Enable bap-tracing plugin build with meson.

Author: Rot127

README.md

@@ -6,6 +6,12 @@ This QEMU fork implements the TCG plugin to generate execution traces in the
 Previous traces were generated with a patched QEMU.
 You can find these in the branches tracewrap-6.2.0 for ARM and x86 and tracewrap-8.1 for Hexagon.
 
+## Dependencies
+
+1. Install [piqi](https://piqi.org/downloads/) so you have the `piqi` binary in `PATH`.
+2. Install the developer package of `protobuf-c`. E.g. `protobuf-c-devel` (Fedora), `libprotobuf-c-dev` (Debian).
+3. QEMU dependencies (see [QEMU docs](https://www.qemu.org/docs/master/devel/build-environment.html)).
+
 ## Building
 
 ```bash

contrib/plugins/bap-tracing/fix_proto_src.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+"""
+This just does:
+sed -i 's/->base/->__base/g' <file>
+sed -i 's/ProtobufCMessage base;/ProtobufCMessage __base;/g' <file>
+"""
+
+import sys
+import re
+
+if len(sys.argv) != 6 or sys.argv[3] != "-o":
+    print("usage: fix_proto_src.py frame.piqi.pb-c.c frame.piqi.pb-c.h -o frame.piqi.pb-c-fixed.c frame.piqi.pb-c-fixed.h")
+    exit(1)
+
+for (in_file, out_file) in zip(sys.argv[1:3], sys.argv[4:6]):
+    with open(in_file, "r") as i:
+        contents = i.read()
+    contents = contents.replace("->base", "->__base")
+    contents = contents.replace("ProtobufCMessage base;", "ProtobufCMessage __base;")
+    contents = re.sub(r'".*frame.piqi.pb-c.h"', '"frame.piqi.pb-c-patched.h"', contents)
+    with open(out_file, "w") as o:
+        o.write(contents)

contrib/plugins/bap-tracing/meson.build

@@ -0,0 +1,48 @@
+piqi = find_program('piqi')
+protoc_c = find_program('protoc-c')
+
+# piqi -> protobuf file.
+piqi_src = custom_target('piqi',
+  input: 'bap-frames/piqi/frame.piqi',
+  output: 'frame.piqi.proto',
+  command: [piqi, 'to-proto', '@INPUT@', '-o', '@OUTPUT@'])
+
+# protobuf file -> C code
+proto_src_raw = custom_target('proto',
+  input: piqi_src,
+  output: ['frame.piqi.pb-c.c', 'frame.piqi.pb-c.h'],
+  command: [protoc_c, '--c_out=.', '@INPUT@'],
+  depends: piqi_src)
+
+# Patch protobuf header: base -> __base.
+# Necessary for the C build.
+# See fix_proto_src.py
+proto_src = custom_target(
+  input: proto_src_raw,
+  output: ['frame.piqi.pb-c-patched.c', 'frame.piqi.pb-c-patched.h'],
+  command: [files('fix_proto_src.py'), '@INPUT@', '-o', '@OUTPUT@'],
+  depends: proto_src_raw
+)
+
+libprotobuf = static_library('protobuf', [proto_src], pic: true)
+dep_libprotobuf = declare_dependency(
+    sources : proto_src,
+    link_with : [libprotobuf],
+)
+
+bap_tracing_src = files(
+  'tracing.c',
+  'tracewrap.c',
+)
+
+if host_os == 'windows'
+  plugin_modules += shared_module('bap_tracing', bap_tracing_src,
+                    include_directories: '../../../include/qemu',
+                    link_depends: [win32_qemu_plugin_api_lib],
+                    link_args: win32_qemu_plugin_api_link_flags,
+                    dependencies: [glib, dep_libprotobuf])
+else
+  plugin_modules += shared_module('bap_tracing', bap_tracing_src,
+                    include_directories: '../../../include/qemu',
+                    dependencies: [glib, dep_libprotobuf])
+endif

contrib/plugins/bap-tracing/trace_consts.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include "trace_info.h"
+// #include "trace_info.h"
 
 const uint64_t magic_number = 7456879624156307493LL;
 const uint64_t magic_number_offset = 0LL;