Re: [PATCH v2 24/24] configure: automatically parse command line for meson -D options

[Paolo Bonzini]

On 13/10/21 09:43, Paolo Bonzini wrote:
> On 12/10/21 20:15, Thomas Huth wrote:
> > Old output with --help:
> >
> >   --enable-trace-backend=B Set trace backend
> >                             Available backends: nop, dtrace, ftrace, 
> > simple, stderr, ust
> >
> > New output:
> >
> >    --enable-trace-backends=CHOICE
> >                             Set available tracing backends [log]
> >
> > Why does it fail to list the choices here? ... it works for the other
> > options like "--enable-malloc"?
>
> Oh, that's a pity: array options don't include the choices in their 
> introspection data.  I'll fix it up ad hoc and submit a patch to Meson.

---------------- 8< ----------------
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: [PATCH] meson-buildoptions: restore list of tracing backends

Manually patch the introspection data to include the tracing backends.

This works around a deficiency in Meson that will be fixed by
https://github.com/mesonbuild/meson/pull/9395.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 scripts/meson-buildoptions.py | 18 +++++++++++++++++-
 scripts/meson-buildoptions.sh |  3 ++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/scripts/meson-buildoptions.py b/scripts/meson-buildoptions.py
index 54b591d8a4..256523c09d 100755
--- a/scripts/meson-buildoptions.py
+++ b/scripts/meson-buildoptions.py
@@ -66,7 +66,7 @@ def sh_print(line=""):
 
 
 def help_line(left, opt, indent, long):
-    right = f"{opt['description']}"
+    right = f'{opt["description"]}'
     if long:
         value = value_to_help(opt["value"])
         if value != "auto":
@@ -150,7 +150,23 @@ def print_parse(options):
     print("}")
 
 
+def fixup_options(options):
+    # Meson <= 0.60 does not include the choices in array options, fix that up
+    for opt in options:
+        if opt["name"] == "trace_backends":
+            opt["choices"] = [
+                "dtrace",
+                "ftrace",
+                "log",
+                "nop",
+                "simple",
+                "syslog",
+                "ust",
+            ]
+
+
 options = load_options(json.load(sys.stdin))
+fixup_options(options)
 print("# This file is generated by meson-buildoptions.py, do not edit!")
 print_help(options)
 print_parse(options)
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 12188c2530..c795a13020 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -16,7 +16,8 @@ meson_options_help() {
   printf "%s\n" '  --enable-tcg-interpreter TCG with bytecode interpreter 
(experimental and'
   printf "%s\n" '                           slow)'
   printf "%s\n" '  --enable-trace-backends=CHOICE'
-  printf "%s\n" '                           Set available tracing backends 
[log]'
+  printf "%s\n" '                           Set available tracing backends 
[log] (choices:'
+  printf "%s\n" '                           
dtrace/ftrace/log/nop/simple/syslog/ust)'
   printf "%s\n" ''
   printf "%s\n" 'Optional features, enabled with --enable-FEATURE and'
   printf "%s\n" 'disabled with --disable-FEATURE, default is enabled if 
available'
--
2.31.1