interpretor/faust-0.9.47mr3/compiler/propagate/labels.cpp

   1 #include "labels.hh"
   2 #include "compatibility.hh"
   3
   4 //=========================== PATHNAME ===============================
   5
   6 /**
   7  * Grammar for labels with pathnames
   8  *-----------------------------------
   9  * <label> = <name> | <path> <name>
  10  * <name> = [^/]+
  11  * <path> = <apath> | <rpath>
  12  * <apath> = '/' | '/' <rpath>
  13  * <rpath> = (<gname> '/')+
  14  * <gname> = ".." | "." | <gtype> <name>
  15  * <gtype> = "h:" | "H:" | "v:" | V:" | "t:" | "T:"
  16  *
  17  */
  18
  19 Sym PATHROOT = symbol ("/");
  20 Tree pathRoot()                                         { return tree(PATHROOT); }
  21 bool isPathRoot(Tree t)                         { return isTree(t, PATHROOT); }
  22
  23 Sym PATHPARENT = symbol ("..");
  24 Tree pathParent()                                       { return tree(PATHPARENT); }
  25 bool isPathParent(Tree t)                       { return isTree(t, PATHPARENT); }
  26
  27 Sym PATHCURRENT = symbol (".");
  28 Tree pathCurrent()                                      { return tree(PATHCURRENT); }
  29 bool isPathCurrent(Tree t)                      { return isTree(t, PATHCURRENT); }
  30
  31
  32
  33 /**
  34  * analyze name for "H:name" | "V:name" etc
  35  */
  36
  37 static Tree encodeName(char g, const string& name)
  38 {
  39     switch (g) {
  40         case 'v':
  41         case 'V': return cons(tree(0), tree(name));
  42
  43         case 'h':
  44         case 'H': return cons(tree(1), tree(name));
  45
  46         case 't':
  47         case 'T': return cons(tree(2), tree(name));
  48
  49         default : return cons(tree(0), tree(name));
  50     }
  51 }
  52
  53
  54 /**
  55  * Analyzes a label and converts it as a path
  56  */
  57
  58 static Tree label2path(const char* label)
  59 {
  60     if (label[0] == 0) {
  61         return cons(tree(""), nil);
  62
  63     } else if (label[0] == '/') {
  64         return cons(pathRoot(), label2path(&label[1]));
  65
  66     } else if ((label[0] == '.') && (label[1] == '/')) {
  67         return label2path(&label[2]);
  68
  69     } else if ((label[0] == '.') && (label[1] == '.') && (label[2] == '/')) {
  70         return cons(pathParent(), label2path(&label[3]));
  71
  72     } else if (label[1] == ':') {
  73         char    g = label[0];
  74         string  s;
  75         int     i = 2;
  76         while ((label[i] != 0) && (label[i] != '/')) {
  77             s.push_back(label[i]);
  78             i++;
  79         }
  80         if (label[i] == '/') i++;
  81         return cons(encodeName(g,s), label2path(&label[i]));
  82
  83     } else {
  84         return cons(tree(label),nil);
  85     }
  86 }
  87
  88
  89 /**
  90  * Concatenate the relative path to the absolute path
  91  * Note that the relpath is top-down while the abspath
  92  * is bottom-up
  93  */
  94
  95 static Tree concatPath(Tree relpath, Tree abspath)
  96 {
  97         if (isList(relpath)) {
  98                 Tree head = hd(relpath);
  99                 if (isPathRoot(head)) {
 100                         return concatPath(tl(relpath), nil);
 101                 } else if (isPathParent(head)) {
 102                         if (!isList(abspath)) {
 103                                 //cerr << "abspath : " << *abspath << endl;
 104                                 return concatPath(tl(relpath), hd(relpath));
 105                         } else {
 106                                 return concatPath(tl(relpath), tl(abspath));
 107                         }
 108                 } else if (isPathCurrent(head)) {
 109                         return concatPath(tl(relpath), abspath);
 110                 } else {
 111                         return concatPath(tl(relpath), cons(head,abspath));
 112                 }
 113         } else {
 114                 assert(isNil(relpath));
 115                 return abspath;
 116         }
 117 }
 118
 119
 120 static Tree normalizeLabel(Tree label, Tree path)
 121 {
 122         // we suppose label = "../label" ou "name/label" ou "name"
 123         //cout << "Normalize Label " << *label << " with path " << *path << endl;
 124         if (isList(label)) {
 125                 return cons(label, path);
 126         } else {
 127                 Sym s;
 128                 assert (isSym(label->node(),&s));
 129                 return concatPath(label2path(name(s)),path);
 130         }
 131 }
 132
 133 Tree normalizePath(Tree path)
 134 {
 135     //cout << "Normalize Path [[" << *path << "]]" << endl;
 136         Tree npath;
 137     if (isNil(path)) {
 138         npath = path;
 139     } else {
 140         npath = normalizeLabel(hd(path), normalizePath(tl(path)));
 141     }
 142     //cout << "              -> [[" << *npath << "]]" << endl;
 143         return npath;
 144 }
 145