Re: [testsuite] PATCH: Add check_effective_target_pie

[H.J. Lu]

On Mon, Jan 12, 2015 at 03:04:20PM -0700, Jeff Law wrote:
> On 01/12/15 14:51, Magnus Granberg wrote:
> >måndag 12 januari 2015 12.11.17 skrev  H.J. Lu:
> >>On Mon, Jan 12, 2015 at 12:03 PM, Jeff Law <l...@redhat.com> wrote:
> >>>On 01/12/15 12:59, H.J. Lu wrote:
> >>>>I don't know if -pg will work PIE on any targets.  For Linux/x86
> >>>>the choices of crt1.o are
> >>>>
> >>>>%{!shared: %{pg|p|profile:gcrt1.o%s;pie:Scrt1.o%s;:crt1.o%s}}
> >>>>
> >>>>-shared, -pg and -pie are mutually exclusive. Those crt1 files are
> >>>>only crt1 files provided by glibc.  You can't even try -pg -pie on
> >>>>Linux without changing glibc.
> >>>
> >>>You're totally missing the point.  What I care about is *why*.
> >>>
> >With -pg it use gcrt1.o object file and that file is not compile with -fPIC.
> >When you build a shared lib on x86_64 all the objects files need to be buiit
> >with -fPIC else you get a error like that one abow and it is the same 
> >problems
> >when you build bin with -fPIE and linke with -pie.
> >Glibc do not provide one that is compile with -fPIC
> Is there some reason why glibc could not provide gcrt1.o compiled with
> -fPIC?

That is a good question. We can compile gcrt1.o with -fPIC and it will
work with both -pg and -pg -pie.  I will open a glibc bug.

Here is the updated patch without the check_profiling_available change.
OK for trunk?

Thanks.

H.J.
---
Subject: [PATCH 1/5] Add check_effective_target_pie

Hi,

This patch adds check_effective_target_pie to check if the current
multilib generates PIE by default.

Thanks.

H.J.
---
2015-01-11  H.J. Lu  <hongjiu...@intel.com>

        * gcc.target/i386/pie.c: New test.

        * lib/target-supports.exp (check_effective_target_pie): New.
---
 gcc/testsuite/gcc.target/i386/pie.c   | 12 ++++++++++++
 gcc/testsuite/lib/target-supports.exp | 10 ++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/i386/pie.c

diff --git a/gcc/testsuite/gcc.target/i386/pie.c 
b/gcc/testsuite/gcc.target/i386/pie.c
new file mode 100644
index 0000000..0a9f5ee
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pie.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target pie } } */
+/* { dg-options "-O2" } */
+
+int foo (void);
+
+int
+main (void)
+{
+  return foo ();
+}
+
+/* { dg-final { scan-assembler "foo@PLT" } } */
diff --git a/gcc/testsuite/lib/target-supports.exp 
b/gcc/testsuite/lib/target-supports.exp
index f5c6db8..0ac9646 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -1080,6 +1080,16 @@ proc check_effective_target_nonpic { } {
     }]
 }
 
+# Return 1 if the current multilib generates PIE by default.
+
+proc check_effective_target_pie { } {
+    return [check_no_compiler_messages pie assembly {
+       #ifndef __PIE__
+       #error unsupported
+       #endif
+    }]
+}
+
 # Return 1 if the target does not use a status wrapper.
 
 proc check_effective_target_unwrapped { } {
-- 
1.9.3