Added build option to enable the leak counting allocator.

Log the allocation count to the client at the end of the main loop.
Fixed two memory leaks in analysis.zig

build.zig

@@ -16,6 +16,12 @@ pub fn build(b: *std.build.Builder) void {
 
     exe.addPackagePath("data", "src/data/0.6.0.zig");
 
+    exe.addBuildOption(
+        bool,
+        "leak_detection",
+        b.option(bool, "leak_detection", "Use testing.LeakCountAllocator to track leaks.") orelse false,
+    );
+
     exe.setTarget(target);
     exe.setBuildMode(mode);
     exe.install();

src/analysis.zig

@@ -30,12 +30,13 @@ pub fn getDocComments(allocator: *std.mem.Allocator, tree: *std.zig.ast.Tree, no
             if (func.doc_comments) |doc_comments| {
                 var doc_it = doc_comments.lines.iterator(0);
                 var lines = std.ArrayList([]const u8).init(allocator);
+                defer lines.deinit();
 
                 while (doc_it.next()) |doc_comment| {
                     _ = try lines.append(std.fmt.trim(tree.tokenSlice(doc_comment.*)[3..]));
                 }
 
-                return try std.mem.join(allocator, "\n", lines.toOwnedSlice());
+                return try std.mem.join(allocator, "\n", lines.items);
             } else {
                 return null;
             }
@@ -45,12 +46,13 @@ pub fn getDocComments(allocator: *std.mem.Allocator, tree: *std.zig.ast.Tree, no
             if (var_decl.doc_comments) |doc_comments| {
                 var doc_it = doc_comments.lines.iterator(0);
                 var lines = std.ArrayList([]const u8).init(allocator);
+                defer lines.deinit();
 
                 while (doc_it.next()) |doc_comment| {
                     _ = try lines.append(std.fmt.trim(tree.tokenSlice(doc_comment.*)[3..]));
                 }
 
-                return try std.mem.join(allocator, "\n", lines.toOwnedSlice());
+                return try std.mem.join(allocator, "\n", lines.items);
             } else {
                 return null;
             }

src/main.zig

@@ -164,7 +164,8 @@ pub fn completeGlobal(id: i64, document: types.TextDocument) !void {
 
     var completions = std.ArrayList(types.CompletionItem).init(allocator);
 
-    // try log("{}", .{&tree.root_node.decls});
+    // @TODO
+    try log("{}", .{&tree.root_node.decls});
     var decls = tree.root_node.decls.iterator(0);
     while (decls.next()) |decl_ptr| {
 
@@ -356,9 +357,14 @@ pub fn processJsonRpc(json: []const u8) !void {
     } else {
         try log("Method without return value not implemented: {}", .{method});
     }
-
 }
 
+const use_leak_count_alloc = @import("build_options").leak_detection;
+
+var leak_alloc_global: std.testing.LeakCountAllocator = undefined;
+// We can now use if(leak_count_alloc) |alloc| {     ... } as a comptime check.
+const leak_count_alloc: ?*std.testing.LeakCountAllocator = if (use_leak_count_alloc) &leak_alloc_global else null;
+
 pub fn main() anyerror!void {
 
     // Init memory
@@ -367,6 +373,12 @@ pub fn main() anyerror!void {
     defer arena.deinit();
     allocator = &arena.allocator;
 
+    if (use_leak_count_alloc) {
+        // Initialize the leak counting allocator.
+        leak_alloc_global = std.testing.LeakCountAllocator.init(allocator);
+        allocator = &leak_alloc_global.allocator;
+    }
+
     // Init buffer for stdin read
 
     var buffer = std.ArrayList(u8).init(allocator);
@@ -391,7 +403,7 @@ pub fn main() anyerror!void {
 
         // var bytes = stdin.read(buffer.items[0..6]) catch return;
 
-        if (offset >= 16 and std.mem.eql(u8, "Content-Length: ", buffer.items[0..16])) {
+        if (offset >= 16 and std.mem.startsWith(u8, buffer.items, "Content-Length: ")) {
 
             index = 16;
             while (index <= offset + 10) : (index += 1) {
@@ -430,7 +442,7 @@ pub fn main() anyerror!void {
             }
 
         } else if (offset >= 16) {
-            try log("Offset is greater than 16!", .{});
+            try log("OffseOt is greater than 16!", .{});
             return;
         }
 
@@ -460,5 +472,8 @@ pub fn main() anyerror!void {
 
         offset += bytes_read;
 
+        if (leak_count_alloc) |leaks| {
+            try log("Allocations alive after message: {}", .{leaks.count});
+        }
     }
 }