emscripten/emlink.py

324 строки
13 KiB
Python

#!/usr/bin/env python2
'''
Fast static linker for emscripten outputs. Specifically this links asm.js modules.
Usage: emlink.py [main module] [side module] [output name]
Main module should be built with -s MAIN_MODULE=1 (and possibly -s DISABLE_GL_EMULATION=1, if you do not need GL emulation)
Side module should be built with -s SIDE_MODULE=1
Note that the output file can be used as a main module, so you can link multiple
side modules into a main module that way.
Limitations:
* Modules cannot be minified (but can be minified after linking)
* We duplicate code in some cases, like overlapping names in different modules, and function aliases
* We only share code between modules, not global variables. Global variables should be declared
in the module that uses them, other modules can reach them through function calls. For example,
a static class function implemented in one module can be called from another, and it can provide
access to static variables on that class. (Note that implementing the static class function in a
header will not work, then the code will be duplicated in each module, with only one of them
able to correctly access the variable - the one in the same module as where the variable is
declared.)
* We do not link in compiled libraries (libc, libc++, etc.) in side modules. If the main module
does not automatically link in the ones that side modules will need, you should compile the
main module with
EMCC_FORCE_STDLIBS=1 emcc ..
which will link in all the libraries (you can also do EMCC_FORCE_STDLIBS=libc for example to
include just libc and its dependencies; run with EMCC_DEBUG=1 to see which are necessary and
include the first one).
Overall, this linking approach should be fast to perform, but generate less-optimal results than
to link all the bitcode together and build to JS as a single project. Final builds should be
done in that approach, but during development static linking can avoid recompiling your entire
project all the time.
'''
import os, subprocess, sys, re
from tools import shared
from tools import js_optimizer
try:
me, main, side, out = sys.argv[:4]
except:
print >> sys.stderr, 'usage: emlink.py [main module] [side module] [output name]'
sys.exit(1)
print 'Main module:', main
print 'Side module:', side
print 'Output:', out
shared.try_delete(out)
class AsmModule():
def __init__(self, filename):
self.filename = filename
self.js = open(filename).read()
self.start_asm = self.js.find(js_optimizer.start_asm_marker)
self.start_funcs = self.js.find(js_optimizer.start_funcs_marker)
self.end_funcs = self.js.rfind(js_optimizer.end_funcs_marker)
self.end_asm = self.js.rfind(js_optimizer.end_asm_marker)
# pre
self.pre_js = self.js[:self.start_asm]
# heap initializer
self.staticbump = int(re.search(shared.JS.memory_staticbump_pattern, self.pre_js).group(1))
if self.staticbump:
self.mem_init_js = re.search(shared.JS.memory_initializer_pattern, self.pre_js).group(0)
# global initializers
global_inits = re.search(shared.JS.global_initializers_pattern, self.pre_js)
if global_inits:
self.global_inits_js = global_inits.group(0)
self.global_inits = map(lambda init: init.split('{')[2][1:].split('(')[0], global_inits.groups(0)[0].split(','))
else:
self.global_inits_js = ''
self.global_inits = []
# imports (and global variables)
first_var = self.js.find('var ', self.js.find('var ', self.start_asm)+4)
self.pre_imports_js = self.js[self.start_asm:first_var]
self.imports_js = self.js[first_var:self.start_funcs]
self.imports = {}
for imp in js_optimizer.import_sig.finditer(self.imports_js):
key, value = imp.group(0).split('var ')[1][:-1].split('=', 1)
self.imports[key] = value
#print >> sys.stderr, 'imports', self.imports
# funcs
self.funcs_js = self.js[self.start_funcs:self.end_funcs]
self.funcs = set([m.group(2) for m in js_optimizer.func_sig.finditer(self.funcs_js)])
#print 'funcs', self.funcs
# tables and exports
post_js = self.js[self.end_funcs:self.end_asm]
ret = post_js.find('return')
self.tables_js = post_js[:ret]
self.exports_js = post_js[ret:]
self.tables = self.parse_tables(self.tables_js)
self.exports = set([export.strip() for export in self.exports_js[self.exports_js.find('{')+1:self.exports_js.find('}')].split(',')])
# post
self.post_js = self.js[self.end_asm:]
self.sendings = {}
for sending in [sending.strip() for sending in self.post_js[self.post_js.find('}, { ')+5:self.post_js.find(' }, buffer);')].split(',')]:
colon = sending.find(':')
self.sendings[sending[:colon].replace('"', '')] = sending[colon+1:].strip()
self.module_defs = set(re.findall('var [\w\d_$]+ = Module\["[\w\d_$]+"\] = asm\["[\w\d_$]+"\];\n', self.post_js))
def relocate_into(self, main):
# heap initializer
if self.staticbump > 0:
new_mem_init = self.mem_init_js[:self.mem_init_js.rfind(', ')] + ', Runtime.GLOBAL_BASE+%d)' % main.staticbump
main.pre_js = re.sub(shared.JS.memory_staticbump_pattern, 'STATICTOP = STATIC_BASE + %d;\n' % (main.staticbump + side.staticbump) + new_mem_init, main.pre_js, count=1)
# Find function name replacements TODO: do not rename duplicate names with duplicate contents, just merge them
replacements = {}
for func in self.funcs:
rep = func
while rep in main.funcs:
rep += '_'
replacements[func] = rep
#print >> sys.stderr, 'replacements:', replacements
# sendings: add invokes for new tables
all_sendings = main.sendings
added_sending = False
for table in self.tables:
if table not in main.tables:
sig = table[table.rfind('_')+1:]
all_sendings['invoke_%s' % sig] = shared.JS.make_invoke(sig, named=False)
added_sending = True
# imports
all_imports = main.imports
for key, value in self.imports.iteritems():
if key in self.funcs or key in main.funcs: continue # external function in one module, implemented in the other
value_concrete = '.' not in value # env.key means it is an import, an external value, and not a concrete one
main_value = main.imports.get(key)
main_value_concrete = main_value and '.' not in main_value
if value_concrete and main_value_concrete: continue # standard global var
if not main_value or value_concrete:
if '+' in value:
# relocate
value = value.replace('(', '').replace(')', '').replace('| 0', '').replace('|0', '').replace(' ', '')
left, right = value.split('+')
assert left == 'H_BASE'
value = str(main.staticbump + int(right))
all_imports[key] = value
if (value_concrete or main_value_concrete) and key in all_sendings:
del all_sendings[key] # import of external value no longer needed
main.imports_js = '\n'.join(['var %s = %s;' % (key, value) for key, value in all_imports.iteritems()]) + '\n'
if added_sending:
sendings_js = ', '.join(['%s: %s' % (key, value) for key, value in all_sendings.iteritems()])
sendings_start = main.post_js.find('}, { ')+5
sendings_end = main.post_js.find(' }, buffer);')
main.post_js = main.post_js[:sendings_start] + sendings_js + main.post_js[sendings_end:]
# check for undefined references to global variables
def check_import(key, value):
if value.startswith('+') or value.endswith('|0'): # ignore functions
if key not in all_sendings:
print >> sys.stderr, 'external variable %s is still not defined after linking' % key
for key, value in all_imports.iteritems(): check_import(key, value)
# tables
f_bases = {}
f_sizes = {}
for table, data in self.tables.iteritems():
main.tables[table] = self.merge_tables(table, main.tables.get(table), data, replacements, f_bases, f_sizes)
main.combine_tables()
# relocate
temp = shared.Building.js_optimizer(self.filename, ['asm', 'relocate', 'last'], extra_info={
'replacements': replacements,
'fBases': f_bases,
'hBase': main.staticbump
})
#print >> sys.stderr, 'relocated side into', temp
relocated_funcs = AsmModule(temp)
shared.try_delete(temp)
main.extra_funcs_js = relocated_funcs.funcs_js.replace(js_optimizer.start_funcs_marker, '\n')
# update function table uses
ft_marker = 'FUNCTION_TABLE_'
def update_fts(what):
updates = []
i = 1 # avoid seeing marker in recursion
while 1:
i = what.find(ft_marker, i)
if i < 0: break;
start = i
end = what.find('[', start)
table = what[i:end]
if table not in f_sizes:
# table was not modified
i += len(ft_marker)
continue
nesting = 1
while nesting > 0:
next = what.find(']', end+1)
nesting -= 1
nesting += what.count('[', end+1, next)
end = next
assert end > 0
mask = what.rfind('&', start, end)
assert mask > 0 and end - mask <= 13
fixed = update_fts(what[start:mask+1] + str(f_sizes[table]-1) + ']')
updates.append((start, end, fixed))
i = end # additional function table uses were done by recursion
# apply updates
if len(updates) == 0: return what
parts = []
so_far = 0
for i in range(len(updates)):
start, end, fixed = updates[i]
parts.append(what[so_far:start])
parts.append(fixed)
so_far = end+1
parts.append(what[so_far:])
return ''.join(parts)
main.funcs_js = update_fts(main.funcs_js)
main.extra_funcs_js = update_fts(main.extra_funcs_js)
# global initializers
if self.global_inits:
my_global_inits = map(lambda init: replacements[init] if init in replacements else init, self.global_inits)
all_global_inits = map(lambda init: '{ func: function() { %s() } }' % init, main.global_inits + my_global_inits)
all_global_inits_js = '/* global initializers */ __ATINIT__.push(' + ','.join(all_global_inits) + ');'
if main.global_inits:
target = main.global_inits_js
else:
target = '// === Body ===\n'
all_global_inits_js = target + all_global_inits_js
main.pre_js = main.pre_js.replace(target, all_global_inits_js)
# exports
def rep_exp(export):
key, value = export.split(':')
if key in replacements:
repped = replacements[key]
return repped + ': ' + repped
return export
my_exports = map(rep_exp, self.exports)
exports = main.exports.union(my_exports)
main.exports_js = 'return {' + ','.join(list(exports)) + '};\n})\n'
# post
def rep_def(deff):
key = deff.split(' ')[1]
if key in replacements:
rep = replacements[key]
return 'var %s = Module["%s"] = asm["%s"];\n' % (rep, rep, rep)
return deff
my_module_defs = map(rep_def, self.module_defs)
new_module_defs = set(my_module_defs).difference(main.module_defs)
if len(new_module_defs) > 0:
position = main.post_js.find('Runtime.') # Runtime is the start of the hardcoded ones
main.post_js = main.post_js[:position] + ''.join(list(new_module_defs)) + '\n' + main.post_js[position:]
def write(self, out):
f = open(out, 'w')
f.write(self.pre_js)
f.write(self.pre_imports_js)
f.write(self.imports_js)
f.write(self.funcs_js)
f.write(self.extra_funcs_js)
f.write(self.tables_js)
f.write(self.exports_js)
f.write(self.post_js)
f.close()
# Utilities
def parse_tables(self, js):
tables = {}
parts = js.split(';')
for part in parts:
if '=' not in part: continue
part = part.split('var ')[1]
name, data = part.split(' = ')
tables[name] = data
return tables
def merge_tables(self, table, main, side, replacements, f_bases, f_sizes):
side = side[1:-1].split(',')
side = map(lambda f: replacements[f] if f in replacements else f, side)
if not main:
f_bases[table] = 0
f_sizes[table] = len(side)
return '[' + ','.join(side) + ']'
main = main[1:-1].split(',')
# TODO: handle non-aliasing case too
assert len(main) % 2 == 0
f_bases[table] = len(main)
ret = main + side
size = 2
while size < len(ret): size *= 2
aborter = ret[1] # we can assume odd indexes have an aborting function with the right signature
ret = ret + [aborter]*(size - len(ret))
assert len(ret) == size
f_sizes[table] = size
return '[' + ','.join(ret) + ']'
def combine_tables(self):
self.tables_js = '// EMSCRIPTEN_END_FUNCS\n'
for table, data in self.tables.iteritems():
self.tables_js += 'var %s = %s;\n' % (table, data)
main = AsmModule(main)
side = AsmModule(side)
side.relocate_into(main)
main.write(out)