616057 - Rebuild Android NDK v5 with PIC

Status: RESOLVED INVALID

(Release Engineering :: General, defect)

Description

[Michael Wu [:mwu]]

I'd like to get the NDK rebuilt with -fPIC so we can remove most of the text relocations in the libraries we build on Android. Text relocations slow down startup and increase memory usage.

I basically did this to get it building with -fPIC:

--- a/build/tools/patches/005-flags.patch
+++ b/build/tools/patches/005-flags.patch
@@ -6,8 +6,8 @@ index 670b620..06c95e9 100644
  LDFLAGS_FOR_TARGET=-mandroid
  
  CFLAGS_FOR_TARGET+= -DANDROID -D__ANDROID__
-+CFLAGS_FOR_TARGET+= -fexceptions
-+CXXFLAGS_FOR_TARGET+= -frtti
++CFLAGS_FOR_TARGET+= -fexceptions -fPIC
++CXXFLAGS_FOR_TARGET+= -frtti -fPIC
  
  # Helper
  prefix-list = $(foreach e, $(2), $(join $1, $e))

I followed the latest instructions on the crystax site to build it. (which are a little different now.. the source pulling part pulls code from a specific date now)

Comment 2

[Mark Finkle (:mfinkle) (use needinfo?)]

From bug 646843:

Mike Hommey [:glandium]:

Currently libgcc.a and libstdc++.a are not built as PIC. From my experiments,
this should get us between 2 and 5% less time spent before main(), provided bug
646815 is fixed as well.

Comment 3

[Mark Finkle (:mfinkle) (use needinfo?)]

Bear - What's the status here?

Comment 4

[Mike Taylor [:bear]]

(In reply to comment #3)
> Bear - What's the status here?

it's on my task list.  right now i'm buildduty and will get back to it after buildduty.

Comment 5

[Chris Cooper [:coop] (he/him)]

Bear is working on deploying the r5 NDK via puppet right now (Bug 657723). Once that's done, we'll revisit this bug and re-compile r5 with -fPIC.

Comment 6

[Mike Hommey [:glandium]]

From bug 646843:

From my experiments, all that is needed is to add --with-pic as a compile option to gcc (which I did through build/tools/build-gcc.sh), and add -fPIC to libgcc config options (which I did through the TARGET_LIBGCC2_CFLAGS variable in src/gcc/gcc-4.4.0/gcc/config/arm/t-arm-softfp, though there's probably a better place)

Comment 7

[Mike Taylor [:bear]]

edited bug title to be very clear that we will be compiling only the r5 NDK with -fPIC support

Comment 8

[Benjamin Stover (:stechz)]

glandium noted in IRC that PIC support may already be in NDK5.

Comment 9

[Mike Taylor [:bear]]

yep, good catch - according to

http://groups.google.com/group/android-ndk/browse_thread/thread/9fd148aa92a6fab6

PIC is available and enabled by default with NDK5