compiler warns when you use GC'ed memory and '--gc:none'

compiler/ccgexprs.nim

@@ -847,6 +847,9 @@ proc genEcho(p: BProc, n: PNode) =
   linefmt(p, cpsStmts, "printf($1$2);$n",
           makeCString(repeatStr(n.len-1, "%s") & tnl), args)
 
+proc gcUsage(n: PNode) =
+  if gSelectedGC == gcNone: message(n.info, warnGcMem, n.renderTree)
+
 proc genStrConcat(p: BProc, e: PNode, d: var TLoc) =
   #   <Nimrod code>
   #   s = 'Hello ' & name & ', how do you feel?' & 'z'
@@ -888,6 +891,7 @@ proc genStrConcat(p: BProc, e: PNode, d: var TLoc) =
     keepAlive(p, tmp)
   else:
     genAssignment(p, d, tmp, {needToKeepAlive}) # no need for deep copying
+  gcUsage(e)
 
 proc genStrAppend(p: BProc, e: PNode, d: var TLoc) =
   #  <Nimrod code>
@@ -925,6 +929,7 @@ proc genStrAppend(p: BProc, e: PNode, d: var TLoc) =
           rdLoc(dest), lens, toRope(L))
   keepAlive(p, dest)
   app(p.s(cpsStmts), appends)
+  gcUsage(e)
 
 proc genSeqElemAppend(p: BProc, e: PNode, d: var TLoc) =
   # seq &= x  -->
@@ -945,6 +950,7 @@ proc genSeqElemAppend(p: BProc, e: PNode, d: var TLoc) =
   initLoc(dest, locExpr, b.t, OnHeap)
   dest.r = rfmt(nil, "$1->data[$1->$2-1]", rdLoc(a), lenField())
   genAssignment(p, dest, b, {needToCopy, afDestIsNil})
+  gcUsage(e)
 
 proc genReset(p: BProc, n: PNode) = 
   var a: TLoc
@@ -987,6 +993,7 @@ proc genNew(p: BProc, e: PNode) =
     rawGenNew(p, a, se.rdLoc)
   else:
     rawGenNew(p, a, nil)
+  gcUsage(e)
 
 proc genNewSeqAux(p: BProc, dest: TLoc, length: PRope) =
   let seqtype = skipTypes(dest.t, abstractVarRange)
@@ -1010,6 +1017,7 @@ proc genNewSeq(p: BProc, e: PNode) =
   initLocExpr(p, e.sons[1], a)
   initLocExpr(p, e.sons[2], b)
   genNewSeqAux(p, a, b.rdLoc)
+  gcUsage(e)
   
 proc genObjConstr(p: BProc, e: PNode, d: var TLoc) =
   var tmp: TLoc
@@ -1021,6 +1029,7 @@ proc genObjConstr(p: BProc, e: PNode, d: var TLoc) =
     rawGenNew(p, tmp, nil)
     t = t.sons[0].skipTypes(abstractInst)
     r = ropef("(*$1)", r)
+    gcUsage(e)
   discard getTypeDesc(p.module, t)
   for i in 1 .. <e.len:
     let it = e.sons[i]
@@ -1059,6 +1068,7 @@ proc genSeqConstr(p: BProc, t: PNode, d: var TLoc) =
     arr.r = rfmt(nil, "$1->data[$2]", rdLoc(d), intLiteral(i))
     arr.s = OnHeap            # we know that sequences are on the heap
     expr(p, t.sons[i], arr)
+  gcUsage(t)
 
 proc genArrToSeq(p: BProc, t: PNode, d: var TLoc) =
   var elem, a, arr: TLoc
@@ -1099,6 +1109,7 @@ proc genNewFinalize(p: BProc, e: PNode) =
   genAssignment(p, a, b, {needToKeepAlive})  # set the object type:
   bt = skipTypes(refType.sons[0], abstractRange)
   genObjectInit(p, cpsStmts, bt, a, false)
+  gcUsage(e)
 
 proc genOf(p: BProc, x: PNode, typ: PType, d: var TLoc) =
   var a: TLoc
@@ -1176,6 +1187,7 @@ proc genRepr(p: BProc, e: PNode, d: var TLoc) =
   else:
     putIntoDest(p, d, e.typ, ropecg(p.module, "#reprAny($1, $2)",
                                    [addrLoc(a), genTypeInfo(p.module, t)]))
+  gcUsage(e)
 
 proc genGetTypeInfo(p: BProc, e: PNode, d: var TLoc) =
   var t = skipTypes(e.sons[1].typ, abstractVarRange)
@@ -1187,6 +1199,7 @@ proc genDollar(p: BProc, n: PNode, d: var TLoc, frmt: string) =
   a.r = ropecg(p.module, frmt, [rdLoc(a)])
   if d.k == locNone: getTemp(p, n.typ, d)
   genAssignment(p, d, a, {needToKeepAlive})
+  gcUsage(n)
 
 proc genArrayLen(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
   var a = e.sons[1]
@@ -1227,10 +1240,12 @@ proc genSetLengthSeq(p: BProc, e: PNode, d: var TLoc) =
       rdLoc(a), rdLoc(b), getTypeDesc(p.module, t),
       getTypeDesc(p.module, t.sons[0])])
   keepAlive(p, a)
+  gcUsage(e)
 
 proc genSetLengthStr(p: BProc, e: PNode, d: var TLoc) =
   binaryStmt(p, e, d, "$1 = #setLengthStr($1, $2);$n")
   keepAlive(p, d)
+  gcUsage(e)
 
 proc genSwap(p: BProc, e: PNode, d: var TLoc) =
   # swap(a, b) -->
@@ -1462,6 +1477,7 @@ proc convCStrToStr(p: BProc, n: PNode, d: var TLoc) =
   initLocExpr(p, n.sons[0], a)
   putIntoDest(p, d, skipTypes(n.typ, abstractVar),
               ropecg(p.module, "#cstrToNimstr($1)", [rdLoc(a)]))
+  gcUsage(n)
 
 proc genStrEquals(p: BProc, e: PNode, d: var TLoc) =
   var x: TLoc

compiler/vmgen.nim

@@ -953,7 +953,7 @@ proc genAsgn(c: PCtx; le, ri: PNode; requiresCopy: bool) =
         c.gABx(le, whichAsgnOpc(le, opcWrGlobal), tmp, s.position)
     else:
       internalAssert s.position > 0 or (s.position == 0 and
-                                        s.kind in {skParam, skResult})
+                                        s.kind in {skParam,skResult,skForVar})
       var dest: TRegister = s.position + ord(s.kind == skParam)
       gen(c, ri, dest)
   else:
@@ -1014,7 +1014,8 @@ proc genRdVar(c: PCtx; n: PNode; dest: var TDest) =
     else:
       c.gABx(n, opcLdGlobal, dest, s.position)
   else:
-    if s.position > 0 or (s.position == 0 and s.kind in {skParam, skResult}):
+    if s.position > 0 or (s.position == 0 and
+                          s.kind in {skParam,skResult,skForVar}):
       if dest < 0:
         dest = s.position + ord(s.kind == skParam)
       else:

lib/system/mmdisp.nim

@@ -114,10 +114,10 @@ when defined(boehmgc):
     proc alloc0(size: int): pointer =
       result = alloc(size)
       zeroMem(result, size)
-    proc realloc(p: Pointer, newsize: int): pointer =
+    proc realloc(p: pointer, newsize: int): pointer =
       result = boehmRealloc(p, newsize)
       if result == nil: raiseOutOfMem()
-    proc dealloc(p: Pointer) = boehmDealloc(p)
+    proc dealloc(p: pointer) = boehmDealloc(p)
     
     proc allocShared(size: int): pointer =
       result = boehmAlloc(size)
@@ -125,26 +125,26 @@ when defined(boehmgc):
     proc allocShared0(size: int): pointer =
       result = alloc(size)
       zeroMem(result, size)
-    proc reallocShared(p: Pointer, newsize: int): pointer =
+    proc reallocShared(p: pointer, newsize: int): pointer =
       result = boehmRealloc(p, newsize)
       if result == nil: raiseOutOfMem()
-    proc deallocShared(p: Pointer) = boehmDealloc(p)
+    proc deallocShared(p: pointer) = boehmDealloc(p)
 
     #boehmGCincremental()
 
     proc GC_disable() = boehmGC_disable()
     proc GC_enable() = boehmGC_enable()
     proc GC_fullCollect() = boehmGCfullCollect()
-    proc GC_setStrategy(strategy: TGC_Strategy) = nil
+    proc GC_setStrategy(strategy: TGC_Strategy) = discard
-    proc GC_enableMarkAndSweep() = nil
+    proc GC_enableMarkAndSweep() = discard
-    proc GC_disableMarkAndSweep() = nil
+    proc GC_disableMarkAndSweep() = discard
     proc GC_getStatistics(): string = return ""
     
     proc getOccupiedMem(): int = return boehmGetHeapSize()-boehmGetFreeBytes()
     proc getFreeMem(): int = return boehmGetFreeBytes()
     proc getTotalMem(): int = return boehmGetHeapSize()
 
-    proc setStackBottom(theStackBottom: pointer) = nil
+    proc setStackBottom(theStackBottom: pointer) = discard
 
   proc initGC() = 
     when defined(macosx): boehmGCinit()
@@ -160,8 +160,8 @@ when defined(boehmgc):
   proc growObj(old: pointer, newsize: int): pointer =
     result = realloc(old, newsize)
 
-  proc nimGCref(p: pointer) {.compilerproc, inline.} = nil
+  proc nimGCref(p: pointer) {.compilerproc, inline.} = discard
-  proc nimGCunref(p: pointer) {.compilerproc, inline.} = nil
+  proc nimGCunref(p: pointer) {.compilerproc, inline.} = discard
   
   proc unsureAsgnRef(dest: ppointer, src: pointer) {.compilerproc, inline.} =
     dest[] = src
@@ -173,15 +173,15 @@ when defined(boehmgc):
   type
     TMemRegion = object {.final, pure.}
   
-  proc Alloc(r: var TMemRegion, size: int): pointer =
+  proc alloc(r: var TMemRegion, size: int): pointer =
     result = boehmAlloc(size)
     if result == nil: raiseOutOfMem()
-  proc Alloc0(r: var TMemRegion, size: int): pointer =
+  proc alloc0(r: var TMemRegion, size: int): pointer =
     result = alloc(size)
     zeroMem(result, size)
-  proc Dealloc(r: var TMemRegion, p: Pointer) = boehmDealloc(p)  
+  proc dealloc(r: var TMemRegion, p: Pointer) = boehmDealloc(p)  
-  proc deallocOsPages(r: var TMemRegion) {.inline.} = nil
+  proc deallocOsPages(r: var TMemRegion) {.inline.} = discard
-  proc deallocOsPages() {.inline.} = nil
+  proc deallocOsPages() {.inline.} = discard
 
   include "system/cellsets"
 elif defined(nogc) and defined(useMalloc):
@@ -193,10 +193,10 @@ elif defined(nogc) and defined(useMalloc):
     proc alloc0(size: int): pointer =
       result = alloc(size)
       zeroMem(result, size)
-    proc realloc(p: Pointer, newsize: int): pointer =
+    proc realloc(p: pointer, newsize: int): pointer =
       result = crealloc(p, newsize)
       if result == nil: raiseOutOfMem()
-    proc dealloc(p: Pointer) = cfree(p)
+    proc dealloc(p: pointer) = cfree(p)
     
     proc allocShared(size: int): pointer =
       result = cmalloc(size)
@@ -204,26 +204,26 @@ elif defined(nogc) and defined(useMalloc):
     proc allocShared0(size: int): pointer =
       result = alloc(size)
       zeroMem(result, size)
-    proc reallocShared(p: Pointer, newsize: int): pointer =
+    proc reallocShared(p: pointer, newsize: int): pointer =
       result = crealloc(p, newsize)
       if result == nil: raiseOutOfMem()
-    proc deallocShared(p: Pointer) = cfree(p)
+    proc deallocShared(p: pointer) = cfree(p)
 
-    proc GC_disable() = nil
+    proc GC_disable() = discard
-    proc GC_enable() = nil
+    proc GC_enable() = discard
-    proc GC_fullCollect() = nil
+    proc GC_fullCollect() = discard
-    proc GC_setStrategy(strategy: TGC_Strategy) = nil
+    proc GC_setStrategy(strategy: TGC_Strategy) = discard
-    proc GC_enableMarkAndSweep() = nil
+    proc GC_enableMarkAndSweep() = discard
-    proc GC_disableMarkAndSweep() = nil
+    proc GC_disableMarkAndSweep() = discard
     proc GC_getStatistics(): string = return ""
     
-    proc getOccupiedMem(): int = nil
+    proc getOccupiedMem(): int = discard
-    proc getFreeMem(): int = nil
+    proc getFreeMem(): int = discard
-    proc getTotalMem(): int = nil
+    proc getTotalMem(): int = discard
     
-    proc setStackBottom(theStackBottom: pointer) = nil
+    proc setStackBottom(theStackBottom: pointer) = discard
 
-  proc initGC() = nil
+  proc initGC() = discard
 
   proc newObj(typ: PNimType, size: int): pointer {.compilerproc.} =
     result = alloc(size)
@@ -235,8 +235,8 @@ elif defined(nogc) and defined(useMalloc):
   proc growObj(old: pointer, newsize: int): pointer =
     result = realloc(old, newsize)
 
-  proc nimGCref(p: pointer) {.compilerproc, inline.} = nil
+  proc nimGCref(p: pointer) {.compilerproc, inline.} = discard
-  proc nimGCunref(p: pointer) {.compilerproc, inline.} = nil
+  proc nimGCunref(p: pointer) {.compilerproc, inline.} = discard
   
   proc unsureAsgnRef(dest: ppointer, src: pointer) {.compilerproc, inline.} =
     dest[] = src
@@ -248,13 +248,13 @@ elif defined(nogc) and defined(useMalloc):
   type
     TMemRegion = object {.final, pure.}
   
-  proc Alloc(r: var TMemRegion, size: int): pointer =
+  proc alloc(r: var TMemRegion, size: int): pointer =
     result = alloc(size)
-  proc Alloc0(r: var TMemRegion, size: int): pointer =
+  proc alloc0(r: var TMemRegion, size: int): pointer =
     result = alloc0(size)
-  proc Dealloc(r: var TMemRegion, p: Pointer) = Dealloc(p)
+  proc dealloc(r: var TMemRegion, p: pointer) = dealloc(p)
-  proc deallocOsPages(r: var TMemRegion) {.inline.} = nil
+  proc deallocOsPages(r: var TMemRegion) {.inline.} = discard
-  proc deallocOsPages() {.inline.} = nil
+  proc deallocOsPages() {.inline.} = discard
 
 elif defined(nogc):
   # Even though we don't want the GC, we cannot simply use C's memory manager
@@ -268,13 +268,13 @@ elif defined(nogc):
   
   include "system/alloc"
 
-  proc initGC() = nil
+  proc initGC() = discard
-  proc GC_disable() = nil
+  proc GC_disable() = discard
-  proc GC_enable() = nil
+  proc GC_enable() = discard
-  proc GC_fullCollect() = nil
+  proc GC_fullCollect() = discard
-  proc GC_setStrategy(strategy: TGC_Strategy) = nil
+  proc GC_setStrategy(strategy: TGC_Strategy) = discard
-  proc GC_enableMarkAndSweep() = nil
+  proc GC_enableMarkAndSweep() = discard
-  proc GC_disableMarkAndSweep() = nil
+  proc GC_disableMarkAndSweep() = discard
   proc GC_getStatistics(): string = return ""
   
   
@@ -287,9 +287,9 @@ elif defined(nogc):
   proc growObj(old: pointer, newsize: int): pointer =
     result = realloc(old, newsize)
 
-  proc setStackBottom(theStackBottom: pointer) = nil
+  proc setStackBottom(theStackBottom: pointer) = discard
-  proc nimGCref(p: pointer) {.compilerproc, inline.} = nil
+  proc nimGCref(p: pointer) {.compilerproc, inline.} = discard
-  proc nimGCunref(p: pointer) {.compilerproc, inline.} = nil
+  proc nimGCunref(p: pointer) {.compilerproc, inline.} = discard
   
   proc unsureAsgnRef(dest: ppointer, src: pointer) {.compilerproc, inline.} =
     dest[] = src

todo.txt

@@ -3,7 +3,6 @@ version 0.9.4
 
 - test&finish first class iterators:
   * nested iterators
-- ``--gc:none`` should complain about when you use the GC
 - ensure (ref T)(a, b) works as a type conversion and type constructor
 - document new templating symbol binding rules
 - make '--implicitStatic:on' the default

web/news.txt

@@ -38,6 +38,8 @@ Changes affecting backwards compatibility
 - ``macros.dumpTree`` and ``macros.dumpLisp`` have been made ``immediate``,
   ``dumpTreeImm`` and ``dumpLispImm`` are now deprecated.
 - The ``nil`` statement has been deprecated, use an empty ``discard`` instead.
+- ``sockets.select`` now prunes sockets that are **not** ready from the list
+  of sockets given to it.
 
 
 Compiler Additions
@@ -54,6 +56,7 @@ Compiler Additions
 - The old evaluation engine has been replaced by a proper register based
   virtual machine. This fixes numerous bugs for ``nimrod i`` and for macro
   evaluation.
+- ``--gc:none`` produces warnings when code uses the GC.
 
 
 Language Additions