[flang][Driver] Enable -pie and -no-pie in flang's driver

[tarunprabhu]

Passing -pie to flang will pass the flag on to the linker. Passing -no-pie will ensure that -pie is not passed to the linker. This behavior is consistent with both clang and gfortran.

Fixes #159970

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-flang-driver

Author: Tarun Prabhu (tarunprabhu)

Changes

Passing -pie to flang will pass the flag on to the linker. Passing -no-pie will ensure that -pie is not passed to the linker. This behavior is consistent with both clang and gfortran.

Fixes #159970

---

Full diff: https://github.com/llvm/llvm-project/pull/164890.diff

2 Files Affected:

• (modified) clang/include/clang/Driver/Options.td (+2-2)
• (modified) flang/test/Driver/misc-flags.f90 (+10)

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 0c9584f1b479f..40ca2f9717d55 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -5999,7 +5999,6 @@ def nofixprebinding : Flag<["-"], "nofixprebinding">;
 def nolibc : Flag<["-"], "nolibc">;
 def nomultidefs : Flag<["-"], "nomultidefs">;
 def nopie : Flag<["-"], "nopie">, Visibility<[ClangOption, FlangOption]>, Flags<[TargetSpecific]>; // OpenBSD
-def no_pie : Flag<["-"], "no-pie">, Visibility<[ClangOption, FlangOption]>;
 def noprebind : Flag<["-"], "noprebind">;
 def noprofilelib : Flag<["-"], "noprofilelib">;
 def noseglinkedit : Flag<["-"], "noseglinkedit">;
@@ -6113,7 +6112,6 @@ defm pthread : BoolOption<"", "pthread",
   PosFlag<SetTrue, [], [ClangOption], "Support POSIX threads in generated code">,
   NegFlag<SetFalse>,
   BothFlags<[], [ClangOption, CC1Option, FlangOption, FC1Option]>>;
-def pie : Flag<["-"], "pie">, Group<Link_Group>;
 def static_pie : Flag<["-"], "static-pie">, Group<Link_Group>;
 def read__only__relocs : Separate<["-"], "read_only_relocs">;
 def remap : Flag<["-"], "remap">;
@@ -6508,6 +6506,8 @@ def fpic : Flag<["-"], "fpic">, Group<f_Group>;
 def fno_pic : Flag<["-"], "fno-pic">, Group<f_Group>;
 def fpie : Flag<["-"], "fpie">, Group<f_Group>;
 def fno_pie : Flag<["-"], "fno-pie">, Group<f_Group>;
+def pie : Flag<["-"], "pie">, Group<Link_Group>;
+def no_pie : Flag<["-"], "no-pie">;
 
 } // let Vis = [Default, FlangOption]
 
diff --git a/flang/test/Driver/misc-flags.f90 b/flang/test/Driver/misc-flags.f90
index 61d763c5b64dd..e594c9cb50517 100644
--- a/flang/test/Driver/misc-flags.f90
+++ b/flang/test/Driver/misc-flags.f90
@@ -10,6 +10,16 @@
 ! Make sure that `-L' is "visible" to Flang's driver
 ! RUN: %flang -L/ -### %s
 
+! Check that '-pie' is "visible" to Flang's driver and is passed on to the
+! linker.
+! RUN: %flang -pie -### %s 2>&1 | FileCheck %s --check-prefix=PIE
+! PIE: "-pie"
+
+! Check that '-no-pie' is "visible" to Flang's driver and that "-pie" is *not*
+! passed to the linker.
+! RUN: %flang -no-pie -### %s 2>&1 | FileCheck %s --check-prefix=NO-PIE
+! NO-PIE-NOT: "-pie"
+
 program hello
   write(*,*), "Hello world!"
 end program hello

[MaskRay]

Add Group<Link_Group>

[tarunprabhu]

Per @MaskRay's comment, I have changed the name of flang/test/Driver/misc-flags.f90 to flang/test/Driver/linker-options.f90. There is another test in flang/test/Driver named linker-flags.f90. Looking at the contents of that file, I think renaming it link-libs.f90 would be good. However, since that is unrelated, it is not done in this PR.

[kiranchandramohan]

LG.

[kiranchandramohan]

LG

[tarunprabhu]

Following investigation of the failure of pre-merge CI, I found that the tests were likely to fail on certain platforms. A number of tests have been added that check the behavior of -pie on various platforms.

@DavidTruby, could you take a look at the Windows tests and see if they look reasonable? They pass for me, but I want to be certain that I have not made any bad assumptions.

@DanielCChen, @kkwli, could you do the same for AIX?

[DanielCChen]

Following investigation of the failure of pre-merge CI, I found that the tests were likely to fail on certain platforms. A number of tests have been added that check the behavior of -pie on various platforms.

@DavidTruby, could you take a look at the Windows tests and see if they look reasonable? They pass for me, but I want to be certain that I have not made any bad assumptions.

@DanielCChen, @kkwli, could you do the same for AIX?

I got error when applying the patch as

> git apply ~/temp/164890.patch
error: patch failed: flang/test/Driver/linker-options.f90:10
error: flang/test/Driver/linker-options.f90: patch does not apply
error: patch failed: flang/test/Driver/linker-options.f90:10
error: flang/test/Driver/linker-options.f90: patch does not apply

Even though flang/test/Driver/misc-flags.f90 is deleted, it still showed up in the patch.

index 61d763c5b64dd..e594c9cb50517 100644
--- a/flang/test/Driver/misc-flags.f90
+++ b/flang/test/Driver/misc-flags.f90
@@ -10,6 +10,16 @@
 ! Make sure that `-L' is "visible" to Flang's driver
 ! RUN: %flang -L/ -### %s

+! Check that '-pie' is "visible" to Flang's driver and is passed on to the
+! linker.
+! RUN: %flang -pie -### %s 2>&1 | FileCheck %s --check-prefix=PIE
+! PIE: "-pie"
+
+! Check that '-no-pie' is "visible" to Flang's driver and that "-pie" is *not*
+! passed to the linker.
+! RUN: %flang -no-pie -### %s 2>&1 | FileCheck %s --check-prefix=NO-PIE
+! NO-PIE-NOT: "-pie"
+
 program hello
   write(*,*), "Hello world!"

[DanielCChen]

The test passed on Both AIX and LoP.
Thanks.

[tarunprabhu]

The test passed on Both AIX and LoP. Thanks.

Thanks for checking Daniel. And apologies for not responding to your first question about the patch not applying. I got tangled up with other things.

[DavidTruby]

LGTM