Commit aa9caf5064

Benjamin Feng <benjamin.feng@glassdoor.com>
2020-01-29 20:18:04
Create leak_count_allocator
1 parent 4d134a0
doc/docgen.zig
@@ -672,7 +672,7 @@ const TermState = enum {
 
 test "term color" {
     const input_bytes = "A\x1b[32;1mgreen\x1b[0mB";
-    const result = try termColor(std.testing.allocator, input_bytes);
+    const result = try termColor(std.testing.leak_count_allocator, input_bytes);
     testing.expectEqualSlices(u8, "A<span class=\"t32\">green</span>B", result);
 }
 
lib/std/fs/path.zig
@@ -665,15 +665,16 @@ pub fn resolvePosix(allocator: *Allocator, paths: []const []const u8) ![]u8 {
 }
 
 test "resolve" {
-    const cwd = try process.getCwdAlloc(testing.allocator);
+    const cwd = try process.getCwdAlloc(testing.leak_count_allocator);
+    defer testing.leak_count_allocator.free(cwd);
     if (builtin.os == .windows) {
         if (windowsParsePath(cwd).kind == WindowsPath.Kind.Drive) {
             cwd[0] = asciiUpper(cwd[0]);
         }
-        testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{"."}), cwd));
+        try testResolveWindows(&[_][]const u8{"."}, cwd);
     } else {
-        testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "a/b/c/", "../../.." }), cwd));
-        testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{"."}), cwd));
+        try testResolvePosix(&[_][]const u8{ "a/b/c/", "../../.." }, cwd);
+        try testResolvePosix(&[_][]const u8{"."}, cwd);
     }
 }
 
@@ -683,66 +684,71 @@ test "resolveWindows" {
         return error.SkipZigTest;
     }
     if (builtin.os == .windows) {
-        const cwd = try process.getCwdAlloc(testing.allocator);
+        const cwd = try process.getCwdAlloc(testing.leak_count_allocator);
+        defer testing.leak_count_allocator.free(cwd);
         const parsed_cwd = windowsParsePath(cwd);
         {
-            const result = testResolveWindows(&[_][]const u8{ "/usr/local", "lib\\zig\\std\\array_list.zig" });
-            const expected = try join(testing.allocator, &[_][]const u8{
+            const expected = try join(testing.leak_count_allocator, &[_][]const u8{
                 parsed_cwd.disk_designator,
                 "usr\\local\\lib\\zig\\std\\array_list.zig",
             });
+            defer testing.leak_count_allocator.free(expected);
             if (parsed_cwd.kind == WindowsPath.Kind.Drive) {
                 expected[0] = asciiUpper(parsed_cwd.disk_designator[0]);
             }
-            testing.expect(mem.eql(u8, result, expected));
+            try testResolveWindows(&[_][]const u8{ "/usr/local", "lib\\zig\\std\\array_list.zig" }, expected);
         }
         {
-            const result = testResolveWindows(&[_][]const u8{ "usr/local", "lib\\zig" });
-            const expected = try join(testing.allocator, &[_][]const u8{
+            const expected = try join(testing.leak_count_allocator, &[_][]const u8{
                 cwd,
                 "usr\\local\\lib\\zig",
             });
+            defer testing.leak_count_allocator.free(expected);
             if (parsed_cwd.kind == WindowsPath.Kind.Drive) {
                 expected[0] = asciiUpper(parsed_cwd.disk_designator[0]);
             }
-            testing.expect(mem.eql(u8, result, expected));
+            try testResolveWindows(&[_][]const u8{ "usr/local", "lib\\zig" }, expected);
         }
     }
 
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:\\a\\b\\c", "/hi", "ok" }), "C:\\hi\\ok"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/blah\\blah", "d:/games", "c:../a" }), "C:\\blah\\a"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/blah\\blah", "d:/games", "C:../a" }), "C:\\blah\\a"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/ignore", "d:\\a/b\\c/d", "\\e.exe" }), "D:\\e.exe"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/ignore", "c:/some/file" }), "C:\\some\\file"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "d:/ignore", "d:some/dir//" }), "D:\\ignore\\some\\dir"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "//server/share", "..", "relative\\" }), "\\\\server\\share\\relative"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/", "//" }), "C:\\"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/", "//dir" }), "C:\\dir"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/", "//server/share" }), "\\\\server\\share\\"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/", "//server//share" }), "\\\\server\\share\\"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "c:/", "///some//dir" }), "C:\\some\\dir"));
-    testing.expect(mem.eql(u8, testResolveWindows(&[_][]const u8{ "C:\\foo\\tmp.3\\", "..\\tmp.3\\cycles\\root.js" }), "C:\\foo\\tmp.3\\cycles\\root.js"));
+    try testResolveWindows(&[_][]const u8{ "c:\\a\\b\\c", "/hi", "ok" }, "C:\\hi\\ok");
+    try testResolveWindows(&[_][]const u8{ "c:/blah\\blah", "d:/games", "c:../a" }, "C:\\blah\\a");
+    try testResolveWindows(&[_][]const u8{ "c:/blah\\blah", "d:/games", "C:../a" }, "C:\\blah\\a");
+    try testResolveWindows(&[_][]const u8{ "c:/ignore", "d:\\a/b\\c/d", "\\e.exe" }, "D:\\e.exe");
+    try testResolveWindows(&[_][]const u8{ "c:/ignore", "c:/some/file" }, "C:\\some\\file");
+    try testResolveWindows(&[_][]const u8{ "d:/ignore", "d:some/dir//" }, "D:\\ignore\\some\\dir");
+    try testResolveWindows(&[_][]const u8{ "//server/share", "..", "relative\\" }, "\\\\server\\share\\relative");
+    try testResolveWindows(&[_][]const u8{ "c:/", "//" }, "C:\\");
+    try testResolveWindows(&[_][]const u8{ "c:/", "//dir" }, "C:\\dir");
+    try testResolveWindows(&[_][]const u8{ "c:/", "//server/share" }, "\\\\server\\share\\");
+    try testResolveWindows(&[_][]const u8{ "c:/", "//server//share" }, "\\\\server\\share\\");
+    try testResolveWindows(&[_][]const u8{ "c:/", "///some//dir" }, "C:\\some\\dir");
+    try testResolveWindows(&[_][]const u8{ "C:\\foo\\tmp.3\\", "..\\tmp.3\\cycles\\root.js" }, "C:\\foo\\tmp.3\\cycles\\root.js");
 }
 
 test "resolvePosix" {
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/a/b", "c" }), "/a/b/c"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/a/b", "c", "//d", "e///" }), "/d/e"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/a/b/c", "..", "../" }), "/a"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/", "..", ".." }), "/"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{"/a/b/c/"}), "/a/b/c"));
-
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/var/lib", "../", "file/" }), "/var/file"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/var/lib", "/../", "file/" }), "/file"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/some/dir", ".", "/absolute/" }), "/absolute"));
-    testing.expect(mem.eql(u8, testResolvePosix(&[_][]const u8{ "/foo/tmp.3/", "../tmp.3/cycles/root.js" }), "/foo/tmp.3/cycles/root.js"));
+    try testResolvePosix(&[_][]const u8{ "/a/b", "c" }, "/a/b/c");
+    try testResolvePosix(&[_][]const u8{ "/a/b", "c", "//d", "e///" }, "/d/e");
+    try testResolvePosix(&[_][]const u8{ "/a/b/c", "..", "../" }, "/a");
+    try testResolvePosix(&[_][]const u8{ "/", "..", ".." }, "/");
+    try testResolvePosix(&[_][]const u8{"/a/b/c/"}, "/a/b/c");
+
+    try testResolvePosix(&[_][]const u8{ "/var/lib", "../", "file/" }, "/var/file");
+    try testResolvePosix(&[_][]const u8{ "/var/lib", "/../", "file/" }, "/file");
+    try testResolvePosix(&[_][]const u8{ "/some/dir", ".", "/absolute/" }, "/absolute");
+    try testResolvePosix(&[_][]const u8{ "/foo/tmp.3/", "../tmp.3/cycles/root.js" }, "/foo/tmp.3/cycles/root.js");
 }
 
-fn testResolveWindows(paths: []const []const u8) []u8 {
-    return resolveWindows(testing.allocator, paths) catch unreachable;
+fn testResolveWindows(paths: []const []const u8, expected: []const u8) !void {
+    const actual = try resolveWindows(testing.leak_count_allocator, paths);
+    defer testing.leak_count_allocator.free(actual);
+    return testing.expect(mem.eql(u8, actual, expected));
 }
 
-fn testResolvePosix(paths: []const []const u8) []u8 {
-    return resolvePosix(testing.allocator, paths) catch unreachable;
+fn testResolvePosix(paths: []const []const u8, expected: []const u8) !void {
+    const actual = try resolvePosix(testing.leak_count_allocator, paths);
+    defer testing.leak_count_allocator.free(actual);
+    return testing.expect(mem.eql(u8, actual, expected));
 }
 
 /// If the path is a file in the current directory (no directory component)
@@ -1126,51 +1132,53 @@ test "relative" {
         // TODO https://github.com/ziglang/zig/issues/3288
         return error.SkipZigTest;
     }
-    testRelativeWindows("c:/blah\\blah", "d:/games", "D:\\games");
-    testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa", "..");
-    testRelativeWindows("c:/aaaa/bbbb", "c:/cccc", "..\\..\\cccc");
-    testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa/bbbb", "");
-    testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa/cccc", "..\\cccc");
-    testRelativeWindows("c:/aaaa/", "c:/aaaa/cccc", "cccc");
-    testRelativeWindows("c:/", "c:\\aaaa\\bbbb", "aaaa\\bbbb");
-    testRelativeWindows("c:/aaaa/bbbb", "d:\\", "D:\\");
-    testRelativeWindows("c:/AaAa/bbbb", "c:/aaaa/bbbb", "");
-    testRelativeWindows("c:/aaaaa/", "c:/aaaa/cccc", "..\\aaaa\\cccc");
-    testRelativeWindows("C:\\foo\\bar\\baz\\quux", "C:\\", "..\\..\\..\\..");
-    testRelativeWindows("C:\\foo\\test", "C:\\foo\\test\\bar\\package.json", "bar\\package.json");
-    testRelativeWindows("C:\\foo\\bar\\baz-quux", "C:\\foo\\bar\\baz", "..\\baz");
-    testRelativeWindows("C:\\foo\\bar\\baz", "C:\\foo\\bar\\baz-quux", "..\\baz-quux");
-    testRelativeWindows("\\\\foo\\bar", "\\\\foo\\bar\\baz", "baz");
-    testRelativeWindows("\\\\foo\\bar\\baz", "\\\\foo\\bar", "..");
-    testRelativeWindows("\\\\foo\\bar\\baz-quux", "\\\\foo\\bar\\baz", "..\\baz");
-    testRelativeWindows("\\\\foo\\bar\\baz", "\\\\foo\\bar\\baz-quux", "..\\baz-quux");
-    testRelativeWindows("C:\\baz-quux", "C:\\baz", "..\\baz");
-    testRelativeWindows("C:\\baz", "C:\\baz-quux", "..\\baz-quux");
-    testRelativeWindows("\\\\foo\\baz-quux", "\\\\foo\\baz", "..\\baz");
-    testRelativeWindows("\\\\foo\\baz", "\\\\foo\\baz-quux", "..\\baz-quux");
-    testRelativeWindows("C:\\baz", "\\\\foo\\bar\\baz", "\\\\foo\\bar\\baz");
-    testRelativeWindows("\\\\foo\\bar\\baz", "C:\\baz", "C:\\baz");
-
-    testRelativePosix("/var/lib", "/var", "..");
-    testRelativePosix("/var/lib", "/bin", "../../bin");
-    testRelativePosix("/var/lib", "/var/lib", "");
-    testRelativePosix("/var/lib", "/var/apache", "../apache");
-    testRelativePosix("/var/", "/var/lib", "lib");
-    testRelativePosix("/", "/var/lib", "var/lib");
-    testRelativePosix("/foo/test", "/foo/test/bar/package.json", "bar/package.json");
-    testRelativePosix("/Users/a/web/b/test/mails", "/Users/a/web/b", "../..");
-    testRelativePosix("/foo/bar/baz-quux", "/foo/bar/baz", "../baz");
-    testRelativePosix("/foo/bar/baz", "/foo/bar/baz-quux", "../baz-quux");
-    testRelativePosix("/baz-quux", "/baz", "../baz");
-    testRelativePosix("/baz", "/baz-quux", "../baz-quux");
+    try testRelativeWindows("c:/blah\\blah", "d:/games", "D:\\games");
+    try testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa", "..");
+    try testRelativeWindows("c:/aaaa/bbbb", "c:/cccc", "..\\..\\cccc");
+    try testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa/bbbb", "");
+    try testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa/cccc", "..\\cccc");
+    try testRelativeWindows("c:/aaaa/", "c:/aaaa/cccc", "cccc");
+    try testRelativeWindows("c:/", "c:\\aaaa\\bbbb", "aaaa\\bbbb");
+    try testRelativeWindows("c:/aaaa/bbbb", "d:\\", "D:\\");
+    try testRelativeWindows("c:/AaAa/bbbb", "c:/aaaa/bbbb", "");
+    try testRelativeWindows("c:/aaaaa/", "c:/aaaa/cccc", "..\\aaaa\\cccc");
+    try testRelativeWindows("C:\\foo\\bar\\baz\\quux", "C:\\", "..\\..\\..\\..");
+    try testRelativeWindows("C:\\foo\\test", "C:\\foo\\test\\bar\\package.json", "bar\\package.json");
+    try testRelativeWindows("C:\\foo\\bar\\baz-quux", "C:\\foo\\bar\\baz", "..\\baz");
+    try testRelativeWindows("C:\\foo\\bar\\baz", "C:\\foo\\bar\\baz-quux", "..\\baz-quux");
+    try testRelativeWindows("\\\\foo\\bar", "\\\\foo\\bar\\baz", "baz");
+    try testRelativeWindows("\\\\foo\\bar\\baz", "\\\\foo\\bar", "..");
+    try testRelativeWindows("\\\\foo\\bar\\baz-quux", "\\\\foo\\bar\\baz", "..\\baz");
+    try testRelativeWindows("\\\\foo\\bar\\baz", "\\\\foo\\bar\\baz-quux", "..\\baz-quux");
+    try testRelativeWindows("C:\\baz-quux", "C:\\baz", "..\\baz");
+    try testRelativeWindows("C:\\baz", "C:\\baz-quux", "..\\baz-quux");
+    try testRelativeWindows("\\\\foo\\baz-quux", "\\\\foo\\baz", "..\\baz");
+    try testRelativeWindows("\\\\foo\\baz", "\\\\foo\\baz-quux", "..\\baz-quux");
+    try testRelativeWindows("C:\\baz", "\\\\foo\\bar\\baz", "\\\\foo\\bar\\baz");
+    try testRelativeWindows("\\\\foo\\bar\\baz", "C:\\baz", "C:\\baz");
+
+    try testRelativePosix("/var/lib", "/var", "..");
+    try testRelativePosix("/var/lib", "/bin", "../../bin");
+    try testRelativePosix("/var/lib", "/var/lib", "");
+    try testRelativePosix("/var/lib", "/var/apache", "../apache");
+    try testRelativePosix("/var/", "/var/lib", "lib");
+    try testRelativePosix("/", "/var/lib", "var/lib");
+    try testRelativePosix("/foo/test", "/foo/test/bar/package.json", "bar/package.json");
+    try testRelativePosix("/Users/a/web/b/test/mails", "/Users/a/web/b", "../..");
+    try testRelativePosix("/foo/bar/baz-quux", "/foo/bar/baz", "../baz");
+    try testRelativePosix("/foo/bar/baz", "/foo/bar/baz-quux", "../baz-quux");
+    try testRelativePosix("/baz-quux", "/baz", "../baz");
+    try testRelativePosix("/baz", "/baz-quux", "../baz-quux");
 }
 
-fn testRelativePosix(from: []const u8, to: []const u8, expected_output: []const u8) void {
-    const result = relativePosix(testing.allocator, from, to) catch unreachable;
+fn testRelativePosix(from: []const u8, to: []const u8, expected_output: []const u8) !void {
+    const result = try relativePosix(testing.leak_count_allocator, from, to);
+    defer testing.leak_count_allocator.free(result);
     testing.expectEqualSlices(u8, expected_output, result);
 }
 
-fn testRelativeWindows(from: []const u8, to: []const u8, expected_output: []const u8) void {
-    const result = relativeWindows(testing.allocator, from, to) catch unreachable;
+fn testRelativeWindows(from: []const u8, to: []const u8, expected_output: []const u8) !void {
+    const result = try relativeWindows(testing.leak_count_allocator, from, to);
+    defer testing.leak_count_allocator.free(result);
     testing.expectEqualSlices(u8, expected_output, result);
 }
lib/std/os/test.zig
@@ -9,7 +9,7 @@ const elf = std.elf;
 const File = std.fs.File;
 const Thread = std.Thread;
 
-const a = std.testing.allocator;
+const a = std.testing.leak_count_allocator;
 
 const builtin = @import("builtin");
 const AtomicRmwOp = builtin.AtomicRmwOp;
lib/std/special/test_runner.zig
@@ -14,6 +14,7 @@ pub fn main() anyerror!void {
 
     for (test_fn_list) |test_fn, i| {
         std.testing.allocator_instance.reset();
+
         var test_node = root_node.start(test_fn.name, null);
         test_node.activate();
         progress.refresh();
@@ -36,6 +37,8 @@ pub fn main() anyerror!void {
                 return err;
             },
         }
+
+        try std.testing.leak_count_allocator_instance.validate();
     }
     root_node.end();
     if (ok_count == test_fn_list.len) {
lib/std/zig/ast.zig
@@ -2287,7 +2287,7 @@ pub const Node = struct {
 test "iterate" {
     var root = Node.Root{
         .base = Node{ .id = Node.Id.Root },
-        .decls = Node.Root.DeclList.init(std.testing.allocator),
+        .decls = Node.Root.DeclList.init(std.testing.leak_count_allocator),
         .eof_token = 0,
     };
     var base = &root.base;
lib/std/array_list.zig
@@ -320,7 +320,7 @@ test "std.ArrayList.basic" {
 }
 
 test "std.ArrayList.orderedRemove" {
-    var list = ArrayList(i32).init(testing.allocator);
+    var list = ArrayList(i32).init(testing.leak_count_allocator);
     defer list.deinit();
 
     try list.append(1);
@@ -347,7 +347,7 @@ test "std.ArrayList.orderedRemove" {
 }
 
 test "std.ArrayList.swapRemove" {
-    var list = ArrayList(i32).init(testing.allocator);
+    var list = ArrayList(i32).init(testing.leak_count_allocator);
     defer list.deinit();
 
     try list.append(1);
@@ -374,7 +374,7 @@ test "std.ArrayList.swapRemove" {
 }
 
 test "std.ArrayList.swapRemoveOrError" {
-    var list = ArrayList(i32).init(testing.allocator);
+    var list = ArrayList(i32).init(testing.leak_count_allocator);
     defer list.deinit();
 
     // Test just after initialization
@@ -402,7 +402,7 @@ test "std.ArrayList.swapRemoveOrError" {
 }
 
 test "std.ArrayList.insert" {
-    var list = ArrayList(i32).init(testing.allocator);
+    var list = ArrayList(i32).init(testing.leak_count_allocator);
     defer list.deinit();
 
     try list.append(1);
@@ -416,7 +416,7 @@ test "std.ArrayList.insert" {
 }
 
 test "std.ArrayList.insertSlice" {
-    var list = ArrayList(i32).init(testing.allocator);
+    var list = ArrayList(i32).init(testing.leak_count_allocator);
     defer list.deinit();
 
     try list.append(1);
@@ -443,7 +443,8 @@ const Item = struct {
 };
 
 test "std.ArrayList: ArrayList(T) of struct T" {
-    var root = Item{ .integer = 1, .sub_items = ArrayList(Item).init(testing.allocator) };
-    try root.sub_items.append(Item{ .integer = 42, .sub_items = ArrayList(Item).init(testing.allocator) });
+    var root = Item{ .integer = 1, .sub_items = ArrayList(Item).init(testing.leak_count_allocator) };
+    defer root.sub_items.deinit();
+    try root.sub_items.append(Item{ .integer = 42, .sub_items = ArrayList(Item).init(testing.leak_count_allocator) });
     testing.expect(root.sub_items.items[0].integer == 42);
 }
lib/std/buffer.zig
@@ -150,7 +150,9 @@ pub const Buffer = struct {
 };
 
 test "simple Buffer" {
-    var buf = try Buffer.init(testing.allocator, "");
+    var buf = try Buffer.init(testing.leak_count_allocator, "");
+    defer buf.deinit();
+
     testing.expect(buf.len() == 0);
     try buf.append("hello");
     try buf.append(" ");
@@ -159,6 +161,7 @@ test "simple Buffer" {
     testing.expect(mem.eql(u8, mem.toSliceConst(u8, buf.toSliceConst().ptr), buf.toSliceConst()));
 
     var buf2 = try Buffer.initFromBuffer(buf);
+    defer buf2.deinit();
     testing.expect(buf.eql(buf2.toSliceConst()));
 
     testing.expect(buf.startsWith("hell"));
@@ -169,14 +172,16 @@ test "simple Buffer" {
 }
 
 test "Buffer.initSize" {
-    var buf = try Buffer.initSize(testing.allocator, 3);
+    var buf = try Buffer.initSize(testing.leak_count_allocator, 3);
+    defer buf.deinit();
     testing.expect(buf.len() == 3);
     try buf.append("hello");
     testing.expect(mem.eql(u8, buf.toSliceConst()[3..], "hello"));
 }
 
 test "Buffer.initCapacity" {
-    var buf = try Buffer.initCapacity(testing.allocator, 10);
+    var buf = try Buffer.initCapacity(testing.leak_count_allocator, 10);
+    defer buf.deinit();
     testing.expect(buf.len() == 0);
     testing.expect(buf.capacity() >= 10);
     const old_cap = buf.capacity();
lib/std/debug.zig
@@ -2193,7 +2193,7 @@ fn readInitialLength(comptime E: type, in_stream: *io.InStream(E), is_64: *bool)
 }
 
 pub const global_allocator = blk: {
-    @compileError("Please switch to std.testing.allocator.");
+    @compileError("Please switch to std.testing.leak_count_allocator.");
 };
 var global_fixed_allocator = std.heap.ThreadSafeFixedBufferAllocator.init(global_allocator_mem[0..]);
 var global_allocator_mem: [100 * 1024]u8 = undefined;
lib/std/fifo.zig
@@ -347,7 +347,7 @@ pub fn LinearFifo(
 }
 
 test "LinearFifo(u8, .Dynamic)" {
-    var fifo = LinearFifo(u8, .Dynamic).init(testing.allocator);
+    var fifo = LinearFifo(u8, .Dynamic).init(testing.leak_count_allocator);
     defer fifo.deinit();
 
     try fifo.write("HELLO");
@@ -422,7 +422,7 @@ test "LinearFifo" {
             var fifo = switch (bt) {
                 .Static => FifoType.init(),
                 .Slice => FifoType.init(buf[0..]),
-                .Dynamic => FifoType.init(testing.allocator),
+                .Dynamic => FifoType.init(testing.leak_count_allocator),
             };
             defer fifo.deinit();
 
lib/std/fmt.zig
@@ -1598,7 +1598,8 @@ test "hexToBytes" {
 test "formatIntValue with comptime_int" {
     const value: comptime_int = 123456789123456789;
 
-    var buf = try std.Buffer.init(std.testing.allocator, "");
+    var buf = try std.Buffer.init(std.testing.leak_count_allocator, "");
+    defer buf.deinit();
     try formatIntValue(value, "", FormatOptions{}, &buf, @TypeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append);
     std.testing.expect(mem.eql(u8, buf.toSlice(), "123456789123456789"));
 }
@@ -1652,19 +1653,23 @@ test "formatType max_depth" {
     inst.a = &inst;
     inst.tu.ptr = &inst.tu;
 
-    var buf0 = try std.Buffer.init(std.testing.allocator, "");
+    var buf0 = try std.Buffer.init(std.testing.leak_count_allocator, "");
+    defer buf0.deinit();
     try formatType(inst, "", FormatOptions{}, &buf0, @TypeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 0);
     std.testing.expect(mem.eql(u8, buf0.toSlice(), "S{ ... }"));
 
-    var buf1 = try std.Buffer.init(std.testing.allocator, "");
+    var buf1 = try std.Buffer.init(std.testing.leak_count_allocator, "");
+    defer buf1.deinit();
     try formatType(inst, "", FormatOptions{}, &buf1, @TypeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 1);
     std.testing.expect(mem.eql(u8, buf1.toSlice(), "S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }"));
 
-    var buf2 = try std.Buffer.init(std.testing.allocator, "");
+    var buf2 = try std.Buffer.init(std.testing.leak_count_allocator, "");
+    defer buf2.deinit();
     try formatType(inst, "", FormatOptions{}, &buf2, @TypeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 2);
     std.testing.expect(mem.eql(u8, buf2.toSlice(), "S{ .a = S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ ... } }, .e = E.Two, .vec = (10.200,2.220) }"));
 
-    var buf3 = try std.Buffer.init(std.testing.allocator, "");
+    var buf3 = try std.Buffer.init(std.testing.leak_count_allocator, "");
+    defer buf3.deinit();
     try formatType(inst, "", FormatOptions{}, &buf3, @TypeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 3);
     std.testing.expect(mem.eql(u8, buf3.toSlice(), "S{ .a = S{ .a = S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ ... } }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ .ptr = TU{ ... } } }, .e = E.Two, .vec = (10.200,2.220) }"));
 }
lib/std/linked_list.zig
@@ -143,7 +143,7 @@ pub fn SinglyLinkedList(comptime T: type) type {
 }
 
 test "basic SinglyLinkedList test" {
-    const allocator = testing.allocator;
+    const allocator = testing.leak_count_allocator;
     var list = SinglyLinkedList(u32).init();
 
     var one = try list.createNode(1, allocator);
@@ -404,7 +404,7 @@ pub fn TailQueue(comptime T: type) type {
 }
 
 test "basic TailQueue test" {
-    const allocator = testing.allocator;
+    const allocator = testing.leak_count_allocator;
     var list = TailQueue(u32).init();
 
     var one = try list.createNode(1, allocator);
@@ -456,7 +456,7 @@ test "basic TailQueue test" {
 }
 
 test "TailQueue concatenation" {
-    const allocator = testing.allocator;
+    const allocator = testing.leak_count_allocator;
     var list1 = TailQueue(u32).init();
     var list2 = TailQueue(u32).init();
 
lib/std/priority_queue.zig
@@ -239,7 +239,7 @@ fn greaterThan(a: u32, b: u32) bool {
 const PQ = PriorityQueue(u32);
 
 test "std.PriorityQueue: add and remove min heap" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
 
     try queue.add(54);
@@ -257,7 +257,7 @@ test "std.PriorityQueue: add and remove min heap" {
 }
 
 test "std.PriorityQueue: add and remove same min heap" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
 
     try queue.add(1);
@@ -275,14 +275,14 @@ test "std.PriorityQueue: add and remove same min heap" {
 }
 
 test "std.PriorityQueue: removeOrNull on empty" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
 
     expect(queue.removeOrNull() == null);
 }
 
 test "std.PriorityQueue: edge case 3 elements" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
 
     try queue.add(9);
@@ -294,7 +294,7 @@ test "std.PriorityQueue: edge case 3 elements" {
 }
 
 test "std.PriorityQueue: peek" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
 
     expect(queue.peek() == null);
@@ -306,7 +306,7 @@ test "std.PriorityQueue: peek" {
 }
 
 test "std.PriorityQueue: sift up with odd indices" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
     const items = [_]u32{ 15, 7, 21, 14, 13, 22, 12, 6, 7, 25, 5, 24, 11, 16, 15, 24, 2, 1 };
     for (items) |e| {
@@ -320,7 +320,7 @@ test "std.PriorityQueue: sift up with odd indices" {
 }
 
 test "std.PriorityQueue: addSlice" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
     const items = [_]u32{ 15, 7, 21, 14, 13, 22, 12, 6, 7, 25, 5, 24, 11, 16, 15, 24, 2, 1 };
     try queue.addSlice(items[0..]);
@@ -333,8 +333,8 @@ test "std.PriorityQueue: addSlice" {
 
 test "std.PriorityQueue: fromOwnedSlice" {
     const items = [_]u32{ 15, 7, 21, 14, 13, 22, 12, 6, 7, 25, 5, 24, 11, 16, 15, 24, 2, 1 };
-    const heap_items = try std.mem.dupe(testing.allocator, u32, items[0..]);
-    var queue = PQ.fromOwnedSlice(testing.allocator, lessThan, heap_items[0..]);
+    const heap_items = try std.mem.dupe(testing.leak_count_allocator, u32, items[0..]);
+    var queue = PQ.fromOwnedSlice(testing.leak_count_allocator, lessThan, heap_items[0..]);
     defer queue.deinit();
 
     const sorted_items = [_]u32{ 1, 2, 5, 6, 7, 7, 11, 12, 13, 14, 15, 15, 16, 21, 22, 24, 24, 25 };
@@ -344,7 +344,7 @@ test "std.PriorityQueue: fromOwnedSlice" {
 }
 
 test "std.PriorityQueue: add and remove max heap" {
-    var queue = PQ.init(testing.allocator, greaterThan);
+    var queue = PQ.init(testing.leak_count_allocator, greaterThan);
     defer queue.deinit();
 
     try queue.add(54);
@@ -362,7 +362,7 @@ test "std.PriorityQueue: add and remove max heap" {
 }
 
 test "std.PriorityQueue: add and remove same max heap" {
-    var queue = PQ.init(testing.allocator, greaterThan);
+    var queue = PQ.init(testing.leak_count_allocator, greaterThan);
     defer queue.deinit();
 
     try queue.add(1);
@@ -380,8 +380,8 @@ test "std.PriorityQueue: add and remove same max heap" {
 }
 
 test "std.PriorityQueue: iterator" {
-    var queue = PQ.init(testing.allocator, lessThan);
-    var map = std.AutoHashMap(u32, void).init(testing.allocator);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
+    var map = std.AutoHashMap(u32, void).init(testing.leak_count_allocator);
     defer {
         queue.deinit();
         map.deinit();
@@ -402,7 +402,7 @@ test "std.PriorityQueue: iterator" {
 }
 
 test "std.PriorityQueue: remove at index" {
-    var queue = PQ.init(testing.allocator, lessThan);
+    var queue = PQ.init(testing.leak_count_allocator, lessThan);
     defer queue.deinit();
 
     try queue.add(3);
lib/std/process.zig
@@ -114,7 +114,7 @@ pub fn getEnvMap(allocator: *Allocator) !BufMap {
 }
 
 test "os.getEnvMap" {
-    var env = try getEnvMap(std.testing.allocator);
+    var env = try getEnvMap(std.testing.leak_count_allocator);
     defer env.deinit();
 }
 
@@ -165,7 +165,7 @@ pub fn getEnvVarOwned(allocator: *mem.Allocator, key: []const u8) GetEnvVarOwned
 }
 
 test "os.getEnvVarOwned" {
-    var ga = std.testing.allocator;
+    var ga = std.testing.leak_count_allocator;
     testing.expectError(error.EnvironmentVariableNotFound, getEnvVarOwned(ga, "BADENV"));
 }
 
@@ -492,10 +492,11 @@ test "windows arg parsing" {
 fn testWindowsCmdLine(input_cmd_line: [*]const u8, expected_args: []const []const u8) void {
     var it = ArgIteratorWindows.initWithCmdLine(input_cmd_line);
     for (expected_args) |expected_arg| {
-        const arg = it.next(std.testing.allocator).? catch unreachable;
+        const arg = it.next(std.testing.leak_count_allocator).? catch unreachable;
+        defer std.testing.leak_count_allocator.free(arg);
         testing.expectEqualSlices(u8, expected_arg, arg);
     }
-    testing.expect(it.next(std.testing.allocator) == null);
+    testing.expect(it.next(std.testing.leak_count_allocator) == null);
 }
 
 pub const UserInfo = struct {
lib/std/testing.zig
@@ -7,6 +7,48 @@ pub const allocator = &allocator_instance.allocator;
 pub var allocator_instance = std.heap.ThreadSafeFixedBufferAllocator.init(allocator_mem[0..]);
 var allocator_mem: [100 * 1024]u8 = undefined;
 
+pub const leak_count_allocator = &leak_count_allocator_instance.allocator;
+pub var leak_count_allocator_instance = LeakCountAllocator.init(allocator);
+const LeakCountAllocator = struct {
+    count: usize,
+    allocator: std.mem.Allocator,
+    internal_allocator: *std.mem.Allocator,
+
+    fn init(allo: *std.mem.Allocator) LeakCountAllocator {
+        return .{
+            .count = 0,
+            .allocator = .{
+                .reallocFn = realloc,
+                .shrinkFn = shrink,
+            },
+            .internal_allocator = allo,
+        };
+    }
+
+    fn realloc(allo: *std.mem.Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) ![]u8 {
+        const self = @fieldParentPtr(LeakCountAllocator, "allocator", allo);
+        if (old_mem.len == 0) {
+            self.count += 1;
+        }
+        return self.internal_allocator.reallocFn(self.internal_allocator, old_mem, old_align, new_size, new_align);
+    }
+
+    fn shrink(allo: *std.mem.Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) []u8 {
+        const self = @fieldParentPtr(LeakCountAllocator, "allocator", allo);
+        if (new_size == 0) {
+            self.count -= 1;
+        }
+        return self.internal_allocator.shrinkFn(self.internal_allocator, old_mem, old_align, new_size, new_align);
+    }
+
+    fn validate(self: LeakCountAllocator) !void {
+        if (self.count > 0) {
+            std.debug.warn("Detected leaked allocations without matching free: {}\n", .{self.count});
+            return error.Leak;
+        }
+    }
+};
+
 /// This function is intended to be used only in tests. It prints diagnostics to stderr
 /// and then aborts when actual_error_union is not expected_error.
 pub fn expectError(expected_error: anyerror, actual_error_union: var) void {
lib/std/unicode.zig
@@ -501,14 +501,16 @@ test "utf16leToUtf8" {
     {
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[0..], 'A');
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[2..], 'a');
-        const utf8 = try utf16leToUtf8Alloc(std.testing.allocator, &utf16le);
+        const utf8 = try utf16leToUtf8Alloc(std.testing.leak_count_allocator, &utf16le);
+        defer std.testing.leak_count_allocator.free(utf8);
         testing.expect(mem.eql(u8, utf8, "Aa"));
     }
 
     {
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[0..], 0x80);
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[2..], 0xffff);
-        const utf8 = try utf16leToUtf8Alloc(std.testing.allocator, &utf16le);
+        const utf8 = try utf16leToUtf8Alloc(std.testing.leak_count_allocator, &utf16le);
+        defer std.testing.leak_count_allocator.free(utf8);
         testing.expect(mem.eql(u8, utf8, "\xc2\x80" ++ "\xef\xbf\xbf"));
     }
 
@@ -516,7 +518,8 @@ test "utf16leToUtf8" {
         // the values just outside the surrogate half range
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[0..], 0xd7ff);
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[2..], 0xe000);
-        const utf8 = try utf16leToUtf8Alloc(std.testing.allocator, &utf16le);
+        const utf8 = try utf16leToUtf8Alloc(std.testing.leak_count_allocator, &utf16le);
+        defer std.testing.leak_count_allocator.free(utf8);
         testing.expect(mem.eql(u8, utf8, "\xed\x9f\xbf" ++ "\xee\x80\x80"));
     }
 
@@ -524,7 +527,8 @@ test "utf16leToUtf8" {
         // smallest surrogate pair
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[0..], 0xd800);
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[2..], 0xdc00);
-        const utf8 = try utf16leToUtf8Alloc(std.testing.allocator, &utf16le);
+        const utf8 = try utf16leToUtf8Alloc(std.testing.leak_count_allocator, &utf16le);
+        defer std.testing.leak_count_allocator.free(utf8);
         testing.expect(mem.eql(u8, utf8, "\xf0\x90\x80\x80"));
     }
 
@@ -532,14 +536,16 @@ test "utf16leToUtf8" {
         // largest surrogate pair
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[0..], 0xdbff);
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[2..], 0xdfff);
-        const utf8 = try utf16leToUtf8Alloc(std.testing.allocator, &utf16le);
+        const utf8 = try utf16leToUtf8Alloc(std.testing.leak_count_allocator, &utf16le);
+        defer std.testing.leak_count_allocator.free(utf8);
         testing.expect(mem.eql(u8, utf8, "\xf4\x8f\xbf\xbf"));
     }
 
     {
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[0..], 0xdbff);
         mem.writeIntSliceLittle(u16, utf16le_as_bytes[2..], 0xdc00);
-        const utf8 = try utf16leToUtf8Alloc(std.testing.allocator, &utf16le);
+        const utf8 = try utf16leToUtf8Alloc(std.testing.leak_count_allocator, &utf16le);
+        defer std.testing.leak_count_allocator.free(utf8);
         testing.expect(mem.eql(u8, utf8, "\xf4\x8f\xb0\x80"));
     }
 }
test/stage1/behavior/const_slice_child.zig
@@ -22,7 +22,7 @@ fn foo(args: [][]const u8) void {
 }
 
 fn bar(argc: usize) void {
-    const args = testing.allocator.alloc([]const u8, argc) catch unreachable;
+    const args = testing.leak_count_allocator.alloc([]const u8, argc) catch unreachable;
     for (args) |_, i| {
         const ptr = argv[i];
         args[i] = ptr[0..strlen(ptr)];
test/standalone/brace_expansion/main.zig
@@ -201,7 +201,7 @@ pub fn main() !void {
 }
 
 test "invalid inputs" {
-    global_allocator = std.testing.allocator;
+    global_allocator = std.testing.leak_count_allocator;
 
     expectError("}ABC", error.InvalidInput);
     expectError("{ABC", error.InvalidInput);
@@ -222,7 +222,7 @@ fn expectError(test_input: []const u8, expected_err: anyerror) void {
 }
 
 test "valid inputs" {
-    global_allocator = std.testing.allocator;
+    global_allocator = std.testing.leak_count_allocator;
 
     expectExpansion("{x,y,z}", "x y z");
     expectExpansion("{A,B}{x,y}", "Ax Ay Bx By");
test/standalone/cat/main.zig
@@ -4,7 +4,7 @@ const process = std.process;
 const fs = std.fs;
 const mem = std.mem;
 const warn = std.debug.warn;
-const allocator = std.testing.allocator;
+const allocator = std.testing.leak_count_allocator;
 
 pub fn main() !void {
     var args_it = process.args();
test/standalone/empty_env/main.zig
@@ -1,6 +1,6 @@
 const std = @import("std");
 
 pub fn main() void {
-    const env_map = std.process.getEnvMap(std.testing.allocator) catch @panic("unable to get env map");
+    const env_map = std.process.getEnvMap(std.testing.leak_count_allocator) catch @panic("unable to get env map");
     std.testing.expect(env_map.count() == 0);
 }
test/standalone/load_dynamic_library/main.zig
@@ -1,8 +1,8 @@
 const std = @import("std");
 
 pub fn main() !void {
-    const args = try std.process.argsAlloc(std.testing.allocator);
-    defer std.process.argsFree(std.testing.allocator, args);
+    const args = try std.process.argsAlloc(std.testing.leak_count_allocator);
+    defer std.process.argsFree(std.testing.leak_count_allocator, args);
 
     const dynlib_name = args[1];
 
test/compare_output.zig
@@ -445,7 +445,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\const std = @import("std");
             \\const io = std.io;
             \\const os = std.os;
-            \\const allocator = std.testing.allocator;
+            \\const allocator = std.testing.leak_count_allocator;
             \\
             \\pub fn main() !void {
             \\    var args_it = std.process.args();
@@ -486,7 +486,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\const std = @import("std");
             \\const io = std.io;
             \\const os = std.os;
-            \\const allocator = std.testing.allocator;
+            \\const allocator = std.testing.leak_count_allocator;
             \\
             \\pub fn main() !void {
             \\    var args_it = std.process.args();
test/compile_errors.zig
@@ -5765,7 +5765,7 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
         \\
         \\export fn entry() void {
         \\    const a = MdNode.Header {
-        \\        .text = MdText.init(&std.testing.allocator),
+        \\        .text = MdText.init(&std.testing.leak_count_allocator),
         \\        .weight = HeaderWeight.H1,
         \\    };
         \\}