cbuilder: upper half of cgen, variable decls (#24423)

The lower half of cgen contains the main proc and HCR init code which
cause a large diff, so they are excluded from this PR. In general things
like generated defines, line directives, the stacktrace macros (`nimfr_`
etc) are also not done, since there are not exact equivalents for these
in NIFC (NIFC does generate line directives but based on the NIF line
info mechanism).

compiler/cbuilderdecls.nim

@@ -397,8 +397,8 @@ type DeclVisibility = enum
   Private
   StaticProc
 
-template addDeclWithVisibility(builder: var Builder, visibility: DeclVisibility, declBody: typed) =
-  ## adds a declaration as in `declBody` with the given visibility
+proc addVisibilityPrefix(builder: var Builder, visibility: DeclVisibility) =
+  # internal proc
   case visibility
   of None: discard
   of Extern:
@@ -415,6 +415,10 @@ template addDeclWithVisibility(builder: var Builder, visibility: DeclVisibility,
     builder.add("N_LIB_PRIVATE ")
   of StaticProc:
     builder.add("static ")
+
+template addDeclWithVisibility(builder: var Builder, visibility: DeclVisibility, declBody: typed) =
+  ## adds a declaration as in `declBody` with the given visibility
+  builder.addVisibilityPrefix(visibility)
   declBody
 
 type ProcParamBuilder = object
@@ -568,3 +572,41 @@ proc addProcVar(builder: var Builder, callConv: TCallingConvention,
   builder.add(params)
   # ensure we are just adding a variable:
   builder.add(";\n")
+
+type VarInitializerKind = enum
+  Assignment, CppConstructor
+
+proc addVar(builder: var Builder, m: BModule, s: PSym, name: string, typ: Snippet, kind = Local, visibility: DeclVisibility = None, initializer: Snippet = "", initializerKind: VarInitializerKind = Assignment) =
+  if sfCodegenDecl in s.flags:
+    builder.add(runtimeFormat(s.cgDeclFrmt, [typ, name]))
+    if initializer.len != 0:
+      if initializerKind == Assignment:
+        builder.add(" = ")
+      builder.add(initializer)
+    builder.add(";\n")
+    return
+  if s.kind in {skLet, skVar, skField, skForVar} and s.alignment > 0:
+    builder.add("NIM_ALIGN(" & $s.alignment & ") ")
+  builder.addVisibilityPrefix(visibility)
+  if kind == Threadvar:
+    if optThreads in m.config.globalOptions:
+      let sym = s.typ.sym
+      if sym != nil and sfCppNonPod in sym.flags:
+        builder.add("NIM_THREAD_LOCAL ")
+      else: builder.add("NIM_THREADVAR ")
+  else:
+    builder.addVarHeader(kind)
+  builder.add(typ)
+  if sfRegister in s.flags: builder.add(" register")
+  if sfVolatile in s.flags: builder.add(" volatile")
+  if sfNoalias in s.flags: builder.add(" NIM_NOALIAS")
+  builder.add(" ")
+  builder.add(name)
+  if initializer.len != 0:
+    if initializerKind == Assignment:
+      builder.add(" = ")
+    builder.add(initializer)
+  builder.add(";\n")
+
+proc addInclude(builder: var Builder, value: Snippet) =
+  builder.add("#include " & value & "\n")

compiler/ccgstmts.nim

@@ -348,13 +348,6 @@ proc genCppParamsForCtor(p: BProc; call: PNode; didGenTemp: var bool): Snippet =
       genOtherArg(p, call, i, typ, res, argBuilder)
   result = extract(res)
 
-proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope, didGenTemp: var bool) =
-  let params = genCppParamsForCtor(p, call, didGenTemp)
-  if params.len == 0:
-    decl = runtimeFormat("$#;\n", [decl])
-  else:
-    decl = runtimeFormat("$#($#);\n", [decl, params])
-
 proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
   if sfGoto in v.flags:
     # translate 'var state {.goto.} = X' into 'goto LX':
@@ -416,18 +409,19 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
       # parameterless constructor followed by an assignment operator. So we
       # generate better code here: 'Foo f = x;'
       genLineDir(p, vn)
-      var decl = localVarDecl(p, vn)
-      var tmp: TLoc
+      var initializer: Snippet = ""
+      var initializerKind: VarInitializerKind = Assignment
       if isCppCtorCall:
         var didGenTemp = false
-        genCppVarForCtor(p, value, decl, didGenTemp)
-        line(p, cpsStmts, decl)
+        initializer = genCppParamsForCtor(p, value, didGenTemp)
+        if initializer.len != 0:
+          initializer = "(" & initializer & ")"
+          initializerKind = CppConstructor
       else:
-        tmp = initLocExprSingleUse(p, value)
-        if value.kind == nkEmpty:
-          lineF(p, cpsStmts, "$#;\n", [decl])
-        else:
-          lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
+        var tmp = initLocExprSingleUse(p, value)
+        if value.kind != nkEmpty:
+          initializer = tmp.rdLoc
+      localVarDecl(p.s(cpsStmts), p, vn, initializer, initializerKind)
       return
     assignLocalVar(p, vn)
     initLocalVar(p, v, imm)

compiler/ccgthreadvars.nim

@@ -19,9 +19,12 @@ proc accessThreadLocalVar(p: BProc, s: PSym) =
   if emulatedThreadVars(p.config) and threadVarAccessed notin p.flags:
     p.flags.incl threadVarAccessed
     incl p.module.flags, usesThreadVars
-    p.procSec(cpsLocals).addf("\tNimThreadVars* NimTV_;$n", [])
-    p.procSec(cpsInit).add(
-      ropecg(p.module, "\tNimTV_ = (NimThreadVars*) #GetThreadLocalVars();$n", []))
+    p.procSec(cpsLocals).addVar(kind = Local,
+      name = "NimTV_",
+      typ = ptrType("NimThreadVars"))
+    p.procSec(cpsInit).addAssignment("NimTV_",
+      cCast(ptrType("NimThreadVars"),
+        cCall(cgsymValue(p.module, "GetThreadLocalVars"))))
 
 proc declareThreadVar(m: BModule, s: PSym, isExtern: bool) =
   if emulatedThreadVars(m.config):
@@ -30,32 +33,35 @@ proc declareThreadVar(m: BModule, s: PSym, isExtern: bool) =
     # allocator for it :-(
     if not containsOrIncl(m.g.nimtvDeclared, s.id):
       m.g.nimtvDeps.add(s.loc.t)
-      m.g.nimtv.addf("$1 $2;$n", [getTypeDesc(m, s.loc.t), s.loc.snippet])
+      m.g.nimtv.addField(name = s.loc.snippet, typ = getTypeDesc(m, s.loc.t))
   else:
-    if isExtern: m.s[cfsVars].add("extern ")
-    elif lfExportLib in s.loc.flags: m.s[cfsVars].add("N_LIB_EXPORT_VAR ")
-    else: m.s[cfsVars].add("N_LIB_PRIVATE ")
-    if optThreads in m.config.globalOptions:
-      let sym = s.typ.sym
-      if sym != nil and sfCppNonPod in sym.flags:
-        m.s[cfsVars].add("NIM_THREAD_LOCAL ")
-      else: m.s[cfsVars].add("NIM_THREADVAR ")
-    m.s[cfsVars].add(getTypeDesc(m, s.loc.t))
-    m.s[cfsVars].addf(" $1;$n", [s.loc.snippet])
+    let vis =
+      if isExtern: Extern
+      elif lfExportLib in s.loc.flags: ExportLibVar
+      else: Private
+    m.s[cfsVars].addVar(m, s,
+      name = s.loc.snippet,
+      typ = getTypeDesc(m, s.loc.t),
+      kind = Threadvar,
+      visibility = vis)
 
 proc generateThreadLocalStorage(m: BModule) =
-  if m.g.nimtv != "" and (usesThreadVars in m.flags or sfMainModule in m.module.flags):
+  if m.g.nimtv.buf.len != 0 and (usesThreadVars in m.flags or sfMainModule in m.module.flags):
     for t in items(m.g.nimtvDeps): discard getTypeDesc(m, t)
     finishTypeDescriptions(m)
     m.s[cfsSeqTypes].addTypedef(name = "NimThreadVars"):
       m.s[cfsSeqTypes].addSimpleStruct(m, name = "", baseType = ""):
-        m.s[cfsSeqTypes].add(m.g.nimtv)
+        m.s[cfsSeqTypes].add(extract(m.g.nimtv))
 
 proc generateThreadVarsSize(m: BModule) =
-  if m.g.nimtv != "":
+  if m.g.nimtv.buf.len != 0:
     let externc = if m.config.backend == backendCpp or
-                       sfCompileToCpp in m.module.flags: "extern \"C\" "
-                  else: ""
-    m.s[cfsProcs].addf(
-      "$#NI NimThreadVarsSize(){return (NI)sizeof(NimThreadVars);}$n",
-      [externc.rope])
+                       sfCompileToCpp in m.module.flags: ExternC
+                  else: None
+    m.s[cfsProcs].addDeclWithVisibility(externc):
+      m.s[cfsProcs].addProcHeaderWithParams(ccNoConvention, "NimThreadVarsSize", "NI"):
+        var params: ProcParamBuilder
+        m.s[cfsProcs].addProcParams(params):
+          discard
+      m.s[cfsProcs].finishProcHeaderWithBody():
+        m.s[cfsProcs].addReturn(cCast("NI", cSizeof("NimThreadVars")))

compiler/ccgtypes.nim

@@ -1690,28 +1690,30 @@ proc genDisplayElem(d: MD5Digest): uint32 =
     result += uint32(d[i])
     result = result shl 8
 
-proc genDisplay(m: BModule; t: PType, depth: int): Rope =
-  result = Rope"{"
+proc genDisplay(result: var Builder, m: BModule; t: PType, depth: int) =
   var x = t
-  var seqs = newSeq[string](depth+1)
+  var seqs = newSeq[Snippet](depth+1)
   var i = 0
   while x != nil:
     x = skipTypes(x, skipPtrs)
-    seqs[i] = $genDisplayElem(MD5Digest(hashType(x, m.config)))
+    seqs[i] = cIntValue(genDisplayElem(MD5Digest(hashType(x, m.config))))
     x = x[0]
     inc i
 
-  for i in countdown(depth, 1):
-    result.add seqs[i] & ", "
-  result.add seqs[0]
-  result.add "}"
-
-proc genVTable(seqs: seq[PSym]): string =
-  result = "{"
-  for i in 0..<seqs.len:
-    if i > 0: result.add ", "
-    result.add "(void *) " & seqs[i].loc.snippet
-  result.add "}"
+  var arr: StructInitializer
+  result.addStructInitializer(arr, siArray):
+    for i in countdown(depth, 1):
+      result.addField(arr, ""):
+        result.add(seqs[i])
+    result.addField(arr, ""):
+      result.add(seqs[0])
+
+proc genVTable(result: var Builder, seqs: seq[PSym]) =
+  var table: StructInitializer
+  result.addStructInitializer(table, siArray):
+    for i in 0..<seqs.len:
+      result.addField(table, ""):
+        result.add(cCast("void*", seqs[i].loc.snippet))
 
 proc genTypeInfoV2OldImpl(m: BModule; t, origType: PType, name: Rope; info: TLineInfo) =
   cgsym(m, "TNimTypeV2")
@@ -1752,23 +1754,22 @@ proc genTypeInfoV2OldImpl(m: BModule; t, origType: PType, name: Rope; info: TLin
   typeEntry.addFieldAssignment(name, "flags", flags)
 
   if objDepth >= 0:
-    let objDisplay = genDisplay(m, t, objDepth)
     let objDisplayStore = getTempName(m)
-    m.s[cfsVars].addArrayVar(kind = Global,
+    m.s[cfsVars].addArrayVarWithInitializer(kind = Global,
         name = objDisplayStore,
         elementType = getTypeDesc(m, getSysType(m.g.graph, unknownLineInfo, tyUInt32), dkVar),
-        len = objDepth + 1,
-        initializer = objDisplay)
+        len = objDepth + 1):
+      genDisplay(m.s[cfsVars], m, t, objDepth)
     typeEntry.addFieldAssignment(name, "display", objDisplayStore)
 
   let dispatchMethods = toSeq(getMethodsPerType(m.g.graph, t))
   if dispatchMethods.len > 0:
     let vTablePointerName = getTempName(m)
-    m.s[cfsVars].addArrayVar(kind = Global,
+    m.s[cfsVars].addArrayVarWithInitializer(kind = Global,
         name = vTablePointerName,
         elementType = "void*",
-        len = dispatchMethods.len,
-        initializer = genVTable(dispatchMethods))
+        len = dispatchMethods.len):
+      genVTable(m.s[cfsVars], dispatchMethods)
     for i in dispatchMethods:
       genProcPrototype(m, i)
     typeEntry.addFieldAssignment(name, "vTable", vTablePointerName)
@@ -1811,13 +1812,12 @@ proc genTypeInfoV2Impl(m: BModule; t, origType: PType, name: Rope; info: TLineIn
           typeEntry.addIntValue(objDepth)
 
         if objDepth >= 0:
-          let objDisplay = genDisplay(m, t, objDepth)
           let objDisplayStore = getTempName(m)
-          m.s[cfsVars].addArrayVar(kind = Const,
+          m.s[cfsVars].addArrayVarWithInitializer(kind = Const,
               name = objDisplayStore,
               elementType = getTypeDesc(m, getSysType(m.g.graph, unknownLineInfo, tyUInt32), dkVar),
-              len = objDepth + 1,
-              initializer = objDisplay)
+              len = objDepth + 1):
+            genDisplay(m.s[cfsVars], m, t, objDepth)
           typeEntry.addField(typeInit, name = "display"):
             typeEntry.add(objDisplayStore)
         if isDefined(m.config, "nimTypeNames"):
@@ -1839,7 +1839,7 @@ proc genTypeInfoV2Impl(m: BModule; t, origType: PType, name: Rope; info: TLineIn
           for i in dispatchMethods:
             genProcPrototype(m, i)
           typeEntry.addField(typeInit, name = "vTable"):
-            typeEntry.add(genVTable(dispatchMethods))
+            genVTable(typeEntry, dispatchMethods)
         else:
           typeEntry.addField(typeInit, name = "flags"):
             typeEntry.addIntValue(flags)