linux/tools/perf/util/demangle-ocaml.c
Fabian Hemmer 292c5ed168 perf tools: Preserve identifier id in OCaml demangler
Some OCaml developers reported that this bit of information is sometimes
useful for disambiguating functions for which the OCaml compiler assigns
the same name, e.g. nested or inlined functions.

Signed-off-by: Fabian Hemmer <copy@copy.sh>
Link: http://lore.kernel.org/lkml/20210226075223.p3s5oz4jbxwnqjtv@nyu
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-03-30 12:45:59 -03:00

69 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include <stdlib.h>
#include "util/string2.h"
#include "demangle-ocaml.h"
#include <linux/ctype.h>
static const char *caml_prefix = "caml";
static const size_t caml_prefix_len = 4;
/* mangled OCaml symbols start with "caml" followed by an upper-case letter */
static bool
ocaml_is_mangled(const char *sym)
{
return 0 == strncmp(sym, caml_prefix, caml_prefix_len)
&& isupper(sym[caml_prefix_len]);
}
/*
* input:
* sym: a symbol which may have been mangled by the OCaml compiler
* return:
* if the input doesn't look like a mangled OCaml symbol, NULL is returned
* otherwise, a newly allocated string containing the demangled symbol is returned
*/
char *
ocaml_demangle_sym(const char *sym)
{
char *result;
int j = 0;
int i;
int len;
if (!ocaml_is_mangled(sym)) {
return NULL;
}
len = strlen(sym);
/* the demangled symbol is always smaller than the mangled symbol */
result = malloc(len + 1);
if (!result)
return NULL;
/* skip "caml" prefix */
i = caml_prefix_len;
while (i < len) {
if (sym[i] == '_' && sym[i + 1] == '_') {
/* "__" -> "." */
result[j++] = '.';
i += 2;
}
else if (sym[i] == '$' && isxdigit(sym[i + 1]) && isxdigit(sym[i + 2])) {
/* "$xx" is a hex-encoded character */
result[j++] = (hex(sym[i + 1]) << 4) | hex(sym[i + 2]);
i += 3;
}
else {
result[j++] = sym[i++];
}
}
result[j] = '\0';
return result;
}