modules: generate modinfo.c

Add script to generate C source with a small
database containing the module meta-data.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jose R. Ziviani <jziviani@suse.de>
Message-Id: <20210624103836.2382472-4-kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/qemu/module.h

@@ -134,4 +134,21 @@ void module_load_qom_all(void);
  */
 #define module_opts(name) modinfo(opts, name)
 
+/*
+ * module info database
+ *
+ * scripts/modinfo-generate.c will build this using the data collected
+ * by scripts/modinfo-collect.py
+ */
+typedef struct QemuModinfo QemuModinfo;
+struct QemuModinfo {
+    const char *name;
+    const char *arch;
+    const char **objs;
+    const char **deps;
+    const char **opts;
+};
+extern const QemuModinfo qemu_modinfo[];
+void module_init_info(const QemuModinfo *info);
+
 #endif

meson.build

@@ -2242,6 +2242,7 @@ subdir('tests/qtest/fuzz')
 ########################
 
 modinfo_collect = find_program('scripts/modinfo-collect.py')
+modinfo_generate = find_program('scripts/modinfo-generate.py')
 modinfo_files = []
 
 block_mods = []
@@ -2267,7 +2268,6 @@ foreach d, list : modules
                                        output: d + '-' + m + '.modinfo',
                                        input: module_ss.sources(),
                                        capture: true,
-                                       build_by_default: true, # to be removed when added to a target
                                        command: [modinfo_collect, '@INPUT@'])
       endif
     else
@@ -2280,6 +2280,17 @@ foreach d, list : modules
   endforeach
 endforeach
 
+if enable_modules
+  modinfo_src = custom_target('modinfo.c',
+                              output: 'modinfo.c',
+                              input: modinfo_files,
+                              command: [modinfo_generate, '@INPUT@'],
+                              capture: true)
+  modinfo_lib = static_library('modinfo', modinfo_src)
+  modinfo_dep = declare_dependency(link_whole: modinfo_lib)
+  softmmu_ss.add(modinfo_dep)
+endif
+
 nm = find_program('nm')
 undefsym = find_program('scripts/undefsym.py')
 block_syms = custom_target('block.syms', output: 'block.syms',

scripts/modinfo-generate.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import os
+import sys
+
+def print_array(name, values):
+    if len(values) == 0:
+        return
+    list = ", ".join(values)
+    print("    .%s = ((const char*[]){ %s, NULL })," % (name, list))
+
+def parse_line(line):
+    kind = ""
+    data = ""
+    get_kind = False
+    get_data = False
+    for item in line.split():
+        if item == "MODINFO_START":
+            get_kind = True
+            continue
+        if item.startswith("MODINFO_END"):
+            get_data = False
+            continue
+        if get_kind:
+            kind = item
+            get_kind = False
+            get_data = True
+            continue
+        if get_data:
+            data += " " + item
+            continue
+    return (kind, data)
+
+def generate(name, lines):
+    arch = ""
+    objs = []
+    deps = []
+    opts = []
+    for line in lines:
+        if line.find("MODINFO_START") != -1:
+            (kind, data) = parse_line(line)
+            if kind == 'obj':
+                objs.append(data)
+            elif kind == 'dep':
+                deps.append(data)
+            elif kind == 'opts':
+                opts.append(data)
+            elif kind == 'arch':
+                arch = data;
+            else:
+                print("unknown:", kind)
+                exit(1)
+
+    print("    .name = \"%s\"," % name)
+    if arch != "":
+        print("    .arch = %s," % arch)
+    print_array("objs", objs)
+    print_array("deps", deps)
+    print_array("opts", opts)
+    print("},{");
+
+def print_pre():
+    print("/* generated by scripts/modinfo-generate.py */")
+    print("#include \"qemu/osdep.h\"")
+    print("#include \"qemu/module.h\"")
+    print("const QemuModinfo qemu_modinfo[] = {{")
+
+def print_post():
+    print("    /* end of list */")
+    print("}};")
+
+def main(args):
+    print_pre()
+    for modinfo in args:
+        with open(modinfo) as f:
+            lines = f.readlines()
+        print("    /* %s */" % modinfo)
+        (basename, ext) = os.path.splitext(modinfo)
+        generate(basename, lines)
+    print_post()
+
+if __name__ == "__main__":
+    main(sys.argv[1:])

softmmu/vl.c

@@ -2755,6 +2755,10 @@ void qemu_init(int argc, char **argv, char **envp)
     error_init(argv[0]);
     qemu_init_exec_dir(argv[0]);
 
+#ifdef CONFIG_MODULES
+    module_init_info(qemu_modinfo);
+#endif
+
     qemu_init_subsystems();
 
     /* first pass of option parsing */

util/module.c

@@ -110,6 +110,17 @@ void module_call_init(module_init_type type)
 }
 
 #ifdef CONFIG_MODULES
+
+static const QemuModinfo module_info_stub[] = { {
+    /* end of list */
+} };
+static const QemuModinfo *module_info = module_info_stub;
+
+void module_init_info(const QemuModinfo *info)
+{
+    module_info = info;
+}
+
 static int module_load_file(const char *fname, bool mayfail, bool export_symbols)
 {
     GModule *g_module;