CI: Detect Android API from the toolchain

ci/android-install-sdk.sh

@@ -14,25 +14,31 @@ mkdir -p sdk/cmdline-tools
 wget -q --tries=20 "https://dl.google.com/android/repository/commandlinetools-linux-${sdk}_latest.zip"
 unzip -q -d sdk/cmdline-tools "commandlinetools-linux-${sdk}_latest.zip"
 
-case "$1" in
+# The API level is passed in (arg 2) so it stays a single source of truth
+# shared with the CC wrapper name in the Dockerfile; only the image variant
+# is arch-specific here.
+arch="$1"
+api="$2"
+if [ -z "${api}" ]; then
+    echo "usage: $0 <arch> <api-level>"
+    exit 1
+fi
+
+case "${arch}" in
     arm | armv7)
-        api=24
         image="system-images;android-${api};default;armeabi-v7a"
         ;;
     aarch64)
-        api=24
         image="system-images;android-${api};google_apis;arm64-v8a"
         ;;
     i686)
-        api=28
         image="system-images;android-${api};default;x86"
         ;;
     x86_64)
-        api=28
         image="system-images;android-${api};default;x86_64"
         ;;
     *)
-        echo "invalid arch: $1"
+        echo "invalid arch: ${arch}"
         exit 1
         ;;
 esac
@@ -66,7 +72,7 @@ cp /android/android-emulator-package.xml /android/sdk/emulator/package.xml
 
 echo "no" |
     ./sdk/cmdline-tools/tools/bin/avdmanager create avd \
-        --name "${1}" \
+        --name "${arch}" \
         --package "${image}" | grep -v = || true
 
 rm -rf "commandlinetools-linux-${sdk}_latest.zip" emulator-linux_x64-9058569.zip

ci/docker/aarch64-linux-android/Dockerfile

@@ -18,18 +18,22 @@ WORKDIR /android/
 COPY android* /android/
 
 ENV ANDROID_ARCH=aarch64
+# Single source of truth for the API level: it selects the emulator system
+# image (passed to android-install-sdk.sh) and names the CC wrapper below, so
+# the toolchain can never drift from the image the tests run on.
+ARG ANDROID_API=24
 ENV PATH=$PATH:/android/linux-x86_64/bin:/android/sdk/cmdline-tools/tools:/android/sdk/platform-tools
 
 RUN /android/android-install-ndk.sh
-RUN /android/android-install-sdk.sh $ANDROID_ARCH
+RUN /android/android-install-sdk.sh $ANDROID_ARCH $ANDROID_API
 RUN mv /root/.android /tmp
 RUN chmod 777 -R /tmp/.android
 RUN chmod 755 /android/sdk/cmdline-tools/tools/* /android/sdk/emulator/qemu/linux-x86_64/*
 
 ENV PATH=$PATH:/rust/bin \
-    CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER=aarch64-linux-android28-clang \
+    CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER=aarch64-linux-android${ANDROID_API}-clang \
     CARGO_TARGET_AARCH64_LINUX_ANDROID_RUNNER=/tmp/runtest \
-    CC_aarch64_linux_android=aarch64-linux-android28-clang \
+    CC_aarch64_linux_android=aarch64-linux-android${ANDROID_API}-clang \
     AR_aarch64_linux_android=llvm-ar \
     HOME=/tmp
 

ci/docker/arm-linux-androideabi/Dockerfile

@@ -18,18 +18,22 @@ WORKDIR /android/
 COPY android* /android/
 
 ENV ANDROID_ARCH=arm
+# Single source of truth for the API level: it selects the emulator system
+# image (passed to android-install-sdk.sh) and names the CC wrapper below, so
+# the toolchain can never drift from the image the tests run on.
+ARG ANDROID_API=24
 ENV PATH=$PATH:/android/linux-x86_64/bin:/android/sdk/cmdline-tools/tools:/android/sdk/platform-tools
 
 RUN /android/android-install-ndk.sh
-RUN /android/android-install-sdk.sh $ANDROID_ARCH
+RUN /android/android-install-sdk.sh $ANDROID_ARCH $ANDROID_API
 RUN mv /root/.android /tmp
 RUN chmod 777 -R /tmp/.android
 RUN chmod 755 /android/sdk/cmdline-tools/tools/* /android/sdk/emulator/qemu/linux-x86_64/*
 
 ENV PATH=$PATH:/rust/bin \
-    CARGO_TARGET_ARM_LINUX_ANDROIDEABI_LINKER=armv7a-linux-androideabi28-clang \
+    CARGO_TARGET_ARM_LINUX_ANDROIDEABI_LINKER=armv7a-linux-androideabi${ANDROID_API}-clang \
     CARGO_TARGET_ARM_LINUX_ANDROIDEABI_RUNNER=/tmp/runtest \
-    CC_arm_linux_androideabi=armv7a-linux-androideabi28-clang \
+    CC_arm_linux_androideabi=armv7a-linux-androideabi${ANDROID_API}-clang \
     AR_arm_linux_androideabi=llvm-ar \
     HOME=/tmp
 

ci/docker/x86_64-linux-android/Dockerfile

@@ -21,15 +21,19 @@ RUN curl -fsSL https://us-apt.pkg.dev/doc/repo-signing-key.gpg \
 
 WORKDIR /android/
 ENV ANDROID_ARCH=x86_64
+# The API level we compile against: this only names the CC wrapper and the toolchain we use.
+# The Android Cuttlefish device is pinned separately and is newer, i.e. capable of testing
+# newer APIs. The toolchain wrapper is held at the same baseline as arm/aarch64 for now.
+ARG ANDROID_API=24
 COPY android-install-ndk.sh /android/
 RUN /android/android-install-ndk.sh
 
 ENV PATH=$PATH:/rust/bin:/android/linux-x86_64/bin \
     ANDROID_SERIAL=127.0.0.1:6520 \
-    CARGO_TARGET_X86_64_LINUX_ANDROID_LINKER=x86_64-linux-android28-clang \
+    CARGO_TARGET_X86_64_LINUX_ANDROID_LINKER=x86_64-linux-android${ANDROID_API}-clang \
     CARGO_TARGET_X86_64_LINUX_ANDROID_RUNNER=/tmp/runtest \
-    CC_x86_64_linux_android=x86_64-linux-android28-clang \
-    CXX_x86_64_linux_android=x86_64-linux-android28-clang++ \
+    CC_x86_64_linux_android=x86_64-linux-android${ANDROID_API}-clang \
+    CXX_x86_64_linux_android=x86_64-linux-android${ANDROID_API}-clang++ \
     AR_x86_64_linux_android=llvm-ar \
     HOME=/tmp
 

libc-test/build.rs

@@ -2060,6 +2060,10 @@ fn test_android(target: &str) {
     };
     let x86 = target.contains("i686") || target.contains("x86_64");
     let aarch64 = target.contains("aarch64");
+    // The API level the NDK toolchain targets, which caps the available libc
+    // API surface (see `Versions`). Detection is required, so unwrap and let a
+    // toolchain we can't read fail loudly rather than silently skip every test.
+    let android = VERSIONS.android.unwrap();
 
     let mut cfg = ctest_cfg();
     cfg.define("_GNU_SOURCE", None);
@@ -2251,8 +2255,7 @@ fn test_android(target: &str) {
             "posix_spawn_file_actions_t" => true,
             "posix_spawnattr_t" => true,
 
-            // Added in API level 24
-            "if_nameindex" => true,
+            "if_nameindex" if android < 24 => true,
 
             _ => false,
         }
@@ -2450,43 +2453,35 @@ fn test_android(target: &str) {
             "reallocarray" => true,
             "__system_property_wait" => true,
 
-            // Added in API level 30, but tests use level 28.
-            "memfd_create" | "mlock2" | "renameat2" | "statx" | "statx_timestamp" => true,
+            "memfd_create" | "mlock2" | "renameat2" | "statx" | "statx_timestamp"
+                if android < 30 =>
+            {
+                true
+            }
 
             // Added in API level 33, but tests use level 28.
             "preadv2" | "pwritev2" => true,
 
             // Added in glibc 2.25.
             "getentropy" => true,
 
-            // Added in API level 28, but some tests use level 24.
-            "getrandom" => true,
-
-            // Added in API level 28, but some tests use level 24.
-            "syncfs" => true,
-
-            // Added in API level 28, but some tests use level 24.
-            "pthread_attr_getinheritsched" | "pthread_attr_setinheritsched" => true,
-            // Added in API level 28, but some tests use level 24.
-            "fread_unlocked" | "fwrite_unlocked" | "fgets_unlocked" | "fflush_unlocked" => true,
-
-            // Added in API level 28, but some tests use level 24.
-            "aligned_alloc" => true,
+            "getrandom" | "syncfs" | "aligned_alloc" if android < 28 => true,
 
-            // Added in API level 26, but some tests use level 24.
-            "getgrent" => true,
+            "pthread_attr_getinheritsched" | "pthread_attr_setinheritsched" if android < 28 => true,
 
-            // Added in API level 26, but some tests use level 24.
-            "setgrent" => true,
-
-            // Added in API level 26, but some tests use level 24.
-            "endgrent" => true,
+            "fread_unlocked" | "fwrite_unlocked" | "fgets_unlocked" | "fflush_unlocked"
+                if android < 28 =>
+            {
+                true
+            }
 
-            // Added in API level 26, but some tests use level 24.
-            "getpwent" | "setpwent" | "endpwent" => true,
+            "getgrent" | "setgrent" | "endgrent" | "getpwent" | "setpwent" | "endpwent"
+                if android < 26 =>
+            {
+                true
+            }
 
-            // Added in API level 26, but some tests use level 24.
-            "getdomainname" | "setdomainname" => true,
+            "getdomainname" | "setdomainname" if android < 26 => true,
 
             // FIXME(android): bad function pointers:
             "isalnum" | "isalpha" | "iscntrl" | "isdigit" | "isgraph" | "islower" | "isprint"
@@ -2504,6 +2499,21 @@ fn test_android(target: &str) {
         }
     });
 
+    cfg.skip_fn_ptrcheck(move |func| {
+        match func {
+            // termios functions are <termios.h> inlines below API 28, so
+            // their C-side address never matches the symbol Rust links.
+            "tcdrain" | "tcflow" | "tcflush" | "tcgetattr" | "tcgetsid" | "tcsendbreak"
+            | "tcsetattr" | "cfgetispeed" | "cfgetospeed" | "cfmakeraw" | "cfsetispeed"
+            | "cfsetospeed" | "cfsetspeed"
+                if android < 28 =>
+            {
+                true
+            }
+            _ => false,
+        }
+    });
+
     cfg.skip_struct_field_type(move |struct_, field| {
         match (struct_.ident(), field.ident()) {
             // This is a weird union, don't check the type.
@@ -6404,6 +6414,8 @@ struct Versions {
     macos: Option<(u32, u32)>,
     emscripten: Option<(u32, u32)>,
     wasi_sdk: Option<(u32, WasiVersion)>,
+    /// Android API level (no minor version).
+    android: Option<u32>,
 }
 
 #[derive(Clone, Copy, Debug, Default)]
@@ -6432,6 +6444,13 @@ impl Versions {
             #include "gnu/libc-version.h"
             #endif
 
+            #ifdef __ANDROID__
+            /* The clang driver predefines __ANDROID_MIN_SDK_VERSION__ from the API level
+             * in the target triple; including api-level.h ensures it is defined even on
+             * toolchains that leave it to the header. */
+            #include "android/api-level.h"
+            #endif
+
             #if defined(__FreeBSD__) \
                 || defined(__NetBSD__) \
                 || defined(__OpenBSD__) \
@@ -6501,6 +6520,11 @@ impl Versions {
                 }
                 "__GLIBC__" => ret.glibc.get_or_insert_default().0 = value.parse().unwrap(),
                 "__GLIBC_MINOR__" => ret.glibc.get_or_insert_default().1 = value.parse().unwrap(),
+                // Clang 12+ predefines the target API level here as a plain integer.
+                // Every NDK wrapper we build with carries an API level, so parse it like
+                // the other version macros above and let a missing value fail loudly at
+                // the unwrap in `test_android` rather than silently skipping tests.
+                "__ANDROID_MIN_SDK_VERSION__" => ret.android = Some(value.parse().unwrap()),
                 "__MAC_OS_X_VERSION_MAX_ALLOWED" => {
                     let caps = mac_re.captures(value).unwrap();
                     let major: u32 = caps[1].parse().unwrap();