diff --git a/doc/docgen.zig b/doc/docgen.zig
index ad13275a4c..1261981af3 100644
--- a/doc/docgen.zig
+++ b/doc/docgen.zig
@@ -8,6 +8,7 @@ const Progress = std.Progress;
 const print = std.debug.print;
 const mem = std.mem;
 const testing = std.testing;
+const Allocator = std.mem.Allocator;
 
 const max_doc_file_size = 10 * 1024 * 1024;
 
@@ -326,7 +327,7 @@ const Action = enum {
     Close,
 };
 
-fn genToc(allocator: *mem.Allocator, tokenizer: *Tokenizer) !Toc {
+fn genToc(allocator: *Allocator, tokenizer: *Tokenizer) !Toc {
     var urls = std.StringHashMap(Token).init(allocator);
     errdefer urls.deinit();
 
@@ -630,7 +631,7 @@ fn genToc(allocator: *mem.Allocator, tokenizer: *Tokenizer) !Toc {
     };
 }
 
-fn urlize(allocator: *mem.Allocator, input: []const u8) ![]u8 {
+fn urlize(allocator: *Allocator, input: []const u8) ![]u8 {
     var buf = std.ArrayList(u8).init(allocator);
     defer buf.deinit();
 
@@ -649,7 +650,7 @@ fn urlize(allocator: *mem.Allocator, input: []const u8) ![]u8 {
     return buf.toOwnedSlice();
 }
 
-fn escapeHtml(allocator: *mem.Allocator, input: []const u8) ![]u8 {
+fn escapeHtml(allocator: *Allocator, input: []const u8) ![]u8 {
     var buf = std.ArrayList(u8).init(allocator);
     defer buf.deinit();
 
@@ -695,7 +696,7 @@ test "term color" {
     testing.expectEqualSlices(u8, "A<span class=\"t32\">green</span>B", result);
 }
 
-fn termColor(allocator: *mem.Allocator, input: []const u8) ![]u8 {
+fn termColor(allocator: *Allocator, input: []const u8) ![]u8 {
     var buf = std.ArrayList(u8).init(allocator);
     defer buf.deinit();
 
@@ -789,8 +790,15 @@ fn isType(name: []const u8) bool {
     return false;
 }
 
-fn tokenizeAndPrintRaw(docgen_tokenizer: *Tokenizer, out: anytype, source_token: Token, raw_src: []const u8) !void {
-    const src = mem.trim(u8, raw_src, " \n");
+fn tokenizeAndPrintRaw(
+    allocator: *Allocator,
+    docgen_tokenizer: *Tokenizer,
+    out: anytype,
+    source_token: Token,
+    raw_src: []const u8,
+) !void {
+    const src_non_terminated = mem.trim(u8, raw_src, " \n");
+    const src = try allocator.dupeZ(u8, src_non_terminated);
     try out.writeAll("<code class=\"zig\">");
     var tokenizer = std.zig.Tokenizer.init(src);
     var index: usize = 0;
@@ -1016,12 +1024,24 @@ fn tokenizeAndPrintRaw(docgen_tokenizer: *Tokenizer, out: anytype, source_token:
     try out.writeAll("</code>");
 }
 
-fn tokenizeAndPrint(docgen_tokenizer: *Tokenizer, out: anytype, source_token: Token) !void {
+fn tokenizeAndPrint(
+    allocator: *Allocator,
+    docgen_tokenizer: *Tokenizer,
+    out: anytype,
+    source_token: Token,
+) !void {
     const raw_src = docgen_tokenizer.buffer[source_token.start..source_token.end];
-    return tokenizeAndPrintRaw(docgen_tokenizer, out, source_token, raw_src);
+    return tokenizeAndPrintRaw(allocator, docgen_tokenizer, out, source_token, raw_src);
 }
 
-fn genHtml(allocator: *mem.Allocator, tokenizer: *Tokenizer, toc: *Toc, out: anytype, zig_exe: []const u8, do_code_tests: bool) !void {
+fn genHtml(
+    allocator: *Allocator,
+    tokenizer: *Tokenizer,
+    toc: *Toc,
+    out: anytype,
+    zig_exe: []const u8,
+    do_code_tests: bool,
+) !void {
     var progress = Progress{};
     const root_node = try progress.start("Generating docgen examples", toc.nodes.len);
     defer root_node.end();
@@ -1048,7 +1068,7 @@ fn genHtml(allocator: *mem.Allocator, tokenizer: *Tokenizer, toc: *Toc, out: any
             },
             .Builtin => |tok| {
                 try out.writeAll("<pre>");
-                try tokenizeAndPrintRaw(tokenizer, out, tok, builtin_code);
+                try tokenizeAndPrintRaw(allocator, tokenizer, out, tok, builtin_code);
                 try out.writeAll("</pre>");
             },
             .HeaderOpen => |info| {
@@ -1069,7 +1089,7 @@ fn genHtml(allocator: *mem.Allocator, tokenizer: *Tokenizer, toc: *Toc, out: any
                 try out.writeAll("</ul>\n");
             },
             .Syntax => |content_tok| {
-                try tokenizeAndPrint(tokenizer, out, content_tok);
+                try tokenizeAndPrint(allocator, tokenizer, out, content_tok);
             },
             .Code => |code| {
                 const raw_source = tokenizer.buffer[code.source_token.start..code.source_token.end];
@@ -1078,7 +1098,7 @@ fn genHtml(allocator: *mem.Allocator, tokenizer: *Tokenizer, toc: *Toc, out: any
                     try out.print("<p class=\"file\">{s}.zig</p>", .{code.name});
                 }
                 try out.writeAll("<pre>");
-                try tokenizeAndPrint(tokenizer, out, code.source_token);
+                try tokenizeAndPrint(allocator, tokenizer, out, code.source_token);
                 try out.writeAll("</pre>");
 
                 if (!do_code_tests) {
@@ -1497,7 +1517,7 @@ fn genHtml(allocator: *mem.Allocator, tokenizer: *Tokenizer, toc: *Toc, out: any
     }
 }
 
-fn exec(allocator: *mem.Allocator, env_map: *std.BufMap, args: []const []const u8) !ChildProcess.ExecResult {
+fn exec(allocator: *Allocator, env_map: *std.BufMap, args: []const []const u8) !ChildProcess.ExecResult {
     const result = try ChildProcess.exec(.{
         .allocator = allocator,
         .argv = args,
@@ -1521,7 +1541,7 @@ fn exec(allocator: *mem.Allocator, env_map: *std.BufMap, args: []const []const u
     return result;
 }
 
-fn getBuiltinCode(allocator: *mem.Allocator, env_map: *std.BufMap, zig_exe: []const u8) ![]const u8 {
+fn getBuiltinCode(allocator: *Allocator, env_map: *std.BufMap, zig_exe: []const u8) ![]const u8 {
     const result = try exec(allocator, env_map, &[_][]const u8{ zig_exe, "build-obj", "--show-builtin" });
     return result.stdout;
 }
diff --git a/doc/langref.html.in b/doc/langref.html.in
index 31de76359e..cd7bc3be5c 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -3025,7 +3025,7 @@ test "@tagName" {
       </p>
       {#code_begin|obj_err|parameter of type 'Foo' not allowed in function with calling convention 'C'#}
 const Foo = enum { a, b, c };
-export fn entry(foo: Foo) void { }
+export fn entry(foo: Foo) void { _ = foo; }
       {#code_end#}
       <p>
       For a C-ABI-compatible enum, provide an explicit tag type to
@@ -3346,7 +3346,7 @@ test "call foo" {
       <p>
       Blocks are used to limit the scope of variable declarations:
       </p>
-      {#code_begin|test_err|undeclared identifier#}
+      {#code_begin|test_err|unused local variable#}
 test "access variable after block scope" {
     {
         var x: i32 = 1;
@@ -3377,7 +3377,7 @@ test "labeled break from labeled block expression" {
 
       {#header_open|Shadowing#}
       <p>It is never allowed for an identifier to "hide" another one by using the same name:</p>
-      {#code_begin|test_err|redefinition#}
+      {#code_begin|test_err|local shadows declaration#}
 const pi = 3.14;
 
 test "inside test block" {
@@ -5257,6 +5257,7 @@ test "float widening" {
 // Compile time coercion of float to int
 test "implicit cast to comptime_int" {
     var f: f32 = 54.0 / 5;
+    _ = f;
 }
       {#code_end#}
       {#header_close#}
@@ -5817,6 +5818,7 @@ fn foo(condition: bool) void {
         if (condition) f32 else u64,
         1234,
         5678);
+    _ = result;
 }
       {#code_end#}
       <p>
@@ -6313,7 +6315,7 @@ pub fn printValue(self: *Writer, value: anytype) !void {
       <p>
       And now, what happens if we give too many arguments to {#syntax#}printf{#endsyntax#}?
       </p>
-      {#code_begin|test_err|Unused argument in "here is a string: '{s}' here is a number: {}#}
+      {#code_begin|test_err|Unused argument in 'here is a string: '{s}' here is a number: {}#}
 const print = @import("std").debug.print;
 
 const a_number: i32 = 1234;
@@ -8853,6 +8855,7 @@ pub fn main() void {
 comptime {
     const array: [5]u8 = "hello".*;
     const garbage = array[5];
+    _ = garbage;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -8873,6 +8876,7 @@ fn foo(x: []const u8) u8 {
 comptime {
     const value: i32 = -1;
     const unsigned = @intCast(u32, value);
+    _ = unsigned;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -8895,6 +8899,7 @@ pub fn main() void {
 comptime {
     const spartan_count: u16 = 300;
     const byte = @intCast(u8, spartan_count);
+    _ = byte;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9028,6 +9033,7 @@ test "wraparound addition and subtraction" {
       {#code_begin|test_err|operation caused overflow#}
 comptime {
     const x = @shlExact(@as(u8, 0b01010101), 2);
+    _ = x;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9046,6 +9052,7 @@ pub fn main() void {
       {#code_begin|test_err|exact shift shifted out 1 bits#}
 comptime {
     const x = @shrExact(@as(u8, 0b10101010), 2);
+    _ = x;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9066,6 +9073,7 @@ comptime {
     const a: i32 = 1;
     const b: i32 = 0;
     const c = a / b;
+    _ = c;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9087,6 +9095,7 @@ comptime {
     const a: i32 = 10;
     const b: i32 = 0;
     const c = a % b;
+    _ = c;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9108,6 +9117,7 @@ comptime {
     const a: u32 = 10;
     const b: u32 = 3;
     const c = @divExact(a, b);
+    _ = c;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9300,6 +9310,7 @@ fn foo(set1: Set1) void {
 comptime {
     const ptr = @intToPtr(*align(1) i32, 0x1);
     const aligned = @alignCast(4, ptr);
+    _ = aligned;
 }
       {#code_end#}
       <p>At runtime:</p>
@@ -9414,6 +9425,7 @@ fn bar(f: *Foo) void {
 comptime {
     const opt_ptr: ?*i32 = null;
     const ptr = @ptrCast(*i32, opt_ptr);
+    _ = ptr;
 }
       {#code_end#}
       <p>At runtime:</p>