[compiler-rt] [sanitizer] Allow *___lcxx_override symbolse in symbolizer (PR #79904)

[Vitaly Buka via llvm-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/79904

We don't intercept them, and they are not called and used only as
markers anyway.


>From a3fa9e9299c2cbffd4f9c70d8722d094a325915a Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka at google.com>
Date: Mon, 29 Jan 2024 13:34:52 -0800
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?=
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Created using spr 1.3.4
---
 .../sanitizer_common/symbolizer/scripts/build_symbolizer.sh | 6 ++++--
 .../sanitizer_common/symbolizer/scripts/global_symbols.txt  | 5 +++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh b/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh
index f24d42cc84e417..7f4082a6cd190e 100755
--- a/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh
+++ b/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh
@@ -191,8 +191,10 @@ $OPT -passes=internalize -internalize-public-api-list=${SYMBOLIZER_API_LIST} all
 $CC $FLAGS -fno-lto -c opt.bc -o symbolizer.o
 
 echo "Checking undefined symbols..."
-nm -f posix -g symbolizer.o | cut -f 1,2 -d \  | LC_COLLATE=C sort -u > undefined.new
-(diff -u $SCRIPT_DIR/global_symbols.txt undefined.new | grep -E "^\+[^+]") && \
+export LC_ALL=C
+nm -f posix -g symbolizer.o | cut -f 1,2 -d \  | sort -u > undefined.new
+grep -Ev "^#|^$" $SCRIPT_DIR/global_symbols.txt | sort -u > expected.new
+(diff -u expected.new undefined.new | grep -E "^\+[^+]") && \
   (echo "Failed: unexpected symbols"; exit 1)
 
 cp -f symbolizer.o $OUTPUT
diff --git a/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt b/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
index 0a4bc6989a0d72..ef522976a2c2da 100644
--- a/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
+++ b/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
@@ -1,3 +1,6 @@
+# This file is used to control symbols used by internal symbolizer. We want to
+# avoid unexpected dependency on function intercepted by sanitizers.
+
 _GLOBAL_OFFSET_TABLE_ U
 _ZN11__sanitizer13internal_mmapEPvjiiiy U
 _ZN11__sanitizer13internal_mmapEPvmiiiy U
@@ -62,6 +65,8 @@ __sanitizer_symbolize_flush T
 __sanitizer_symbolize_frame T
 __sanitizer_symbolize_set_demangle T
 __sanitizer_symbolize_set_inline_frames T
+__start___lcxx_override U
+__stop___lcxx_override U
 __strdup U
 __udivdi3 U
 __umoddi3 U