Lower the default dwarf version for android

Author: ejjeong

src/librustc_back/target/aarch64_linux_android.rs

@@ -13,6 +13,7 @@ use target::Target;
 pub fn target() -> Target {
     let mut base = super::linux_base::opts();
     base.pre_link_args.push("-Wl,--allow-multiple-definition".to_string());
+    base.is_like_android = true;
     base.position_independent_executables = true;
     Target {
         data_layout: "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-\

src/librustc_back/target/arm_linux_androideabi.rs

@@ -16,6 +16,7 @@ pub fn target() -> Target {
     // Many of the symbols defined in compiler-rt are also defined in libgcc.  Android
     // linker doesn't like that by default.
     base.pre_link_args.push("-Wl,--allow-multiple-definition".to_string());
+    base.is_like_android = true;
     // FIXME #17437 (and #17448): Android doesn't support position dependent executables anymore.
     base.position_independent_executables = false;
 

src/librustc_back/target/mod.rs

@@ -158,6 +158,9 @@ pub struct TargetOptions {
     /// only realy used for figuring out how to find libraries, since Windows uses its own
     /// library naming convention. Defaults to false.
     pub is_like_windows: bool,
+    /// Whether the target toolchain is like Android's. Only useful for compiling against Android.
+    /// Defaults to false.
+    pub is_like_android: bool,
     /// Whether the linker support GNU-like arguments such as -O. Defaults to false.
     pub linker_is_gnu: bool,
     /// Whether the linker support rpaths or not. Defaults to false.
@@ -197,6 +200,7 @@ impl Default for TargetOptions {
             staticlib_suffix: ".a".to_string(),
             is_like_osx: false,
             is_like_windows: false,
+            is_like_android: false,
             linker_is_gnu: false,
             has_rpath: false,
             no_compiler_rt: false,

src/librustc_trans/trans/debuginfo.rs

@@ -736,7 +736,9 @@ pub fn finalize(cx: &CrateContext) {
         // instruct LLVM to emit an older version of dwarf, however,
         // for OS X to understand. For more info see #11352
         // This can be overridden using --llvm-opts -dwarf-version,N.
-        if cx.sess().target.target.options.is_like_osx {
+        // Android has the same issue (#22398)
+        if cx.sess().target.target.options.is_like_osx ||
+           cx.sess().target.target.options.is_like_android {
             llvm::LLVMRustAddModuleFlag(cx.llmod(),
                                         "Dwarf Version\0".as_ptr() as *const _,
                                         2)