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| author | Ryan Prichard <rprichard@google.com> | 2019-06-12 17:47:39 -0700 |
|---|---|---|
| committer | Ryan Prichard <rprichard@google.com> | 2019-06-12 17:47:39 -0700 |
| commit | 2808734be2f4bb0f10f81203901022b1288358d9 (patch) | |
| tree | 17d0ec6f2c3afa14b250e90a1b38cd6773c81f32 /docs | |
| parent | b334cc4b91e7b993352330b59a1f9dc97d81e65a (diff) | |
| download | ndk-2808734be2f4bb0f10f81203901022b1288358d9.tar.gz | |
Pass -fno-experimental-isel to avoid Clang bug
For ARM64 -O0, Clang uses the GlobalISel instruction selector, which can
generate debug info with bad line number info. Pass -fno-experimental-isel
to turn off GlobalISel until the upstream LLVM issue is fixed.
Bug: https://github.com/android-ndk/ndk/issues/1004
Test: checkbuild.py && run_tests.py
Change-Id: I0aa92a8c57ce1cebd38ccc3d14dd3147477bc4b0
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/BuildSystemMaintainers.md | 5 | ||||
| -rw-r--r-- | docs/changelogs/Changelog-r20.md | 4 | ||||
| -rw-r--r-- | docs/changelogs/Changelog-r21.md | 4 |
3 files changed, 13 insertions, 0 deletions
diff --git a/docs/BuildSystemMaintainers.md b/docs/BuildSystemMaintainers.md index 598432271..3e0a888a1 100644 --- a/docs/BuildSystemMaintainers.md +++ b/docs/BuildSystemMaintainers.md @@ -363,9 +363,14 @@ assembler. If using `-fno-integrated-as`, you must explicitly pass use the integrated assembler, and this flag is not needed in that case. See [Issue 906]. +Clang outputs debug info with bad line number info when compiling for ARM64 and +`-O0` (no optimizations). To work around this issue, pass +`-fno-experimental-isel` to Clang. See [Issue 1004]. + [Issue 635]: https://github.com/android-ndk/ndk/issues/635 [Issue 884]: https://github.com/android-ndk/ndk/issues/884 [Issue 906]: https://github.com/android-ndk/ndk/issues/906 +[Issue 1004]: https://github.com/android-ndk/ndk/issues/1004 [Position-independent executables]: https://en.wikipedia.org/wiki/Position-independent_code#Position-independent_executables ## Useful Arguments diff --git a/docs/changelogs/Changelog-r20.md b/docs/changelogs/Changelog-r20.md index d49a1900d..907a35a62 100644 --- a/docs/changelogs/Changelog-r20.md +++ b/docs/changelogs/Changelog-r20.md @@ -52,6 +52,9 @@ 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 1004]: Clang outputs debug info with bad line number info when + compiling for ARM64 and `-O0` (no optimizations). Third-party build systems + can pass `-fno-experimental-isel` to Clang to work around this issue. * This version of the NDK is incompatible with the Android Gradle plugin version 3.0 or older. If you see an error like `No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android`, @@ -64,4 +67,5 @@ For Android Studio issues, follow the docs on the [Android Studio site]. [Issue 884]: https://github.com/android-ndk/ndk/issues/884 [Issue 888]: https://github.com/android-ndk/ndk/issues/888 [Issue 906]: https://github.com/android-ndk/ndk/issues/906 +[Issue 1004]: https://github.com/android-ndk/ndk/issues/1004 [use plugin version 3.1 or newer]: https://developer.android.com/studio/releases/gradle-plugin#updating-plugin diff --git a/docs/changelogs/Changelog-r21.md b/docs/changelogs/Changelog-r21.md index a22735f2d..c51f99bbb 100644 --- a/docs/changelogs/Changelog-r21.md +++ b/docs/changelogs/Changelog-r21.md @@ -45,6 +45,9 @@ 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 1004]: Clang outputs debug info with bad line number info when + compiling for ARM64 and `-O0` (no optimizations). Third-party build systems + can pass `-fno-experimental-isel` to Clang to work around this issue. * This version of the NDK is incompatible with the Android Gradle plugin version 3.0 or older. If you see an error like `No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android`, @@ -56,4 +59,5 @@ For Android Studio issues, follow the docs on the [Android Studio site]. [Issue 855]: https://github.com/android-ndk/ndk/issues/855 [Issue 884]: https://github.com/android-ndk/ndk/issues/884 [Issue 906]: https://github.com/android-ndk/ndk/issues/906 +[Issue 1004]: https://github.com/android-ndk/ndk/issues/1004 [use plugin version 3.1 or newer]: https://developer.android.com/studio/releases/gradle-plugin#updating-plugin |