[Qemu-devel] [PATCH 2/2] Add dynamic generation of module_block.h

["Marc Marí" <markmb@redhat.com>]

To simplify the addition of new block modules, add a script that generates
include/qemu/module_block.h automatically from the modules' source code.

This script assumes that the QEMU coding style rules are followed.

Signed-off-by: Marc Marí <markmb@redhat.com>
---
 .gitignore                      |   1 +
 Makefile                        |  10 ++-
 scripts/modules/module_block.py | 132 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 140 insertions(+), 3 deletions(-)
 create mode 100755 scripts/modules/module_block.py

diff --git a/.gitignore b/.gitignore
index 61bc492..8a37067 100644
--- a/.gitignore
+++ b/.gitignore
@@ -105,3 +105,4 @@ cscope.*
 tags
 TAGS
 *~
+/include/qemu/module_block.h
diff --git a/Makefile b/Makefile
index 340d9c8..47d593e 100644
--- a/Makefile
+++ b/Makefile
@@ -73,6 +73,8 @@ GENERATED_HEADERS += trace/generated-ust-provider.h
 GENERATED_SOURCES += trace/generated-ust.c
 endif
 
+GENERATED_HEADERS += include/qemu/module_block.h
+
 # Don't try to regenerate Makefile or configure
 # We don't generate any of them
 Makefile: ;
@@ -219,9 +221,6 @@ Makefile: $(version-obj-y) $(version-lobj-y)
 libqemustub.a: $(stub-obj-y)
 libqemuutil.a: $(util-obj-y)
 
-block-modules = $(foreach o,$(block-obj-m),"$(basename $(subst /,-,$o))",) NULL
-util/module.o-cflags = -D'CONFIG_BLOCK_MODULES=$(block-modules)'
-
 ######################################################################
 
 qemu-img.o: qemu-img-cmds.h
@@ -313,6 +312,11 @@ msi:
 	@echo MSI build not configured or dependency resolution failed (reconfigure with --enable-guest-agent-msi option)
 endif
 
+include/qemu/module_block.h: $(SRC_PATH)/scripts/modules/module_block.py
+	$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/modules/module_block.py \
+		"./include/qemu/" $(patsubst %.mo,%.c,$(block-obj-m)), \
+		"  GEN   $@")
+
 clean:
 # avoid old build problems by removing potentially incorrect old files
 	rm -f config.mak op-i386.h opc-i386.h gen-op-i386.h op-arm.h opc-arm.h gen-op-arm.h
diff --git a/scripts/modules/module_block.py b/scripts/modules/module_block.py
new file mode 100755
index 0000000..a9a9412
--- /dev/null
+++ b/scripts/modules/module_block.py
@@ -0,0 +1,132 @@
+#!/usr/bin/python
+#
+# Module information generator
+#
+# Copyright Red Hat, Inc. 2015
+#
+# Authors:
+#  Marc Mari <markmb@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2.
+# See the COPYING file in the top-level directory.
+
+import sys
+import os
+
+def get_string_struct(line):
+    data = line.split()
+
+    # data[0] -> struct element name
+    # data[1] -> =
+    # data[2] -> value
+
+    return data[2].replace('"', '')[:-1]
+
+def add_module(fhader, library, format_name, protocol_name,
+                probe, probe_device):
+    lines = []
+    lines.append('.library_name = "' + library + '",')
+    if format_name != "":
+        lines.append('.format_name = "' + format_name + '",')
+    if protocol_name != "":
+        lines.append('.protocol_name = "' + protocol_name + '",')
+    if probe:
+        lines.append('.has_probe = true,')
+    if probe_device:
+        lines.append('.has_probe_device = true,')
+
+    text = '\n\t'.join(lines)
+    fheader.write('\n\t{\n\t' + text + '\n\t},')
+
+def process_file(fheader, filename):
+    # This parser assumes the coding style rules are being followed
+    with open(filename, "r") as cfile:
+        found_something = False
+        found_start = False
+        library, _ = os.path.splitext(os.path.basename(filename))
+        for line in cfile:
+            if found_start:
+                line = line.replace('\n', '')
+                if line.find(".format_name") != -1:
+                    format_name = get_string_struct(line)
+                elif line.find(".protocol_name") != -1:
+                    protocol_name = get_string_struct(line)
+                elif line.find(".bdrv_probe") != -1:
+                    probe = True
+                elif line.find(".bdrv_probe_device") != -1:
+                    probe_device = True
+                elif line == "};":
+                    add_module(fheader, library, format_name, protocol_name,
+                                probe, probe_device)
+                    found_start = False
+            elif line.find("static BlockDriver") != -1:
+                found_something = True
+                found_start = True
+                format_name = ""
+                protocol_name = ""
+                probe = False
+                probe_device = False
+
+        if not found_something:
+            print("No BlockDriver struct found in " + filename + ". \
+                    Is this really a module?")
+            sys.exit(1)
+
+def print_top(fheader):
+    fheader.write('''/* AUTOMATICALLY GENERATED, DO NOT MODIFY */
+/*
+ * QEMU Block Module Infrastructure
+ *
+ * Copyright Red Hat, Inc. 2015
+ *
+ * Authors:
+ *  Marc Mari       <markmb@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+''')
+
+    fheader.write('''#ifndef QEMU_MODULE_BLOCK_H
+#define QEMU_MODULE_BLOCK_H
+
+#include "qemu-common.h"
+
+static const struct {
+    const char *format_name;
+    const char *protocol_name;
+    const char *library_name;
+    bool has_probe;
+    bool has_probe_device;
+} block_driver_module[] = {''')
+
+def print_bottom(fheader):
+    fheader.write('''
+};
+
+#endif''')
+
+# First argument: output folder
+# All other arguments: modules source files (.c)
+output_dir = sys.argv[1]
+if not os.path.isdir(output_dir):
+    print("Folder " + output_dir + " does not exist")
+    sys.exit(1)
+
+path = output_dir + 'module_block.h'
+
+with open(path, 'w') as fheader:
+    print_top(fheader)
+
+    for filename in sys.argv[2:]:
+        if os.path.isfile(filename):
+            process_file(fheader, filename)
+        else:
+            print("File " + filename + " does not exist.")
+            sys.exit(1)
+
+    print_bottom(fheader)
+
+sys.exit(0)
-- 
2.4.3