270 lines
6.4 KiB
C
270 lines
6.4 KiB
C
|
#include <string.h>
|
||
|
|
#include "util.h"
|
||
|
|
#include "debug.h"
|
||
|
|
|
||
|
|
#include "demangle-rust.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Mangled Rust symbols look like this:
|
||
|
|
*
|
||
|
|
* _$LT$std..sys..fd..FileDesc$u20$as$u20$core..ops..Drop$GT$::drop::hc68340e1baa4987a
|
||
|
|
*
|
||
|
|
* The original symbol is:
|
||
|
|
*
|
||
|
|
* <std::sys::fd::FileDesc as core::ops::Drop>::drop
|
||
|
|
*
|
||
|
|
* The last component of the path is a 64-bit hash in lowercase hex, prefixed
|
||
|
|
* with "h". Rust does not have a global namespace between crates, an illusion
|
||
|
|
* which Rust maintains by using the hash to distinguish things that would
|
||
|
|
* otherwise have the same symbol.
|
||
|
|
*
|
||
|
|
* Any path component not starting with a XID_Start character is prefixed with
|
||
|
|
* "_".
|
||
|
|
*
|
||
|
|
* The following escape sequences are used:
|
||
|
|
*
|
||
|
|
* "," => $C$
|
||
|
|
* "@" => $SP$
|
||
|
|
* "*" => $BP$
|
||
|
|
* "&" => $RF$
|
||
|
|
* "<" => $LT$
|
||
|
|
* ">" => $GT$
|
||
|
|
* "(" => $LP$
|
||
|
|
* ")" => $RP$
|
||
|
|
* " " => $u20$
|
||
|
|
* "'" => $u27$
|
||
|
|
* "[" => $u5b$
|
||
|
|
* "]" => $u5d$
|
||
|
|
* "~" => $u7e$
|
||
|
|
*
|
||
|
|
* A double ".." means "::" and a single "." means "-".
|
||
|
|
*
|
||
|
|
* The only characters allowed in the mangled symbol are a-zA-Z0-9 and _.:$
|
||
|
|
*/
|
||
|
|
|
||
|
|
static const char *hash_prefix = "::h";
|
||
|
|
static const size_t hash_prefix_len = 3;
|
||
|
|
static const size_t hash_len = 16;
|
||
|
|
|
||
|
|
static bool is_prefixed_hash(const char *start);
|
||
|
|
static bool looks_like_rust(const char *sym, size_t len);
|
||
|
|
static bool unescape(const char **in, char **out, const char *seq, char value);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* INPUT:
|
||
|
|
* sym: symbol that has been through BFD-demangling
|
||
|
|
*
|
||
|
|
* This function looks for the following indicators:
|
||
|
|
*
|
||
|
|
* 1. The hash must consist of "h" followed by 16 lowercase hex digits.
|
||
|
|
*
|
||
|
|
* 2. As a sanity check, the hash must use between 5 and 15 of the 16 possible
|
||
|
|
* hex digits. This is true of 99.9998% of hashes so once in your life you
|
||
|
|
* may see a false negative. The point is to notice path components that
|
||
|
|
* could be Rust hashes but are probably not, like "haaaaaaaaaaaaaaaa". In
|
||
|
|
* this case a false positive (non-Rust symbol has an important path
|
||
|
|
* component removed because it looks like a Rust hash) is worse than a
|
||
|
|
* false negative (the rare Rust symbol is not demangled) so this sets the
|
||
|
|
* balance in favor of false negatives.
|
||
|
|
*
|
||
|
|
* 3. There must be no characters other than a-zA-Z0-9 and _.:$
|
||
|
|
*
|
||
|
|
* 4. There must be no unrecognized $-sign sequences.
|
||
|
|
*
|
||
|
|
* 5. There must be no sequence of three or more dots in a row ("...").
|
||
|
|
*/
|
||
|
|
bool
|
||
|
|
rust_is_mangled(const char *sym)
|
||
|
|
{
|
||
|
|
size_t len, len_without_hash;
|
||
|
|
|
||
|
|
if (!sym)
|
||
|
|
return false;
|
||
|
|
|
||
|
|
len = strlen(sym);
|
||
|
|
if (len <= hash_prefix_len + hash_len)
|
||
|
|
/* Not long enough to contain "::h" + hash + something else */
|
||
|
|
return false;
|
||
|
|
|
||
|
|
len_without_hash = len - (hash_prefix_len + hash_len);
|
||
|
|
if (!is_prefixed_hash(sym + len_without_hash))
|
||
|
|
return false;
|
||
|
|
|
||
|
|
return looks_like_rust(sym, len_without_hash);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* A hash is the prefix "::h" followed by 16 lowercase hex digits. The hex
|
||
|
|
* digits must comprise between 5 and 15 (inclusive) distinct digits.
|
||
|
|
*/
|
||
|
|
static bool is_prefixed_hash(const char *str)
|
||
|
|
{
|
||
|
|
const char *end;
|
||
|
|
bool seen[16];
|
||
|
|
size_t i;
|
||
|
|
int count;
|
||
|
|
|
||
|
|
if (strncmp(str, hash_prefix, hash_prefix_len))
|
||
|
|
return false;
|
||
|
|
str += hash_prefix_len;
|
||
|
|
|
||
|
|
memset(seen, false, sizeof(seen));
|
||
|
|
for (end = str + hash_len; str < end; str++)
|
||
|
|
if (*str >= '0' && *str <= '9')
|
||
|
|
seen[*str - '0'] = true;
|
||
|
|
else if (*str >= 'a' && *str <= 'f')
|
||
|
|
seen[*str - 'a' + 10] = true;
|
||
|
|
else
|
||
|
|
return false;
|
||
|
|
|
||
|
|
/* Count how many distinct digits seen */
|
||
|
|
count = 0;
|
||
|
|
for (i = 0; i < 16; i++)
|
||
|
|
if (seen[i])
|
||
|
|
count++;
|
||
|
|
|
||
|
|
return count >= 5 && count <= 15;
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool looks_like_rust(const char *str, size_t len)
|
||
|
|
{
|
||
|
|
const char *end = str + len;
|
||
|
|
|
||
|
|
while (str < end)
|
||
|
|
switch (*str) {
|
||
|
|
case '$':
|
||
|
|
if (!strncmp(str, "$C$", 3))
|
||
|
|
str += 3;
|
||
|
|
else if (!strncmp(str, "$SP$", 4)
|
||
|
|
|| !strncmp(str, "$BP$", 4)
|
||
|
|
|| !strncmp(str, "$RF$", 4)
|
||
|
|
|| !strncmp(str, "$LT$", 4)
|
||
|
|
|| !strncmp(str, "$GT$", 4)
|
||
|
|
|| !strncmp(str, "$LP$", 4)
|
||
|
|
|| !strncmp(str, "$RP$", 4))
|
||
|
|
str += 4;
|
||
|
|
else if (!strncmp(str, "$u20$", 5)
|
||
|
|
|| !strncmp(str, "$u27$", 5)
|
||
|
|
|| !strncmp(str, "$u5b$", 5)
|
||
|
|
|| !strncmp(str, "$u5d$", 5)
|
||
|
|
|| !strncmp(str, "$u7e$", 5))
|
||
|
|
str += 5;
|
||
|
|
else
|
||
|
|
return false;
|
||
|
|
break;
|
||
|
|
case '.':
|
||
|
|
/* Do not allow three or more consecutive dots */
|
||
|
|
if (!strncmp(str, "...", 3))
|
||
|
|
return false;
|
||
|
|
/* Fall through */
|
||
|
|
case 'a' ... 'z':
|
||
|
|
case 'A' ... 'Z':
|
||
|
|
case '0' ... '9':
|
||
|
|
case '_':
|
||
|
|
case ':':
|
||
|
|
str++;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* INPUT:
|
||
|
|
* sym: symbol for which rust_is_mangled(sym) returns true
|
||
|
|
*
|
||
|
|
* The input is demangled in-place because the mangled name is always longer
|
||
|
|
* than the demangled one.
|
||
|
|
*/
|
||
|
|
void
|
||
|
|
rust_demangle_sym(char *sym)
|
||
|
|
{
|
||
|
|
const char *in;
|
||
|
|
char *out;
|
||
|
|
const char *end;
|
||
|
|
|
||
|
|
if (!sym)
|
||
|
|
return;
|
||
|
|
|
||
|
|
in = sym;
|
||
|
|
out = sym;
|
||
|
|
end = sym + strlen(sym) - (hash_prefix_len + hash_len);
|
||
|
|
|
||
|
|
while (in < end)
|
||
|
|
switch (*in) {
|
||
|
|
case '$':
|
||
|
|
if (!(unescape(&in, &out, "$C$", ',')
|
||
|
|
|| unescape(&in, &out, "$SP$", '@')
|
||
|
|
|| unescape(&in, &out, "$BP$", '*')
|
||
|
|
|| unescape(&in, &out, "$RF$", '&')
|
||
|
|
|| unescape(&in, &out, "$LT$", '<')
|
||
|
|
|| unescape(&in, &out, "$GT$", '>')
|
||
|
|
|| unescape(&in, &out, "$LP$", '(')
|
||
|
|
|| unescape(&in, &out, "$RP$", ')')
|
||
|
|
|| unescape(&in, &out, "$u20$", ' ')
|
||
|
|
|| unescape(&in, &out, "$u27$", '\'')
|
||
|
|
|| unescape(&in, &out, "$u5b$", '[')
|
||
|
|
|| unescape(&in, &out, "$u5d$", ']')
|
||
|
|
|| unescape(&in, &out, "$u7e$", '~'))) {
|
||
|
|
pr_err("demangle-rust: unexpected escape sequence");
|
||
|
|
goto done;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case '_':
|
||
|
|
/*
|
||
|
|
* If this is the start of a path component and the next
|
||
|
|
* character is an escape sequence, ignore the
|
||
|
|
* underscore. The mangler inserts an underscore to make
|
||
|
|
* sure the path component begins with a XID_Start
|
||
|
|
* character.
|
||
|
|
*/
|
||
|
|
if ((in == sym || in[-1] == ':') && in[1] == '$')
|
||
|
|
in++;
|
||
|
|
else
|
||
|
|
*out++ = *in++;
|
||
|
|
break;
|
||
|
|
case '.':
|
||
|
|
if (in[1] == '.') {
|
||
|
|
/* ".." becomes "::" */
|
||
|
|
*out++ = ':';
|
||
|
|
*out++ = ':';
|
||
|
|
in += 2;
|
||
|
|
} else {
|
||
|
|
/* "." becomes "-" */
|
||
|
|
*out++ = '-';
|
||
|
|
in++;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case 'a' ... 'z':
|
||
|
|
case 'A' ... 'Z':
|
||
|
|
case '0' ... '9':
|
||
|
|
case ':':
|
||
|
|
*out++ = *in++;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
pr_err("demangle-rust: unexpected character '%c' in symbol\n",
|
||
|
|
*in);
|
||
|
|
goto done;
|
||
|
|
}
|
||
|
|
|
||
|
|
done:
|
||
|
|
*out = '\0';
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool unescape(const char **in, char **out, const char *seq, char value)
|
||
|
|
{
|
||
|
|
size_t len = strlen(seq);
|
||
|
|
|
||
|
|
if (strncmp(*in, seq, len))
|
||
|
|
return false;
|
||
|
|
|
||
|
|
**out = value;
|
||
|
|
|
||
|
|
*in += len;
|
||
|
|
*out += 1;
|
||
|
|
|
||
|
|
return true;
|
||
|
|
}
|