From ff08dabdf63d016d75848880d214c80e87b72054 Mon Sep 17 00:00:00 2001
From: Alexander Grund <Flamefire@users.noreply.github.com>
Date: Sun, 11 Apr 2021 16:13:06 +0200
Subject: [PATCH] Suppress UB failure in libc++ filebuf::swap

This triggers UB when filebuf is closed
See https://bugs.llvm.org/show_bug.cgi?id=49923
---
 .github/workflows/posix.yml | 5 +++--
 ubsan-blacklist             | 3 +++
 2 files changed, 6 insertions(+), 2 deletions(-)
 create mode 100644 ubsan-blacklist

diff --git a/.github/workflows/posix.yml b/.github/workflows/posix.yml
index b4876f4..1de2b0d 100644
--- a/.github/workflows/posix.yml
+++ b/.github/workflows/posix.yml
@@ -59,7 +59,8 @@ jobs:
 
       - name: Setup config vars
         run: |
-          echo "LIBRARY=${GITHUB_REPOSITORY#*/}" >> $GITHUB_ENV
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
           echo "B2_COMPILER=${{matrix.compiler}}" >> $GITHUB_ENV
           ${{matrix.compiler}} --version
           if [[ "${{matrix.compiler}}" =~ clang ]]; then
@@ -75,7 +76,7 @@ jobs:
           echo "B2_CXXSTD=${{matrix.cxxstd}}" >> $GITHUB_ENV
           if [[ "${{matrix.sanitize}}" == "yes" ]]; then
             echo "B2_ASAN=address-sanitizer=norecover" >> $GITHUB_ENV
-            echo "B2_UBSAN=undefined-sanitizer=norecover" >> $GITHUB_ENV
+            echo "B2_UBSAN=undefined-sanitizer=norecover cxxflags=-fsanitize-blacklist=libs/$LIBRARY/ubsan-blacklist" >> $GITHUB_ENV
           fi
           [[ "${{matrix.linkflags}}" == "" ]] || echo "B2_LINKFLAGS=linkflags=${{matrix.linkflags}}" >> $GITHUB_ENV
 
diff --git a/ubsan-blacklist b/ubsan-blacklist
new file mode 100644
index 0000000..0e60418
--- /dev/null
+++ b/ubsan-blacklist
@@ -0,0 +1,3 @@
+[undefined]
+# libcxx invokes UB when swapping a closed filebuf
+fun:_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE4swapERS3_