scripts/objdump-func: Support multiple functions

Allow specifying multiple functions on the cmdline.  Note this removes
the secret EXTRA_ARGS feature.

While at it, spread out the awk to make it more readable.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/0bf5f4f5978660985037b24c6db49b114374eb4d.1681325924.git.jpoimboe@kernel.org

scripts/objdump-func

@@ -3,7 +3,7 @@
 #
 # Disassemble a single function.
 #
-# usage: objdump-func <file> <func>
+# usage: objdump-func <file> <func> [<func> ...]
 
 set -o errexit
 set -o nounset
@@ -13,17 +13,33 @@ OBJDUMP="${CROSS_COMPILE:-}objdump"
 command -v gawk >/dev/null 2>&1 || die "gawk isn't installed"
 
 usage() {
-	echo "usage: objdump-func <file> <func>" >&2
+	echo "usage: objdump-func <file> <func> [<func> ...]" >&2
 	exit 1
 }
 
 [[ $# -lt 2 ]] && usage
 
 OBJ=$1; shift
-FUNC=$1; shift
-
-# Secret feature to allow adding extra objdump args at the end
-EXTRA_ARGS=$@
-
-# Note this also matches compiler-added suffixes like ".cold", etc
-${OBJDUMP} -wdr $EXTRA_ARGS $OBJ | gawk -M -v f=$FUNC '/^$/ { P=0; } $0 ~ "<" f "(\\..*)?>:" { P=1; O=strtonum("0x" $1); } { if (P) { o=strtonum("0x" $1); printf("%04x ", o-O); print $0; } }'
+FUNCS=("$@")
+
+${OBJDUMP} -wdr $OBJ | gawk -M -v _funcs="${FUNCS[*]}" '
+	BEGIN { split(_funcs, funcs); }
+	/^$/ { func_match=0; }
+	/<.*>:/ {
+		f = gensub(/.*<(.*)>:/, "\\1", 1);
+		for (i in funcs) {
+			# match compiler-added suffixes like ".cold", etc
+			if (f ~ "^" funcs[i] "(\\..*)?") {
+				func_match = 1;
+				base = strtonum("0x" $1);
+				break;
+			}
+		}
+	}
+	{
+		if (func_match) {
+			addr = strtonum("0x" $1);
+			printf("%04x ", addr - base);
+			print;
+		}
+	}'