scripts: add a script to generate syscall_nr.h

This script is needed for targets based on asm-generic syscall numbers generation

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200316085620.309769-2-laurent@vivier.eu>
[lv: added file in MAINTAINERS]

MAINTAINERS

@@ -2450,6 +2450,7 @@ F: default-configs/*-linux-user.mak
 F: scripts/qemu-binfmt-conf.sh
 F: scripts/update-syscalltbl.sh
 F: scripts/update-mips-syscall-args.sh
+F: scripts/gensyscalls.sh
 
 Tiny Code Generator (TCG)
 -------------------------

scripts/gensyscalls.sh

@@ -0,0 +1,102 @@
+#!/bin/sh
+#
+# Update syscall_nr.h files from linux headers asm-generic/unistd.h
+#
+# This code is licensed under the GPL version 2 or later.  See
+# the COPYING file in the top-level directory.
+#
+
+linux="$1"
+output="$2"
+
+TMP=$(mktemp -d)
+
+if [ "$linux" = "" ] ; then
+    echo "Needs path to linux source tree" 1>&2
+    exit 1
+fi
+
+if [ "$output" = "" ] ; then
+    output="$PWD"
+fi
+
+upper()
+{
+    echo "$1" | tr "[:lower:]" "[:upper:]" | tr "[:punct:]" "_"
+}
+
+qemu_arch()
+{
+    case "$1" in
+    arm64)
+        echo "aarch64"
+        ;;
+    *)
+        echo "$1"
+        ;;
+    esac
+}
+
+read_includes()
+{
+    arch=$1
+    bits=$2
+
+     cpp -P -nostdinc -fdirectives-only \
+        -D_UAPI_ASM_$(upper ${arch})_BITSPERLONG_H \
+        -D__BITS_PER_LONG=${bits} \
+        -I${linux}/arch/${arch}/include/uapi/ \
+        -I${linux}/include/uapi \
+        -I${TMP} \
+        "${linux}/arch/${arch}/include/uapi/asm/unistd.h"
+}
+
+filter_defines()
+{
+    grep -e "#define __NR_" -e "#define __NR3264"
+}
+
+rename_defines()
+{
+    sed "s/ __NR_/ TARGET_NR_/g;s/(__NR_/(TARGET_NR_/g"
+}
+
+evaluate_values()
+{
+    sed "s/#define TARGET_NR_/QEMU TARGET_NR_/" | \
+    cpp -P -nostdinc | \
+    sed "s/^QEMU /#define /"
+}
+
+generate_syscall_nr()
+{
+    arch=$1
+    bits=$2
+    file="$3"
+    guard="$(upper LINUX_USER_$(qemu_arch $arch)_$(basename "$file"))"
+
+    (echo "/*"
+    echo " * This file contains the system call numbers."
+    echo " * Do not modify."
+    echo " * This file is generated by scripts/gensyscalls.sh"
+    echo " */"
+    echo "#ifndef ${guard}"
+    echo "#define ${guard}"
+    echo
+    read_includes $arch $bits | filter_defines | rename_defines | \
+                                evaluate_values | sort -n -k 3
+    echo
+    echo "#endif /* ${guard} */"
+    echo) > "$file"
+}
+
+mkdir "$TMP/asm"
+> "$TMP/asm/bitsperlong.h"
+
+generate_syscall_nr arm64 64 "$output/linux-user/aarch64/syscall_nr.h"
+generate_syscall_nr nios2 32 "$output/linux-user/nios2/syscall_nr.h"
+generate_syscall_nr openrisc 32 "$output/linux-user/openrisc/syscall_nr.h"
+
+generate_syscall_nr riscv 32 "$output/linux-user/riscv/syscall32_nr.h"
+generate_syscall_nr riscv 64 "$output/linux-user/riscv/syscall64_nr.h"
+rm -fr "$TMP"