Convert wasm-sourcemap call from subprocess to library call. NFC (#25373)

Fixes: #25323

Author: sbc100

tools/building.py

@@ -5,6 +5,7 @@
 
 from .toolchain_profiler import ToolchainProfiler
 
+import importlib
 import json
 import logging
 import os
@@ -1145,8 +1146,11 @@ def emit_wasm_source_map(wasm_file, map_file, final_wasm):
   # source file paths must be relative to the location of the map (which is
   # emitted alongside the wasm)
   base_path = os.path.dirname(os.path.abspath(final_wasm))
-  sourcemap_cmd = [sys.executable, '-E', path_from_root('tools/wasm-sourcemap.py'),
-                   wasm_file,
+
+  # TODO(sbc): Rename wasm-sourcemap so it can be imported directly without
+  # importlib.
+  wasm_sourcemap = importlib.import_module('tools.wasm-sourcemap')
+  sourcemap_cmd = [wasm_file,
                    '--dwarfdump=' + LLVM_DWARFDUMP,
                    '-o',  map_file,
                    '--basepath=' + base_path]
@@ -1157,7 +1161,10 @@ def emit_wasm_source_map(wasm_file, map_file, final_wasm):
   if settings.GENERATE_SOURCE_MAP == 2:
     sourcemap_cmd += ['--sources']
 
-  check_call(sourcemap_cmd)
+  # TODO(sbc): Convert to using library internal API instead of running `main` here
+  rtn = wasm_sourcemap.main(sourcemap_cmd)
+  if rtn != 0:
+    exit_with_error('wasm-sourcemap failed (%s)', sourcemap_cmd)
 
 
 def get_binaryen_feature_flags():

tools/wasm-sourcemap.py

@@ -33,7 +33,7 @@
 logger = logging.getLogger('wasm-sourcemap')
 
 
-def parse_args():
+def parse_args(args):
   parser = argparse.ArgumentParser(prog='wasm-sourcemap.py', description=__doc__)
   parser.add_argument('wasm', help='wasm file')
   parser.add_argument('-o', '--output', help='output source map')
@@ -46,7 +46,7 @@ def parse_args():
   parser.add_argument('--dwarfdump', help="path to llvm-dwarfdump executable")
   parser.add_argument('--dwarfdump-output', nargs='?', help=argparse.SUPPRESS)
   parser.add_argument('--basepath', help='base path for source files, which will be relative to this')
-  return parser.parse_args()
+  return parser.parse_args(args)
 
 
 class Prefixes:
@@ -361,8 +361,8 @@ def build_sourcemap(entries, code_section_offset, options):
           'mappings': ','.join(mappings)}
 
 
-def main():
-  options = parse_args()
+def main(args):
+  options = parse_args(args)
 
   wasm_input = options.wasm
   with open(wasm_input, 'rb') as infile:
@@ -394,4 +394,4 @@ def main():
 
 if __name__ == '__main__':
   logging.basicConfig(level=logging.DEBUG if os.environ.get('EMCC_DEBUG') else logging.INFO)
-  sys.exit(main())
+  sys.exit(main(sys.argv[1:]))