Don't force -pie for Android.

[danalbert]

Summary

There is no -no-pie flag that can override this, so making it default
to being on for Android means it is no longer possible to create
non-PIE executables on Android. While current versions of Android
support (and the most recent requires) PIE, ICS and earlier versions
of Android cannot run PIE executables, so this needs to be optional.

[danalbert]

Alexey: you introduced this behavior in http://reviews.llvm.org/D2668

IMO it's the build system's job to pass -pie for Android, not the driver's. If this really needs to be in the driver then it needs to be guarded to only be forced on if LTO is being used.

[srhines]

Looks good (and fixes the past release problem).

[thakis]

Thanks, this caused us grief at some point too. I think if you pass -Bsymbolic, -pie gets disabled (?), so iirc I saw a target that passed -Bsymbolic just to get rid of -pie. (My memory is hazy, but I'm sure that I wanted to remove this behavior at some point.)

lib/Driver/Tools.cpp

void gnutools::Link::ConstructJob(Compilation &C, const JobAction &JA,
   const toolchains::Linux& ToolChain =
     static_cast<const toolchains::Linux&>(getToolChain());
   const Driver &D = ToolChain.getDriver();
   const bool isAndroid =
     ToolChain.getTriple().getEnvironment() == llvm::Triple::Android;
   const bool IsPIE =
     !Args.hasArg(options::OPT_shared) &&
     !Args.hasArg(options::OPT_static) &&
-    (Args.hasArg(options::OPT_pie) || ToolChain.isPIEDefault() ||
-     // On Android every code is PIC so every executable is PIE
-     // Cannot use isPIEDefault here since otherwise
-     // PIE only logic will be enabled during compilation
-     isAndroid);
+    (Args.hasArg(options::OPT_pie) || ToolChain.isPIEDefault());
 
   ArgStringList CmdArgs;
 
   // Silence warning for "clang -g foo.o -o foo"
   Args.ClaimAllArgs(options::OPT_g_Group);
   // and "clang -emit-llvm foo.o -o foo"
   Args.ClaimAllArgs(options::OPT_emit_llvm);
   // and for "clang -w foo.o -o foo". Other warning options are already

test/Driver/gold-lto.c

 // RUN:     -march=armv7a -Wl,-plugin-opt=foo \
 // RUN:     | FileCheck %s --check-prefix=CHECK-ARM-V7A
 // CHECK-ARM-V7A: "-plugin" "{{.*}}/LLVMgold.so"
 // CHECK-ARM-V7A: "-plugin-opt=mcpu=cortex-a8"
 // CHECK-ARM-V7A: "-plugin-opt=foo"
 //
 // RUN: %clang -target i686-linux-android -### %t.o -flto 2>&1 \
 // RUN:     | FileCheck %s --check-prefix=CHECK-X86-ANDROID
-// CHECK-X86-ANDROID: "-pie"
 // CHECK-X86-ANDROID: "-plugin" "{{.*}}/LLVMgold.so"

test/Driver/linux-ld.c

 // CHECK-ANDROID-PIE: "{{.*}}{{/|\\\\}}crtbegin_dynamic.o"
 // CHECK-ANDROID-PIE: "-L[[SYSROOT]]/usr/lib"
 // CHECK-ANDROID-PIE-NOT: "gcc_s"
 // CHECK-ANDROID-PIE: "-lgcc"
 // CHECK-ANDROID-PIE-NOT: "gcc_s"
 // CHECK-ANDROID-PIE: "{{.*}}{{/|\\\\}}crtend_android.o"
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
 // RUN:     --target=arm-linux-androideabi \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=arm-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=aarch64-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=arm64-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=mipsel-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=mips64el-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=i686-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=x86_64-linux-android \
+// RUN:   | FileCheck --check-prefix=CHECK-ANDROID-NO-DEFAULT-PIE %s
+// CHECK-ANDROID-NO-DEFAULT-PIE-NOT: -pie
+// RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
+// RUN:     --target=arm-linux-androideabi \
 // RUN:     --gcc-toolchain="" \
 // RUN:     --sysroot=%S/Inputs/basic_android_tree/sysroot \
 // RUN:   | FileCheck --check-prefix=CHECK-ANDROID-32 %s
 // RUN: %clang -no-canonical-prefixes %s -### -o %t.o 2>&1 \
 // RUN:     --target=arm-linux-android \
 // RUN:     --gcc-toolchain="" \
 // RUN:     --sysroot=%S/Inputs/basic_android_tree/sysroot \
 // RUN:   | FileCheck --check-prefix=CHECK-ANDROID-32 %s