[Bug]: clang silently ignores garbage target versions

[DanAlbert]

Description

Invalid android versions are silently ignored by clang.

$ ~/Library/Android/sdk/ndk/24.0.8215888/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++ -target aarch64-linux-android31 -dM -E - < /dev/null | grep __ANDROID_MIN_SDK_VERSION__
#define __ANDROID_API__ __ANDROID_MIN_SDK_VERSION__
#define __ANDROID_MIN_SDK_VERSION__ 31
$ ~/Library/Android/sdk/ndk/24.0.8215888/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++ -target aarch64-linux-androidS -dM -E - < /dev/null | grep __ANDROID_MIN_SDK_VERSION__
# Not set.

In the second case, android/api-level.h (which will be included transitively by any file that includes any libc header) will set __ANDROID_API__ to __ANDROID_API_FUTURE__ (AKA 10000), but won't set __ANDROID_MIN_SDK_VERSION__ at all.

Upstream bug

No response

Commit to cherry-pick

No response

Affected versions

r24, r25, Canary

Canary version

No response

Host OS

Linux, Mac, Windows

Host OS version

all

Affected ABIs

armeabi-v7a, arm64-v8a, x86, x86_64

[rprichard]

Also see internal issue, http://b/236753843 (Platform build system passes codename for clang -target, which expects an integer).

[appujee]

good task for intern so i'm claiming it.

[enh-google]

see also internal issue http://b/315788463 where this is still silently breaking things internally 1.5 years later...

[appujee]

Even options like ./bin/clang a.cpp -c -target i686-linux-andfasdf compile silently.

[ZijunZhaoCCK]

Even options like ./bin/clang a.cpp -c -target i686-linux-andfasdf compile silently.

Now I just detect the version after android. How about making it a followup?

[appujee]

yeah sure.

[pirama-arumuga-nainar]

@ZijunZhaoCCK fixed the "invalid version" parts in llvm/llvm-project#75373. We will pull this into the next release. There is follow-up to detect invalid "environments" (i686-linux-andfasdf).

[DanAlbert]

@pirama-arumuga-nainar since it was merged last week, you mean the next-next release, right? r28? Or is that going to be cherry-picked into the r27 toolchain?

[pirama-arumuga-nainar]

We can cherry-pick to the r27 toolchain.