Avoid generating libc struct info with em++

Since internal musl code refuses to be compiled with em++.

Author: kleisauke

src/struct_info_internal.json src/struct_info_libc.jsonsrc/struct_info_internal.json renamed to src/struct_info_libc.json

@@ -45,17 +45,5 @@
               "global_locale"
             ]
         }
-    },
-    {
-        "file": "cxa_exception.h",
-        "structs": {
-            "__cxxabiv1::__cxa_exception": [
-              "exceptionDestructor",
-              "referenceCount",
-              "exceptionType",
-              "caught",
-              "rethrown"
-            ]
-        }
     }
 ]

src/struct_info_libcxx.json

@@ -0,0 +1,17 @@
+[
+    // ===========================================
+    // libcxx - internal
+    // ===========================================
+    {
+        "file": "cxa_exception.h",
+        "structs": {
+            "__cxxabiv1::__cxa_exception": [
+              "exceptionDestructor",
+              "referenceCount",
+              "exceptionType",
+              "caught",
+              "rethrown"
+            ]
+        }
+    }
+]

tools/gen_struct_info.py

@@ -196,7 +196,7 @@ def gen_inspect_code(path, struct, code):
   c_ascent(code)
 
 
-def inspect_headers(headers, cflags):
+def inspect_headers(headers, cflags, cxx=False):
   code = ['#include <stdio.h>', '#include <stddef.h>']
   for header in headers:
     code.append('#include "' + header['name'] + '"')
@@ -254,18 +254,18 @@ def inspect_headers(headers, cflags):
   show('Compiling generated code...')
 
   # -Oz optimizes enough to avoid warnings on code size/num locals
-  cmd = [shared.EMXX] + cflags + ['-o', js_file[1], src_file[1],
-                                  '-O0',
-                                  '-Werror',
-                                  '-Wno-format',
-                                  '-nostdlib',
-                                  compiler_rt,
-                                  '-s', 'BOOTSTRAPPING_STRUCT_INFO=1',
-                                  '-s', 'LLD_REPORT_UNDEFINED=1',
-                                  '-s', 'STRICT',
-                                  # Use SINGLE_FILE=1 so there is only a single
-                                  # file to cleanup.
-                                  '-s', 'SINGLE_FILE']
+  cmd = [shared.EMXX if cxx else shared.EMCC] + cflags + ['-o', js_file[1], src_file[1],
+                                                          '-O0',
+                                                          '-Werror',
+                                                          '-Wno-format',
+                                                          '-nostdlib',
+                                                          compiler_rt,
+                                                          '-s', 'BOOTSTRAPPING_STRUCT_INFO=1',
+                                                          '-s', 'LLD_REPORT_UNDEFINED=1',
+                                                          '-s', 'STRICT',
+                                                          # Use SINGLE_FILE=1 so there is only a single
+                                                          # file to cleanup.
+                                                          '-s', 'SINGLE_FILE']
 
   # Default behavior for emcc is to warn for binaryen version check mismatches
   # so we should try to match that behavior.
@@ -311,13 +311,13 @@ def merge_info(target, src):
     target['structs'][key] = value
 
 
-def inspect_code(headers, cflags):
+def inspect_code(headers, cflags, cxx=False):
   if not DEBUG:
-    info = inspect_headers(headers, cflags)
+    info = inspect_headers(headers, cflags, cxx)
   else:
     info = {'defines': {}, 'structs': {}}
     for header in headers:
-      merge_info(info, inspect_headers([header], cflags))
+      merge_info(info, inspect_headers([header], cflags, cxx))
   return info
 
 
@@ -375,7 +375,8 @@ def main(args):
 
   default_json_files = [
       shared.path_from_root('src', 'struct_info.json'),
-      shared.path_from_root('src', 'struct_info_internal.json')
+      shared.path_from_root('src', 'struct_info_libc.json'),
+      shared.path_from_root('src', 'struct_info_libcxx.json')
   ]
   parser = argparse.ArgumentParser(description='Generate JSON infos for structs.')
   parser.add_argument('json', nargs='*',
@@ -411,6 +412,9 @@ def main(args):
   internal_cflags = [
     '-I' + shared.path_from_root('system', 'lib', 'libc', 'musl', 'src', 'internal'),
     '-I' + shared.path_from_root('system', 'lib', 'libc', 'musl', 'src', 'include'),
+  ]
+
+  internal_cxxflags = [
     '-I' + shared.path_from_root('system', 'lib', 'libcxxabi', 'src'),
     '-D__USING_EMSCRIPTEN_EXCEPTIONS__',
   ]
@@ -421,12 +425,16 @@ def main(args):
   for f in args.json:
     # This is a JSON file, parse it.
     header_files = parse_json(f)
+    cxx = False
     # Inspect all collected structs.
-    if 'internal' in f:
+    if 'libcxx' in f:
+      use_cflags = cflags + internal_cxxflags
+      cxx = True
+    elif 'libc' in f:
       use_cflags = cflags + internal_cflags
     else:
       use_cflags = cflags
-    info_fragment = inspect_code(header_files, use_cflags)
+    info_fragment = inspect_code(header_files, use_cflags, cxx)
     merge_info(info, info_fragment)
 
   output_json(info, args.output)