List Linux directories with their file attributes through the FFM API

resources/bundles/org.eclipse.core.filesystem/generateLinuxH.sh

@@ -0,0 +1,153 @@
+#!/bin/sh
+# Regenerates the glibc bindings in src-gen. Needs jextract on the PATH,
+# https://jdk.java.net/jextract/, and has to run on Linux.
+#
+# No --library: that would emit libraryLookup("libc.so"), which cannot be opened
+# on glibc, where the library is libc.so.6. Without it the generated lookup falls
+# back to the linker's default lookup, which already sees libc.
+set -eu
+cd "$(dirname "$0")"
+
+rm -rf src-gen/org/linux
+jextract --output src-gen \
+	--define-macro _GNU_SOURCE \
+	--include-function statx \
+	--include-function opendir \
+	--include-function readdir \
+	--include-function closedir \
+	--include-function dirfd \
+	--include-function readlinkat \
+	--include-struct statx \
+	--include-struct statx_timestamp \
+	--include-struct dirent \
+	--include-constant AT_SYMLINK_NOFOLLOW \
+	--include-constant AT_STATX_SYNC_AS_STAT \
+	--include-constant STATX_TYPE \
+	--include-constant STATX_MODE \
+	--include-constant STATX_SIZE \
+	--include-constant STATX_MTIME \
+	--include-constant ENOENT \
+	--include-constant PATH_MAX \
+	--include-constant S_IFMT \
+	--include-constant S_IFDIR \
+	--include-constant S_IFLNK \
+	--include-constant S_IRUSR --include-constant S_IWUSR --include-constant S_IXUSR \
+	--include-constant S_IRGRP --include-constant S_IWGRP --include-constant S_IXGRP \
+	--include-constant S_IROTH --include-constant S_IWOTH --include-constant S_IXOTH \
+	--target-package org.linux \
+	--header-class-name LibC \
+	dirent.h errno.h fcntl.h limits.h sys/stat.h unistd.h
+
+# jextract cannot select single struct fields or accessors, so drop every generated
+# member that neither the sources in src nor another kept member refer to.
+find src -name '*.java' | xargs awk -v gen="$(echo src-gen/org/linux/*.java)" '
+function code(line) {
+	# Drops comments and string literals, which name fields without using them.
+	if (line ~ /^[[:space:]]*(\/\*|\*|\/\/)/) {
+		return ""
+	}
+	gsub(/"[^"]*"/, "\"\"", line)
+	return line "\n"
+}
+function mentions(text, token,    rest, i, before, after) {
+	rest = text
+	while ((i = index(rest, token)) > 0) {
+		before = i == 1 ? "" : substr(rest, i - 1, 1)
+		after = substr(rest, i + length(token), 1)
+		if (before !~ /[[:alnum:]_$.]/ && after !~ /[[:alnum:]_$]/) {
+			return 1
+		}
+		rest = substr(rest, i + length(token))
+	}
+	return 0
+}
+{ sources = sources code($0) }
+END {
+	n = split(gen, files, " ")
+	for (f = 1; f <= n; f++) {
+		cls = files[f]; sub(/.*\//, "", cls); sub(/\.java$/, "", cls)
+		unit = cls; sub(/\$shared$/, "", unit)
+		depth = 0; javadoc = 0; complete = 1; phase = "head"
+		while ((getline line < files[f]) > 0) {
+			if (phase == "head") {
+				head[f] = head[f] line "\n"
+				if (line ~ /^(public )?(final )?class /) { phase = "body" }
+				continue
+			}
+			if (phase == "tail" || (depth == 0 && line == "}")) {
+				phase = "tail"; tail[f] = tail[f] line "\n"
+				continue
+			}
+			if (m == 0 || complete) {
+				m++; mfile[m] = f; mcls[m] = cls; munit[m] = unit; complete = 0
+				if (line ~ /^[[:space:]]*$/) { blank[m] = 1; complete = 1 }
+			}
+			text[m] = text[m] line "\n"
+			if (blank[m]) { continue }
+			if (line ~ /^[[:space:]]*\/\*\*/) { javadoc = 1 }
+			if (javadoc) {
+				if (line ~ /\*\//) { javadoc = 0 }
+				continue
+			}
+			mcode[m] = mcode[m] code(line)
+			if (name[m] == "") {
+				decl = line
+				if (decl ~ /class [[:alnum:]_$]+/) {
+					sub(/.*class /, "", decl); sub(/[^[:alnum:]_$].*/, "", decl)
+				} else {
+					sub(/[[:space:]]*[=(;].*/, "", decl); sub(/.*[[:space:]]/, "", decl)
+				}
+				name[m] = decl
+				public[m] = line ~ /^[[:space:]]*public /
+			}
+			opened = gsub(/\{/, "{", line); closed = gsub(/\}/, "}", line)
+			depth += opened - closed
+			if (depth == 0 && line ~ /[;}][[:space:]]*$/) { complete = 1 }
+		}
+		close(files[f])
+	}
+	# Keeps what is reachable from the sources, repeating until nothing changes.
+	do {
+		changed = 0
+		used = sources
+		for (i = 1; i <= m; i++) { if (keep[i]) { used = used mcode[i] } }
+		for (i = 1; i <= m; i++) {
+			if (keep[i] || blank[i]) { continue }
+			found = name[i] == mcls[i] || mentions(used, mcls[i] "." name[i]) || mentions(used, munit[i] "." name[i])
+			for (j = 1; !found && j <= m; j++) {
+				if (keep[j] && munit[j] == munit[i] && mentions(mcode[j], name[i])) { found = 1 }
+			}
+			if (found) { keep[i] = 1; changed = 1 }
+		}
+	} while (changed)
+	for (f = 1; f <= n; f++) {
+		out = head[f]
+		for (i = 1; i <= m; i++) {
+			if (mfile[i] == f && (keep[i] || blank[i])) { out = out text[i] }
+		}
+		printf "%s%s", out, tail[f] > files[f]
+		close(files[f])
+	}
+}'
+
+# The bundle's compiler settings report unused imports and every non-NLS string, so drop
+# the imports a file does not use and suppress the rest on each top-level class.
+used() {
+	grep -vE '^[[:space:]]*(import |\*|/\*\*|//)' "$2" \
+		| grep -qE "(^|[^.[:alnum:]_\$])($1)([^[:alnum:]_\$]|\$)"
+}
+for f in src-gen/org/linux/*.java; do
+	cat -s "$f" > "$f.tmp" && mv "$f.tmp" "$f"
+	for entry in \
+		'java.lang.invoke.*=MethodHandles?|MethodType|VarHandle' \
+		'java.nio.ByteOrder=ByteOrder' \
+		'java.util.*=Arrays|Objects|Optional|List|Map' \
+		'java.util.function.*=Consumer|Function|Supplier|BiFunction|IntFunction' \
+		'java.util.stream.*=Stream|IntStream|Collectors' \
+		'static java.lang.foreign.ValueLayout.*=JAVA_[A-Z_]+|ADDRESS(_UNALIGNED)?|Of[A-Z][a-z]+' \
+		'static java.lang.foreign.MemoryLayout.PathElement.*=groupElement|sequenceElement|dereferenceElement'; do
+		import=$(printf '%s' "${entry%%=*}" | sed 's/[.*]/\\&/g')
+		used "${entry#*=}" "$f" || sed -i "\\|^import $import;\$|d" "$f"
+	done
+	sed -i 's/^\(public \)\{0,1\}\(final \)\{0,1\}class /@SuppressWarnings("all")\n&/' "$f"
+done

resources/bundles/org.eclipse.core.filesystem/src-gen/org/linux/LibC$shared.java

@@ -0,0 +1,35 @@
+// Generated by jextract
+
+package org.linux;
+
+import java.lang.foreign.*;
+import java.util.*;
+import java.util.stream.*;
+
+
+@SuppressWarnings("all")
+public class LibC$shared {
+
+    LibC$shared() {
+        // Should not be called directly
+    }
+
+    public static final ValueLayout.OfByte C_CHAR =(ValueLayout.OfByte)Linker.nativeLinker().canonicalLayouts().get("char");
+    public static final ValueLayout.OfShort C_SHORT = (ValueLayout.OfShort) Linker.nativeLinker().canonicalLayouts().get("short");
+    public static final ValueLayout.OfInt C_INT = (ValueLayout.OfInt) Linker.nativeLinker().canonicalLayouts().get("int");
+    public static final ValueLayout.OfLong C_LONG_LONG = (ValueLayout.OfLong) Linker.nativeLinker().canonicalLayouts().get("long long");
+    public static final AddressLayout C_POINTER = ((AddressLayout) Linker.nativeLinker().canonicalLayouts().get("void*"))
+            .withTargetLayout(MemoryLayout.sequenceLayout(java.lang.Long.MAX_VALUE, C_CHAR));
+    public static final ValueLayout.OfLong C_LONG = (ValueLayout.OfLong) Linker.nativeLinker().canonicalLayouts().get("long");
+
+    static final boolean TRACE_DOWNCALLS = Boolean.getBoolean("jextract.trace.downcalls");
+
+    static void traceDowncall(String name, Object... args) {
+         String traceArgs = Arrays.stream(args)
+                       .map(Object::toString)
+                       .collect(Collectors.joining(", "));
+         System.out.printf("%s(%s)\n", name, traceArgs);
+    }
+
+}
+