| // go-encode-id.cc -- Go identifier encoding hooks |
| |
| // Copyright 2016 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include "go-location.h" |
| #include "go-linemap.h" |
| #include "go-encode-id.h" |
| |
| // Return whether the character c is OK to use in the assembler. |
| |
| static bool |
| char_needs_encoding(char c) |
| { |
| switch (c) |
| { |
| case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': |
| case 'G': case 'H': case 'I': case 'J': case 'K': case 'L': |
| case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R': |
| case 'S': case 'T': case 'U': case 'V': case 'W': case 'X': |
| case 'Y': case 'Z': |
| case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': |
| case 'g': case 'h': case 'i': case 'j': case 'k': case 'l': |
| case 'm': case 'n': case 'o': case 'p': case 'q': case 'r': |
| case 's': case 't': case 'u': case 'v': case 'w': case 'x': |
| case 'y': case 'z': |
| case '0': case '1': case '2': case '3': case '4': |
| case '5': case '6': case '7': case '8': case '9': |
| case '_': case '.': case '$': case '/': |
| return false; |
| default: |
| return true; |
| } |
| } |
| |
| // Return whether the identifier needs to be translated because it |
| // contains non-ASCII characters. |
| |
| bool |
| go_id_needs_encoding(const std::string& str) |
| { |
| for (std::string::const_iterator p = str.begin(); |
| p != str.end(); |
| ++p) |
| if (char_needs_encoding(*p)) |
| return true; |
| return false; |
| } |
| |
| // Pull the next UTF-8 character out of P and store it in *PC. Return |
| // the number of bytes read. |
| |
| static size_t |
| fetch_utf8_char(const char* p, unsigned int* pc) |
| { |
| unsigned char c = *p; |
| if ((c & 0x80) == 0) |
| { |
| *pc = c; |
| return 1; |
| } |
| size_t len = 0; |
| while ((c & 0x80) != 0) |
| { |
| ++len; |
| c <<= 1; |
| } |
| unsigned int rc = *p & ((1 << (7 - len)) - 1); |
| for (size_t i = 1; i < len; i++) |
| { |
| unsigned int u = p[i]; |
| rc <<= 6; |
| rc |= u & 0x3f; |
| } |
| *pc = rc; |
| return len; |
| } |
| |
| // Encode an identifier using ASCII characters. |
| |
| std::string |
| go_encode_id(const std::string &id) |
| { |
| std::string ret; |
| const char* p = id.c_str(); |
| const char* pend = p + id.length(); |
| while (p < pend) |
| { |
| unsigned int c; |
| size_t len = fetch_utf8_char(p, &c); |
| if (len == 1 && !char_needs_encoding(c)) |
| ret += c; |
| else |
| { |
| ret += "$U"; |
| char buf[30]; |
| snprintf(buf, sizeof buf, "%x", c); |
| ret += buf; |
| ret += "$"; |
| } |
| p += len; |
| } |
| return ret; |
| } |
| |
| std::string |
| go_selectively_encode_id(const std::string &id) |
| { |
| if (go_id_needs_encoding(id)) |
| return go_encode_id(id); |
| return std::string(); |
| } |