Cairo介绍及源码构建安装（2）
接前一篇文章：Cairo介绍及源码构建安装（1）
四、Cairo构建与安装
1. 源码修改
（1）修改lookup-symbol.c
修改命令如下：
sed 's/PTR/void */' -i util/cairo-trace/lookup-symbol.c这句的意思是将util/cairo-trace/lookup-symbol.c文件中所有地方的“PTR”替换为“void *”。
lookup-symbol.c文件原始内容如下：
/* cairo-trace - a utility to record and replay calls to the Cairo library.
*
* Copyright © 2008 Chris Wilson
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see
This file was part of GNU Binutils.
*/
#include "config.h"
#define true 1
#define false 0
#include "lookup-symbol.h"
#include
#include
#include
#include
#include
#include
#if HAVE_BFD
#include
struct symtab {
bfd *bfd;
asymbol **syms;
};
struct symbol {
int found;
bfd_vma pc;
struct symtab *symtab;
const char *filename;
const char *functionname;
unsigned int line;
};
static void
_symtab_fini (struct symtab *symtab)
{
free (symtab->syms);
if (symtab->bfd != NULL)
bfd_close (symtab->bfd);
}
/* Read in the symbol table. */
static int
_symtab_init (struct symtab *symtab, const char *filename)
{
char **matching;
long symcount;
unsigned int size;
symtab->bfd = NULL;
symtab->syms = NULL;
symtab->bfd = bfd_openr (filename, NULL);
if (symtab->bfd == NULL)
goto BAIL;
if (bfd_check_format (symtab->bfd, bfd_archive))
goto BAIL;
if (! bfd_check_format_matches (symtab->bfd, bfd_object, &matching))
goto BAIL;
symcount = bfd_read_minisymbols (symtab->bfd, false, (PTR) &symtab->syms, &size);
if (symcount == 0) {
symcount = bfd_read_minisymbols (symtab->bfd, true /* dynamic */ ,
(PTR) &symtab->syms, &size);
}
if (symcount < 0)
goto BAIL;
if ((bfd_get_file_flags (symtab->bfd) & HAS_SYMS) == 0)
goto BAIL;
return 1;
BAIL:
_symtab_fini (symtab);
return 0;
}
/* Look for an address in a section.
* This is called via bfd_map_over_sections.
*/
static void
find_address_in_section (bfd *abfd,
asection *section,
void *data)
{
bfd_vma vma;
bfd_size_type size;
struct symbol *symbol = data;
struct symtab *symtab = symbol->symtab;
if (symbol->found)
return;
if ((bfd_section_flags (section) & SEC_ALLOC) == 0)
return;
vma = bfd_section_vma (section);
if (symbol->pc < vma)
return;
size = bfd_section_size (section);
if (symbol->pc >= vma + size)
return;
symbol->found = bfd_find_nearest_line (symtab->bfd, section,
symtab->syms,
symbol->pc - vma,
&symbol->filename,
&symbol->functionname,
&symbol->line);
}
static void
_symbol_fini (struct symbol *symbol)
{
}
static void
_symbol_init (struct symbol *symbol, struct symtab *symtab, bfd_vma addr)
{
symbol->found = false;
symbol->symtab = symtab;
symbol->pc = addr;
}
static void
_symbol_print (struct symbol *symbol, char *buf, int buflen, const char *filename)
{
const char *name, *h;
char path[1024];
if (! symbol->found)
return;
name = symbol->functionname;
if (name == NULL || *name == '\0')
name = "??";
if (symbol->filename != NULL)
filename = symbol->filename;
if (strcmp (filename, "/proc/self/exe") == 0) {
int len = readlink ("/proc/self/exe", path, sizeof (path) - 1);
if (len != -1) {
path[len] = '\0';
filename = path;
}
}
h = strrchr (filename, '/');
if (h != NULL)
filename = h + 1;
if (symbol->line) {
snprintf (buf, buflen, "%s() [%s:%u]",
name, filename, symbol->line);
} else {
snprintf (buf, buflen, "%s() [%s]", name, filename);
}
}
#endif
struct file_match {
const char *file;
ElfW(Addr) address;
ElfW(Addr) base;
void *hdr;
};
static int
find_matching_file (struct dl_phdr_info *info, size_t size, void *data)
{
struct file_match *match = data;
/* This code is modeled from Gfind_proc_info-lsb.c:callback() from libunwind */
long n;
const ElfW(Phdr) *phdr;
ElfW(Addr) load_base = info->dlpi_addr;
phdr = info->dlpi_phdr;
for (n = info->dlpi_phnum; --n >= 0; phdr++) {
if (phdr->p_type == PT_LOAD) {
ElfW(Addr) vaddr = phdr->p_vaddr + load_base;
if (match->address >= vaddr &&
match->address < vaddr + phdr->p_memsz)
{
/* we found a match */
match->file = info->dlpi_name;
match->base = info->dlpi_addr;
return 1;
}
}
}
return 0;
}
struct symbol_cache_entry {
const void *ptr;
struct symbol_cache_entry *hash_prev, *hash_next;
char name[0];
};
static struct symbol_cache_entry *symbol_cache_hash[13477];
static pthread_mutex_t symbol_cache_mutex = PTHREAD_MUTEX_INITIALIZER;
char *
lookup_symbol (char *buf, int buflen, const void *ptr)
{
struct file_match match;
#if HAVE_BFD
struct symtab symtab;
struct symbol symbol;
#endif
struct symbol_cache_entry *cache;
int bucket;
int len;
bucket = (uintptr_t) ptr % (sizeof (symbol_cache_hash) / sizeof (symbol_cache_hash[0]));
pthread_mutex_lock (&symbol_cache_mutex);
for (cache = symbol_cache_hash[bucket];
cache != NULL;
cache = cache->hash_next)
{
if (cache->ptr == ptr) {
if (cache->hash_prev != NULL) {
cache->hash_prev->hash_next = cache->hash_next;
if (cache->hash_next != NULL)
cache->hash_next->hash_prev = cache->hash_prev;
cache->hash_prev = NULL;
cache->hash_next = symbol_cache_hash[bucket];
symbol_cache_hash[bucket]->hash_prev = cache;
symbol_cache_hash[bucket] = cache;
}
pthread_mutex_unlock (&symbol_cache_mutex);
return cache->name;
}
}
pthread_mutex_unlock (&symbol_cache_mutex);
match.file = NULL;
match.address = (ElfW(Addr)) ptr;
dl_iterate_phdr (find_matching_file, &match);
snprintf (buf, buflen, "0x%llx",
(long long unsigned int) match.address);
if (match.file == NULL || *match.file == '\0')
match.file = "/proc/self/exe";
#if HAVE_BFD
if (_symtab_init (&symtab, match.file)) {
_symbol_init (&symbol, &symtab, match.address - match.base);
bfd_map_over_sections (symtab.bfd, find_address_in_section, &symbol);
if (symbol.found)
_symbol_print (&symbol, buf, buflen, match.file);
_symbol_fini (&symbol);
_symtab_fini (&symtab);
}
#endif
len = strlen (buf);
cache = malloc (sizeof (struct symbol_cache_entry) + len + 1);
if (cache != NULL) {
cache->ptr = ptr;
memcpy (cache->name, buf, len + 1);
pthread_mutex_lock (&symbol_cache_mutex);
cache->hash_prev = NULL;
cache->hash_next = symbol_cache_hash[bucket];
if (symbol_cache_hash[bucket] != NULL)
symbol_cache_hash[bucket]->hash_prev = cache;
symbol_cache_hash[bucket] = cache;
pthread_mutex_unlock (&symbol_cache_mutex);
}
return buf;
} 真正需要替换的只有2处，代码片段如下：
symcount = bfd_read_minisymbols (symtab->bfd, false, (PTR) &symtab->syms, &size);
if (symcount == 0) {
symcount = bfd_read_minisymbols (symtab->bfd, true /* dynamic */ ,
(PTR) &symtab->syms, &size);
}
if (symcount < 0)
goto BAIL;执行命令后，这段内容变为：
symcount = bfd_read_minisymbols (symtab->bfd, false, (void *) &symtab->syms, &size);
if (symcount == 0) {
symcount = bfd_read_minisymbols (symtab->bfd, true /* dynamic */ ,
(void *) &symtab->syms, &size);
}
if (symcount < 0)
goto BAIL;
（2）修改cairo-script-interpreter.pc.in
修改命令如下：
sed -e "/@prefix@/a exec_prefix=@exec_prefix@" \
-i util/cairo-script/cairo-script-interpreter.pc.in这句的意思是在util/cairo-script/cairo-script-interpreter.pc.in文件中找到包含“@prefix@”的一行，在其下方添加一行内容：exec_prefix=@exec_prefix@。
cairo-script-interpreter.pc.in文件原始内容如下：
prefix=@prefix@
libdir=@libdir@
includedir=@includedir@
Name: cairo-script-interpreter
Description: script surface backend for cairo graphics library
Version: @VERSION@
Requires: cairo
Libs: -L${libdir} -lcairo-script-interpreter
Cflags: -I${includedir}/cairo
执行命令后，文件内容变为：
prefix=@prefix@
exec_prefix=@exec_prefix@
libdir=@libdir@
includedir=@includedir@
Name: cairo-script-interpreter
Description: script surface backend for cairo graphics library
Version: @VERSION@
Requires: cairo
Libs: -L${libdir} -lcairo-script-interpreter
Cflags: -I${includedir}/cairo