Re: [PATCH 1/2] Autogenerate gdb/syscalls/linux-defaults.xml.in (groups) from strace sources

[Simon Marchi <simark@simark.ca>]

On 2/24/23 18:26, Pedro Alves wrote:
> I noticed that "catch syscall group:process" doesn't catch clone3,
> while it does catch clone.
> 
> The catch syscall group information is recorded in the
> gdb/syscalls/linux-defaults.xml.in file, which says:
> 
>   <!-- The group field information was based on strace.  -->
> 
> So I looked at the strace sources, to confirm that clone3 is in fact
> recorded in the "process" group there too, and to check what other
> syscalls might be missing groups.
> 
> After some digging, I found that strace records the group info in C
> arrays, with entries like:
> ...
> [ 61] = { 4,	TP,		SEN(wait4),			"wait4"			},
> [ 62] = { 2,	TS|TP,		SEN(kill),			"kill"			},
> [ 63] = { 1,	0,		SEN(uname),			"uname"			},
> ...
> 
> You can see the current master's table for Linux x86-64 here:
> 
>   https://github.com/strace/strace/blob/e88e5e9ae6da68f22d15f9be3193b1412ac9aa02/src/linux/x86_64/syscallent.h
> 
> The column with TS|TP above is what defines each syscall's groups.  So
> I wrote a script that extracts this information and generates
> linux-defaults.xml.in.

Thanks, that LGTM.

I think the filename passed around is not actually used, so you can do:

---

diff --git a/gdb/syscalls/update-linux-defaults.sh b/gdb/syscalls/update-linux-defaults.sh
index 2c001aa3b8a9..bf74f1e321a8 100755
--- a/gdb/syscalls/update-linux-defaults.sh
+++ b/gdb/syscalls/update-linux-defaults.sh
@@ -35,8 +35,6 @@ fi
 
 pre ()
 {
-    f="$1"
-
     year=$(date +%Y)
 
     cat <<EOF
@@ -61,9 +59,7 @@ post ()
 
 generate ()
 {
-    f="$1"
-
-    pre "$f"
+    pre
 
     grep -rn -E "T[A-Z][,|]" "$d/src/linux/" \
 	| sed -e 's/\(T[A-Z][,|].*\)/\x03&/' -e 's/.*\x03//' \
@@ -92,4 +88,4 @@ generate ()
 f=linux-defaults.xml.in
 
 echo "Generating $f"
-generate "$t" > "$f"
+generate > "$f"

---

I was tipped off by this shellcheck warning:

In update-linux-defaults.sh line 95:
generate "$t" > "$f"
          ^-- SC2154 (warning): t is referenced but not assigned.

Simon