meta: write a script to generate `src/init/syscalls.c`

1 files changed, 44 insertions, 0 deletions

diff --git a/tools/syscall_wrappers.awk b/tools/syscall_wrappers.awk
new file mode 100644
index 0000000..c1f980e
--- /dev/null
+++ b/tools/syscall_wrappers.awk
@@ -0,0 +1,44 @@
+BEGIN {
+	print "\
+/* generated by tools/syscall_wrappers.awk\n\
+ * don't modify manually, instead run:\n\
+ *     make src/init/syscalls.c\n\
+ */\n\
+#include <shared/syscalls.h>\n\
+\n";
+}
+
+/_syscall\(/ { next; } # skipping _syscall(), it's implemented elsewhere
+
+/\);/ {
+	sub(/;/, " {");
+	print $0;
+
+	name   = substr($0, match($0, /_syscall_[^(]+/), RLENGTH);
+	params = substr($0, match($0, /\(.+\)/) + 1, RLENGTH - 2);
+	if (params == "void") params = ""
+
+	split(params, p, /,/);
+	for (i = 0; i <= 4; i += 1) {
+		if (p[i]) {
+			# p[i] is a parameter, convert it into an expression to pass to _syscall()
+			sub(/^ */, "", p[i]); # strip
+			split(p[i], words, / /);
+			if (length(words) != 1) {
+				var = words[length(words)];
+				sub(/\*/, "", var);
+				if (words[1] != "int") var = "(int)" var;
+			}
+			p[i] = var;
+		} else {
+			p[i] = 0;
+		}
+	}
+
+	printf "\t";
+	if (!index($0, "_Noreturn")) printf "return ";
+	printf "_syscall(%s, %s, %s, %s, %s);\n", toupper(name), p[1], p[2], p[3], p[4];
+	if (index($0, "_Noreturn")) print "\t__builtin_unreachable();";
+
+	print "}\n";
+}