build-system: clean up TCG/TCI configury

Make CONFIG_TCG_INTERPRETER a Meson option, and enable TCI (though with
a warning) if the host CPU is unsupported, making it more similar to
other --enable-* options.

Remove TCG-specific include paths from !CONFIG_TCG builds.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -359,7 +359,7 @@ sanitizers="no"
 tsan="no"
 fortify_source="$default_feature"
 strip_opt="yes"
-tcg_interpreter="no"
+tcg_interpreter="false"
 bigendian="no"
 mingw32="no"
 gcov="no"
@@ -1119,9 +1119,9 @@ for opt do
   ;;
   --enable-whpx) whpx="enabled"
   ;;
-  --disable-tcg-interpreter) tcg_interpreter="no"
+  --disable-tcg-interpreter) tcg_interpreter="true"
   ;;
-  --enable-tcg-interpreter) tcg_interpreter="yes"
+  --enable-tcg-interpreter) tcg_interpreter="false"
   ;;
   --disable-cap-ng)  cap_ng="disabled"
   ;;
@@ -5834,11 +5834,6 @@ fi
 if test "$optreset" = "yes" ; then
   echo "HAVE_OPTRESET=y" >> $config_host_mak
 fi
-if test "$tcg" = "enabled"; then
-  if test "$tcg_interpreter" = "yes" ; then
-    echo "CONFIG_TCG_INTERPRETER=y" >> $config_host_mak
-  fi
-fi
 if test "$fdatasync" = "yes" ; then
   echo "CONFIG_FDATASYNC=y" >> $config_host_mak
 fi

disas/meson.build

@@ -22,5 +22,3 @@ common_ss.add(when: 'CONFIG_SH4_DIS', if_true: files('sh4.c'))
 common_ss.add(when: 'CONFIG_SPARC_DIS', if_true: files('sparc.c'))
 common_ss.add(when: 'CONFIG_XTENSA_DIS', if_true: files('xtensa.c'))
 common_ss.add(when: capstone, if_true: files('capstone.c'))
-
-specific_ss.add(when: 'CONFIG_TCG_INTERPRETER', if_true: files('tci.c'))

meson.build

@@ -113,25 +113,8 @@ if targetos == 'linux'
                         language: ['c', 'cpp'])
 endif
 
-if 'CONFIG_TCG_INTERPRETER' in config_host
-  tcg_arch = 'tci'
-elif config_host['ARCH'] == 'sparc64'
-  tcg_arch = 'sparc'
-elif config_host['ARCH'] == 's390x'
-  tcg_arch = 's390'
-elif config_host['ARCH'] in ['x86_64', 'x32']
-  tcg_arch = 'i386'
-elif config_host['ARCH'] == 'ppc64'
-  tcg_arch = 'ppc'
-elif config_host['ARCH'] in ['riscv32', 'riscv64']
-  tcg_arch = 'riscv'
-else
-  tcg_arch = config_host['ARCH']
-endif
-add_project_arguments('-iquote', meson.current_source_dir() / 'tcg' / tcg_arch,
-                      '-iquote', '.',
+add_project_arguments('-iquote', '.',
                       '-iquote', meson.current_source_dir(),
-                      '-iquote', meson.current_source_dir() / 'accel/tcg',
                       '-iquote', meson.current_source_dir() / 'include',
                       '-iquote', meson.current_source_dir() / 'disas/libvixl',
                       language: ['c', 'cpp', 'objc'])
@@ -226,14 +209,33 @@ if not get_option('hax').disabled()
     accelerators += 'CONFIG_HAX'
   endif
 endif
+
+tcg_arch = config_host['ARCH']
 if not get_option('tcg').disabled()
   if cpu not in supported_cpus
-    if 'CONFIG_TCG_INTERPRETER' in config_host
+    if get_option('tcg_interpreter')
       warning('Unsupported CPU @0@, will use TCG with TCI (experimental)'.format(cpu))
     else
       error('Unsupported CPU @0@, try --enable-tcg-interpreter'.format(cpu))
     endif
   endif
+  if get_option('tcg_interpreter')
+    tcg_arch = 'tci'
+  elif config_host['ARCH'] == 'sparc64'
+    tcg_arch = 'sparc'
+  elif config_host['ARCH'] == 's390x'
+    tcg_arch = 's390'
+  elif config_host['ARCH'] in ['x86_64', 'x32']
+    tcg_arch = 'i386'
+  elif config_host['ARCH'] == 'ppc64'
+    tcg_arch = 'ppc'
+  elif config_host['ARCH'] in ['riscv32', 'riscv64']
+    tcg_arch = 'riscv'
+  endif
+  add_project_arguments('-iquote', meson.current_source_dir() / 'tcg' / tcg_arch,
+                        '-iquote', meson.current_source_dir() / 'accel/tcg',
+                        language: ['c', 'cpp', 'objc'])
+
   accelerators += 'CONFIG_TCG'
   config_host += { 'CONFIG_TCG': 'y' }
 endif
@@ -1234,7 +1236,9 @@ foreach target : target_dirs
     if sym == 'CONFIG_TCG' or target in accelerator_targets.get(sym, [])
       config_target += { sym: 'y' }
       config_all += { sym: 'y' }
-      if sym == 'CONFIG_XEN' and have_xen_pci_passthrough
+      if sym == 'CONFIG_TCG' and tcg_arch == 'tci'
+        config_target += { 'CONFIG_TCG_INTERPRETER': 'y' }
+      elif sym == 'CONFIG_XEN' and have_xen_pci_passthrough
         config_target += { 'CONFIG_XEN_PCI_PASSTHROUGH': 'y' }
       endif
       accel_kconfig += [ sym + '=y' ]
@@ -2411,7 +2415,7 @@ summary_info += {'WHPX support':      config_all.has_key('CONFIG_WHPX')}
 summary_info += {'TCG support':       config_all.has_key('CONFIG_TCG')}
 if config_all.has_key('CONFIG_TCG')
   summary_info += {'TCG debug enabled': config_host.has_key('CONFIG_DEBUG_TCG')}
-  summary_info += {'TCG interpreter':   config_host.has_key('CONFIG_TCG_INTERPRETER')}
+  summary_info += {'TCG interpreter':   tcg_arch == 'tci'}
 endif
 summary_info += {'malloc trim support': has_malloc_trim}
 summary_info += {'RDMA support':      config_host.has_key('CONFIG_RDMA')}

meson_options.txt

@@ -37,6 +37,8 @@ option('xen_pci_passthrough', type: 'feature', value: 'auto',
        description: 'Xen PCI passthrough support')
 option('tcg', type: 'feature', value: 'auto',
        description: 'TCG support')
+option('tcg_interpreter', type: 'boolean', value: false,
+       description: 'TCG bytecode interpreter (TCI)')
 option('cfi', type: 'boolean', value: 'false',
        description: 'Control-Flow Integrity (CFI)')
 option('cfi_debug', type: 'boolean', value: 'false',