diff --git a/clang/test/utils/update-verify-tests/Inputs/duplicate-diag.c b/clang/test/utils/update-verify-tests/Inputs/duplicate-diag.c
deleted file mode 100644
index 8c7e46c6eca9c1..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/duplicate-diag.c
+++ /dev/null
@@ -1,8 +0,0 @@
-void foo() {
-    // expected-error@+1{{use of undeclared identifier 'a'}}
-    a = 2; a = 2;
-    b = 2; b = 2;
-    // expected-error@+1 3{{use of undeclared identifier 'c'}}
-    c = 2; c = 2;
-    // expected-error 2{{asdf}}
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/duplicate-diag.c.expected b/clang/test/utils/update-verify-tests/Inputs/duplicate-diag.c.expected
deleted file mode 100644
index 6214ff382f4495..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/duplicate-diag.c.expected
+++ /dev/null
@@ -1,8 +0,0 @@
-void foo() {
-    // expected-error@+1 2{{use of undeclared identifier 'a'}}
-    a = 2; a = 2;
-    // expected-error@+1 2{{use of undeclared identifier 'b'}}
-    b = 2; b = 2;
-    // expected-error@+1 2{{use of undeclared identifier 'c'}}
-    c = 2; c = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/infer-indentation.c b/clang/test/utils/update-verify-tests/Inputs/infer-indentation.c
deleted file mode 100644
index 0210ac35fd5cd1..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/infer-indentation.c
+++ /dev/null
@@ -1,8 +0,0 @@
-void foo() {
-         //     expected-error@+1    2      {{use of undeclared identifier 'a'}}
-    a = 2; a = 2; b = 2; b = 2; c = 2;
-         //     expected-error@+1    2      {{asdf}}
-    d = 2;
-    e = 2; f = 2;                 //     expected-error    2      {{use of undeclared identifier 'e'}}
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/infer-indentation.c.expected b/clang/test/utils/update-verify-tests/Inputs/infer-indentation.c.expected
deleted file mode 100644
index 5c5aaeeef97acf..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/infer-indentation.c.expected
+++ /dev/null
@@ -1,11 +0,0 @@
-void foo() {
-         //     expected-error@+3          {{use of undeclared identifier 'c'}}
-         //     expected-error@+2    2      {{use of undeclared identifier 'b'}}
-         //     expected-error@+1    2      {{use of undeclared identifier 'a'}}
-    a = 2; a = 2; b = 2; b = 2; c = 2;
-         //     expected-error@+1          {{use of undeclared identifier 'd'}}
-    d = 2;
-    //     expected-error@+1          {{use of undeclared identifier 'f'}}
-    e = 2; f = 2;                 //     expected-error          {{use of undeclared identifier 'e'}}
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/leave-existing-diags.c b/clang/test/utils/update-verify-tests/Inputs/leave-existing-diags.c
deleted file mode 100644
index 1aa8d088e97273..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/leave-existing-diags.c
+++ /dev/null
@@ -1,11 +0,0 @@
-void foo() {
-    a = 2;
-    // expected-error@-1{{use of undeclared identifier 'a'}}
-    b = 2;// expected-error{{use of undeclared identifier 'b'}}
-    c = 2;
-    // expected-error@5{{use of undeclared identifier 'c'}}
-    d = 2; // expected-error-re{{use of {{.*}} identifier 'd'}}
-
-    e = 2; // error to trigger mismatch
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/leave-existing-diags.c.expected b/clang/test/utils/update-verify-tests/Inputs/leave-existing-diags.c.expected
deleted file mode 100644
index 6b621061bbfbbd..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/leave-existing-diags.c.expected
+++ /dev/null
@@ -1,12 +0,0 @@
-void foo() {
-    a = 2;
-    // expected-error@-1{{use of undeclared identifier 'a'}}
-    b = 2;// expected-error{{use of undeclared identifier 'b'}}
-    c = 2;
-    // expected-error@5{{use of undeclared identifier 'c'}}
-    d = 2; // expected-error-re{{use of {{.*}} identifier 'd'}}
-
-    // expected-error@+1{{use of undeclared identifier 'e'}}
-    e = 2; // error to trigger mismatch
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/multiple-errors.c b/clang/test/utils/update-verify-tests/Inputs/multiple-errors.c
deleted file mode 100644
index e230e0a337bf49..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/multiple-errors.c
+++ /dev/null
@@ -1,6 +0,0 @@
-void foo() {
-    a = 2;
-    b = 2;
-
-    c = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/multiple-errors.c.expected b/clang/test/utils/update-verify-tests/Inputs/multiple-errors.c.expected
deleted file mode 100644
index 27dc1f30a26faf..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/multiple-errors.c.expected
+++ /dev/null
@@ -1,9 +0,0 @@
-void foo() {
-    // expected-error@+1{{use of undeclared identifier 'a'}}
-    a = 2;
-    // expected-error@+1{{use of undeclared identifier 'b'}}
-    b = 2;
-
-    // expected-error@+1{{use of undeclared identifier 'c'}}
-    c = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/multiple-missing-errors-same-line.c b/clang/test/utils/update-verify-tests/Inputs/multiple-missing-errors-same-line.c
deleted file mode 100644
index 03f723d44bbe82..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/multiple-missing-errors-same-line.c
+++ /dev/null
@@ -1,8 +0,0 @@
-void foo() {
-    a = 2; b = 2; c = 2;
-}
-
-void bar() {
-    x = 2; y = 2; z = 2;
-    // expected-error@-1{{use of undeclared identifier 'x'}}
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/multiple-missing-errors-same-line.c.expected b/clang/test/utils/update-verify-tests/Inputs/multiple-missing-errors-same-line.c.expected
deleted file mode 100644
index 24b57f4353d95d..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/multiple-missing-errors-same-line.c.expected
+++ /dev/null
@@ -1,13 +0,0 @@
-void foo() {
-    // expected-error@+3{{use of undeclared identifier 'c'}}
-    // expected-error@+2{{use of undeclared identifier 'b'}}
-    // expected-error@+1{{use of undeclared identifier 'a'}}
-    a = 2; b = 2; c = 2;
-}
-
-void bar() {
-    x = 2; y = 2; z = 2;
-    // expected-error@-1{{use of undeclared identifier 'x'}}
-    // expected-error@-2{{use of undeclared identifier 'y'}}
-    // expected-error@-3{{use of undeclared identifier 'z'}}
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/no-checks.c b/clang/test/utils/update-verify-tests/Inputs/no-checks.c
deleted file mode 100644
index 8fd1f7cd333705..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/no-checks.c
+++ /dev/null
@@ -1,3 +0,0 @@
-void foo() {
-    bar = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/no-checks.c.expected b/clang/test/utils/update-verify-tests/Inputs/no-checks.c.expected
deleted file mode 100644
index e80548fbe50f2c..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/no-checks.c.expected
+++ /dev/null
@@ -1,4 +0,0 @@
-void foo() {
-    // expected-error@+1{{use of undeclared identifier 'bar'}}
-    bar = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/no-diags.c b/clang/test/utils/update-verify-tests/Inputs/no-diags.c
deleted file mode 100644
index 66d169be439402..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/no-diags.c
+++ /dev/null
@@ -1,5 +0,0 @@
-void foo() {
-    // expected-error@+1{{asdf}}
-    int a = 2;
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/no-diags.c.expected b/clang/test/utils/update-verify-tests/Inputs/no-diags.c.expected
deleted file mode 100644
index 05230284945702..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/no-diags.c.expected
+++ /dev/null
@@ -1,5 +0,0 @@
-// expected-no-diagnostics
-void foo() {
-    int a = 2;
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/no-expected-diags.c b/clang/test/utils/update-verify-tests/Inputs/no-expected-diags.c
deleted file mode 100644
index 78b72e1357da76..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/no-expected-diags.c
+++ /dev/null
@@ -1,4 +0,0 @@
-// expected-no-diagnostics
-void foo() {
-    a = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/no-expected-diags.c.expected b/clang/test/utils/update-verify-tests/Inputs/no-expected-diags.c.expected
deleted file mode 100644
index d948ffce56189a..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/no-expected-diags.c.expected
+++ /dev/null
@@ -1,4 +0,0 @@
-void foo() {
-    // expected-error@+1{{use of undeclared identifier 'a'}}
-    a = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/non-default-prefix.c b/clang/test/utils/update-verify-tests/Inputs/non-default-prefix.c
deleted file mode 100644
index 3d63eaf0f1b878..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/non-default-prefix.c
+++ /dev/null
@@ -1,5 +0,0 @@
-void foo() {
-    a = 2; // check-error{{asdf}}
-           // expected-error@-1{ignored}}
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/non-default-prefix.c.expected b/clang/test/utils/update-verify-tests/Inputs/non-default-prefix.c.expected
deleted file mode 100644
index a877f86922123d..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/non-default-prefix.c.expected
+++ /dev/null
@@ -1,5 +0,0 @@
-void foo() {
-    a = 2; // check-error{{use of undeclared identifier 'a'}}
-           // expected-error@-1{ignored}}
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/update-same-line.c b/clang/test/utils/update-verify-tests/Inputs/update-same-line.c
deleted file mode 100644
index 5278ce0c57c319..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/update-same-line.c
+++ /dev/null
@@ -1,4 +0,0 @@
-void foo() {
-    bar = 2;     //   expected-error       {{asdf}}
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/update-same-line.c.expected b/clang/test/utils/update-verify-tests/Inputs/update-same-line.c.expected
deleted file mode 100644
index 8ba47f788319b1..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/update-same-line.c.expected
+++ /dev/null
@@ -1,4 +0,0 @@
-void foo() {
-    bar = 2;     //   expected-error       {{use of undeclared identifier 'bar'}}
-}
-
diff --git a/clang/test/utils/update-verify-tests/Inputs/update-single-check.c b/clang/test/utils/update-verify-tests/Inputs/update-single-check.c
deleted file mode 100644
index 20b011bfc3d77e..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/update-single-check.c
+++ /dev/null
@@ -1,4 +0,0 @@
-void foo() {
-    // expected-error@+1{{asdf}}
-    bar = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/Inputs/update-single-check.c.expected b/clang/test/utils/update-verify-tests/Inputs/update-single-check.c.expected
deleted file mode 100644
index e80548fbe50f2c..00000000000000
--- a/clang/test/utils/update-verify-tests/Inputs/update-single-check.c.expected
+++ /dev/null
@@ -1,4 +0,0 @@
-void foo() {
-    // expected-error@+1{{use of undeclared identifier 'bar'}}
-    bar = 2;
-}
diff --git a/clang/test/utils/update-verify-tests/duplicate-diag.test b/clang/test/utils/update-verify-tests/duplicate-diag.test
deleted file mode 100644
index 3163ce46199c3f..00000000000000
--- a/clang/test/utils/update-verify-tests/duplicate-diag.test
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: cp %S/Inputs/duplicate-diag.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/duplicate-diag.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
-
diff --git a/clang/test/utils/update-verify-tests/infer-indentation.test b/clang/test/utils/update-verify-tests/infer-indentation.test
deleted file mode 100644
index 6ba2f5d9d505bf..00000000000000
--- a/clang/test/utils/update-verify-tests/infer-indentation.test
+++ /dev/null
@@ -1,3 +0,0 @@
-# RUN: cp %S/Inputs/infer-indentation.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/infer-indentation.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
diff --git a/clang/test/utils/update-verify-tests/leave-existing-diags.test b/clang/test/utils/update-verify-tests/leave-existing-diags.test
deleted file mode 100644
index cde690ef715a67..00000000000000
--- a/clang/test/utils/update-verify-tests/leave-existing-diags.test
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: cp %S/Inputs/leave-existing-diags.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/leave-existing-diags.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
-
diff --git a/clang/test/utils/update-verify-tests/lit.local.cfg b/clang/test/utils/update-verify-tests/lit.local.cfg
deleted file mode 100644
index a0b6afccc25010..00000000000000
--- a/clang/test/utils/update-verify-tests/lit.local.cfg
+++ /dev/null
@@ -1,25 +0,0 @@
-import lit.util
-
-# python 2.7 backwards compatibility
-try:
-    from shlex import quote as shell_quote
-except ImportError:
-    from pipes import quote as shell_quote
-
-if config.standalone_build:
-    # These tests require the update-verify-tests.py script from the clang
-    # source tree, so skip these tests if we are doing standalone builds.
-    config.unsupported = True
-else:
-    config.suffixes = [".test"]
-
-    script_path = os.path.join(
-        config.clang_src_dir, "utils", "update-verify-tests.py"
-    )
-    python = shell_quote(config.python_executable)
-    config.substitutions.append(
-        (
-            "%update-verify-tests",
-            "%s %s" % (python, shell_quote(script_path)),
-        )
-    )
diff --git a/clang/test/utils/update-verify-tests/multiple-errors.test b/clang/test/utils/update-verify-tests/multiple-errors.test
deleted file mode 100644
index 1332ef365dc863..00000000000000
--- a/clang/test/utils/update-verify-tests/multiple-errors.test
+++ /dev/null
@@ -1,3 +0,0 @@
-# RUN: cp %S/Inputs/multiple-errors.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/multiple-errors.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
diff --git a/clang/test/utils/update-verify-tests/multiple-missing-errors-same-line.test b/clang/test/utils/update-verify-tests/multiple-missing-errors-same-line.test
deleted file mode 100644
index a9c21cd77e192b..00000000000000
--- a/clang/test/utils/update-verify-tests/multiple-missing-errors-same-line.test
+++ /dev/null
@@ -1,3 +0,0 @@
-# RUN: cp %S/Inputs/multiple-missing-errors-same-line.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/multiple-missing-errors-same-line.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
diff --git a/clang/test/utils/update-verify-tests/no-checks.test b/clang/test/utils/update-verify-tests/no-checks.test
deleted file mode 100644
index f6ea91fa552be4..00000000000000
--- a/clang/test/utils/update-verify-tests/no-checks.test
+++ /dev/null
@@ -1,3 +0,0 @@
-# RUN: cp %S/Inputs/no-checks.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/no-checks.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
diff --git a/clang/test/utils/update-verify-tests/no-diags.test b/clang/test/utils/update-verify-tests/no-diags.test
deleted file mode 100644
index 464fe8894253b6..00000000000000
--- a/clang/test/utils/update-verify-tests/no-diags.test
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: cp %S/Inputs/no-diags.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/no-diags.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
-
diff --git a/clang/test/utils/update-verify-tests/no-expected-diags.test b/clang/test/utils/update-verify-tests/no-expected-diags.test
deleted file mode 100644
index 75235f17a64a29..00000000000000
--- a/clang/test/utils/update-verify-tests/no-expected-diags.test
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: cp %S/Inputs/no-expected-diags.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/no-expected-diags.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
-
diff --git a/clang/test/utils/update-verify-tests/non-default-prefix.test b/clang/test/utils/update-verify-tests/non-default-prefix.test
deleted file mode 100644
index e581755a6e6038..00000000000000
--- a/clang/test/utils/update-verify-tests/non-default-prefix.test
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: cp %S/Inputs/non-default-prefix.c %t.c && not %clang_cc1 -verify=check %t.c 2>&1 | %update-verify-tests --prefix check
-# RUN: diff -u %S/Inputs/non-default-prefix.c.expected %t.c
-# RUN: %clang_cc1 -verify=check %t.c
-
diff --git a/clang/test/utils/update-verify-tests/update-same-line.test b/clang/test/utils/update-verify-tests/update-same-line.test
deleted file mode 100644
index 324768eae5faac..00000000000000
--- a/clang/test/utils/update-verify-tests/update-same-line.test
+++ /dev/null
@@ -1,4 +0,0 @@
-# RUN: cp %S/Inputs/update-same-line.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/update-same-line.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
-
diff --git a/clang/test/utils/update-verify-tests/update-single-check.test b/clang/test/utils/update-verify-tests/update-single-check.test
deleted file mode 100644
index 2cb1ae3bcbd3b8..00000000000000
--- a/clang/test/utils/update-verify-tests/update-single-check.test
+++ /dev/null
@@ -1,3 +0,0 @@
-# RUN: cp %S/Inputs/update-single-check.c %t.c && not %clang_cc1 -verify %t.c 2>&1 | %update-verify-tests
-# RUN: diff -u %S/Inputs/update-single-check.c.expected %t.c
-# RUN: %clang_cc1 -verify %t.c
diff --git a/clang/utils/UpdateVerifyTests/core.py b/clang/utils/UpdateVerifyTests/core.py
deleted file mode 100644
index d1350cdbb698b6..00000000000000
--- a/clang/utils/UpdateVerifyTests/core.py
+++ /dev/null
@@ -1,452 +0,0 @@
-import sys
-import re
-
-DEBUG = False
-
-
-def dprint(*args):
-    if DEBUG:
-        print(*args, file=sys.stderr)
-
-
-class KnownException(Exception):
-    pass
-
-
-def parse_error_category(s, prefix):
-    if "no expected directives found" in s:
-        return None
-    parts = s.split("diagnostics")
-    diag_category = parts[0]
-    category_parts = parts[0].strip().strip("'").split("-")
-    expected = category_parts[0]
-    if expected != prefix:
-        raise Exception(
-            f"expected prefix '{prefix}', but found '{expected}'. Multiple verify prefixes are not supported."
-        )
-    diag_category = category_parts[1]
-    if "seen but not expected" in parts[1]:
-        seen = True
-    elif "expected but not seen" in parts[1]:
-        seen = False
-    else:
-        raise KnownException(f"unexpected category '{parts[1]}'")
-    return (diag_category, seen)
-
-
-diag_error_re = re.compile(r"File (\S+) Line (\d+): (.+)")
-diag_error_re2 = re.compile(r"File \S+ Line \d+ \(directive at (\S+):(\d+)\): (.+)")
-
-
-def parse_diag_error(s):
-    m = diag_error_re2.match(s)
-    if not m:
-        m = diag_error_re.match(s)
-    if not m:
-        return None
-    return (m.group(1), int(m.group(2)), m.group(3))
-
-
-class Line:
-    def __init__(self, content, line_n):
-        self.content = content
-        self.diag = None
-        self.line_n = line_n
-        self.targeting_diags = []
-
-    def update_line_n(self, n):
-        self.line_n = n
-
-    def render(self):
-        if not self.diag:
-            return self.content
-        assert "{{DIAG}}" in self.content
-        res = self.content.replace("{{DIAG}}", self.diag.render())
-        if not res.strip():
-            return ""
-        return res
-
-
-class Diag:
-    def __init__(
-        self,
-        prefix,
-        diag_content,
-        category,
-        parsed_target_line_n,
-        line_is_absolute,
-        count,
-        line,
-        is_re,
-        whitespace_strings,
-        is_from_source_file,
-    ):
-        self.prefix = prefix
-        self.diag_content = diag_content
-        self.category = category
-        self.parsed_target_line_n = parsed_target_line_n
-        self.line_is_absolute = line_is_absolute
-        self.count = count
-        self.line = line
-        self.target = None
-        self.is_re = is_re
-        self.absolute_target()
-        self.whitespace_strings = whitespace_strings
-        self.is_from_source_file = is_from_source_file
-
-    def decrement_count(self):
-        self.count -= 1
-        assert self.count >= 0
-
-    def increment_count(self):
-        assert self.count >= 0
-        self.count += 1
-
-    def unset_target(self):
-        assert self.target is not None
-        self.target.targeting_diags.remove(self)
-        self.target = None
-
-    def set_target(self, target):
-        if self.target:
-            self.unset_target()
-        self.target = target
-        self.target.targeting_diags.append(self)
-
-    def absolute_target(self):
-        if self.target:
-            return self.target.line_n
-        if self.line_is_absolute:
-            return self.parsed_target_line_n
-        return self.line.line_n + self.parsed_target_line_n
-
-    def relative_target(self):
-        return self.absolute_target() - self.line.line_n
-
-    def take(self, other_diag):
-        assert self.count == 0
-        assert other_diag.count > 0
-        assert other_diag.target == self.target
-        assert not other_diag.line_is_absolute
-        assert not other_diag.is_re and not self.is_re
-        self.line_is_absolute = False
-        self.diag_content = other_diag.diag_content
-        self.count = other_diag.count
-        self.category = other_diag.category
-        self.count = other_diag.count
-        other_diag.count = 0
-
-    def render(self):
-        assert self.count >= 0
-        if self.count == 0:
-            return ""
-        line_location_s = ""
-        if self.relative_target() != 0:
-            if self.line_is_absolute:
-                line_location_s = f"@{self.absolute_target()}"
-            elif self.relative_target() > 0:
-                line_location_s = f"@+{self.relative_target()}"
-            else:
-                line_location_s = (
-                    f"@{self.relative_target()}"  # the minus sign is implicit
-                )
-        count_s = "" if self.count == 1 else f"{self.count}"
-        re_s = "-re" if self.is_re else ""
-        if self.whitespace_strings:
-            whitespace1_s = self.whitespace_strings[0]
-            whitespace2_s = self.whitespace_strings[1]
-            whitespace3_s = self.whitespace_strings[2]
-        else:
-            whitespace1_s = " "
-            whitespace2_s = ""
-            whitespace3_s = ""
-        if count_s and not whitespace2_s:
-            whitespace2_s = " "  # required to parse correctly
-        elif not count_s and whitespace2_s == " ":
-            """Don't emit a weird extra space.
-            However if the whitespace is something other than the
-            standard single space, let it be to avoid disrupting manual formatting.
-            The existence of a non-empty whitespace2_s implies this was parsed with
-            a count > 1 and then decremented, otherwise this whitespace would have
-            been parsed as whitespace3_s.
-            """
-            whitespace2_s = ""
-        return f"//{whitespace1_s}{self.prefix}-{self.category}{re_s}{line_location_s}{whitespace2_s}{count_s}{whitespace3_s}{{{{{self.diag_content}}}}}"
-
-
-expected_diag_re = re.compile(
-    r"//(\s*)([a-zA-Z]+)-(note|warning|error)(-re)?(@[+-]?\d+)?(?:(\s*)(\d+))?(\s*)\{\{(.*)\}\}"
-)
-
-
-def parse_diag(line, filename, lines, prefix):
-    s = line.content
-    ms = expected_diag_re.findall(s)
-    if not ms:
-        return None
-    if len(ms) > 1:
-        raise KnownException(
-            f"multiple diags on line {filename}:{line.line_n}. Aborting due to missing implementation."
-        )
-    [
-        whitespace1_s,
-        check_prefix,
-        category_s,
-        re_s,
-        target_line_s,
-        whitespace2_s,
-        count_s,
-        whitespace3_s,
-        diag_s,
-    ] = ms[0]
-    if check_prefix != prefix:
-        return None
-    if not target_line_s:
-        target_line_n = 0
-        is_absolute = False
-    elif target_line_s.startswith("@+"):
-        target_line_n = int(target_line_s[2:])
-        is_absolute = False
-    elif target_line_s.startswith("@-"):
-        target_line_n = int(target_line_s[1:])
-        is_absolute = False
-    else:
-        target_line_n = int(target_line_s[1:])
-        is_absolute = True
-    count = int(count_s) if count_s else 1
-    line.content = expected_diag_re.sub("{{DIAG}}", s)
-
-    return Diag(
-        prefix,
-        diag_s,
-        category_s,
-        target_line_n,
-        is_absolute,
-        count,
-        line,
-        bool(re_s),
-        [whitespace1_s, whitespace2_s, whitespace3_s],
-        True,
-    )
-
-
-def add_line(new_line, lines):
-    lines.insert(new_line.line_n - 1, new_line)
-    for i in range(new_line.line_n, len(lines)):
-        line = lines[i]
-        assert line.line_n == i
-        line.update_line_n(i + 1)
-    assert all(line.line_n == i + 1 for i, line in enumerate(lines))
-
-
-def remove_line(old_line, lines):
-    lines.remove(old_line)
-    for i in range(old_line.line_n - 1, len(lines)):
-        line = lines[i]
-        assert line.line_n == i + 2
-        line.update_line_n(i + 1)
-    assert all(line.line_n == i + 1 for i, line in enumerate(lines))
-
-
-indent_re = re.compile(r"\s*")
-
-
-def get_indent(s):
-    return indent_re.match(s).group(0)
-
-
-def orig_line_n_to_new_line_n(line_n, orig_lines):
-    return orig_lines[line_n - 1].line_n
-
-
-def add_diag(orig_line_n, diag_s, diag_category, lines, orig_lines, prefix):
-    line_n = orig_line_n_to_new_line_n(orig_line_n, orig_lines)
-    target = lines[line_n - 1]
-    for other in target.targeting_diags:
-        if other.is_re:
-            raise KnownException(
-                "mismatching diag on line with regex matcher. Skipping due to missing implementation"
-            )
-    reverse = (
-        True
-        if [other for other in target.targeting_diags if other.relative_target() < 0]
-        else False
-    )
-
-    targeting = [
-        other for other in target.targeting_diags if not other.line_is_absolute
-    ]
-    targeting.sort(reverse=reverse, key=lambda d: d.relative_target())
-    prev_offset = 0
-    prev_line = target
-    direction = -1 if reverse else 1
-    for d in targeting:
-        if d.relative_target() != prev_offset + direction:
-            break
-        prev_offset = d.relative_target()
-        prev_line = d.line
-    total_offset = prev_offset - 1 if reverse else prev_offset + 1
-    if reverse:
-        new_line_n = prev_line.line_n + 1
-    else:
-        new_line_n = prev_line.line_n
-    assert new_line_n == line_n + (not reverse) - total_offset
-
-    new_line = Line(get_indent(prev_line.content) + "{{DIAG}}\n", new_line_n)
-    add_line(new_line, lines)
-
-    whitespace_strings = prev_line.diag.whitespace_strings if prev_line.diag else None
-    new_diag = Diag(
-        prefix,
-        diag_s,
-        diag_category,
-        total_offset,
-        False,
-        1,
-        new_line,
-        False,
-        whitespace_strings,
-        False,
-    )
-    new_line.diag = new_diag
-    new_diag.set_target(target)
-
-
-def remove_dead_diags(lines):
-    for line in lines:
-        if not line.diag or line.diag.count != 0:
-            continue
-        if line.render() == "":
-            remove_line(line, lines)
-        else:
-            assert line.diag.is_from_source_file
-            for other_diag in line.targeting_diags:
-                if (
-                    other_diag.is_from_source_file
-                    or other_diag.count == 0
-                    or other_diag.category != line.diag.category
-                ):
-                    continue
-                if other_diag.is_re or line.diag.is_re:
-                    continue
-                line.diag.take(other_diag)
-                remove_line(other_diag.line, lines)
-
-
-def has_live_diags(lines):
-    for line in lines:
-        if line.diag and line.diag.count > 0:
-            return True
-    return False
-
-
-def get_expected_no_diags_line_n(lines, prefix):
-    for line in lines:
-        if f"{prefix}-no-diagnostics" in line.content:
-            return line.line_n
-    return None
-
-
-def update_test_file(filename, diag_errors, prefix, updated_test_files):
-    dprint(f"updating test file {filename}")
-    if filename in updated_test_files:
-        raise KnownException(f"{filename} already updated, but got new output")
-    else:
-        updated_test_files.add(filename)
-    with open(filename, "r") as f:
-        lines = [Line(line, i + 1) for i, line in enumerate(f.readlines())]
-    orig_lines = list(lines)
-    expected_no_diags_line_n = get_expected_no_diags_line_n(orig_lines, prefix)
-
-    for line in lines:
-        diag = parse_diag(line, filename, lines, prefix)
-        if diag:
-            line.diag = diag
-            diag.set_target(lines[diag.absolute_target() - 1])
-
-    for line_n, diag_s, diag_category, seen in diag_errors:
-        if seen:
-            continue
-        # this is a diagnostic expected but not seen
-        assert lines[line_n - 1].diag
-        if diag_s != lines[line_n - 1].diag.diag_content:
-            raise KnownException(
-                f"{filename}:{line_n} - found diag {lines[line_n - 1].diag.diag_content} but expected {diag_s}"
-            )
-        if diag_category != lines[line_n - 1].diag.category:
-            raise KnownException(
-                f"{filename}:{line_n} - found {lines[line_n - 1].diag.category} diag but expected {diag_category}"
-            )
-        lines[line_n - 1].diag.decrement_count()
-    diag_errors_left = []
-    diag_errors.sort(reverse=True, key=lambda t: t[0])
-    for line_n, diag_s, diag_category, seen in diag_errors:
-        if not seen:
-            continue
-        target = orig_lines[line_n - 1]
-        other_diags = [
-            d
-            for d in target.targeting_diags
-            if d.diag_content == diag_s and d.category == diag_category
-        ]
-        other_diag = other_diags[0] if other_diags else None
-        if other_diag:
-            other_diag.increment_count()
-        else:
-            add_diag(line_n, diag_s, diag_category, lines, orig_lines, prefix)
-    remove_dead_diags(lines)
-    has_diags = has_live_diags(lines)
-    with open(filename, "w") as f:
-        if not has_diags and expected_no_diags_line_n is None:
-            f.write("// expected-no-diagnostics\n")
-        for line in lines:
-            if has_diags and line.line_n == expected_no_diags_line_n:
-                continue
-            f.write(line.render())
-
-
-def update_test_files(errors, prefix):
-    errors_by_file = {}
-    for (filename, line, diag_s), (diag_category, seen) in errors:
-        if filename not in errors_by_file:
-            errors_by_file[filename] = []
-        errors_by_file[filename].append((line, diag_s, diag_category, seen))
-    updated_test_files = set()
-    for filename, diag_errors in errors_by_file.items():
-        try:
-            update_test_file(filename, diag_errors, prefix, updated_test_files)
-        except KnownException as e:
-            return f"Error in update-verify-tests while updating {filename}: {e}"
-    updated_files = list(updated_test_files)
-    assert updated_files
-    if len(updated_files) == 1:
-        return f"updated file {updated_files[0]}"
-    updated_files_s = "\n\t".join(updated_files)
-    return "updated files:\n\t{updated_files_s}"
-
-
-def check_expectations(tool_output, prefix):
-    """
-    The entry point function.
-    Called by the stand-alone update-verify-tests.py as well as litplugin.py.
-    """
-    curr = []
-    curr_category = None
-    try:
-        for line in tool_output:
-            if line.startswith("error: "):
-                curr_category = parse_error_category(line[len("error: ") :], prefix)
-                continue
-
-            diag_error = parse_diag_error(line.strip())
-            if diag_error:
-                curr.append((diag_error, curr_category))
-            else:
-                dprint("no match")
-                dprint(line.strip())
-    except KnownException as e:
-        return f"Error in update-verify-tests while parsing tool output: {e}"
-    if curr:
-        return update_test_files(curr, prefix)
-    else:
-        return "no mismatching diagnostics found"
diff --git a/clang/utils/update-verify-tests.py b/clang/utils/update-verify-tests.py
deleted file mode 100644
index e2874a8c049ef3..00000000000000
--- a/clang/utils/update-verify-tests.py
+++ /dev/null
@@ -1,38 +0,0 @@
-import sys
-import argparse
-from UpdateVerifyTests.core import check_expectations
-
-"""
- Pipe output from clang's -verify into this script to have the test case updated to expect the actual diagnostic output.
- When inserting new expected-* checks it will place them on the line before the location of the diagnostic, with an @+1,
- or @+N for some N if there are multiple diagnostics emitted on the same line. If the current checks are using @-N for
- this line, the new check will follow that convention also.
- Existing checks will be left untouched as much as possible, including their location and whitespace content, to minimize
- diffs. If inaccurate their count will be updated, or the check removed entirely.
-
- Missing features:
-  - multiple prefixes on the same line (-verify=my-prefix,my-other-prefix)
-  - multiple prefixes on separate RUN lines (RUN: -verify=my-prefix\nRUN: -verify my-other-prefix)
-  - regexes with expected-*-re: existing ones will be left untouched if accurate, but the script will abort if there are any
-    diagnostic mismatches on the same line.
-  - multiple checks targeting the same line are supported, but a line may only contain one check
-  - if multiple checks targeting the same line are failing the script is not guaranteed to produce a minimal diff
-
-Example usage:
-  clang -verify [file] | python3 update-verify-tests.py
-  clang -verify=check [file] | python3 update-verify-tests.py --prefix check
-"""
-
-
-def main():
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument(
-        "--prefix", default="expected", help="The prefix passed to -verify"
-    )
-    args = parser.parse_args()
-    output = check_expectations(sys.stdin.readlines(), args.prefix)
-    print(output)
-
-
-if __name__ == "__main__":
-    main()