diff --git a/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/run-find-all-symbols.py b/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/run-find-all-symbols.py
index 49a1b14932644..6158876d15f76 100755
--- a/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/run-find-all-symbols.py
+++ b/clang-tools-extra/clang-include-fixer/find-all-symbols/tool/run-find-all-symbols.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # =- run-find-all-symbols.py - Parallel find-all-symbols runner -*- python  -*-=#
 #
diff --git a/clang-tools-extra/clangd/test/remote-index/pipeline_helper.py b/clang-tools-extra/clangd/test/remote-index/pipeline_helper.py
index afdac985221a7..c9432341d304a 100644
--- a/clang-tools-extra/clangd/test/remote-index/pipeline_helper.py
+++ b/clang-tools-extra/clangd/test/remote-index/pipeline_helper.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ===- pipeline_helper.py - Remote Index pipeline Helper *- python -------*--===#
 #
diff --git a/clang/bindings/python/examples/cindex/cindex-dump.py b/clang/bindings/python/examples/cindex/cindex-dump.py
index 10c3e4ba2dba4..79d3441e87fad 100644
--- a/clang/bindings/python/examples/cindex/cindex-dump.py
+++ b/clang/bindings/python/examples/cindex/cindex-dump.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ===- cindex-dump.py - cindex/Python Source Dump -------------*- python -*--===#
 #
diff --git a/clang/bindings/python/examples/cindex/cindex-includes.py b/clang/bindings/python/examples/cindex/cindex-includes.py
index 4e8bae19005cd..0b021f4554f59 100644
--- a/clang/bindings/python/examples/cindex/cindex-includes.py
+++ b/clang/bindings/python/examples/cindex/cindex-includes.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ===- cindex-includes.py - cindex/Python Inclusion Graph -----*- python -*--===#
 #
diff --git a/clang/docs/tools/generate_formatted_state.py b/clang/docs/tools/generate_formatted_state.py
index 2de43dc383f55..f857320ada1b7 100755
--- a/clang/docs/tools/generate_formatted_state.py
+++ b/clang/docs/tools/generate_formatted_state.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # A tool to parse creates a document outlining how clang formatted the
 # LLVM project is.
 
diff --git a/clang/test/Analysis/check-analyzer-fixit.py b/clang/test/Analysis/check-analyzer-fixit.py
index b616255de89b0..5c19461fd5d82 100644
--- a/clang/test/Analysis/check-analyzer-fixit.py
+++ b/clang/test/Analysis/check-analyzer-fixit.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ===- check-analyzer-fixit.py - Static Analyzer test helper ---*- python -*-===#
 #
diff --git a/clang/test/Analysis/csv2json.py b/clang/test/Analysis/csv2json.py
index 6e1aca9a51779..642610140153e 100644
--- a/clang/test/Analysis/csv2json.py
+++ b/clang/test/Analysis/csv2json.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ===- csv2json.py - Static Analyzer test helper ---*- python -*-===#
 #
diff --git a/clang/test/Driver/ftime-trace-sections.py b/clang/test/Driver/ftime-trace-sections.py
index 02afa4ac54eb7..46248e546d94a 100644
--- a/clang/test/Driver/ftime-trace-sections.py
+++ b/clang/test/Driver/ftime-trace-sections.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import json, sys, time
 
diff --git a/clang/tools/include-mapping/test.py b/clang/tools/include-mapping/test.py
index 81803855dac8f..7293b5a19d883 100755
--- a/clang/tools/include-mapping/test.py
+++ b/clang/tools/include-mapping/test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===- test.py -  ---------------------------------------------*- python -*--===#
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/clang/tools/scan-build/bin/set-xcode-analyzer b/clang/tools/scan-build/bin/set-xcode-analyzer
index 8e4a5794594a6..5d52c96c59052 100755
--- a/clang/tools/scan-build/bin/set-xcode-analyzer
+++ b/clang/tools/scan-build/bin/set-xcode-analyzer
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # [PR 11661] Note that we hardwire to /usr/bin/python because we
 # want to the use the system version of Python on Mac OS X.
diff --git a/clang/tools/scan-view/bin/scan-view b/clang/tools/scan-view/bin/scan-view
index d01aebb4029a7..f3375804654d2 100755
--- a/clang/tools/scan-view/bin/scan-view
+++ b/clang/tools/scan-view/bin/scan-view
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/clang/tools/scan-view/share/Reporter.py b/clang/tools/scan-view/share/Reporter.py
index 21874b378687e..aa16a47524c8b 100644
--- a/clang/tools/scan-view/share/Reporter.py
+++ b/clang/tools/scan-view/share/Reporter.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 """Methods for reporting bugs."""
diff --git a/clang/tools/scan-view/share/startfile.py b/clang/tools/scan-view/share/startfile.py
index c72475e8b6212..a10df214d0046 100644
--- a/clang/tools/scan-view/share/startfile.py
+++ b/clang/tools/scan-view/share/startfile.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 """Utility for opening a file using the default application in a cross-platform
diff --git a/clang/utils/ABITest/ABITestGen.py b/clang/utils/ABITest/ABITestGen.py
index 119b3299ffa60..b04cc3d29d8d8 100755
--- a/clang/utils/ABITest/ABITestGen.py
+++ b/clang/utils/ABITest/ABITestGen.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import absolute_import, division, print_function
 from pprint import pprint
diff --git a/clang/utils/CIndex/completion_logger_server.py b/clang/utils/CIndex/completion_logger_server.py
index ff33331fc53c5..5888fb10fc768 100755
--- a/clang/utils/CIndex/completion_logger_server.py
+++ b/clang/utils/CIndex/completion_logger_server.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 from __future__ import absolute_import, division, print_function
 import sys
 from socket import *
diff --git a/clang/utils/CaptureCmd b/clang/utils/CaptureCmd
index 705585c3bb041..5ffdfe560edf0 100755
--- a/clang/utils/CaptureCmd
+++ b/clang/utils/CaptureCmd
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """CaptureCmd - A generic tool for capturing information about the
 invocations of another program.
diff --git a/clang/utils/CmpDriver b/clang/utils/CmpDriver
index 12ce7a3250f66..c2b6ab5ecb1aa 100755
--- a/clang/utils/CmpDriver
+++ b/clang/utils/CmpDriver
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 A simple utility that compares tool invocations and exit codes issued by
diff --git a/clang/utils/FindSpecRefs b/clang/utils/FindSpecRefs
index 9097f93f28d63..3ad581b3dd7d1 100755
--- a/clang/utils/FindSpecRefs
+++ b/clang/utils/FindSpecRefs
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import re
diff --git a/clang/utils/FuzzTest b/clang/utils/FuzzTest
index 0e043df7cf08e..c4c956b6eb501 100755
--- a/clang/utils/FuzzTest
+++ b/clang/utils/FuzzTest
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 This is a generic fuzz testing tool, see --help for more information.
diff --git a/clang/utils/TestUtils/deep-stack.py b/clang/utils/TestUtils/deep-stack.py
index 4cf5789abdb12..85376dcedc280 100755
--- a/clang/utils/TestUtils/deep-stack.py
+++ b/clang/utils/TestUtils/deep-stack.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import absolute_import, division, print_function
 
diff --git a/clang/utils/analyzer/CmpRuns.py b/clang/utils/analyzer/CmpRuns.py
index 94c9907bff315..76444d2a44580 100644
--- a/clang/utils/analyzer/CmpRuns.py
+++ b/clang/utils/analyzer/CmpRuns.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 CmpRuns - A simple tool for comparing two static analyzer runs to determine
diff --git a/clang/utils/analyzer/SATest.py b/clang/utils/analyzer/SATest.py
index d70e33f24c2df..8b07effd8b83b 100755
--- a/clang/utils/analyzer/SATest.py
+++ b/clang/utils/analyzer/SATest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import sys
diff --git a/clang/utils/analyzer/SATestAdd.py b/clang/utils/analyzer/SATestAdd.py
index 84e6d44b42822..05bebabb3601b 100644
--- a/clang/utils/analyzer/SATestAdd.py
+++ b/clang/utils/analyzer/SATestAdd.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 Static Analyzer qualification infrastructure: adding a new project to
diff --git a/clang/utils/analyzer/SATestBuild.py b/clang/utils/analyzer/SATestBuild.py
index 66e1ab72985cd..ff1a42de2c569 100644
--- a/clang/utils/analyzer/SATestBuild.py
+++ b/clang/utils/analyzer/SATestBuild.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 Static Analyzer qualification infrastructure.
diff --git a/clang/utils/analyzer/SATestUpdateDiffs.py b/clang/utils/analyzer/SATestUpdateDiffs.py
index 1c5ffaaa2e330..e1416510d0178 100644
--- a/clang/utils/analyzer/SATestUpdateDiffs.py
+++ b/clang/utils/analyzer/SATestUpdateDiffs.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 Update reference results for static analyzer.
diff --git a/clang/utils/analyzer/SumTimerInfo.py b/clang/utils/analyzer/SumTimerInfo.py
index 01614e41a065c..9772bff335f4b 100644
--- a/clang/utils/analyzer/SumTimerInfo.py
+++ b/clang/utils/analyzer/SumTimerInfo.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 Script to Summarize statistics in the scan-build output.
diff --git a/clang/utils/analyzer/exploded-graph-rewriter.py b/clang/utils/analyzer/exploded-graph-rewriter.py
index dcda91e8a6809..9198fcbfd184e 100755
--- a/clang/utils/analyzer/exploded-graph-rewriter.py
+++ b/clang/utils/analyzer/exploded-graph-rewriter.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ===- exploded-graph-rewriter.py - ExplodedGraph dump tool -----*- python -*--#
 #
diff --git a/clang/utils/check_cfc/check_cfc.py b/clang/utils/check_cfc/check_cfc.py
index 8d42ec532bbb7..6b793937a5d08 100755
--- a/clang/utils/check_cfc/check_cfc.py
+++ b/clang/utils/check_cfc/check_cfc.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Check CFC - Check Compile Flow Consistency
 
diff --git a/clang/utils/check_cfc/obj_diff.py b/clang/utils/check_cfc/obj_diff.py
index 9d602593a4e1a..02e0ebdf0efcd 100755
--- a/clang/utils/check_cfc/obj_diff.py
+++ b/clang/utils/check_cfc/obj_diff.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import absolute_import, division, print_function
 
diff --git a/clang/utils/check_cfc/test_check_cfc.py b/clang/utils/check_cfc/test_check_cfc.py
index cd4441b702cde..a23ad2ccbee41 100755
--- a/clang/utils/check_cfc/test_check_cfc.py
+++ b/clang/utils/check_cfc/test_check_cfc.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Test internal functions within check_cfc.py."""
 
diff --git a/clang/utils/clangdiag.py b/clang/utils/clangdiag.py
index 8c47b1cbcfff3..e4b94e5757cbc 100755
--- a/clang/utils/clangdiag.py
+++ b/clang/utils/clangdiag.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/clang/utils/modfuzz.py b/clang/utils/modfuzz.py
index 49ac522cd17e1..7c00102c2cca5 100644
--- a/clang/utils/modfuzz.py
+++ b/clang/utils/modfuzz.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # To use:
 #  1) Update the 'decls' list below with your fuzzing configuration.
diff --git a/clang/utils/token-delta.py b/clang/utils/token-delta.py
index 7c2375c03013f..4fe5798033f41 100755
--- a/clang/utils/token-delta.py
+++ b/clang/utils/token-delta.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import absolute_import, division, print_function
 import os
diff --git a/clang/www/builtins.py b/clang/www/builtins.py
index 849e6bd4a816d..235de1a157cd1 100755
--- a/clang/www/builtins.py
+++ b/clang/www/builtins.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys, fileinput
 
diff --git a/compiler-rt/lib/asan/scripts/asan_symbolize.py b/compiler-rt/lib/asan/scripts/asan_symbolize.py
index 8ecd66c745119..f60a8307ec60e 100755
--- a/compiler-rt/lib/asan/scripts/asan_symbolize.py
+++ b/compiler-rt/lib/asan/scripts/asan_symbolize.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===- lib/asan/scripts/asan_symbolize.py -----------------------------------===#
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/compiler-rt/lib/fuzzer/scripts/unbalanced_allocs.py b/compiler-rt/lib/fuzzer/scripts/unbalanced_allocs.py
index 7ba7e09cb4e50..c8c19a017eb3f 100755
--- a/compiler-rt/lib/fuzzer/scripts/unbalanced_allocs.py
+++ b/compiler-rt/lib/fuzzer/scripts/unbalanced_allocs.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===- lib/fuzzer/scripts/unbalanced_allocs.py ------------------------------===#
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/compiler-rt/lib/sanitizer_common/scripts/gen_dynamic_list.py b/compiler-rt/lib/sanitizer_common/scripts/gen_dynamic_list.py
index fdbceae165e0d..e4b33e6637b0e 100755
--- a/compiler-rt/lib/sanitizer_common/scripts/gen_dynamic_list.py
+++ b/compiler-rt/lib/sanitizer_common/scripts/gen_dynamic_list.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===- lib/sanitizer_common/scripts/gen_dynamic_list.py ---------------------===#
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/compiler-rt/lib/sanitizer_common/scripts/sancov.py b/compiler-rt/lib/sanitizer_common/scripts/sancov.py
index 31055086350ab..06906aabf18e8 100755
--- a/compiler-rt/lib/sanitizer_common/scripts/sancov.py
+++ b/compiler-rt/lib/sanitizer_common/scripts/sancov.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Merge or print the coverage data collected by asan's coverage.
 # Input files are sequences of 4-byte integers.
 # We need to merge these integers into a set and then
diff --git a/cross-project-tests/debuginfo-tests/dexter/dexter.py b/cross-project-tests/debuginfo-tests/dexter/dexter.py
index 8473cff3c7135..ac507dc2f5ee0 100755
--- a/cross-project-tests/debuginfo-tests/dexter/dexter.py
+++ b/cross-project-tests/debuginfo-tests/dexter/dexter.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # DExTer : Debugging Experience Tester
 # ~~~~~~   ~         ~~         ~   ~~
 #
diff --git a/libc/AOR_v20.02/math/tools/plot.py b/libc/AOR_v20.02/math/tools/plot.py
index 9ce6b0308dd57..4bbd866993c89 100755
--- a/libc/AOR_v20.02/math/tools/plot.py
+++ b/libc/AOR_v20.02/math/tools/plot.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ULP error plot tool.
 #
diff --git a/libc/utils/docgen/docgen.py b/libc/utils/docgen/docgen.py
index 5a57987b3c51e..59cfbd54561c7 100755
--- a/libc/utils/docgen/docgen.py
+++ b/libc/utils/docgen/docgen.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ====- Generate documentation for libc functions  ------------*- python -*--==#
 #
diff --git a/libcxx/test/libcxx-03/transitive_includes/to_csv.py b/libcxx/test/libcxx-03/transitive_includes/to_csv.py
index 69d94deedf6f5..658aa6e657632 100755
--- a/libcxx/test/libcxx-03/transitive_includes/to_csv.py
+++ b/libcxx/test/libcxx-03/transitive_includes/to_csv.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/test/libcxx/transitive_includes/to_csv.py b/libcxx/test/libcxx/transitive_includes/to_csv.py
index 69d94deedf6f5..658aa6e657632 100755
--- a/libcxx/test/libcxx/transitive_includes/to_csv.py
+++ b/libcxx/test/libcxx/transitive_includes/to_csv.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/generate_abi_list.py b/libcxx/utils/generate_abi_list.py
index 94e49dca60af1..5e99b14bec72e 100755
--- a/libcxx/utils/generate_abi_list.py
+++ b/libcxx/utils/generate_abi_list.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/generate_escaped_output_table.py b/libcxx/utils/generate_escaped_output_table.py
index 59dd707ae6126..6be7d128ed5f1 100755
--- a/libcxx/utils/generate_escaped_output_table.py
+++ b/libcxx/utils/generate_escaped_output_table.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/generate_extended_grapheme_cluster_table.py b/libcxx/utils/generate_extended_grapheme_cluster_table.py
index eba88a4f48776..7bfb4f41520c7 100755
--- a/libcxx/utils/generate_extended_grapheme_cluster_table.py
+++ b/libcxx/utils/generate_extended_grapheme_cluster_table.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/generate_extended_grapheme_cluster_test.py b/libcxx/utils/generate_extended_grapheme_cluster_test.py
index e0a6003ecd53c..29a3e14014e8d 100755
--- a/libcxx/utils/generate_extended_grapheme_cluster_test.py
+++ b/libcxx/utils/generate_extended_grapheme_cluster_test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index f6f252751b3e3..5c9893bf2c742 100644
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 from builtins import range
diff --git a/libcxx/utils/generate_indic_conjunct_break_table.py b/libcxx/utils/generate_indic_conjunct_break_table.py
index 580d8157ffebf..4ecb9a135948b 100755
--- a/libcxx/utils/generate_indic_conjunct_break_table.py
+++ b/libcxx/utils/generate_indic_conjunct_break_table.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/generate_iwyu_mapping.py b/libcxx/utils/generate_iwyu_mapping.py
index ab3e3f14e14d8..35da70f62f264 100644
--- a/libcxx/utils/generate_iwyu_mapping.py
+++ b/libcxx/utils/generate_iwyu_mapping.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import libcxx.header_information
diff --git a/libcxx/utils/generate_width_estimation_table.py b/libcxx/utils/generate_width_estimation_table.py
index f81f0ba77489e..3f41ce1657bdd 100644
--- a/libcxx/utils/generate_width_estimation_table.py
+++ b/libcxx/utils/generate_width_estimation_table.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/run.py b/libcxx/utils/run.py
index 6b4d615444bcf..b97e1edf05a91 100755
--- a/libcxx/utils/run.py
+++ b/libcxx/utils/run.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/ssh.py b/libcxx/utils/ssh.py
index 77e79ce3d71fb..65041757e54ac 100755
--- a/libcxx/utils/ssh.py
+++ b/libcxx/utils/ssh.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/libcxx/utils/sym_diff.py b/libcxx/utils/sym_diff.py
index 8d2ff14c65429..c371c0b697b2a 100755
--- a/libcxx/utils/sym_diff.py
+++ b/libcxx/utils/sym_diff.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/lld/test/MachO/tools/generate-cfi-funcs.py b/lld/test/MachO/tools/generate-cfi-funcs.py
index 4617bd578e591..d56dceeaf7da1 100755
--- a/lld/test/MachO/tools/generate-cfi-funcs.py
+++ b/lld/test/MachO/tools/generate-cfi-funcs.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Generate skeletal functions with a variety .cfi_ directives.
 The purpose is to produce object-file test inputs to lld with a
diff --git a/lld/test/MachO/tools/validate-unwind-info.py b/lld/test/MachO/tools/validate-unwind-info.py
index 1cc82f8279273..b111601215477 100755
--- a/lld/test/MachO/tools/validate-unwind-info.py
+++ b/lld/test/MachO/tools/validate-unwind-info.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Validate compact unwind info by cross checking the llvm-objdump
 reports of the input object file vs final linked output.
diff --git a/lld/utils/benchmark.py b/lld/utils/benchmark.py
index 7202e07ec438d..aeb9f62d2f311 100755
--- a/lld/utils/benchmark.py
+++ b/lld/utils/benchmark.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
diff --git a/lldb/docs/use/tutorials/writing-custom-commands.md b/lldb/docs/use/tutorials/writing-custom-commands.md
index d53b7e473a505..3d69bfaf6c018 100644
--- a/lldb/docs/use/tutorials/writing-custom-commands.md
+++ b/lldb/docs/use/tutorials/writing-custom-commands.md
@@ -349,7 +349,7 @@ a few of them.  Here's a trivial example of adding two "utility" commands into a
 "my-utilities" container:
 
 ```python3
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 
diff --git a/lldb/examples/python/armv7_cortex_m_target_defintion.py b/lldb/examples/python/armv7_cortex_m_target_defintion.py
index 8225670f33e6b..6e2b699502e6f 100755
--- a/lldb/examples/python/armv7_cortex_m_target_defintion.py
+++ b/lldb/examples/python/armv7_cortex_m_target_defintion.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===-- armv7_cortex_m_target_definition.py.py ------------------*- C++ -*-===//
 #
 #                     The LLVM Compiler Infrastructure
diff --git a/lldb/examples/python/bsd.py b/lldb/examples/python/bsd.py
index 141d522b563ae..38a6ee2d35480 100755
--- a/lldb/examples/python/bsd.py
+++ b/lldb/examples/python/bsd.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import cmd
 import optparse
diff --git a/lldb/examples/python/cmdtemplate.py b/lldb/examples/python/cmdtemplate.py
index be4c2da53ee06..d9be65dd698e7 100644
--- a/lldb/examples/python/cmdtemplate.py
+++ b/lldb/examples/python/cmdtemplate.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ---------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/delta.py b/lldb/examples/python/delta.py
index f847b95ab119f..35f155bdea100 100755
--- a/lldb/examples/python/delta.py
+++ b/lldb/examples/python/delta.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # This module will enable GDB remote packet logging when the
diff --git a/lldb/examples/python/disasm-stress-test.py b/lldb/examples/python/disasm-stress-test.py
index 62b2b90a2860a..774787d0381cb 100755
--- a/lldb/examples/python/disasm-stress-test.py
+++ b/lldb/examples/python/disasm-stress-test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import datetime
diff --git a/lldb/examples/python/disasm.py b/lldb/examples/python/disasm.py
index df0d41584eac7..61b3f8a980bef 100755
--- a/lldb/examples/python/disasm.py
+++ b/lldb/examples/python/disasm.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/file_extract.py b/lldb/examples/python/file_extract.py
index 1a9b313b28589..4862ddec2d985 100755
--- a/lldb/examples/python/file_extract.py
+++ b/lldb/examples/python/file_extract.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import string
 import struct
diff --git a/lldb/examples/python/gdbremote.py b/lldb/examples/python/gdbremote.py
index 0bbfc1a0f1eed..2f2d82c3d3d54 100755
--- a/lldb/examples/python/gdbremote.py
+++ b/lldb/examples/python/gdbremote.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # This module will enable GDB remote packet logging when the
diff --git a/lldb/examples/python/globals.py b/lldb/examples/python/globals.py
index 1457b7612e283..3a33aef7dc26b 100755
--- a/lldb/examples/python/globals.py
+++ b/lldb/examples/python/globals.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # For the shells csh, tcsh:
diff --git a/lldb/examples/python/in_call_stack.py b/lldb/examples/python/in_call_stack.py
index c699355ce0045..c4a21b42b8d4f 100755
--- a/lldb/examples/python/in_call_stack.py
+++ b/lldb/examples/python/in_call_stack.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 
 def __lldb_init_module(debugger, internal_dict):
diff --git a/lldb/examples/python/lldb_module_utils.py b/lldb/examples/python/lldb_module_utils.py
index 2346ae37bec5c..c661cbdac4bf7 100644
--- a/lldb/examples/python/lldb_module_utils.py
+++ b/lldb/examples/python/lldb_module_utils.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import optparse
diff --git a/lldb/examples/python/lldbtk.py b/lldb/examples/python/lldbtk.py
index 72fe91e4e932e..d5f7b862c7f19 100644
--- a/lldb/examples/python/lldbtk.py
+++ b/lldb/examples/python/lldbtk.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import shlex
diff --git a/lldb/examples/python/mach_o.py b/lldb/examples/python/mach_o.py
index 8c280689f845d..4b29328960384 100755
--- a/lldb/examples/python/mach_o.py
+++ b/lldb/examples/python/mach_o.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import cmd
 import dict_utils
diff --git a/lldb/examples/python/memory.py b/lldb/examples/python/memory.py
index 985deb89d1ab9..77f6458e847a3 100755
--- a/lldb/examples/python/memory.py
+++ b/lldb/examples/python/memory.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/operating_system.py b/lldb/examples/python/operating_system.py
index f8e7abd73a09b..7bea86c7d24ba 100644
--- a/lldb/examples/python/operating_system.py
+++ b/lldb/examples/python/operating_system.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import struct
diff --git a/lldb/examples/python/performance.py b/lldb/examples/python/performance.py
index b86b5a52522e0..90b00b7c5e6d8 100755
--- a/lldb/examples/python/performance.py
+++ b/lldb/examples/python/performance.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/process_events.py b/lldb/examples/python/process_events.py
index 6225ae06b78e9..c8301b18f8d82 100755
--- a/lldb/examples/python/process_events.py
+++ b/lldb/examples/python/process_events.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/sbvalue.py b/lldb/examples/python/sbvalue.py
index fd40382817193..f9c238df74b93 100755
--- a/lldb/examples/python/sbvalue.py
+++ b/lldb/examples/python/sbvalue.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 
diff --git a/lldb/examples/python/shadow.py b/lldb/examples/python/shadow.py
index 3093ebb2d6120..adb4c22ae6655 100644
--- a/lldb/examples/python/shadow.py
+++ b/lldb/examples/python/shadow.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import shlex
diff --git a/lldb/examples/python/sources.py b/lldb/examples/python/sources.py
index cea2fd03344d4..55a23bf5915ba 100644
--- a/lldb/examples/python/sources.py
+++ b/lldb/examples/python/sources.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import shlex
diff --git a/lldb/examples/python/stacks.py b/lldb/examples/python/stacks.py
index 1dc3c7acfed67..8e5ec96853052 100755
--- a/lldb/examples/python/stacks.py
+++ b/lldb/examples/python/stacks.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import lldb
 import optparse
 import shlex
diff --git a/lldb/examples/python/symbolication.py b/lldb/examples/python/symbolication.py
index b16745ee963c9..82eab755ea390 100755
--- a/lldb/examples/python/symbolication.py
+++ b/lldb/examples/python/symbolication.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/types.py b/lldb/examples/python/types.py
index e5b4766e8c0d8..1e2fe48796b9f 100755
--- a/lldb/examples/python/types.py
+++ b/lldb/examples/python/types.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ----------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/lldb/examples/python/x86_64_linux_target_definition.py b/lldb/examples/python/x86_64_linux_target_definition.py
index 6c9aab10e9495..1ff9bc6305c49 100644
--- a/lldb/examples/python/x86_64_linux_target_definition.py
+++ b/lldb/examples/python/x86_64_linux_target_definition.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===-- x86_64_linux_target_definition.py -----------------------------*- C++ -*-===//
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/lldb/examples/python/x86_64_qemu_target_definition.py b/lldb/examples/python/x86_64_qemu_target_definition.py
index 75a8000033181..b7acdeea377e7 100644
--- a/lldb/examples/python/x86_64_qemu_target_definition.py
+++ b/lldb/examples/python/x86_64_qemu_target_definition.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===-- x86_64_qemu_target_definition.py -----------------------------*- C++ -*-===//
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/lldb/examples/python/x86_64_target_definition.py b/lldb/examples/python/x86_64_target_definition.py
index c6f2e0888e037..535171e23932a 100644
--- a/lldb/examples/python/x86_64_target_definition.py
+++ b/lldb/examples/python/x86_64_target_definition.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===-- x86_64_target_definition.py -----------------------------*- C++ -*-===//
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
index 8eb64b4ab8b2b..70191c44868e4 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import binascii
 import json
diff --git a/lldb/scripts/analyze-project-deps.py b/lldb/scripts/analyze-project-deps.py
index 4724367e2e722..307267dea0a7d 100755
--- a/lldb/scripts/analyze-project-deps.py
+++ b/lldb/scripts/analyze-project-deps.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import itertools
diff --git a/lldb/scripts/verify_api.py b/lldb/scripts/verify_api.py
index 9d14a58121bfb..2bd0360c2a3a7 100755
--- a/lldb/scripts/verify_api.py
+++ b/lldb/scripts/verify_api.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import subprocess
 import optparse
diff --git a/lldb/test/API/dotest.py b/lldb/test/API/dotest.py
index 4d20c585e630e..02cacc56b9b1b 100755
--- a/lldb/test/API/dotest.py
+++ b/lldb/test/API/dotest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 if __name__ == "__main__":
     import use_lldb_suite
diff --git a/lldb/test/API/functionalities/plugins/python_os_plugin/operating_system2.py b/lldb/test/API/functionalities/plugins/python_os_plugin/operating_system2.py
index 3ba68e40cb80a..1afa0b5a60695 100644
--- a/lldb/test/API/functionalities/plugins/python_os_plugin/operating_system2.py
+++ b/lldb/test/API/functionalities/plugins/python_os_plugin/operating_system2.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import struct
diff --git a/lldb/test/API/functionalities/plugins/python_os_plugin/os_plugin_in_dsym/operating_system.py b/lldb/test/API/functionalities/plugins/python_os_plugin/os_plugin_in_dsym/operating_system.py
index 0f9cec670b73f..d3427810c59c8 100644
--- a/lldb/test/API/functionalities/plugins/python_os_plugin/os_plugin_in_dsym/operating_system.py
+++ b/lldb/test/API/functionalities/plugins/python_os_plugin/os_plugin_in_dsym/operating_system.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import struct
diff --git a/lldb/test/API/functionalities/plugins/python_os_plugin/stepping_plugin_threads/operating_system.py b/lldb/test/API/functionalities/plugins/python_os_plugin/stepping_plugin_threads/operating_system.py
index 855cdbaf7cdc8..8acd395707592 100644
--- a/lldb/test/API/functionalities/plugins/python_os_plugin/stepping_plugin_threads/operating_system.py
+++ b/lldb/test/API/functionalities/plugins/python_os_plugin/stepping_plugin_threads/operating_system.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import lldb
 import struct
diff --git a/lldb/test/API/functionalities/postmortem/FreeBSDKernel/tools/copy-sparse.py b/lldb/test/API/functionalities/postmortem/FreeBSDKernel/tools/copy-sparse.py
index 69da526b4f804..3d75c37a5874b 100644
--- a/lldb/test/API/functionalities/postmortem/FreeBSDKernel/tools/copy-sparse.py
+++ b/lldb/test/API/functionalities/postmortem/FreeBSDKernel/tools/copy-sparse.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import re
diff --git a/lldb/test/API/test_runner/test/inferior.py b/lldb/test/API/test_runner/test/inferior.py
index 7ecadb61ae8bf..1221ba9c10c3b 100755
--- a/lldb/test/API/test_runner/test/inferior.py
+++ b/lldb/test/API/test_runner/test/inferior.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """Inferior program used by process control tests."""
 
 import argparse
diff --git a/lldb/test/API/test_runner/test/test_process_control.py b/lldb/test/API/test_runner/test/test_process_control.py
index 8a510529ddd50..01c339be93d5c 100755
--- a/lldb/test/API/test_runner/test/test_process_control.py
+++ b/lldb/test/API/test_runner/test/test_process_control.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 See https://llvm.org/LICENSE.txt for license information.
diff --git a/lldb/test/Shell/Quit/expect_exit_code.py b/lldb/test/Shell/Quit/expect_exit_code.py
index 436eb70406081..5537405aecd2f 100755
--- a/lldb/test/Shell/Quit/expect_exit_code.py
+++ b/lldb/test/Shell/Quit/expect_exit_code.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import subprocess
 import sys
diff --git a/lldb/test/Shell/Register/Core/Inputs/strip-coredump.py b/lldb/test/Shell/Register/Core/Inputs/strip-coredump.py
index b6aeae24c29a5..f927261d77d53 100755
--- a/lldb/test/Shell/Register/Core/Inputs/strip-coredump.py
+++ b/lldb/test/Shell/Register/Core/Inputs/strip-coredump.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Strip unnecessary data from a core dump to reduce its size.
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/lldb/test/Shell/ScriptInterpreter/Python/Crashlog/patch-crashlog.py b/lldb/test/Shell/ScriptInterpreter/Python/Crashlog/patch-crashlog.py
index f417a090e85fe..d955ecc824533 100644
--- a/lldb/test/Shell/ScriptInterpreter/Python/Crashlog/patch-crashlog.py
+++ b/lldb/test/Shell/ScriptInterpreter/Python/Crashlog/patch-crashlog.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import json
 import os
diff --git a/lldb/test/Shell/helper/build.py b/lldb/test/Shell/helper/build.py
index a5a7e997be044..4f66a1ca3c642 100755
--- a/lldb/test/Shell/helper/build.py
+++ b/lldb/test/Shell/helper/build.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import os
diff --git a/lldb/utils/lui/lui.py b/lldb/utils/lui/lui.py
index 27ed8f382af85..1e7781631d848 100755
--- a/lldb/utils/lui/lui.py
+++ b/lldb/utils/lui/lui.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 ##===-- lui.py -----------------------------------------------*- Python -*-===##
 ##
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/lldb/utils/lui/sandbox.py b/lldb/utils/lui/sandbox.py
index d05c2682c9796..d3b757e2eb097 100755
--- a/lldb/utils/lui/sandbox.py
+++ b/lldb/utils/lui/sandbox.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 ##===-- sandbox.py -------------------------------------------*- Python -*-===##
 ##
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/llvm/cmake/modules/CrossCompile.cmake b/llvm/cmake/modules/CrossCompile.cmake
index bfbd9cfd4063f..2a69c5133c56f 100644
--- a/llvm/cmake/modules/CrossCompile.cmake
+++ b/llvm/cmake/modules/CrossCompile.cmake
@@ -101,6 +101,7 @@ function(llvm_create_cross_target project_name target_name toolchain buildtype)
         -DLLVM_INCLUDE_BENCHMARKS=OFF
         -DLLVM_INCLUDE_TESTS=OFF
         -DLLVM_TABLEGEN_FLAGS="${LLVM_TABLEGEN_FLAGS}"
+        -DPYTHON_EXECUTABLE="${PYTHON_EXECUTABLE}"
         ${build_type_flags} ${linker_flag} ${external_clang_dir} ${libc_flags}
         ${ARGN}
     WORKING_DIRECTORY ${${project_name}_${target_name}_BUILD}
diff --git a/llvm/examples/Kaleidoscope/MCJIT/cached/genk-timing.py b/llvm/examples/Kaleidoscope/MCJIT/cached/genk-timing.py
index 2e39f103cd9f3..604819ecd7061 100644
--- a/llvm/examples/Kaleidoscope/MCJIT/cached/genk-timing.py
+++ b/llvm/examples/Kaleidoscope/MCJIT/cached/genk-timing.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/examples/Kaleidoscope/MCJIT/cached/split-lib.py b/llvm/examples/Kaleidoscope/MCJIT/cached/split-lib.py
index 7a289e868a9ce..ebe04d75704d6 100644
--- a/llvm/examples/Kaleidoscope/MCJIT/cached/split-lib.py
+++ b/llvm/examples/Kaleidoscope/MCJIT/cached/split-lib.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/examples/Kaleidoscope/MCJIT/complete/genk-timing.py b/llvm/examples/Kaleidoscope/MCJIT/complete/genk-timing.py
index 9045541cbe4e8..1f6f7ff5ed154 100644
--- a/llvm/examples/Kaleidoscope/MCJIT/complete/genk-timing.py
+++ b/llvm/examples/Kaleidoscope/MCJIT/complete/genk-timing.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/examples/Kaleidoscope/MCJIT/complete/split-lib.py b/llvm/examples/Kaleidoscope/MCJIT/complete/split-lib.py
index c920e594e675a..1267540b8ad65 100644
--- a/llvm/examples/Kaleidoscope/MCJIT/complete/split-lib.py
+++ b/llvm/examples/Kaleidoscope/MCJIT/complete/split-lib.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/examples/Kaleidoscope/MCJIT/lazy/genk-timing.py b/llvm/examples/Kaleidoscope/MCJIT/lazy/genk-timing.py
index 2e39f103cd9f3..604819ecd7061 100644
--- a/llvm/examples/Kaleidoscope/MCJIT/lazy/genk-timing.py
+++ b/llvm/examples/Kaleidoscope/MCJIT/lazy/genk-timing.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/test/BugPoint/compile-custom.ll.py b/llvm/test/BugPoint/compile-custom.ll.py
index 8f3e3c41d7799..42271b6752e61 100755
--- a/llvm/test/BugPoint/compile-custom.ll.py
+++ b/llvm/test/BugPoint/compile-custom.ll.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/test/Other/opt-bisect-helper.py b/llvm/test/Other/opt-bisect-helper.py
index 86c0851272e2c..efdb846a9456b 100755
--- a/llvm/test/Other/opt-bisect-helper.py
+++ b/llvm/test/Other/opt-bisect-helper.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/test/TableGen/JSON-check.py b/llvm/test/TableGen/JSON-check.py
index 296a5dcfc4fdc..ea78641670483 100644
--- a/llvm/test/TableGen/JSON-check.py
+++ b/llvm/test/TableGen/JSON-check.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 import subprocess
diff --git a/llvm/tools/opt-viewer/extract-reproducers.py b/llvm/tools/opt-viewer/extract-reproducers.py
index 610439d6f4c94..b70703e0e9d7c 100644
--- a/llvm/tools/opt-viewer/extract-reproducers.py
+++ b/llvm/tools/opt-viewer/extract-reproducers.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 desc = """
 A script to extract ConstraintElimination's reproducer remarks. The extracted
diff --git a/llvm/tools/opt-viewer/opt-diff.py b/llvm/tools/opt-viewer/opt-diff.py
index 2763ca4010c8a..09fa4a32ab692 100755
--- a/llvm/tools/opt-viewer/opt-diff.py
+++ b/llvm/tools/opt-viewer/opt-diff.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/tools/opt-viewer/opt-stats.py b/llvm/tools/opt-viewer/opt-stats.py
index 716143b31a890..3d7fed60202f6 100755
--- a/llvm/tools/opt-viewer/opt-stats.py
+++ b/llvm/tools/opt-viewer/opt-stats.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/tools/opt-viewer/opt-viewer.py b/llvm/tools/opt-viewer/opt-viewer.py
index c9c7db726f765..6fb8a8dc795f1 100755
--- a/llvm/tools/opt-viewer/opt-viewer.py
+++ b/llvm/tools/opt-viewer/opt-viewer.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/tools/opt-viewer/optrecord.py b/llvm/tools/opt-viewer/optrecord.py
index 8014204a64f45..a35edac17a05f 100644
--- a/llvm/tools/opt-viewer/optrecord.py
+++ b/llvm/tools/opt-viewer/optrecord.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/utils/DSAclean.py b/llvm/utils/DSAclean.py
index 1b833ff893248..1b6ced1fd7892 100755
--- a/llvm/utils/DSAclean.py
+++ b/llvm/utils/DSAclean.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # changelog:
 # 10/13/2005b: replaced the # in tmp(.#*)* with alphanumeric and _, this will then remove
diff --git a/llvm/utils/DSAextract.py b/llvm/utils/DSAextract.py
index 96f818bd2a831..0b935e9d2a4e2 100755
--- a/llvm/utils/DSAextract.py
+++ b/llvm/utils/DSAextract.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # this is a script to extract given named nodes from a dot file, with
 # the associated edges.  An edge is kept iff for edge x -> y
diff --git a/llvm/utils/Misc/zkill b/llvm/utils/Misc/zkill
index bc0bfd586f7a4..b2971423c6d9d 100755
--- a/llvm/utils/Misc/zkill
+++ b/llvm/utils/Misc/zkill
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import re
diff --git a/llvm/utils/Reviewing/find_interesting_reviews.py b/llvm/utils/Reviewing/find_interesting_reviews.py
index c006691079b64..e3e84a8be8cf1 100644
--- a/llvm/utils/Reviewing/find_interesting_reviews.py
+++ b/llvm/utils/Reviewing/find_interesting_reviews.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/utils/Target/ARM/analyze-match-table.py b/llvm/utils/Target/ARM/analyze-match-table.py
index c14b1a19fe39e..9864c5a0a44dc 100644
--- a/llvm/utils/Target/ARM/analyze-match-table.py
+++ b/llvm/utils/Target/ARM/analyze-match-table.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/utils/abtest.py b/llvm/utils/abtest.py
index a799c8764b290..a2db15e1cbbef 100755
--- a/llvm/utils/abtest.py
+++ b/llvm/utils/abtest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Given a previous good compile narrow down miscompiles.
 # Expects two directories named "before" and "after" each containing a set of
diff --git a/llvm/utils/bisect b/llvm/utils/bisect
index 9df2cd9e1136b..adc7030738a77 100755
--- a/llvm/utils/bisect
+++ b/llvm/utils/bisect
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # The way you use this is you create a script that takes in as its first
 # argument a count. The script passes into LLVM the count via a command
diff --git a/llvm/utils/bugpoint_gisel_reducer.py b/llvm/utils/bugpoint_gisel_reducer.py
index 116ec792e921d..ee4f2093c59f7 100755
--- a/llvm/utils/bugpoint_gisel_reducer.py
+++ b/llvm/utils/bugpoint_gisel_reducer.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Reduces GlobalISel failures.
 
diff --git a/llvm/utils/chunk-print-before-all.py b/llvm/utils/chunk-print-before-all.py
index 6ad126e4dff09..987c7e4bd0ede 100755
--- a/llvm/utils/chunk-print-before-all.py
+++ b/llvm/utils/chunk-print-before-all.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Given a -print-before-all and/or -print-after-all -print-module-scope log from
 # an opt invocation, chunk it into a series of individual IR files, one for each
diff --git a/llvm/utils/clang-parse-diagnostics-file b/llvm/utils/clang-parse-diagnostics-file
index 1f720c34544a7..b4bd7b47bc2fb 100755
--- a/llvm/utils/clang-parse-diagnostics-file
+++ b/llvm/utils/clang-parse-diagnostics-file
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import plistlib
diff --git a/llvm/utils/convert-constraint-log-to-z3.py b/llvm/utils/convert-constraint-log-to-z3.py
index a3c33f2ef4599..d34b5915d4a6d 100755
--- a/llvm/utils/convert-constraint-log-to-z3.py
+++ b/llvm/utils/convert-constraint-log-to-z3.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """
 Helper script to convert the log generated by '-debug-only=constraint-system'
diff --git a/llvm/utils/create_ladder_graph.py b/llvm/utils/create_ladder_graph.py
index f11aaf39bfa96..8894d35636108 100755
--- a/llvm/utils/create_ladder_graph.py
+++ b/llvm/utils/create_ladder_graph.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """A ladder graph creation program.
 
 This is a python program that creates c source code that will generate
diff --git a/llvm/utils/docker/scripts/llvm_checksum/llvm_checksum.py b/llvm/utils/docker/scripts/llvm_checksum/llvm_checksum.py
index 5fa569aec540d..85bde61487c95 100755
--- a/llvm/utils/docker/scripts/llvm_checksum/llvm_checksum.py
+++ b/llvm/utils/docker/scripts/llvm_checksum/llvm_checksum.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """ A small program to compute checksums of LLVM checkout.
 """
 from __future__ import absolute_import
diff --git a/llvm/utils/extract-section.py b/llvm/utils/extract-section.py
index bb4e252155372..cbe9ed3cfc930 100755
--- a/llvm/utils/extract-section.py
+++ b/llvm/utils/extract-section.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 from __future__ import print_function
 
 """
diff --git a/llvm/utils/extract_symbols.py b/llvm/utils/extract_symbols.py
index 388723421d660..7a30c77ea93cc 100755
--- a/llvm/utils/extract_symbols.py
+++ b/llvm/utils/extract_symbols.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """A tool for extracting a list of symbols to export
 
diff --git a/llvm/utils/extract_vplan.py b/llvm/utils/extract_vplan.py
index cff6f5074d771..4afccf7d13572 100755
--- a/llvm/utils/extract_vplan.py
+++ b/llvm/utils/extract_vplan.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # This script extracts the VPlan digraphs from the vectoriser debug messages
 # and saves them in individual dot files (one for each plan). Optionally, and
diff --git a/llvm/utils/indirect_calls.py b/llvm/utils/indirect_calls.py
index c18cffb26e7ae..03299270afca4 100755
--- a/llvm/utils/indirect_calls.py
+++ b/llvm/utils/indirect_calls.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """A tool for looking for indirect jumps and calls in x86 binaries.
 
diff --git a/llvm/utils/lint/common_lint.py b/llvm/utils/lint/common_lint.py
index 07b8fc5899e55..14fd7b790c41e 100644
--- a/llvm/utils/lint/common_lint.py
+++ b/llvm/utils/lint/common_lint.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Common lint functions applicable to multiple types of files.
 
diff --git a/llvm/utils/lint/cpp_lint.py b/llvm/utils/lint/cpp_lint.py
index 3734ba456626f..646cd8eae12dd 100755
--- a/llvm/utils/lint/cpp_lint.py
+++ b/llvm/utils/lint/cpp_lint.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Checks C++ files to make sure they conform to LLVM standards, as specified in
 # http://llvm.org/docs/CodingStandards.html .
diff --git a/llvm/utils/lint/generic_lint.py b/llvm/utils/lint/generic_lint.py
index 18e6e67e29a6e..130c952b24bd6 100755
--- a/llvm/utils/lint/generic_lint.py
+++ b/llvm/utils/lint/generic_lint.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Checks files to make sure they conform to LLVM standards which can be applied
 # to any programming language: at present, line length and trailing whitespace.
diff --git a/llvm/utils/lit/lit/ProgressBar.py b/llvm/utils/lit/lit/ProgressBar.py
index 382b8f2e52540..692d5100e1572 100644
--- a/llvm/utils/lit/lit/ProgressBar.py
+++ b/llvm/utils/lit/lit/ProgressBar.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Source: http://code.activestate.com/recipes/475116/, with
 # modifications by Daniel Dunbar.
diff --git a/llvm/utils/lit/tests/Inputs/check_path.py b/llvm/utils/lit/tests/Inputs/check_path.py
index 62c906846fbb5..dfca004d50758 100644
--- a/llvm/utils/lit/tests/Inputs/check_path.py
+++ b/llvm/utils/lit/tests/Inputs/check_path.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/utils/lit/tests/Inputs/fake-externals/cd b/llvm/utils/lit/tests/Inputs/fake-externals/cd
index 9d9612dca4d2e..ab05763f44c82 100755
--- a/llvm/utils/lit/tests/Inputs/fake-externals/cd
+++ b/llvm/utils/lit/tests/Inputs/fake-externals/cd
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import fake_external
 
diff --git a/llvm/utils/lit/tests/Inputs/fake-externals/diff b/llvm/utils/lit/tests/Inputs/fake-externals/diff
index 9d9612dca4d2e..ab05763f44c82 100755
--- a/llvm/utils/lit/tests/Inputs/fake-externals/diff
+++ b/llvm/utils/lit/tests/Inputs/fake-externals/diff
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import fake_external
 
diff --git a/llvm/utils/lit/tests/Inputs/fake-externals/env b/llvm/utils/lit/tests/Inputs/fake-externals/env
index 9d9612dca4d2e..ab05763f44c82 100755
--- a/llvm/utils/lit/tests/Inputs/fake-externals/env
+++ b/llvm/utils/lit/tests/Inputs/fake-externals/env
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import fake_external
 
diff --git a/llvm/utils/lit/tests/Inputs/fake-externals/export b/llvm/utils/lit/tests/Inputs/fake-externals/export
index 9d9612dca4d2e..ab05763f44c82 100755
--- a/llvm/utils/lit/tests/Inputs/fake-externals/export
+++ b/llvm/utils/lit/tests/Inputs/fake-externals/export
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import fake_external
 
diff --git a/llvm/utils/lit/tests/Inputs/fake-externals/mkdir b/llvm/utils/lit/tests/Inputs/fake-externals/mkdir
index 9d9612dca4d2e..ab05763f44c82 100755
--- a/llvm/utils/lit/tests/Inputs/fake-externals/mkdir
+++ b/llvm/utils/lit/tests/Inputs/fake-externals/mkdir
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import fake_external
 
diff --git a/llvm/utils/lit/tests/Inputs/fake-externals/rm b/llvm/utils/lit/tests/Inputs/fake-externals/rm
index 9d9612dca4d2e..ab05763f44c82 100755
--- a/llvm/utils/lit/tests/Inputs/fake-externals/rm
+++ b/llvm/utils/lit/tests/Inputs/fake-externals/rm
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import fake_external
 
diff --git a/llvm/utils/lit/tests/Inputs/googletest-crash/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-crash/DummySubDir/OneTest.py
index f8fe95cbfbb30..4573cbd136aaa 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-crash/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-crash/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-detect-duplicate/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-detect-duplicate/DummySubDir/OneTest.py
index bd48ccc6d63a6..7404103d54fc3 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-detect-duplicate/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-detect-duplicate/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-discovery-failed/subdir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-discovery-failed/subdir/OneTest.py
index 4816459dee45a..c430bc99e5548 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-discovery-failed/subdir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-discovery-failed/subdir/OneTest.py
@@ -1,3 +1,3 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 raise SystemExit("We are not a valid gtest executable!")
diff --git a/llvm/utils/lit/tests/Inputs/googletest-format-respect-gtest-sharding-env-vars/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-format-respect-gtest-sharding-env-vars/DummySubDir/OneTest.py
index 0aa5d0ba39cbf..411a93e5f756f 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-format-respect-gtest-sharding-env-vars/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-format-respect-gtest-sharding-env-vars/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-format/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-format/DummySubDir/OneTest.py
index c45a710d52dae..21b38ef219999 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-format/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-format/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-no-sharding/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-no-sharding/DummySubDir/OneTest.py
index 38d76cd637fb5..140da7558065a 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-no-sharding/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-no-sharding/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-prefix/DummySubDir/test_one.py b/llvm/utils/lit/tests/Inputs/googletest-prefix/DummySubDir/test_one.py
index 0aa5d0ba39cbf..411a93e5f756f 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-prefix/DummySubDir/test_one.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-prefix/DummySubDir/test_one.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-sanitizer-error/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-sanitizer-error/DummySubDir/OneTest.py
index 0811149b1110c..55906c9cf468b 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-sanitizer-error/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-sanitizer-error/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/googletest-timeout/DummySubDir/OneTest.py b/llvm/utils/lit/tests/Inputs/googletest-timeout/DummySubDir/OneTest.py
index d1698c69f4d12..53d8c41924b95 100644
--- a/llvm/utils/lit/tests/Inputs/googletest-timeout/DummySubDir/OneTest.py
+++ b/llvm/utils/lit/tests/Inputs/googletest-timeout/DummySubDir/OneTest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import os
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-bad-encoding.py b/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-bad-encoding.py
index a5a2bc9da8af7..b6c85833684ee 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-bad-encoding.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-bad-encoding.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 
diff --git a/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-control-chars.py b/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-control-chars.py
index 34f08a03de0e7..05febc5413915 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-control-chars.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-format/external_shell/write-control-chars.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/shtest-not/fail.py b/llvm/utils/lit/tests/Inputs/shtest-not/fail.py
index d64b8cb0f895a..a01abefad1124 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-not/fail.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-not/fail.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import print_environment
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/shtest-not/fail2.py b/llvm/utils/lit/tests/Inputs/shtest-not/fail2.py
index e9fb0bc0f91e0..e57f190cce572 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-not/fail2.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-not/fail2.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import print_environment
 import sys
diff --git a/llvm/utils/lit/tests/Inputs/shtest-not/pass.py b/llvm/utils/lit/tests/Inputs/shtest-not/pass.py
index bd113596b7db0..9d5f8bf69ff42 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-not/pass.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-not/pass.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import print_environment
 
diff --git a/llvm/utils/lit/tests/Inputs/shtest-output-printing/write-a-lot.py b/llvm/utils/lit/tests/Inputs/shtest-output-printing/write-a-lot.py
index 5dbb94a41cbfd..5d3926a397425 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-output-printing/write-a-lot.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-output-printing/write-a-lot.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/check_args.py b/llvm/utils/lit/tests/Inputs/shtest-shell/check_args.py
index 2ad14c4017eab..6c5a841d9196c 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-shell/check_args.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/check_args.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import platform
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py b/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py
index 9463251d823ab..f5e78b157a5d4 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stderr.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 
diff --git a/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py b/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py
index 357089d4899b5..56919479c79ac 100644
--- a/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py
+++ b/llvm/utils/lit/tests/Inputs/shtest-shell/write-to-stdout-and-stderr.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 
diff --git a/llvm/utils/llvm-gisel-cov.py b/llvm/utils/llvm-gisel-cov.py
index 9d9526e0558a5..e55f7a03f3831 100755
--- a/llvm/utils/llvm-gisel-cov.py
+++ b/llvm/utils/llvm-gisel-cov.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 Summarize the information in the given coverage files.
 
diff --git a/llvm/utils/llvm-original-di-preservation.py b/llvm/utils/llvm-original-di-preservation.py
index cdca2ec8153b8..af79a553efa8b 100755
--- a/llvm/utils/llvm-original-di-preservation.py
+++ b/llvm/utils/llvm-original-di-preservation.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Debugify summary for the original debug info testing.
 #
diff --git a/llvm/utils/merge-json.py b/llvm/utils/merge-json.py
index f5b9dcf11c4cd..23db551b16666 100644
--- a/llvm/utils/merge-json.py
+++ b/llvm/utils/merge-json.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """A command line utility to merge two JSON files.
 
 This is a python program that merges two JSON files into a single one. The
diff --git a/llvm/utils/prepare-code-coverage-artifact.py b/llvm/utils/prepare-code-coverage-artifact.py
index b865211088c8e..8e9a5b3b8ff3c 100755
--- a/llvm/utils/prepare-code-coverage-artifact.py
+++ b/llvm/utils/prepare-code-coverage-artifact.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/llvm/utils/release/findRegressions-nightly.py b/llvm/utils/release/findRegressions-nightly.py
index 1fcc54d33deb6..99d872631a6b1 100755
--- a/llvm/utils/release/findRegressions-nightly.py
+++ b/llvm/utils/release/findRegressions-nightly.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 from __future__ import print_function
 
 import re, string, sys, os, time
diff --git a/llvm/utils/release/findRegressions-simple.py b/llvm/utils/release/findRegressions-simple.py
index 81fbfa980a3a6..6e855ef835363 100755
--- a/llvm/utils/release/findRegressions-simple.py
+++ b/llvm/utils/release/findRegressions-simple.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 import re, string, sys, os, time, math
diff --git a/llvm/utils/remote-exec.py b/llvm/utils/remote-exec.py
index 4d646c5d3e282..9c586e7e7ef3e 100644
--- a/llvm/utils/remote-exec.py
+++ b/llvm/utils/remote-exec.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ===----------------------------------------------------------------------===##
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
diff --git a/llvm/utils/schedcover.py b/llvm/utils/schedcover.py
index caa73b6d6a747..04b2f6a23182b 100755
--- a/llvm/utils/schedcover.py
+++ b/llvm/utils/schedcover.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # This creates a CSV file from the output of the debug output of subtarget:
 #   llvm-tblgen --gen-subtarget --debug-only=subtarget-emitter
diff --git a/llvm/utils/shuffle_fuzz.py b/llvm/utils/shuffle_fuzz.py
index c03c77ce092a6..f3619edf3108b 100755
--- a/llvm/utils/shuffle_fuzz.py
+++ b/llvm/utils/shuffle_fuzz.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """A shuffle vector fuzz tester.
 
diff --git a/llvm/utils/shuffle_select_fuzz_tester.py b/llvm/utils/shuffle_select_fuzz_tester.py
index f51945b530d3f..192a607d50bf0 100755
--- a/llvm/utils/shuffle_select_fuzz_tester.py
+++ b/llvm/utils/shuffle_select_fuzz_tester.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """A shuffle-select vector fuzz tester.
 
diff --git a/llvm/utils/sort_includes.py b/llvm/utils/sort_includes.py
index d30efd0b438d1..d62d2c965dc60 100755
--- a/llvm/utils/sort_includes.py
+++ b/llvm/utils/sort_includes.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Script to sort the top-most block of #include lines.
 
diff --git a/llvm/utils/testgen/mc-bundling-x86-gen.py b/llvm/utils/testgen/mc-bundling-x86-gen.py
index a75f94bec814f..283a26a9997d6 100644
--- a/llvm/utils/testgen/mc-bundling-x86-gen.py
+++ b/llvm/utils/testgen/mc-bundling-x86-gen.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Auto-generates an exhaustive and repetitive test for correct bundle-locked
 # alignment on x86.
diff --git a/llvm/utils/unicode-case-fold.py b/llvm/utils/unicode-case-fold.py
index 9639aa0dc44b4..831e422364027 100755
--- a/llvm/utils/unicode-case-fold.py
+++ b/llvm/utils/unicode-case-fold.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 Unicode case folding database conversion utility
 
diff --git a/llvm/utils/wciia.py b/llvm/utils/wciia.py
index 7240d3c2a9ff2..3391576fa3cdf 100755
--- a/llvm/utils/wciia.py
+++ b/llvm/utils/wciia.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """
 wciia - Whose Code Is It Anyway
 
diff --git a/mlir/utils/lldb-scripts/action_debugging.py b/mlir/utils/lldb-scripts/action_debugging.py
index 2371967bf72a4..9eba576944f90 100644
--- a/mlir/utils/lldb-scripts/action_debugging.py
+++ b/mlir/utils/lldb-scripts/action_debugging.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # ---------------------------------------------------------------------
 # Be sure to add the python path that points to the LLDB shared library.
diff --git a/openmp/runtime/tools/summarizeStats.py b/openmp/runtime/tools/summarizeStats.py
index c1a59288fae7f..d426f75a9fea7 100644
--- a/openmp/runtime/tools/summarizeStats.py
+++ b/openmp/runtime/tools/summarizeStats.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 
 import pandas as pd
diff --git a/polly/lib/External/isl/imath/tests/gmp-compat-test/genctest.py b/polly/lib/External/isl/imath/tests/gmp-compat-test/genctest.py
index ed0e6c6a00727..f2d664a9d0770 100644
--- a/polly/lib/External/isl/imath/tests/gmp-compat-test/genctest.py
+++ b/polly/lib/External/isl/imath/tests/gmp-compat-test/genctest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import sys
 import gmpapi
 from gmpapi import void
diff --git a/polly/lib/External/isl/imath/tests/gmp-compat-test/gendata.py b/polly/lib/External/isl/imath/tests/gmp-compat-test/gendata.py
index 3ca17ff359d91..bf9644c0d1900 100644
--- a/polly/lib/External/isl/imath/tests/gmp-compat-test/gendata.py
+++ b/polly/lib/External/isl/imath/tests/gmp-compat-test/gendata.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import random
 import gmpapi
 
diff --git a/polly/lib/External/isl/imath/tests/gmp-compat-test/genpytest.py b/polly/lib/External/isl/imath/tests/gmp-compat-test/genpytest.py
index 1b5a38ce829b3..06a2e5a593729 100644
--- a/polly/lib/External/isl/imath/tests/gmp-compat-test/genpytest.py
+++ b/polly/lib/External/isl/imath/tests/gmp-compat-test/genpytest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import gmpapi
 import sys
diff --git a/polly/lib/External/isl/imath/tests/gmp-compat-test/gmpapi.py b/polly/lib/External/isl/imath/tests/gmp-compat-test/gmpapi.py
index d3eeeba288384..00641d12ff02a 100644
--- a/polly/lib/External/isl/imath/tests/gmp-compat-test/gmpapi.py
+++ b/polly/lib/External/isl/imath/tests/gmp-compat-test/gmpapi.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 
diff --git a/polly/lib/External/isl/imath/tests/gmp-compat-test/runtest.py b/polly/lib/External/isl/imath/tests/gmp-compat-test/runtest.py
index 3677acb480573..3cf2c31d645f7 100644
--- a/polly/lib/External/isl/imath/tests/gmp-compat-test/runtest.py
+++ b/polly/lib/External/isl/imath/tests/gmp-compat-test/runtest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/polly/lib/External/isl/imath/tools/findthreshold.py b/polly/lib/External/isl/imath/tools/findthreshold.py
index fbb325e1da916..15637c855fa8b 100644
--- a/polly/lib/External/isl/imath/tools/findthreshold.py
+++ b/polly/lib/External/isl/imath/tools/findthreshold.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 ##
 ## Name:     findthreshold.py
 ## Purpose:  Find a good threshold for recursive multiplication.
diff --git a/polly/lib/External/isl/imath/tools/mkdoc.py b/polly/lib/External/isl/imath/tools/mkdoc.py
index 34432dd28a2d8..5fb0b287f1f51 100644
--- a/polly/lib/External/isl/imath/tools/mkdoc.py
+++ b/polly/lib/External/isl/imath/tools/mkdoc.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 ##
 ## Name:    mkdoc.py
 ## Purpose: Extract documentation from header files.
diff --git a/polly/utils/jscop2cloog.py b/polly/utils/jscop2cloog.py
index 29383974f2678..65a49e3bd8494 100755
--- a/polly/utils/jscop2cloog.py
+++ b/polly/utils/jscop2cloog.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 import argparse, os
 import json
 
diff --git a/polly/utils/pyscop/jscop2iscc.py b/polly/utils/pyscop/jscop2iscc.py
index 42f4cc180f1fb..982cdab68988c 100755
--- a/polly/utils/pyscop/jscop2iscc.py
+++ b/polly/utils/pyscop/jscop2iscc.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 import argparse, isl, os
 import json