Clarify ASan KI in the changelogs.

Test: None
Bug: https://github.com/android-ndk/ndk/issues/988
Change-Id: I9047240acedb677a3c44c93992cf6283a6475369

3 files changed, 59 insertions, 21 deletions

diff --git a/docs/changelogs/Changelog-r19.md b/docs/changelogs/Changelog-r19.md
index c4c2018fa..5af0efa1b 100644
--- a/docs/changelogs/Changelog-r19.md
+++ b/docs/changelogs/Changelog-r19.md
@@ -156,18 +156,26 @@ Known Issues
    `-march=armv7-a` when building for 32-bit ARM with the non-integrated
    assembler, or use the integrated assembler. ndk-build and CMake already
    contain these workarounds.
- * [Issue 988]: Exception handling with libc++_shared when using ASan via
-   wrap.sh can crash. To workaround this issue, ensure that your application's
-   libc++_shared.so is in `LD_PRELOAD` in your `wrap.sh` as in the following
-   example:
+ * [Issue 988]: Exception handling when using ASan via wrap.sh can crash. To
+   workaround this issue when using libc++_shared, ensure that your
+   application's libc++_shared.so is in `LD_PRELOAD` in your `wrap.sh` as in the
+   following example:
 
    ```bash
    #!/system/bin/sh
    HERE="$(cd "$(dirname "$0")" && pwd)"
    export ASAN_OPTIONS=log_to_syslog=false,allow_user_segv_handler=1
-   export LD_PRELOAD="$HERE/libclang_rt.asan-aarch64-android.so $HERE/libc++_shared.so"
-   exec "$@"
-   ```
+   ASAN_LIB=$(ls $HERE/libclang_rt.asan-*-android.so)
+   if [ -f "$HERE/libc++_shared.so" ]; then
+       # Workaround for https://github.com/android-ndk/ndk/issues/988.
+       export LD_PRELOAD="$ASAN_LIB $HERE/libc++_shared.so"
+   else
+       export LD_PRELOAD="$ASAN_LIB"
+   fi
+   "$@"
+    ```
+
+   There is no known workaround for libc++_static.
 
    Note that because this is a platform bug rather than an NDK bug this
    workaround will be necessary for this use case to work on all devices until
diff --git a/docs/changelogs/Changelog-r20.md b/docs/changelogs/Changelog-r20.md
index d497ff26e..602b336a4 100644
--- a/docs/changelogs/Changelog-r20.md
+++ b/docs/changelogs/Changelog-r20.md
@@ -52,18 +52,33 @@ For Android Studio issues, follow the docs on the [Android Studio site].
    `-march=armv7-a` when building for 32-bit ARM with the non-integrated
    assembler, or use the integrated assembler. ndk-build and CMake already
    contain these workarounds.
- * [Issue 988]: Exception handling with libc++_shared when using ASan via
-   wrap.sh can crash. To workaround this issue, ensure that your application's
-   libc++_shared.so is in `LD_PRELOAD` in your `wrap.sh` as in the following
-   example:
+ * [Issue 906]: Clang does not pass `-march=armv7-a` to the assembler when using
+   `-fno-integrated-as`. This results in the assembler generating ARMv5
+   instructions. Note that by default Clang uses the integrated assembler which
+   does not have this problem. To workaround this issue, explicitly use
+   `-march=armv7-a` when building for 32-bit ARM with the non-integrated
+   assembler, or use the integrated assembler. ndk-build and CMake already
+   contain these workarounds.
+ * [Issue 988]: Exception handling when using ASan via wrap.sh can crash. To
+   workaround this issue when using libc++_shared, ensure that your
+   application's libc++_shared.so is in `LD_PRELOAD` in your `wrap.sh` as in the
+   following example:
 
    ```bash
    #!/system/bin/sh
    HERE="$(cd "$(dirname "$0")" && pwd)"
    export ASAN_OPTIONS=log_to_syslog=false,allow_user_segv_handler=1
-   export LD_PRELOAD="$HERE/libclang_rt.asan-aarch64-android.so $HERE/libc++_shared.so"
-   exec "$@"
-   ```
+   ASAN_LIB=$(ls $HERE/libclang_rt.asan-*-android.so)
+   if [ -f "$HERE/libc++_shared.so" ]; then
+       # Workaround for https://github.com/android-ndk/ndk/issues/988.
+       export LD_PRELOAD="$ASAN_LIB $HERE/libc++_shared.so"
+   else
+       export LD_PRELOAD="$ASAN_LIB"
+   fi
+   "$@"
+    ```
+
+   There is no known workaround for libc++_static.
 
    Note that because this is a platform bug rather than an NDK bug this
    workaround will be necessary for this use case to work on all devices until
diff --git a/docs/changelogs/Changelog-r21.md b/docs/changelogs/Changelog-r21.md
index 47b0e5fb8..4318ce977 100644
--- a/docs/changelogs/Changelog-r21.md
+++ b/docs/changelogs/Changelog-r21.md
@@ -62,18 +62,33 @@ For Android Studio issues, follow the docs on the [Android Studio site].
    `-march=armv7-a` when building for 32-bit ARM with the non-integrated
    assembler, or use the integrated assembler. ndk-build and CMake already
    contain these workarounds.
- * [Issue 988]: Exception handling with libc++_shared when using ASan via
-   wrap.sh can crash. To workaround this issue, ensure that your application's
-   libc++_shared.so is in `LD_PRELOAD` in your `wrap.sh` as in the following
-   example:
+ * [Issue 906]: Clang does not pass `-march=armv7-a` to the assembler when using
+   `-fno-integrated-as`. This results in the assembler generating ARMv5
+   instructions. Note that by default Clang uses the integrated assembler which
+   does not have this problem. To workaround this issue, explicitly use
+   `-march=armv7-a` when building for 32-bit ARM with the non-integrated
+   assembler, or use the integrated assembler. ndk-build and CMake already
+   contain these workarounds.
+ * [Issue 988]: Exception handling when using ASan via wrap.sh can crash. To
+   workaround this issue when using libc++_shared, ensure that your
+   application's libc++_shared.so is in `LD_PRELOAD` in your `wrap.sh` as in the
+   following example:
 
    ```bash
    #!/system/bin/sh
    HERE="$(cd "$(dirname "$0")" && pwd)"
    export ASAN_OPTIONS=log_to_syslog=false,allow_user_segv_handler=1
-   export LD_PRELOAD="$HERE/libclang_rt.asan-aarch64-android.so $HERE/libc++_shared.so"
-   exec "$@"
-   ```
+   ASAN_LIB=$(ls $HERE/libclang_rt.asan-*-android.so)
+   if [ -f "$HERE/libc++_shared.so" ]; then
+       # Workaround for https://github.com/android-ndk/ndk/issues/988.
+       export LD_PRELOAD="$ASAN_LIB $HERE/libc++_shared.so"
+   else
+       export LD_PRELOAD="$ASAN_LIB"
+   fi
+   "$@"
+    ```
+
+   There is no known workaround for libc++_static.
 
    Note that because this is a platform bug rather than an NDK bug this
    workaround will be necessary for this use case to work on all devices until