t.currOptions = g.config.options + s.options
   t.guards.beSmart = optStaticBoundsCheck in t.currOptions
   t.locked = @[]
   t.graph = g
@@ -1237,7 +1195,6 @@ proc trackProc*(c: PContext; s: PSym, body: PNode) =
   if not isNil(ensuresSpec):
     patchResult(t, ensuresSpec)
     effects[ensuresEffects] = ensuresSpec
-    discard prove(t, ensuresSpec)
 
   if sfThread in s.flags and t.gcUnsafe:
     if optThreads in g.config.globalOptions and optThreadAnalysis in g.config.globalOptions:
@@ -1262,6 +1219,8 @@ proc trackProc*(c: PContext; s: PSym, body: PNode) =
     message(g.config, s.info, warnLockLevel,
       "declared lock level is $1, but real lock level is $2" %
         [$s.typ.lockLevel, $t.maxLockLevel])
+  when defined(drnim):
+    if c.graph.strongSemCheck != nil: c.graph.strongSemCheck(c.graph, s, body)
   when defined(useDfa):
     if s.name.s == "testp":
       dataflowAnalysis(s, body)
@@ -1277,3 +1236,5 @@ proc trackStmt*(c: PContext; module: PSym; n: PNode, isTopLevel: bool) =
   initEffects(g, effects, module, t, c)
   t.isTopLevel = isTopLevel
   track(t, n)
+  when defined(drnim):
+    if c.graph.strongSemCheck != nil: c.graph.strongSemCheck(c.graph, module, n)

compiler/spawn.nim

@@ -11,7 +11,7 @@
 
 import ast, types, idents, magicsys, msgs, options, modulegraphs,
   lowerings
-from trees import getMagic
+from trees import getMagic, getRoot
 
 proc callProc(a: PNode): PNode =
   result = newNodeI(nkCall, a.info)
@@ -74,7 +74,7 @@ proc addLocalVar(g: ModuleGraph; varSection, varInit: PNode; owner: PSym; typ: P
         varInit.add call
       else:
         varInit.add newFastAsgnStmt(newSymNode(result), v)
-    else:      
+    else:
       if useShallowCopy and typeNeedsNoDeepCopy(typ) or optTinyRtti in g.config.globalOptions:
         varInit.add newFastAsgnStmt(newSymNode(result), v)
       else:
@@ -196,7 +196,7 @@ proc createCastExpr(argsParam: PSym; objType: PType): PNode =
   result.typ = newType(tyPtr, objType.owner)
   result.typ.rawAddSon(objType)
 
-proc setupArgsForConcurrency(g: ModuleGraph; n: PNode; objType: PType; 
+proc setupArgsForConcurrency(g: ModuleGraph; n: PNode; objType: PType;
                              owner: PSym; scratchObj: PSym,
                              castExpr, call,
                              varSection, varInit, result: PNode) =
@@ -221,23 +221,6 @@ proc setupArgsForConcurrency(g: ModuleGraph; n: PNode; objType: PType;
                            indirectAccess(castExpr, field, n.info))
     call.add(newSymNode(temp))
 
-proc getRoot*(n: PNode): PSym =
-  ## ``getRoot`` takes a *path* ``n``. A path is an lvalue expression
-  ## like ``obj.x[i].y``. The *root* of a path is the symbol that can be
-  ## determined as the owner; ``obj`` in the example.
-  case n.kind
-  of nkSym:
-    if n.sym.kind in {skVar, skResult, skTemp, skLet, skForVar}:
-      result = n.sym
-  of nkDotExpr, nkBracketExpr, nkHiddenDeref, nkDerefExpr,
-      nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr:
-    result = getRoot(n[0])
-  of nkHiddenStdConv, nkHiddenSubConv, nkConv:
-    result = getRoot(n[1])
-  of nkCallKinds:
-    if getMagic(n) == mSlice: result = getRoot(n[1])
-  else: discard
-
 proc setupArgsForParallelism(g: ModuleGraph; n: PNode; objType: PType;
                              owner: PSym; scratchObj: PSym;
                              castExpr, call,
@@ -344,7 +327,7 @@ proc wrapProcForSpawn*(g: ModuleGraph; owner: PSym; spawnExpr: PNode; retType: P
     if {tfThread, tfNoSideEffect} * n[0].typ.flags == {}:
       localError(g.config, n.info, "'spawn' takes a GC safe call expression")
 
-  var fn = n[0] 
+  var fn = n[0]
   let
     name = (if fn.kind == nkSym: fn.sym.name.s else: genPrefix) & "Wrapper"
     wrapperProc = newSym(skProc, getIdent(g.cache, name), owner, fn.info, g.config.options)