Cleaned up mmdisp.nim, moved implementations into lib/system/mm/ (#13254)

lib/system/mm/malloc.nim

@@ -0,0 +1,80 @@
+
+proc allocImpl(size: Natural): pointer =
+  c_malloc(size.csize_t)
+
+proc alloc0Impl(size: Natural): pointer =
+  c_calloc(size.csize_t, 1)
+
+proc reallocImpl(p: pointer, newsize: Natural): pointer =
+  c_realloc(p, newSize.csize_t)
+
+proc realloc0Impl(p: pointer, oldsize, newsize: Natural): pointer =
+  result = realloc(p, newsize.csize_t)
+  if newsize > oldsize:
+    zeroMem(cast[pointer](cast[int](result) + oldsize), newsize - oldsize)
+
+proc deallocImpl(p: pointer) =
+  c_free(p)
+
+
+# The shared allocators map on the regular ones
+
+proc allocSharedImpl(size: Natural): pointer =
+  allocImpl(size)
+
+proc allocShared0Impl(size: Natural): pointer =
+  alloc0Impl(size)
+
+proc reallocSharedImpl(p: pointer, newsize: Natural): pointer =
+  reallocImpl(p, newsize)
+
+proc reallocShared0Impl(p: pointer, oldsize, newsize: Natural): pointer =
+  realloc0Impl(p, oldsize, newsize)
+
+proc deallocSharedImpl(p: pointer) = deallocImpl(p)
+
+
+# Empty stubs for the GC
+
+proc GC_disable() = discard
+proc GC_enable() = discard
+proc GC_fullCollect() = discard
+proc GC_setStrategy(strategy: GC_Strategy) = discard
+proc GC_enableMarkAndSweep() = discard
+proc GC_disableMarkAndSweep() = discard
+
+proc getOccupiedMem(): int = discard
+proc getFreeMem(): int = discard
+proc getTotalMem(): int = discard
+
+proc nimGC_setStackBottom(theStackBottom: pointer) = discard
+
+proc initGC() = discard
+
+proc newObjNoInit(typ: PNimType, size: int): pointer =
+  result = alloc(size)
+
+proc growObj(old: pointer, newsize: int): pointer =
+  result = realloc(old, newsize)
+
+proc nimGCref(p: pointer) {.compilerproc, inline.} = discard
+proc nimGCunref(p: pointer) {.compilerproc, inline.} = discard
+
+proc unsureAsgnRef(dest: PPointer, src: pointer) {.compilerproc, inline.} =
+  dest[] = src
+proc asgnRef(dest: PPointer, src: pointer) {.compilerproc, inline.} =
+  dest[] = src
+proc asgnRefNoCycle(dest: PPointer, src: pointer) {.compilerproc, inline,
+  deprecated: "old compiler compat".} = asgnRef(dest, src)
+
+type
+  MemRegion = object
+
+proc alloc(r: var MemRegion, size: int): pointer =
+  result = alloc(size)
+proc alloc0Impl(r: var MemRegion, size: int): pointer =
+  result = alloc0Impl(size)
+proc dealloc(r: var MemRegion, p: pointer) = dealloc(p)
+proc deallocOsPages(r: var MemRegion) {.inline.} = discard
+proc deallocOsPages() {.inline.} = discard
+