Bazel add html support (#765)
* allow the bazel toolchain to output html files
* allow for cc_binary rule names to end in .js
* fix python name
* continue to call emcc instead of em++ for now
* small cleanup
Co-authored-by: Mitch Foley <mitchfoley@chromium.org>
diff --git a/bazel/emscripten_toolchain/crosstool.bzl b/bazel/emscripten_toolchain/crosstool.bzl
index 0da1cb0..10c15cb 100644
--- a/bazel/emscripten_toolchain/crosstool.bzl
+++ b/bazel/emscripten_toolchain/crosstool.bzl
@@ -436,6 +436,11 @@
# https://emscripten.org/docs/debugging/Sanitizers.html
feature(name = "wasm_asan"),
feature(name = "wasm_ubsan"),
+
+ feature(
+ name = "output_format_js",
+ enabled = True,
+ ),
]
crosstool_default_flag_sets = [
@@ -547,6 +552,11 @@
flags = ["-s", "PRINTF_LONG_DOUBLE=1"],
features = ["precise_long_double_printf"],
),
+ flag_set(
+ actions = all_link_actions,
+ flags = ["--oformat=js"],
+ features = ["output_format_js"],
+ ),
# Opt
flag_set(
diff --git a/bazel/emscripten_toolchain/link_wrapper.py b/bazel/emscripten_toolchain/link_wrapper.py
index a746ae8..1e26bde 100644
--- a/bazel/emscripten_toolchain/link_wrapper.py
+++ b/bazel/emscripten_toolchain/link_wrapper.py
@@ -3,19 +3,20 @@
This wrapper currently serves the following purposes.
-1. Ensures we always link to file with .js extension. The upstream default
- it to link to an llvm bitcode file which is never (AFAICT) want to do that.
-
-2. When building with --config=wasm the final output is multiple files, usually
+1. When building with --config=wasm the final output is multiple files, usually
at least one .js and one .wasm file. Since the cc_binary link step only
allows a single output, we must tar up the outputs into a single file.
-3. Add quotes around arguments that need them in the response file to work
+2. Add quotes around arguments that need them in the response file to work
around a bazel quirk.
+
+3. Ensure the external_debug_info section of the wasm points at the correct
+ bazel path.
"""
from __future__ import print_function
+import argparse
import os
import subprocess
import sys
@@ -25,20 +26,8 @@
param_filename = sys.argv[1][1:]
param_file_args = [l.strip() for l in open(param_filename, 'r').readlines()]
-output_index = param_file_args.index('-o') + 1
-orig_output = js_output = param_file_args[output_index]
-outdir = os.path.dirname(orig_output)
-
-# google3-only(TODO(b/139440956): Default to False once the bug is fixed)
-replace_response_file = any(' ' in a for a in param_file_args)
-
-if not os.path.splitext(orig_output)[1]:
- js_output = orig_output + '.js'
- param_file_args[output_index] = js_output
- replace_response_file = True
-
# Re-write response file if needed.
-if replace_response_file:
+if any(' ' in a for a in param_file_args):
new_param_filename = param_filename + '.modified'
with open(new_param_filename, 'w') as f:
for param in param_file_args:
@@ -54,8 +43,41 @@
if rtn != 0:
sys.exit(1)
-js_name = os.path.basename(js_output)
-base_name = os.path.splitext(js_name)[0]
+# Parse the arguments that we gave to the linker to determine what the output
+# file is named and what the output format is.
+parser = argparse.ArgumentParser(add_help=False)
+parser.add_argument('-o')
+parser.add_argument('--oformat')
+options = parser.parse_known_args(param_file_args)[0]
+output_file = options.o
+oformat = options.oformat
+outdir = os.path.dirname(output_file)
+base_name = os.path.basename(output_file)
+
+# The output file name is the name of the build rule that was built.
+# Add an appropriate file extension based on --oformat.
+if oformat is not None:
+ base_name_split = os.path.splitext(base_name)
+
+ # If the output name has no extension, give it the appropriate extension.
+ if not base_name_split[1]:
+ os.rename(output_file, output_file + '.' + oformat)
+
+ # If the output name does have an extension and it matches the output format,
+ # change the base_name so it doesn't have an extension.
+ elif base_name_split[1] == '.' + oformat:
+ base_name = base_name_split[0]
+
+ # If the output name does have an extension and it does not match the output
+ # format, change the base_name so it doesn't have an extension and rename
+ # the output_file so it has the proper extension.
+ # Note that if you do something like name your build rule "foo.js" and pass
+ # "--oformat=html", emscripten will write to the same file for both the js and
+ # html output, overwriting the js output entirely with the html.
+ # Please don't do that.
+ else:
+ base_name = base_name_split[0]
+ os.rename(output_file, os.path.join(outdir, base_name + '.' + oformat))
files = []
extensions = [
@@ -67,7 +89,8 @@
'.worker.js',
'.data',
'.js.symbols',
- '.wasm.debug.wasm'
+ '.wasm.debug.wasm',
+ '.html'
]
for ext in extensions:
@@ -112,7 +135,7 @@
binary_part = '1' + binary_part
final_bytes.append(int(binary_part, 2))
# Finally, add the actual filename.
- final_bytes.extend(base_name + '.wasm.debug.wasm')
+ final_bytes.extend((base_name + '.wasm.debug.wasm').encode())
# Write our length + filename bytes to a temp file.
with open('debugsection.tmp', 'wb+') as f:
@@ -134,11 +157,11 @@
if len(files) > 1:
cmd = ['tar', 'cf', 'tmp.tar'] + files
subprocess.check_call(cmd, cwd=outdir)
- os.rename(os.path.join(outdir, 'tmp.tar'), orig_output)
+ os.rename(os.path.join(outdir, 'tmp.tar'), output_file)
elif len(files) == 1:
# Otherwise, if only have a single output than move it to the expected name
- if files[0] != os.path.basename(orig_output):
- os.rename(os.path.join(outdir, files[0]), orig_output)
+ if files[0] != os.path.basename(output_file):
+ os.rename(os.path.join(outdir, files[0]), output_file)
else:
print('emcc.py did not appear to output any known files!')
sys.exit(1)
diff --git a/bazel/emscripten_toolchain/wasm_binary.py b/bazel/emscripten_toolchain/wasm_binary.py
index 97df45b..641c0d6 100644
--- a/bazel/emscripten_toolchain/wasm_binary.py
+++ b/bazel/emscripten_toolchain/wasm_binary.py
@@ -77,6 +77,7 @@
ensure(os.path.join(args.output_path, stem + '.fetch.js'))
ensure(os.path.join(args.output_path, stem + '.js.symbols'))
ensure(os.path.join(args.output_path, stem + '.wasm.debug.wasm'))
+ ensure(os.path.join(args.output_path, stem + '.html'))
if __name__ == '__main__':
diff --git a/bazel/emscripten_toolchain/wasm_cc_binary.bzl b/bazel/emscripten_toolchain/wasm_cc_binary.bzl
index 01780e2..9128b7a 100644
--- a/bazel/emscripten_toolchain/wasm_cc_binary.bzl
+++ b/bazel/emscripten_toolchain/wasm_cc_binary.bzl
@@ -74,6 +74,7 @@
ctx.outputs.data,
ctx.outputs.symbols,
ctx.outputs.dwarf,
+ ctx.outputs.html,
]
ctx.actions.run(
@@ -103,6 +104,7 @@
"data": "{}/{}.data".format(name, basename),
"symbols": "{}/{}.js.symbols".format(name, basename),
"dwarf": "{}/{}.wasm.debug.wasm".format(name, basename),
+ "html": "{}/{}.html".format(name, basename),
}
return outputs
