meson: add common hw files

Those files will be compiled once per base architecture ("arm" in this
case), instead of being compiled for every variant/bitness of
architecture.

We make sure to not include target cpu definitions (exec/cpu-defs.h) by
defining header guard directly. This way, a given compilation unit can
access a specific cpu definition, but not access to compile time defines
associated.

Previous commits took care to clean up some headers to not rely on
cpu-defs.h content.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250325045915.994760-24-pierrick.bouvier@linaro.org>

1 files changed, 36 insertions, 1 deletions

diff --git a/meson.build b/meson.build
index 6579493..bcb9d39 100644
--- a/meson.build
+++ b/meson.build
@@ -3682,6 +3682,7 @@ hw_arch = {}
 target_arch = {}
 target_system_arch = {}
 target_user_arch = {}
+hw_common_arch = {}
 
 # NOTE: the trace/ subdirectory needs the qapi_trace_events variable
 # that is filled in by qapi/.
@@ -4079,6 +4080,34 @@ common_all = static_library('common',
                             implicit_include_directories: false,
                             dependencies: common_ss.all_dependencies())
 
+# construct common libraries per base architecture
+hw_common_arch_libs = {}
+foreach target : target_dirs
+  config_target = config_target_mak[target]
+  target_base_arch = config_target['TARGET_BASE_ARCH']
+
+  # check if already generated
+  if target_base_arch in hw_common_arch_libs
+    continue
+  endif
+
+  if target_base_arch in hw_common_arch
+    target_inc = [include_directories('target' / target_base_arch)]
+    src = hw_common_arch[target_base_arch]
+    lib = static_library(
+      'hw_' + target_base_arch,
+      build_by_default: false,
+      sources: src.all_sources() + genh,
+      include_directories: common_user_inc + target_inc,
+      implicit_include_directories: false,
+      # prevent common code to access cpu compile time
+      # definition, but still allow access to cpu.h
+      c_args: ['-DCPU_DEFS_H', '-DCOMPILING_SYSTEM_VS_USER', '-DCONFIG_SOFTMMU'],
+      dependencies: src.all_dependencies())
+    hw_common_arch_libs += {target_base_arch: lib}
+  endif
+endforeach
+
 if have_rust
   # We would like to use --generate-cstr, but it is only available
   # starting with bindgen 0.66.0.  The oldest supported versions
@@ -4244,8 +4273,14 @@ foreach target : target_dirs
   arch_deps += t.dependencies()
 
   target_common = common_ss.apply(config_target, strict: false)
-  objects = common_all.extract_objects(target_common.sources())
+  objects = [common_all.extract_objects(target_common.sources())]
   arch_deps += target_common.dependencies()
+  if target_type == 'system' and target_base_arch in hw_common_arch_libs
+    src = hw_common_arch[target_base_arch].apply(config_target, strict: false)
+    lib = hw_common_arch_libs[target_base_arch]
+    objects += lib.extract_objects(src.sources())
+    arch_deps += src.dependencies()
+  endif
 
   target_specific = specific_ss.apply(config_target, strict: false)
   arch_srcs += target_specific.sources()