Update rustc's information on Android's sanitizers

This patch updates sanitizier support definitions for Android inside the
compiler.  It also adjusts the logic to make sure no pre-built sanitizer
runtime libraries are emitted as these are instead provided dynamically
on Android targets.

Author: chriswailes

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1090,11 +1090,12 @@ fn add_sanitizer_libraries(sess: &Session, crate_type: CrateType, linker: &mut d
     // both executables and dynamic shared objects. Everywhere else the runtimes
     // are currently distributed as static libraries which should be linked to
     // executables only.
-    let needs_runtime = match crate_type {
-        CrateType::Executable => true,
-        CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro => sess.target.is_like_osx,
-        CrateType::Rlib | CrateType::Staticlib => false,
-    };
+    let needs_runtime = !sess.target.is_like_android
+        && match crate_type {
+            CrateType::Executable => true,
+            CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro => sess.target.is_like_osx,
+            CrateType::Rlib | CrateType::Staticlib => false,
+        };
 
     if !needs_runtime {
         return;

compiler/rustc_target/src/spec/android_base.rs

@@ -1,10 +1,12 @@
-use crate::spec::TargetOptions;
+use crate::spec::{SanitizerSet, TargetOptions};
 
 pub fn opts() -> TargetOptions {
     let mut base = super::linux_base::opts();
     base.os = "android".into();
+    base.is_like_android = true;
     base.default_dwarf_version = 2;
     base.has_thread_local = false;
+    base.supported_sanitizers = SanitizerSet::ADDRESS;
     // This is for backward compatibility, see https://github.com/rust-lang/rust/issues/49867
     // for context. (At that time, there was no `-C force-unwind-tables`, so the only solution
     // was to always emit `uwtable`).

compiler/rustc_target/src/spec/i686_unknown_linux_gnu.rs

@@ -1,9 +1,10 @@
-use crate::spec::{LinkerFlavor, StackProbeType, Target};
+use crate::spec::{LinkerFlavor, SanitizerSet, StackProbeType, Target};
 
 pub fn target() -> Target {
     let mut base = super::linux_gnu_base::opts();
     base.cpu = "pentium4".into();
     base.max_atomic_width = Some(64);
+    base.supported_sanitizers = SanitizerSet::ADDRESS;
     base.add_pre_link_args(LinkerFlavor::Gcc, &["-m32"]);
     // don't use probe-stack=inline-asm until rust#83139 and rust#84667 are resolved
     base.stack_probes = StackProbeType::Call;

compiler/rustc_target/src/spec/mod.rs

@@ -1379,6 +1379,8 @@ pub struct TargetOptions {
     pub is_like_msvc: bool,
     /// Whether a target toolchain is like WASM.
     pub is_like_wasm: bool,
+    /// Whether a target toolchain is like Android, implying a Linux kernel and a Bionic libc
+    pub is_like_android: bool,
     /// Default supported version of DWARF on this platform.
     /// Useful because some platforms (osx, bsd) only want up to DWARF2.
     pub default_dwarf_version: u32,
@@ -1671,6 +1673,7 @@ impl Default for TargetOptions {
             is_like_windows: false,
             is_like_msvc: false,
             is_like_wasm: false,
+            is_like_android: false,
             default_dwarf_version: 4,
             allows_weak_linkage: true,
             has_rpath: false,
@@ -2318,6 +2321,7 @@ impl Target {
         key!(is_like_windows, bool);
         key!(is_like_msvc, bool);
         key!(is_like_wasm, bool);
+        key!(is_like_android, bool);
         key!(default_dwarf_version, u32);
         key!(allows_weak_linkage, bool);
         key!(has_rpath, bool);
@@ -2568,6 +2572,7 @@ impl ToJson for Target {
         target_option_val!(is_like_windows);
         target_option_val!(is_like_msvc);
         target_option_val!(is_like_wasm);
+        target_option_val!(is_like_android);
         target_option_val!(default_dwarf_version);
         target_option_val!(allows_weak_linkage);
         target_option_val!(has_rpath);

src/tools/compiletest/src/util.rs

@@ -11,9 +11,15 @@ mod tests;
 pub const ASAN_SUPPORTED_TARGETS: &[&str] = &[
     "aarch64-apple-darwin",
     "aarch64-fuchsia",
+    "aarch64-linux-android",
     "aarch64-unknown-linux-gnu",
+    "arm-linux-androideabi",
+    "armv7-linux-androideabi",
+    "i686-linux-android",
+    "i686-unknown-linux-gnu",
     "x86_64-apple-darwin",
     "x86_64-fuchsia",
+    "x86_64-linux-android",
     "x86_64-unknown-freebsd",
     "x86_64-unknown-linux-gnu",
 ];