cbuilder: ccgexprs sweep part 1, basic if stmts (#24381)

Most of what ccgexprs uses is now ported to cbuilder, so this PR makes
around ~25% of ccgexprs use it, along with adding `if` stmts (no
`while`/`switch` and `for` which is only used as `for (tmp = a; tmp < b;
tmp++)`). The `if` builder does not add indents for blocks since we
can't make `Builder` an object yet rather than an alias to `string`,
this will likely be one of the last refactors.

Somewhat unrelated but `ccgtypes` is not ready yet because proc
signatures are not implemented.

compiler/cbuilderbase.nim

@@ -27,6 +27,50 @@ import std/formatfloat
 proc addFloatValue(builder: var Builder, val: float) =
   builder.addFloat(val)
 
-proc cFloatValue(val: float): Snippet =
-  result = ""
-  result.addFloat(val)
+template cFloatValue(val: float): Snippet = $val
+
+proc int64Literal(i: BiggestInt; result: var Builder) =
+  if i > low(int64):
+    result.add "IL64($1)" % [rope(i)]
+  else:
+    result.add "(IL64(-9223372036854775807) - IL64(1))"
+
+proc uint64Literal(i: uint64; result: var Builder) =
+  result.add rope($i & "ULL")
+
+proc intLiteral(i: BiggestInt; result: var Builder) =
+  if i > low(int32) and i <= high(int32):
+    result.addIntValue(i)
+  elif i == low(int32):
+    # Nim has the same bug for the same reasons :-)
+    result.add "(-2147483647 -1)"
+  elif i > low(int64):
+    result.add "IL64($1)" % [rope(i)]
+  else:
+    result.add "(IL64(-9223372036854775807) - IL64(1))"
+
+proc intLiteral(i: Int128; result: var Builder) =
+  intLiteral(toInt64(i), result)
+
+proc cInt64Literal(i: BiggestInt): Snippet =
+  if i > low(int64):
+    result = "IL64($1)" % [rope(i)]
+  else:
+    result = "(IL64(-9223372036854775807) - IL64(1))"
+
+proc cUint64Literal(i: uint64): Snippet =
+  result = $i & "ULL"
+
+proc cIntLiteral(i: BiggestInt): Snippet =
+  if i > low(int32) and i <= high(int32):
+    result = rope(i)
+  elif i == low(int32):
+    # Nim has the same bug for the same reasons :-)
+    result = "(-2147483647 -1)"
+  elif i > low(int64):
+    result = "IL64($1)" % [rope(i)]
+  else:
+    result = "(IL64(-9223372036854775807) - IL64(1))"
+
+proc cIntLiteral(i: Int128): Snippet =
+  result = cIntLiteral(toInt64(i))

compiler/cbuilderexprs.nim

@@ -2,8 +2,15 @@
 # XXX add stuff like NI, NIM_NIL as constants
 
 proc constType(t: Snippet): Snippet =
+  # needs manipulation of `t` in nifc
   "NIM_CONST " & t
 
+proc constPtrType(t: Snippet): Snippet =
+  t & "* NIM_CONST"
+
+proc ptrConstType(t: Snippet): Snippet =
+  "NIM_CONST " & t & "*"
+
 proc ptrType(t: Snippet): Snippet =
   t & "*"
 
@@ -26,6 +33,11 @@ proc wrapPar(value: Snippet): Snippet =
   # used for expression group, no-op on sexp
   "(" & value & ")"
 
+proc removeSinglePar(value: Snippet): Snippet =
+  # removes a single paren layer expected to exist, to silence Wparentheses-equality
+  assert value[0] == '(' and value[^1] == ')'
+  value[1..^2]
+
 template addCast(builder: var Builder, typ: Snippet, valueBody: typed) =
   ## adds a cast to `typ` with value built by `valueBody`
   builder.add "(("
@@ -75,16 +87,26 @@ template addCall(builder: var Builder, call: out CallBuilder, callee: Snippet, b
   body
   finishCallBuilder(builder, call)
 
-proc addNullaryCall(builder: var Builder, callee: Snippet) =
-  builder.add(callee)
-  builder.add("()")
-
-proc addUnaryCall(builder: var Builder, callee: Snippet, arg: Snippet) =
+proc addCall(builder: var Builder, callee: Snippet, args: varargs[Snippet]) =
   builder.add(callee)
   builder.add("(")
-  builder.add(arg)
+  if args.len != 0:
+    builder.add(args[0])
+    for i in 1 ..< args.len:
+      builder.add(", ")
+      builder.add(args[i])
   builder.add(")")
 
+proc cCall(callee: Snippet, args: varargs[Snippet]): Snippet =
+  result = callee
+  result.add("(")
+  if args.len != 0:
+    result.add(args[0])
+    for i in 1 ..< args.len:
+      result.add(", ")
+      result.add(args[i])
+  result.add(")")
+
 proc addSizeof(builder: var Builder, val: Snippet) =
   builder.add("sizeof(")
   builder.add(val)

compiler/cbuilderstmts.nim

@@ -1,28 +1,94 @@
-template addAssignment(builder: var Builder, lhs: Snippet, valueBody: typed) =
+template addAssignmentWithValue(builder: var Builder, lhs: Snippet, valueBody: typed) =
   builder.add(lhs)
   builder.add(" = ")
   valueBody
   builder.add(";\n")
 
-template addFieldAssignment(builder: var Builder, lhs: Snippet, name: string, valueBody: typed) =
+template addFieldAssignmentWithValue(builder: var Builder, lhs: Snippet, name: string, valueBody: typed) =
   builder.add(lhs)
   builder.add("." & name & " = ")
   valueBody
   builder.add(";\n")
 
-template addDerefFieldAssignment(builder: var Builder, lhs: Snippet, name: string, valueBody: typed) =
+template addAssignment(builder: var Builder, lhs, rhs: Snippet) =
+  builder.addAssignmentWithValue(lhs):
+    builder.add(rhs)
+
+template addFieldAssignment(builder: var Builder, lhs: Snippet, name: string, rhs: Snippet) =
+  builder.addFieldAssignmentWithValue(lhs, name):
+    builder.add(rhs)
+
+template addMutualFieldAssignment(builder: var Builder, lhs, rhs: Snippet, name: string) =
+  builder.addFieldAssignmentWithValue(lhs, name):
+    builder.add(rhs)
+    builder.add("." & name)
+
+template addAssignment(builder: var Builder, lhs: Snippet, rhs: int | int64 | uint64 | Int128) =
+  builder.addAssignmentWithValue(lhs):
+    builder.addIntValue(rhs)
+
+template addFieldAssignment(builder: var Builder, lhs: Snippet, name: string, rhs: int | int64 | uint64 | Int128) =
+  builder.addFieldAssignmentWithValue(lhs, name):
+    builder.addIntValue(rhs)
+
+template addDerefFieldAssignment(builder: var Builder, lhs: Snippet, name: string, rhs: Snippet) =
   builder.add(lhs)
   builder.add("->" & name & " = ")
-  valueBody
+  builder.add(rhs)
   builder.add(";\n")
 
-template addSubscriptAssignment(builder: var Builder, lhs: Snippet, index: Snippet, valueBody: typed) =
+template addSubscriptAssignment(builder: var Builder, lhs: Snippet, index: Snippet, rhs: Snippet) =
   builder.add(lhs)
   builder.add("[" & index & "] = ")
-  valueBody
+  builder.add(rhs)
   builder.add(";\n")
 
 template addStmt(builder: var Builder, stmtBody: typed) =
   ## makes an expression built by `stmtBody` into a statement
   stmtBody
   builder.add(";\n")
+
+proc addCallStmt(builder: var Builder, callee: Snippet, args: varargs[Snippet]) =
+  builder.addStmt():
+    builder.addCall(callee, args)
+
+# XXX blocks need indent tracker in `Builder` object
+
+template addSingleIfStmt(builder: var Builder, cond: Snippet, body: typed) =
+  builder.add("if (")
+  builder.add(cond)
+  builder.add(") {\n")
+  body
+  builder.add("}\n")
+
+template addSingleIfStmtWithCond(builder: var Builder, condBody: typed, body: typed) =
+  builder.add("if (")
+  condBody
+  builder.add(") {\n")
+  body
+  builder.add("}\n")
+
+type IfStmt = object
+  needsElse: bool
+
+template addIfStmt(builder: var Builder, stmt: out IfStmt, body: typed) =
+  stmt = IfStmt(needsElse: false)
+  body
+  builder.add("\n")
+
+template addElifBranch(builder: var Builder, stmt: var IfStmt, cond: Snippet, body: typed) =
+  if stmt.needsElse:
+    builder.add(" else ")
+  else:
+    stmt.needsElse = true
+  builder.add("if (")
+  builder.add(cond)
+  builder.add(") {\n")
+  body
+  builder.add("}")
+
+template addElseBranch(builder: var Builder, stmt: var IfStmt, body: typed) =
+  assert stmt.needsElse
+  builder.add(" else {\n")
+  body
+  builder.add("}")