Add hash map for metadata fields and add a 'zonMeta' attribute to out…

…put nix expression
nix-community · Jun 11, 2024 · 60317f4 · 60317f4
1 parent 4394c25
commit 60317f4
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Showing 4 changed files with 98 additions and 47 deletions.
diff --git a/src/codegen.zig b/src/codegen.zig
@@ -6,14 +6,15 @@ const mem = std.mem;
 const Dependency = @import("Dependency.zig");
 
 const Entry = StringHashMap(Dependency).Entry;
+const MetaEntry = StringHashMap([]const u8).Entry;
 
-pub fn write(alloc: Allocator, out: anytype, deps: StringHashMap(Dependency)) !void {
+pub fn write(alloc: Allocator, out: anytype, meta: StringHashMap([]const u8), deps: StringHashMap(Dependency)) !void {
     try out.writeAll(
         \\# generated by zon2nix (https://github.com/nix-community/zon2nix)
         \\
         \\{ linkFarm, fetchzip }:
         \\
-        \\linkFarm "zig-packages" [
+        \\(linkFarm "zig-packages" [
         \\
     );
 
@@ -40,9 +41,38 @@ pub fn write(alloc: Allocator, out: anytype, deps: StringHashMap(Dependency)) !v
         , .{ key, dep.url, dep.nix_hash });
     }
 
-    try out.writeAll("]\n");
+    try out.writeAll("])");
+
+    const meta_len = meta.count();
+    if (meta_len > 0) {
+        try out.writeAll(".overrideAttrs {\n  passthru.zonMeta = {\n");
+
+        var meta_entries = try alloc.alloc(MetaEntry, meta_len);
+        var meta_iter = meta.iterator();
+        for (0..meta_len) |i| {
+            meta_entries[i] = meta_iter.next().?;
+        }
+        mem.sortUnstable(MetaEntry, meta_entries, {}, metaLessThan);
+
+        for (meta_entries) |entry| {
+            const key = entry.key_ptr.*;
+            const value = entry.value_ptr.*;
+
+            try out.print(
+                \\    "{s}" = "{s}";
+                \\
+            , .{ key, value });
+        }
+
+        try out.writeAll("  };\n}");
+    }
+    try out.writeAll("\n");
 }
 
 fn lessThan(_: void, lhs: Entry, rhs: Entry) bool {
     return mem.order(u8, lhs.key_ptr.*, rhs.key_ptr.*) == .lt;
 }
+
+fn metaLessThan(_: void, lhs: MetaEntry, rhs: MetaEntry) bool {
+    return mem.order(u8, lhs.key_ptr.*, rhs.key_ptr.*) == .lt;
+}
diff --git a/src/fetch.zig b/src/fetch.zig
@@ -79,7 +79,8 @@ pub fn fetch(alloc: Allocator, deps: *StringHashMap(Dependency)) !void {
             };
             defer file.close();
 
-            try parse(alloc, deps, file);
+            var meta = StringHashMap([]const u8).init(alloc);
+            try parse(alloc, &meta, deps, file);
             if (deps.count() > len_before) {
                 done = false;
             }

diff --git a/src/main.zig b/src/main.zig
@@ -28,12 +28,13 @@ pub fn main() !void {
     defer arena.deinit();
     const alloc = arena.allocator();
 
+    var meta = StringHashMap([]const u8).init(alloc);
     var deps = StringHashMap(Dependency).init(alloc);
-    try parse(alloc, &deps, file);
+    try parse(alloc, &meta, &deps, file);
     try fetch(alloc, &deps);
 
     var out = io.bufferedWriter(io.getStdOut().writer());
-    try write(alloc, out.writer(), deps);
+    try write(alloc, out.writer(), meta, deps);
     try out.flush();
 }
 

diff --git a/src/parse.zig b/src/parse.zig
@@ -9,7 +9,7 @@ const string_literal = std.zig.string_literal;
 
 const Dependency = @import("Dependency.zig");
 
-pub fn parse(alloc: Allocator, deps: *StringHashMap(Dependency), file: File) !void {
+pub fn parse(alloc: Allocator, meta: *StringHashMap([]const u8), deps: *StringHashMap(Dependency), file: File) !void {
     const content = try alloc.allocSentinel(u8, try file.getEndPos(), 0);
     _ = try file.reader().readAll(content);
 
@@ -21,44 +21,16 @@ pub fn parse(alloc: Allocator, deps: *StringHashMap(Dependency), file: File) !vo
     };
 
     for (root_init.ast.fields) |field_idx| {
-        if (!mem.eql(u8, try parseFieldName(alloc, ast, field_idx), "dependencies")) {
-            continue;
-        }
-
-        const deps_init = ast.fullStructInit(&buf, field_idx) orelse {
-            return error.ParseError;
-        };
-
-        for (deps_init.ast.fields) |dep_idx| {
-            var dep: Dependency = .{
-                .url = undefined,
-                .nix_hash = undefined,
-                .done = false,
-            };
-            var hash: []const u8 = undefined;
-            var has_url = false;
-            var has_hash = false;
-
-            const dep_init = ast.fullStructInit(&buf, dep_idx) orelse {
-                return error.parseError;
-            };
-
-            for (dep_init.ast.fields) |dep_field_idx| {
-                const name = try parseFieldName(alloc, ast, dep_field_idx);
-
-                if (mem.eql(u8, name, "url")) {
-                    dep.url = try parseString(alloc, ast, dep_field_idx);
-                    has_url = true;
-                } else if (mem.eql(u8, name, "hash")) {
-                    hash = try parseString(alloc, ast, dep_field_idx);
-                    has_hash = true;
-                }
-            }
-
-            if (has_url and has_hash) {
-                _ = try deps.getOrPutValue(hash, dep);
-            } else {
-                return error.parseError;
+        const field_name = try parseFieldName(alloc, ast, field_idx);
+        if (mem.eql(u8, field_name, "dependencies")) {
+            try parseDependency(alloc, ast, field_idx, deps);
+        } else if (mem.eql(u8, field_name, "paths")) {
+            // TODO: implement parsing of 'paths' array
+        } else {
+            if (parseString(alloc, ast, field_idx)) |value| {
+                _ = try meta.getOrPutValue(field_name, value);
+            } else |_| {
+                // Ignore field if metadata value isn't a string.
             }
         }
     }
@@ -70,7 +42,53 @@ fn parseFieldName(alloc: Allocator, ast: Ast, idx: Index) ![]const u8 {
 }
 
 fn parseString(alloc: Allocator, ast: Ast, idx: Index) ![]const u8 {
-    return string_literal.parseAlloc(alloc, ast.tokenSlice(ast.nodes.items(.main_token)[idx]));
+    const token = ast.tokenSlice(ast.nodes.items(.main_token)[idx]);
+    return switch (token[0]) {
+        // Check if the start of the token looks like a string to avoid
+        // unreachable error when trying to parse a non-string.
+        '"', '\\' => string_literal.parseAlloc(alloc, token),
+        else => error.ParseError,
+    };
+}
+
+fn parseDependency(alloc: Allocator, ast: Ast, field_idx: Index, deps: *StringHashMap(Dependency)) !void {
+    var buf: [2]Index = undefined;
+    const deps_init = ast.fullStructInit(&buf, field_idx) orelse {
+        return error.ParseError;
+    };
+
+    for (deps_init.ast.fields) |dep_idx| {
+        var dep: Dependency = .{
+            .url = undefined,
+            .nix_hash = undefined,
+            .done = false,
+        };
+        var hash: []const u8 = undefined;
+        var has_url = false;
+        var has_hash = false;
+
+        const dep_init = ast.fullStructInit(&buf, dep_idx) orelse {
+            return error.parseError;
+        };
+
+        for (dep_init.ast.fields) |dep_field_idx| {
+            const name = try parseFieldName(alloc, ast, dep_field_idx);
+
+            if (mem.eql(u8, name, "url")) {
+                dep.url = try parseString(alloc, ast, dep_field_idx);
+                has_url = true;
+            } else if (mem.eql(u8, name, "hash")) {
+                hash = try parseString(alloc, ast, dep_field_idx);
+                has_hash = true;
+            }
+        }
+
+        if (has_url and has_hash) {
+            _ = try deps.getOrPutValue(hash, dep);
+        } else {
+            return error.parseError;
+        }
+    }
 }
 
 test parse {
@@ -82,9 +100,10 @@ test parse {
     defer arena.deinit();
     const alloc = arena.allocator();
 
+    var meta = StringHashMap([]const u8).init(alloc);
     var deps = StringHashMap(Dependency).init(alloc);
     const basic = try fs.cwd().openFile("fixtures/basic.zon", .{});
-    try parse(alloc, &deps, basic);
+    try parse(alloc, &meta, &deps, basic);
     basic.close();
 
     try testing.expectEqual(deps.count(), 3);