[Driver] Default arm-linux-androideabi to -z max-page-size=4096

[MaskRay]

Summary

Similar to D55029. The requirement arises when discussing increasing
default max-page-size for lld ARM (D77330).

For the record, the default max-page-size on the 3 commonly used linkers:

• GNU ld since

https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89
defaults to 65536

• GNU gold remains 4096
• lld currently uses 4096 but may increase to 65536 (D77330)

[srhines]

Thank you for making this clear.

[thieta]

Thanks for handling this!

[MaskRay]

Clarify a comment

clang/lib/Driver/ToolChains/Linux.cpp

Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
   }
 
   if (Distro.IsOpenSUSE() || Distro.IsUbuntu() || Distro.IsAlpineLinux() ||
       Triple.isAndroid()) {
     ExtraOpts.push_back("-z");
     ExtraOpts.push_back("relro");
   }
 
-  // The lld default page size is too large for Aarch64, which produces much
-  // larger .so files and images for arm64 device targets. Use 4KB page size
-  // for Android arm64 targets instead.
-  if (Triple.isAArch64() && Triple.isAndroid()) {
+  // Android ARM/AArch64 use max-page-size=4096 to reduce VMA usage. Note, lld
+  // from 11 onwards default max-page-size to 65536 for both ARM and AArch64.
+  if ((Triple.isARM() || Triple.isAArch64()) && Triple.isAndroid()) {
     ExtraOpts.push_back("-z");
     ExtraOpts.push_back("max-page-size=4096");
   }
 
   if (GCCInstallation.getParentLibPath().find("opt/rh/devtoolset") !=
       StringRef::npos)
     // With devtoolset on RHEL, we want to add a bin directory that is relative
     // to the detected gcc install, because if we are using devtoolset gcc then

clang/test/Driver/android-link.cpp

-// Check that we automatically add relevant linker flags for Android aarch64.
+// Check that we add relevant linker flags for Android ARM/AArch64.
+
+// RUN: %clang -### -target arm-linux-androideabi %s 2>&1 | \
+// RUN:   FileCheck --check-prefix=MAX-PAGE-SIZE %s
 
 // RUN: %clang -target aarch64-none-linux-android \
 // RUN:   -### -v %s 2> %t
 // RUN: FileCheck -check-prefix=GENERIC-ARM < %t %s
 //
 // RUN: %clang -target aarch64-none-linux-android \
 // RUN:   -mcpu=cortex-a53 -### -v %s 2> %t
 // RUN: FileCheck -check-prefix=CORTEX-A53 < %t %s
 //
 // RUN: %clang -target aarch64-none-linux-android \
 // RUN:   -mcpu=cortex-a57 -### -v %s 2> %t
 // RUN: FileCheck -check-prefix=CORTEX-A57 < %t %s
 //
 // RUN: %clang -target aarch64-none-linux-android \
 // RUN:   -### -v %s 2> %t
 // RUN: FileCheck -check-prefix=MAX-PAGE-SIZE < %t %s
 //
 // GENERIC-ARM: --fix-cortex-a53-843419
 // CORTEX-A53: --fix-cortex-a53-843419
 // CORTEX-A57-NOT: --fix-cortex-a53-843419
-// MAX-PAGE-SIZE: max-page-size=4096
+// MAX-PAGE-SIZE: "-z" "max-page-size=4096"