fd/decode: Build generate_rd executable rather

A seperate meson project with mesa as a subproject was required to
compile the generate_rd executable for replaying rddecompiler
generated source. That approach was overly complicated, now the
generate_rd executable is now compiled as a part of building the
freedreno tools with a blank generate-rd.cc file that can be replaced
with the source generated by rddecompiler.

Signed-off-by: Mark Collins <mark@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28253>

docs/drivers/freedreno.rst

@@ -467,7 +467,7 @@ Given the address space bounds the generated program creates a new ``rd`` which
 could be used to override cmdstream with 'replay'. Generated ``rd`` is not replayable
 on its own and depends on buffers provided by the source ``rd``.
 
-C source could be compiled using rdcompiler-meson.build as an example.
+C source could be compiled by putting it into src/freedreno/decode/generate-rd.cc.
 
 The workflow would look like this:
 
@@ -476,15 +476,15 @@ The workflow would look like this:
 
 .. code-block:: sh
 
-  ./rddecompiler -s %cmd_stream_n% example.rd > generate_rd.c
+  ./rddecompiler -s %cmd_stream_n% example.rd > src/freedreno/decode/generate-rd.cc
 
-3. Edit the command stream;
-4. Compile it back, see rdcompiler-meson.build for the instructions;
+3. Edit the command stream;;
+4. Compile and deploy freedreno tools;
 5. Plug the generator into cmdstream replay:
 
 .. code-block:: sh
 
-  ./replay --override=%cmd_stream_№% --generator=~/generate_rd
+  ./replay --override=%cmd_stream_№% --generator=generate_rd
 
 6. Repeat 3-5.
 

src/freedreno/decode/generate-rd.cc

@@ -0,0 +1,7 @@
+/* This is a placeholder file that should be replaced with the contents
+ * generated by the rddecompiler from a trace file.
+*/
+int main(int argc, char **argv)
+{
+	return 1;
+}

src/freedreno/decode/meson.build

@@ -140,6 +140,26 @@ if dep_libarchive.found()
     build_by_default: with_tools.contains('freedreno'),
     install: install_fd_decode_tools,
   )
+
+  generate_rd = executable(
+    'generate_rd',
+    [
+      'generate-rd.cc'
+    ],
+    include_directories: [
+      inc_freedreno,
+      inc_freedreno_rnn,
+      inc_include,
+      inc_src,
+    ],
+    link_with: [
+      libfreedreno_cffdec,
+    ],
+    dependencies : [
+      idep_nir,
+    ],
+    install: install_fd_decode_tools,
+  )
 else
   warning('libarchive not found, not building replay or rddecompiler')
 endif

src/freedreno/decode/rdcompiler-meson.build

@@ -1,44 +0,0 @@
-# An example meson.build for .rd decompiled into C source via rddecompiler.
-# It uses Mesa as a subproject since the generated sources depend on
-# generated headers with registers info and on some utils.
-# Before compiling, create "subprojects" directory and create a link
-# to mesa there.
-
-project('generate_rd', ['c', 'cpp'], default_options : ['c_std=c11', 'cpp_std=c++17'])
-
-mesa_options = ['gallium-drivers=',
-                'vulkan-drivers=',
-                'glx=disabled',
-                'tools=freedreno']
-
-if host_machine.system() == 'android'
-  mesa_options += ['platforms=android',
-                   'platform-sdk-version=28',
-                   'android-stub=true']
-endif
-
-mesa_proj = subproject('mesa', default_options : mesa_options)
-
-add_project_arguments(mesa_proj.get_variable('pre_args'), language : ['c', 'cpp'])
-add_project_arguments(mesa_proj.get_variable('c_args'),   language : ['c'])
-add_project_arguments(mesa_proj.get_variable('c_cpp_args'), language : ['c', 'cpp'])
-add_project_arguments(mesa_proj.get_variable('cpp_args'), language : ['cpp'])
-
-generate_rd = executable(
-  'generate_rd',
-  [
-    'generate_rd.cc'
-  ],
-  include_directories: [
-    mesa_proj.get_variable('inc_freedreno'),
-    mesa_proj.get_variable('inc_freedreno_rnn'),
-    mesa_proj.get_variable('inc_include'),
-    mesa_proj.get_variable('inc_src'),
-  ],
-  link_with: [
-    mesa_proj.get_variable('libfreedreno_cffdec'),
-  ],
-  dependencies : [
-    mesa_proj.get_variable('idep_nir'),
-  ],
-)