[ABI] Introduce an ABI checker that diffs symbols

test/abi/macOS/arm64/stdlib-asserts.swift

@@ -0,0 +1,43 @@
+// RUN: %empty-directory(%t)
+// RUN: %llvm-nm -g --defined-only -f just-symbols %stdlib_dir/arm64/libswiftCore.dylib > %t/symbols
+// RUN: %abi-symbol-checker %s %t/symbols --base %S/stdlib.swift
+// RUN: diff -u %S/../../Inputs/macOS/arm64/stdlib/baseline-asserts %t/symbols
+
+// REQUIRES: swift_stdlib_asserts
+// REQUIRES: STDLIB_VARIANT=macosx-arm64
+
+// *** DO NOT DISABLE OR XFAIL THIS TEST. *** (See comment below.)
+
+// Welcome, Build Wrangler!
+//
+// This file lists APIs that have recently changed in a way that potentially
+// indicates an ABI- or source-breaking problem.
+//
+// A failure in this test indicates that there is a potential breaking change in
+// the Standard Library. If you observe a failure outside of a PR test, please
+// reach out to the Standard Library team directly to make sure this gets
+// resolved quickly! If your own PR fails in this test, you probably have an
+// ABI- or source-breaking change in your commits. Please go and fix it.
+//
+// Please DO NOT DISABLE THIS TEST. In addition to ignoring the current set of
+// ABI breaks, XFAILing this test also silences any future ABI breaks that may
+// land on this branch, which simply generates extra work for the next person
+// that picks up the mess.
+//
+// Instead of disabling this test, you'll need to extend the list of expected
+// changes at the bottom. (You'll also need to do this if your own PR triggers
+// false positives, or if you have special permission to break things.) You can
+// find a diff of what needs to be added in the output of the failed test run.
+// The order of lines doesn't matter, and you can also include comments to refer
+// to any bugs you filed.
+//
+// Thank you for your help ensuring the stdlib remains compatible with its past!
+//                                            -- Your friendly stdlib engineers
+
+// *** NOTE: ***
+// You will normally add new entries in 'abi/macOS/arm64/stdlib.swift' instead
+// of this file. This file is dedicated for assert only symbols.
+
+// Standard Library Symbols
+
+// Runtime Symbols

test/abi/macOS/arm64/stdlib.swift

@@ -0,0 +1,48 @@
+// RUN: %empty-directory(%t)
+// RUN: %llvm-nm -g --defined-only -f just-symbols %stdlib_dir/arm64/libswiftCore.dylib > %t/symbols
+// RUN: %abi-symbol-checker %s %t/symbols
+// RUN: diff -u %S/../../Inputs/macOS/arm64/stdlib/baseline %t/symbols
+
+// REQUIRES: swift_stdlib_no_asserts
+// REQUIRES: STDLIB_VARIANT=macosx-arm64
+
+// *** DO NOT DISABLE OR XFAIL THIS TEST. *** (See comment below.)
+
+// Welcome, Build Wrangler!
+//
+// This file lists APIs that have recently changed in a way that potentially
+// indicates an ABI- or source-breaking problem.
+//
+// A failure in this test indicates that there is a potential breaking change in
+// the Standard Library. If you observe a failure outside of a PR test, please
+// reach out to the Standard Library team directly to make sure this gets
+// resolved quickly! If your own PR fails in this test, you probably have an
+// ABI- or source-breaking change in your commits. Please go and fix it.
+//
+// Please DO NOT DISABLE THIS TEST. In addition to ignoring the current set of
+// ABI breaks, XFAILing this test also silences any future ABI breaks that may
+// land on this branch, which simply generates extra work for the next person
+// that picks up the mess.
+//
+// Instead of disabling this test, you'll need to extend the list of expected
+// changes at the bottom. (You'll also need to do this if your own PR triggers
+// false positives, or if you have special permission to break things.) You can
+// find a diff of what needs to be added in the output of the failed test run.
+// The order of lines doesn't matter, and you can also include comments to refer
+// to any bugs you filed.
+//
+// Thank you for your help ensuring the stdlib remains compatible with its past!
+//                                            -- Your friendly stdlib engineers
+
+// Standard Library Symbols
+
+// Swift._getRetainCount(Swift.AnyObject) -> Swift.UInt
+Added: _$ss15_getRetainCountySuyXlF
+
+// Swift._getWeakRetainCount(Swift.AnyObject) -> Swift.UInt
+Added: _$ss19_getWeakRetainCountySuyXlF
+
+// Swift._getUnownedRetainCount(Swift.AnyObject) -> Swift.UInt
+Added: _$ss22_getUnownedRetainCountySuyXlF
+
+// Runtime Symbols

test/abi/macOS/x86_64/stdlib-asserts.swift

@@ -0,0 +1,43 @@
+// RUN: %empty-directory(%t)
+// RUN: %llvm-nm -g --defined-only -f just-symbols %stdlib_dir/x86_64/libswiftCore.dylib > %t/symbols
+// RUN: %abi-symbol-checker %s %t/symbols --base %S/stdlib.swift
+// RUN: diff -u %S/../../Inputs/macOS/x86_64/stdlib/baseline-asserts %t/symbols
+
+// REQUIRES: swift_stdlib_asserts
+// REQUIRES: STDLIB_VARIANT=macosx-x86_64
+
+// *** DO NOT DISABLE OR XFAIL THIS TEST. *** (See comment below.)
+
+// Welcome, Build Wrangler!
+//
+// This file lists APIs that have recently changed in a way that potentially
+// indicates an ABI- or source-breaking problem.
+//
+// A failure in this test indicates that there is a potential breaking change in
+// the Standard Library. If you observe a failure outside of a PR test, please
+// reach out to the Standard Library team directly to make sure this gets
+// resolved quickly! If your own PR fails in this test, you probably have an
+// ABI- or source-breaking change in your commits. Please go and fix it.
+//
+// Please DO NOT DISABLE THIS TEST. In addition to ignoring the current set of
+// ABI breaks, XFAILing this test also silences any future ABI breaks that may
+// land on this branch, which simply generates extra work for the next person
+// that picks up the mess.
+//
+// Instead of disabling this test, you'll need to extend the list of expected
+// changes at the bottom. (You'll also need to do this if your own PR triggers
+// false positives, or if you have special permission to break things.) You can
+// find a diff of what needs to be added in the output of the failed test run.
+// The order of lines doesn't matter, and you can also include comments to refer
+// to any bugs you filed.
+//
+// Thank you for your help ensuring the stdlib remains compatible with its past!
+//                                            -- Your friendly stdlib engineers
+
+// *** NOTE: ***
+// You will normally add new entries in 'abi/macOS/x86_64/stdlib.swift' instead
+// of this file. This file is dedicated for assert only symbols.
+
+// Standard Library Symbols
+
+// Runtime Symbols

test/abi/macOS/x86_64/stdlib.swift

@@ -0,0 +1,48 @@
+// RUN: %empty-directory(%t)
+// RUN: %llvm-nm -g --defined-only -f just-symbols %stdlib_dir/x86_64/libswiftCore.dylib > %t/symbols
+// RUN: %abi-symbol-checker %s %t/symbols
+// RUN: diff -u %S/../../Inputs/macOS/x86_64/stdlib/baseline %t/symbols
+
+// REQUIRES: swift_stdlib_no_asserts
+// REQUIRES: STDLIB_VARIANT=macosx-x86_64
+
+// *** DO NOT DISABLE OR XFAIL THIS TEST. *** (See comment below.)
+
+// Welcome, Build Wrangler!
+//
+// This file lists APIs that have recently changed in a way that potentially
+// indicates an ABI- or source-breaking problem.
+//
+// A failure in this test indicates that there is a potential breaking change in
+// the Standard Library. If you observe a failure outside of a PR test, please
+// reach out to the Standard Library team directly to make sure this gets
+// resolved quickly! If your own PR fails in this test, you probably have an
+// ABI- or source-breaking change in your commits. Please go and fix it.
+//
+// Please DO NOT DISABLE THIS TEST. In addition to ignoring the current set of
+// ABI breaks, XFAILing this test also silences any future ABI breaks that may
+// land on this branch, which simply generates extra work for the next person
+// that picks up the mess.
+//
+// Instead of disabling this test, you'll need to extend the list of expected
+// changes at the bottom. (You'll also need to do this if your own PR triggers
+// false positives, or if you have special permission to break things.) You can
+// find a diff of what needs to be added in the output of the failed test run.
+// The order of lines doesn't matter, and you can also include comments to refer
+// to any bugs you filed.
+//
+// Thank you for your help ensuring the stdlib remains compatible with its past!
+//                                            -- Your friendly stdlib engineers
+
+// Standard Library Symbols
+
+// Swift._getRetainCount(Swift.AnyObject) -> Swift.UInt
+Added: _$ss15_getRetainCountySuyXlF
+
+// Swift._getWeakRetainCount(Swift.AnyObject) -> Swift.UInt
+Added: _$ss19_getWeakRetainCountySuyXlF
+
+// Swift._getUnownedRetainCount(Swift.AnyObject) -> Swift.UInt
+Added: _$ss22_getUnownedRetainCountySuyXlF
+
+// Runtime Symbols

test/lit.cfg

@@ -360,6 +360,7 @@ config.swift_libexec_dir = make_path(config.swift, '..', '..', 'libexec')
 config.swift_share_dir = make_path(config.swift, '..', '..', 'share')
 config.round_trip_syntax_test = make_path(config.swift_utils, 'round-trip-syntax-test')
 config.refactor_check_compiles = make_path(config.swift_utils, 'refactor-check-compiles.py')
+config.abi_symbol_checker = make_path(config.swift_utils, 'swift-abi-symbol-checker.py')
 
 config.link = lit.util.which('link', config.environment.get('PATH', '')) or      \
               lit.util.which('lld-link', config.environment.get('PATH', ''))
@@ -778,6 +779,8 @@ config.available_features.add("VENDOR=" + run_vendor)
 
 config.available_features.add("SWIFT_VERSION=" + swift_version)
 
+config.available_features.add("STDLIB_VARIANT={}".format(config.variant_suffix[1:]))
+
 if "optimized_stdlib" in config.available_features:
   config.available_features.add("optimized_stdlib_" + run_cpu)
 
@@ -2596,6 +2599,7 @@ config.substitutions.append(('%scale-test',
                              '{} {} --swiftc-binary={} --tmpdir=%t --exclude-timers'.format(
                                  shell_quote(sys.executable), config.scale_test,
                                  config.swiftc)))
+config.substitutions.append(('%abi-symbol-checker', '%s %s' % (shell_quote(sys.executable), config.abi_symbol_checker)))
 config.substitutions.append(('%target-sil-opt\(mock-sdk:([^)]+)\)',
                              SubstituteCaptures(r'%s \1 %s' % (
                                  escape_for_substitute_captures(subst_target_sil_opt_mock_sdk),

utils/swift-abi-symbol-checker.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+
+import argparse
+import sys
+
+
+def getAdditionsAndRemovals(changesFile):
+    changesF = open(changesFile)
+    changes = changesF.read()
+    changesF.close()
+
+    # Get rid of lines that start with either '//' or a newline
+    changes = [c for c in changes.splitlines() if not c.startswith('//') and c != '']
+
+    # Filter the changes for lines that start with Added
+    additions = [a for a in changes if a.startswith('Added')]
+    # Filter the changes for lines that start with Removed
+    removals = [r for r in changes if r.startswith('Removed')]
+
+    # Map the additions by removing the 'Added: ' prefix to get just the symbol
+    additions = list(map(lambda a: a.removeprefix('Added: '), additions))
+    # Map the removals by removing the 'Removed: ' prefix to get just the symbol
+    removals = list(map(lambda r: r.removeprefix('Removed: '), removals))
+
+    return (additions, removals)
+
+
+def checkSymbols(args):
+    # If we were passed a base file, read those changes first. This most likely
+    # occurs in assert configurations getting the non-assert base.
+    baseAdditions = []
+    baseRemovals = []
+
+    if args.base:
+        (baseAdditions, baseRemovals) = getAdditionsAndRemovals(args.base)
+
+    (additions, removals) = getAdditionsAndRemovals(args.changes)
+
+    # Append the base additions and removals to ours.
+    additions.extend(baseAdditions)
+    removals.extend(baseRemovals)
+
+    # We need to write back to the temporary symbol file for diffing
+    symbolsF = open(args.symbols, 'r+')
+
+    symbols = symbolsF.read().splitlines()
+
+    # Check for added symbols that are not actually in the just built dylib.
+    notInDylib = [a for a in additions if a not in symbols]
+
+    # If there were symbols marked as 'Added' in the changes file, but they didn't
+    # actually appear in the dylib then print those symbols out and fail.
+    if notInDylib:
+        for symbol in notInDylib:
+            print(('{} was marked as \'Added\', but it was not found in the '
+                   'just built library').format(symbol))
+
+        sys.exit(-1)
+
+    # Filter the built symbols for the additions because we're removing them to
+    # get back to the baseline
+    symbols = [s for s in symbols if s not in additions]
+
+    # Append the removals into the symbol list to get back to the baseline
+    symbols.extend(removals)
+
+    # Sort the end result to write back
+    symbols.sort()
+
+    # Go back to beginning of the file and purge everything
+    symbolsF.seek(0)
+    symbolsF.truncate()
+
+    # Append a newline to each symbol (because writelines doesn't do that for us)
+    symbols = list(map(lambda s: s + '\n', symbols))
+
+    # Write all of our symbols back into the symbols file
+    symbolsF.writelines(symbols)
+
+    # Done
+    symbolsF.close()
+
+
+def main(arguments):
+    parser = argparse.ArgumentParser(
+        description='Change absolute install names to use @rpath')
+
+    parser.add_argument('changes', help='the changes file')
+    parser.add_argument('symbols', help='the symbols file')
+    parser.add_argument('--base', help='the base changes file')
+
+    args = parser.parse_args(arguments)
+
+    checkSymbols(args)
+
+
+sys.exit(main(sys.argv[1:]))