1 files changed, 231 insertions, 0 deletions
diff --git a/rod/c2nim/cpp.nim b/rod/c2nim/cpp.nim
new file mode 100755
index 000000000..61873628e
--- /dev/null
+++ b/rod/c2nim/cpp.nim
@@ -0,0 +1,231 @@
+# Preprocessor support
+
+const
+  c2nimSymbol = "C2NIM"
+
+proc eatNewLine(p: var TParser, n: PNode) = 
+  if p.tok.xkind == pxLineComment:
+    skipCom(p, n)
+    if p.tok.xkind == pxNewLine: getTok(p)
+  else:
+    eat(p, pxNewLine)
+
+proc parseDefineBody(p: var TParser, tmplDef: PNode): string = 
+  if p.tok.xkind == pxCurlyLe or 
+    (p.tok.xkind == pxSymbol and (declKeyword(p.tok.s) or stmtKeyword(p.tok.s))):
+    addSon(tmplDef, statement(p))
+    result = "stmt"
+  elif p.tok.xkind in {pxLineComment, pxNewLine}:
+    addSon(tmplDef, buildStmtList(newNodeP(nkNilLit, p)))
+    result = "stmt"
+  else:
+    addSon(tmplDef, buildStmtList(expression(p)))
+    result = "expr"
+
+proc parseDefine(p: var TParser): PNode = 
+  if p.tok.xkind == pxDirectiveParLe: 
+    # a macro with parameters:
+    result = newNodeP(nkTemplateDef, p)
+    getTok(p)
+    addSon(result, skipIdent(p))
+    eat(p, pxParLe)
+    var params = newNodeP(nkFormalParams, p)
+    # return type; not known yet:
+    addSon(params, nil)  
+    var identDefs = newNodeP(nkIdentDefs, p)
+    while p.tok.xkind != pxParRi: 
+      addSon(identDefs, skipIdent(p))
+      skipStarCom(p, nil)
+      if p.tok.xkind != pxComma: break
+      getTok(p)
+    addSon(identDefs, newIdentNodeP("expr", p))
+    addSon(identDefs, nil)
+    addSon(params, identDefs)
+    eat(p, pxParRi)
+    
+    addSon(result, nil) # no generic parameters
+    addSon(result, params)
+    addSon(result, nil) # no pragmas
+    var kind = parseDefineBody(p, result)
+    params.sons[0] = newIdentNodeP(kind, p)
+    eatNewLine(p, result)
+  else:
+    # a macro without parameters:
+    result = newNodeP(nkConstSection, p)
+    while p.tok.xkind == pxDirective and p.tok.s == "define":
+      getTok(p) # skip #define
+      var c = newNodeP(nkConstDef, p)
+      addSon(c, skipIdent(p))
+      addSon(c, nil)
+      skipStarCom(p, c)
+      if p.tok.xkind in {pxLineComment, pxNewLine, pxEof}:
+        addSon(c, newIdentNodeP("true", p))
+      else:
+        addSon(c, expression(p))
+      addSon(result, c)
+      eatNewLine(p, c)
+  
+proc isDir(p: TParser, dir: string): bool = 
+  result = p.tok.xkind in {pxDirectiveParLe, pxDirective} and p.tok.s == dir
+
+proc parseInclude(p: var TParser): PNode = 
+  result = newNodeP(nkImportStmt, p)
+  while isDir(p, "include"):
+    getTok(p) # skip "include"
+    if p.tok.xkind == pxStrLit:
+      var file = newStrNodeP(nkStrLit, p.tok.s, p)
+      addSon(result, file)
+      getTok(p)
+      skipStarCom(p, file)
+    elif p.tok.xkind == pxLt: 
+      while p.tok.xkind notin {pxEof, pxNewLine, pxLineComment}: getTok(p)
+    else:
+      parMessage(p, errXExpected, "string literal")
+    eatNewLine(p, nil)
+  if sonsLen(result) == 0: 
+    # we only parsed includes that we chose to ignore:
+    result = nil
+
+proc definedExprAux(p: var TParser): PNode = 
+  result = newNodeP(nkCall, p)
+  addSon(result, newIdentNodeP("defined", p))
+  addSon(result, skipIdent(p))
+
+proc parseStmtList(p: var TParser): PNode = 
+  result = newNodeP(nkStmtList, p)
+  while true: 
+    case p.tok.xkind
+    of pxEof: break 
+    of pxDirectiveParLe, pxDirective: 
+      case p.tok.s
+      of "else", "endif", "elif": break
+    else: nil
+    addSon(result, statement(p))
+  
+proc parseIfDirAux(p: var TParser, result: PNode) = 
+  addSon(result.sons[0], parseStmtList(p))
+  while isDir(p, "elif"): 
+    var b = newNodeP(nkElifBranch, p)
+    getTok(p)
+    addSon(b, expression(p))
+    eatNewLine(p, nil)
+    addSon(b, parseStmtList(p))
+    addSon(result, b)
+  if isDir(p, "else"): 
+    var s = newNodeP(nkElse, p)
+    while p.tok.xkind notin {pxEof, pxNewLine, pxLineComment}: getTok(p)
+    eatNewLine(p, nil)
+    addSon(s, parseStmtList(p))
+    addSon(result, s)
+  if isDir(p, "endif"): 
+    while p.tok.xkind notin {pxEof, pxNewLine, pxLineComment}: getTok(p)
+    eatNewLine(p, nil)
+  else: 
+    parMessage(p, errXExpected, "#endif")
+  
+proc specialIf(p: TParser): bool = 
+  ExpectIdent(p)
+  result = p.tok.s == c2nimSymbol
+  
+proc chooseBranch(whenStmt: PNode, branch: int): PNode = 
+  var L = sonsLen(whenStmt)
+  if branch < L: 
+    if L == 2 and whenStmt[1].kind == nkElse or branch == 0: 
+      result = lastSon(whenStmt[branch])
+    else:
+      var b = whenStmt[branch]
+      assert(b.kind == nkElifBranch)
+      result = newNodeI(nkWhenStmt, whenStmt.info)
+      for i in branch .. L-1:
+        addSon(result, whenStmt[i])
+  
+proc skipIfdefCPlusPlus(p: var TParser): PNode =
+  while p.tok.xkind != pxEof:
+    if isDir(p, "endif"): 
+      while p.tok.xkind notin {pxEof, pxNewLine, pxLineComment}: getTok(p)
+      eatNewLine(p, nil)
+      return
+    getTok(p)
+  parMessage(p, errXExpected, "#endif")
+  
+proc parseIfdefDir(p: var TParser): PNode = 
+  result = newNodeP(nkWhenStmt, p)
+  addSon(result, newNodeP(nkElifBranch, p))
+  getTok(p)
+  var special = specialIf(p)
+  if p.tok.s == "__cplusplus": 
+    return skipIfdefCPlusPlus(p)
+  addSon(result.sons[0], definedExprAux(p))
+  eatNewLine(p, nil)
+  parseIfDirAux(p, result)
+  if special: 
+    result = chooseBranch(result, 0)
+
+proc parseIfndefDir(p: var TParser): PNode = 
+  result = newNodeP(nkWhenStmt, p)
+  addSon(result, newNodeP(nkElifBranch, p))
+  getTok(p)
+  var special = specialIf(p)
+  var e = newNodeP(nkCall, p)
+  addSon(e, newIdentNodeP("not", p))
+  addSon(e, definedExprAux(p))
+  eatNewLine(p, nil)
+  addSon(result.sons[0], e)
+  parseIfDirAux(p, result)
+  if special:
+    result = chooseBranch(result, 1)
+
+proc parseIfDir(p: var TParser): PNode = 
+  result = newNodeP(nkWhenStmt, p)
+  addSon(result, newNodeP(nkElifBranch, p))
+  getTok(p)
+  addSon(result.sons[0], expression(p))
+  eatNewLine(p, nil)
+  parseIfDirAux(p, result)
+
+proc parseMangleDir(p: var TParser) = 
+  var col = getColumn(p.lex) + 2
+  getTok(p)
+  if p.tok.xkind != pxStrLit: ExpectIdent(p)
+  try:
+    var pattern = parsePeg(
+      input = p.tok.s, 
+      filename = p.lex.filename, 
+      line = p.lex.linenumber, 
+      col = col)
+    getTok(p)
+    if p.tok.xkind != pxStrLit: ExpectIdent(p)
+    p.options.mangleRules.add((pattern, p.tok.s))
+    getTok(p)
+  except EInvalidPeg:
+    parMessage(p, errUser, getCurrentExceptionMsg())
+  eatNewLine(p, nil)
+
+proc parseDir(p: var TParser): PNode = 
+  assert(p.tok.xkind in {pxDirective, pxDirectiveParLe})
+  case p.tok.s
+  of "define": result = parseDefine(p)
+  of "include": result = parseInclude(p)
+  of "ifdef": result = parseIfdefDir(p)
+  of "ifndef": result = parseIfndefDir(p)
+  of "if": result = parseIfDir(p)
+  of "cdecl", "stdcall", "ref": 
+    discard setOption(p.options, p.tok.s)
+    getTok(p)
+    eatNewLine(p, nil)
+  of "dynlib", "header", "prefix", "suffix", "skip": 
+    var key = p.tok.s
+    getTok(p)
+    if p.tok.xkind != pxStrLit: ExpectIdent(p)
+    discard setOption(p.options, key, p.tok.s)
+    getTok(p)
+    eatNewLine(p, nil)
+  of "mangle":
+    parseMangleDir(p)
+  else: 
+    # ignore unimportant/unknown directive ("undef", "pragma", "error")
+    while true:
+      getTok(p)
+      if p.tok.xkind in {pxEof, pxNewLine, pxLineComment}: break
+    eatNewLine(p, nil)
+