diff options
author | Joshua Haberman <joshua@reverberate.org> | 2011-02-25 19:01:58 -0800 |
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committer | Joshua Haberman <joshua@reverberate.org> | 2011-02-25 19:01:58 -0800 |
commit | 65b57a281390310f0097cbdb9d7967d97f94679c (patch) | |
tree | 2ae338915fb49f345e7c5671936f0ead41dafb3a /src/upb_textprinter.c | |
parent | a75a305c77acd6800b81204f387f7a437a62fe6b (diff) |
Added escaping for text output.
Diffstat (limited to 'src/upb_textprinter.c')
-rw-r--r-- | src/upb_textprinter.c | 55 |
1 files changed, 53 insertions, 2 deletions
diff --git a/src/upb_textprinter.c b/src/upb_textprinter.c index 7e99ebd..076e1df 100644 --- a/src/upb_textprinter.c +++ b/src/upb_textprinter.c @@ -8,6 +8,7 @@ #include <inttypes.h> #include <stdlib.h> +#include <ctype.h> #include "upb_def.h" #include "upb_string.h" @@ -20,6 +21,56 @@ struct _upb_textprinter { #define CHECK(x) if ((x) < 0) goto err; +static int upb_textprinter_putescaped(upb_textprinter *p, upb_string *str, + bool preserve_utf8) { + // Based on CEscapeInternal() from Google's protobuf release. + // TODO; we could write directly into a bytesink's buffer instead. + char dstbuf[4096], *dst = dstbuf, *dstend = dstbuf + sizeof(dstbuf); + const char *src = upb_string_getrobuf(str), *end = src + upb_string_len(str); + + // I think hex is prettier and more useful, but proto2 uses octal; should + // investigate whether it can parse hex also. + bool use_hex = false; + bool last_hex_escape = false; // true if last output char was \xNN + + for (; src < end; src++) { + if (dstend - dst < 4) { + upb_string str = UPB_STACK_STRING_LEN(dstbuf, dst - dstbuf); + CHECK(upb_bytesink_putstr(p->bytesink, &str, &p->status)); + dst = dstbuf; + } + + bool is_hex_escape = false; + switch (*src) { + case '\n': *(dst++) = '\\'; *(dst++) = 'n'; break; + case '\r': *(dst++) = '\\'; *(dst++) = 'r'; break; + case '\t': *(dst++) = '\\'; *(dst++) = 't'; break; + case '\"': *(dst++) = '\\'; *(dst++) = '\"'; break; + case '\'': *(dst++) = '\\'; *(dst++) = '\''; break; + case '\\': *(dst++) = '\\'; *(dst++) = '\\'; break; + default: + // Note that if we emit \xNN and the src character after that is a hex + // digit then that digit must be escaped too to prevent it being + // interpreted as part of the character code by C. + if ((!preserve_utf8 || (uint8_t)*src < 0x80) && + (!isprint(*src) || (last_hex_escape && isxdigit(*src)))) { + sprintf(dst, (use_hex ? "\\x%02x" : "\\%03o"), (uint8_t)*src); + is_hex_escape = use_hex; + dst += 4; + } else { + *(dst++) = *src; break; + } + } + last_hex_escape = is_hex_escape; + } + // Flush remaining data. + upb_string outstr = UPB_STACK_STRING_LEN(dstbuf, dst - dstbuf); + CHECK(upb_bytesink_putstr(p->bytesink, &outstr, &p->status)); + return 0; +err: + return -1; +} + static int upb_textprinter_indent(upb_textprinter *p) { if(!p->single_line) for(int i = 0; i < p->indent_depth; i++) @@ -81,9 +132,9 @@ static upb_flow_t upb_textprinter_value(void *_p, upb_fielddef *f, CASE("%hhu", bool); case UPB_TYPE(STRING): case UPB_TYPE(BYTES): - // TODO: escaping. CHECK(upb_bytesink_putstr(p->bytesink, UPB_STRLIT("\""), &p->status)); - CHECK(upb_bytesink_putstr(p->bytesink, upb_value_getstr(val), &p->status)) + CHECK(upb_textprinter_putescaped(p, upb_value_getstr(val), + f->type == UPB_TYPE(STRING))); CHECK(upb_bytesink_putstr(p->bytesink, UPB_STRLIT("\""), &p->status)); break; } |