cbuilder: use constants for type names, some cleanups (#24438)

As described in #24432

compiler/cbuilderbase.nim

@@ -120,6 +120,43 @@ proc cIntLiteral*(i: BiggestInt): Snippet =
 proc cIntLiteral*(i: Int128): Snippet =
   result = cIntLiteral(toInt64(i))
 
+const
+  NimInt* = "NI"
+  NimInt8* = "NI8"
+  NimInt16* = "NI16"
+  NimInt32* = "NI32"
+  NimInt64* = "NI64"
+  CInt* = "int"
+  NimUint* = "NU"
+  NimUint8* = "NU8"
+  NimUint16* = "NU16"
+  NimUint32* = "NU32"
+  NimUint64* = "NU64"
+  NimFloat* = "NF"
+  NimFloat32* = "NF32"
+  NimFloat64* = "NF64"
+  NimFloat128* = "NF128" # not actually defined
+  NimNan* = "NAN"
+  NimInf* = "INF"
+  NimBool* = "NIM_BOOL"
+  NimTrue* = "NIM_TRUE"
+  NimFalse* = "NIM_FALSE"
+  NimChar* = "NIM_CHAR"
+  CChar* = "char"
+  NimCstring* = "NCSTRING"
+  NimNil* = "NIM_NIL"
+  CNil* = "NULL"
+  NimStrlitFlag* = "NIM_STRLIT_FLAG"
+  CVoid* = "void"
+  CPointer* = "void*"
+  CConstPointer* = "NIM_CONST void*"
+
+proc cIntType*(bits: int): Snippet =
+  "NI" & $bits
+
+proc cUintType*(bits: int): Snippet =
+  "NU" & $bits
+
 type
   IfBuilderState* = enum
     WaitingIf, WaitingElseIf, InBlock

compiler/cbuilderdecls.nim

@@ -271,7 +271,7 @@ proc startSimpleStruct(obj: var Builder; m: BModule; name: string; baseType: Sni
 proc finishSimpleStruct(obj: var Builder; m: BModule; info: StructBuilderInfo) =
   if info.baseKind == bcNone and info.preFieldsLen == obj.buf.len:
     # no fields were added, add dummy field
-    obj.addField(name = "dummy", typ = "char")
+    obj.addField(name = "dummy", typ = CChar)
   if info.named:
     obj.add("};\n")
   else:
@@ -330,7 +330,7 @@ proc startStruct(obj: var Builder; m: BModule; t: PType; name: string; baseType:
         t.n != nil and t.n.len == 1 and t.n[0].kind == nkSym and
         t.n[0].sym.typ.skipTypes(abstractInst).kind == tyUncheckedArray:
       # only consists of flexible array field, add *initial* dummy field
-      obj.addField(name = "dummy", typ = "char")
+      obj.addField(name = "dummy", typ = CChar)
   of bcCppInherit: discard
   of bcNoneRtti:
     obj.addField(name = "m_type", typ = ptrType(cgsymValue(m, "TNimType")))
@@ -343,7 +343,7 @@ proc finishStruct(obj: var Builder; m: BModule; t: PType; info: StructBuilderInf
   if info.baseKind == bcNone and info.preFieldsLen == obj.buf.len and
       t.itemId notin m.g.graph.memberProcsPerType:
     # no fields were added, add dummy field
-    obj.addField(name = "dummy", typ = "char")
+    obj.addField(name = "dummy", typ = CChar)
   if info.named:
     obj.add("};\n")
   else:

compiler/cbuilderexprs.nim

@@ -1,6 +1,3 @@
-# XXX make complex ones like bitOr use builder instead
-# XXX add stuff like NI, NIM_NIL as constants
-
 proc constType(t: Snippet): Snippet =
   # needs manipulation of `t` in nifc
   "NIM_CONST " & t
@@ -87,9 +84,6 @@ proc dotField(a, b: Snippet): Snippet =
 proc derefField(a, b: Snippet): Snippet =
   a & "->" & b
 
-proc bitOr(a, b: Snippet): Snippet =
-  "(" & a & " | " & b & ")"
-
 type CallBuilder = object
   needsComma: bool
 

compiler/cbuilderstmts.nim

@@ -322,3 +322,8 @@ template addCPragma(builder: var Builder, val: Snippet) =
   builder.add("#pragma ")
   builder.add(val)
   builder.addNewline()
+
+proc addDiscard(builder: var Builder, val: Snippet) =
+  builder.add("(void)")
+  builder.add(val)
+  builder.addLineEnd(";")

compiler/ccgcalls.nim

@@ -213,20 +213,20 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
   let ra = rdLoc(a)
   let rb = rdLoc(b)
   let rc = rdLoc(c)
-  let lengthExpr = cOp(Add, "NI", cOp(Sub, "NI", rc, rb), cIntValue(1))
+  let lengthExpr = cOp(Add, NimInt, cOp(Sub, NimInt, rc, rb), cIntValue(1))
   case ty.kind
   of tyArray:
     let first = toInt64(firstOrd(p.config, ty))
     if first == 0:
-      result = (cCast(ptrType(dest), cOp(Add, "NI", ra, rb)), lengthExpr)
+      result = (cCast(ptrType(dest), cOp(Add, NimInt, ra, rb)), lengthExpr)
     else:
       let lit = cIntLiteral(first)
-      result = (cCast(ptrType(dest), cOp(Add, "NI", ra, cOp(Sub, "NI", rb, lit))), lengthExpr)
+      result = (cCast(ptrType(dest), cOp(Add, NimInt, ra, cOp(Sub, NimInt, rb, lit))), lengthExpr)
   of tyOpenArray, tyVarargs:
     let data = if reifiedOpenArray(q[1]): dotField(ra, "Field0") else: ra
-    result = (cCast(ptrType(dest), cOp(Add, "NI", data, rb)), lengthExpr)
+    result = (cCast(ptrType(dest), cOp(Add, NimInt, data, rb)), lengthExpr)
   of tyUncheckedArray, tyCstring:
-    result = (cCast(ptrType(dest), cOp(Add, "NI", ra, rb)), lengthExpr)
+    result = (cCast(ptrType(dest), cOp(Add, NimInt, ra, rb)), lengthExpr)
   of tyString, tySequence:
     let atyp = skipTypes(a.t, abstractInst)
     if formalType.skipTypes(abstractInst).kind in {tyVar} and atyp.kind == tyString and
@@ -241,8 +241,8 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
       val = ra
     result = (
       cIfExpr(dataFieldAccessor(p, val),
-        cCast(ptrType(dest), cOp(Add, "NI", dataField(p, val), rb)),
-        "NIM_NIL"),
+        cCast(ptrType(dest), cOp(Add, NimInt, dataField(p, val), rb)),
+        NimNil),
       lengthExpr)
   else:
     result = ("", "")
@@ -295,13 +295,13 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Builder) =
         let ra = a.rdLoc
         var t = TLoc(snippet: cDeref(ra))
         let lt = lenExpr(p, t)
-        result.add(cIfExpr(dataFieldAccessor(p, t.snippet), dataField(p, t.snippet), "NIM_NIL"))
+        result.add(cIfExpr(dataFieldAccessor(p, t.snippet), dataField(p, t.snippet), NimNil))
         result.addArgumentSeparator()
         result.add(lt)
       else:
         let ra = a.rdLoc
         let la = lenExpr(p, a)
-        result.add(cIfExpr(dataFieldAccessor(p, ra), dataField(p, ra), "NIM_NIL"))
+        result.add(cIfExpr(dataFieldAccessor(p, ra), dataField(p, ra), NimNil))
         result.addArgumentSeparator()
         result.add(la)
     of tyArray:
@@ -315,7 +315,7 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Builder) =
         let ra = a.rdLoc
         var t = TLoc(snippet: cDeref(ra))
         let lt = lenExpr(p, t)
-        result.add(cIfExpr(dataFieldAccessor(p, t.snippet), dataField(p, t.snippet), "NIM_NIL"))
+        result.add(cIfExpr(dataFieldAccessor(p, t.snippet), dataField(p, t.snippet), NimNil))
         result.addArgumentSeparator()
         result.add(lt)
       of tyArray:
@@ -767,7 +767,7 @@ proc genPatternCall(p: BProc; ri: PNode; pat: string; typ: PType; result: var Bu
       var idx, stars: int = 0
       if scanCppGenericSlot(pat, i, idx, stars):
         var t = resolveStarsInCppType(typ, idx, stars)
-        if t == nil: result.add("void")
+        if t == nil: result.add(CVoid)
         else: result.add(getTypeDesc(p.module, t))
     else:
       let start = i