--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/d/dmd/identifier.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,188 @@
+
+/* Compiler implementation of the D programming language
+ * Copyright (C) 1999-2019 by The D Language Foundation, All Rights Reserved
+ * written by Walter Bright
+ * http://www.digitalmars.com
+ * Distributed under the Boost Software License, Version 1.0.
+ * http://www.boost.org/LICENSE_1_0.txt
+ * https://github.com/D-Programming-Language/dmd/blob/master/src/identifier.c
+ */
+
+#include "root/dsystem.h"
+#include "root/root.h"
+
+#include "identifier.h"
+#include "mars.h"
+#include "id.h"
+#include "tokens.h"
+#include "utf.h"
+
+Identifier::Identifier(const char *string, size_t length, int value)
+{
+    //printf("Identifier('%s', %d)\n", string, value);
+    this->string = string;
+    this->value = value;
+    this->len = length;
+}
+
+Identifier::Identifier(const char *string)
+{
+    //printf("Identifier('%s')\n", string);
+    this->string = string;
+    this->value = TOKidentifier;
+    this->len = strlen(string);
+}
+
+Identifier *Identifier::create(const char *string)
+{
+    return new Identifier(string);
+}
+
+bool Identifier::equals(RootObject *o)
+{
+    return this == o || strncmp(string,o->toChars(),len+1) == 0;
+}
+
+int Identifier::compare(RootObject *o)
+{
+    return strncmp(string, o->toChars(), len + 1);
+}
+
+const char *Identifier::toChars()
+{
+    return string;
+}
+
+int Identifier::getValue() const
+{
+    return value;
+}
+
+const char *Identifier::toHChars2()
+{
+    const char *p = NULL;
+
+    if (this == Id::ctor) p = "this";
+    else if (this == Id::dtor) p = "~this";
+    else if (this == Id::unitTest) p = "unittest";
+    else if (this == Id::dollar) p = "$";
+    else if (this == Id::withSym) p = "with";
+    else if (this == Id::result) p = "result";
+    else if (this == Id::returnLabel) p = "return";
+    else
+    {   p = toChars();
+        if (*p == '_')
+        {
+            if (strncmp(p, "_staticCtor", 11) == 0)
+                p = "static this";
+            else if (strncmp(p, "_staticDtor", 11) == 0)
+                p = "static ~this";
+            else if (strncmp(p, "__invariant", 11) == 0)
+                p = "invariant";
+        }
+    }
+
+    return p;
+}
+
+void Identifier::print()
+{
+    fprintf(stderr, "%s",string);
+}
+
+int Identifier::dyncast() const
+{
+    return DYNCAST_IDENTIFIER;
+}
+
+StringTable Identifier::stringtable;
+
+Identifier *Identifier::generateId(const char *prefix)
+{
+    static size_t i;
+
+    return generateId(prefix, ++i);
+}
+
+Identifier *Identifier::generateId(const char *prefix, size_t i)
+{   OutBuffer buf;
+
+    buf.writestring(prefix);
+    buf.printf("%llu", (ulonglong)i);
+
+    char *id = buf.peekString();
+    return idPool(id);
+}
+
+/********************************************
+ * Create an identifier in the string table.
+ */
+
+Identifier *Identifier::idPool(const char *s, size_t len)
+{
+    StringValue *sv = stringtable.update(s, len);
+    Identifier *id = (Identifier *) sv->ptrvalue;
+    if (!id)
+    {
+        id = new Identifier(sv->toDchars(), len, TOKidentifier);
+        sv->ptrvalue = (char *)id;
+    }
+    return id;
+}
+
+Identifier *Identifier::idPool(const char *s, size_t len, int value)
+{
+    StringValue *sv = stringtable.insert(s, len, NULL);
+    assert(sv);
+    Identifier *id = new Identifier(sv->toDchars(), len, value);
+    sv->ptrvalue = (char *)id;
+    return id;
+}
+
+/**********************************
+ * Determine if string is a valid Identifier.
+ * Returns:
+ *      0       invalid
+ */
+
+bool Identifier::isValidIdentifier(const char *p)
+{
+    size_t len;
+    size_t idx;
+
+    if (!p || !*p)
+        goto Linvalid;
+
+    if (*p >= '0' && *p <= '9')         // beware of isdigit() on signed chars
+        goto Linvalid;
+
+    len = strlen(p);
+    idx = 0;
+    while (p[idx])
+    {
+        dchar_t dc;
+        const char *q = utf_decodeChar((const utf8_t *)p, len, &idx, &dc);
+        if (q)
+            goto Linvalid;
+
+        if (!((dc >= 0x80 && isUniAlpha(dc)) || isalnum(dc) || dc == '_'))
+            goto Linvalid;
+    }
+    return true;
+
+Linvalid:
+    return false;
+}
+
+Identifier *Identifier::lookup(const char *s, size_t len)
+{
+    StringValue *sv = stringtable.lookup(s, len);
+    if (!sv)
+        return NULL;
+    return (Identifier *)sv->ptrvalue;
+}
+
+void Identifier::initTable()
+{
+    stringtable._init(28000);
+}