Re: [PATCH][PR91749][arm] FDPIC: Handle -mflip-thumb

[Ramana Radhakrishnan]

On Mon, Sep 16, 2019 at 2:40 PM Christophe Lyon
 wrote:
>
> [Re-sending in plain text-mode, sorry for the duplicates]
>
> Hi,
>
> In PR91749, we have ICEs because -mflip-thumb switches to Thumb-1 (the
> default target cpu does not support Thumb-2).
>
> Although we already filter this in arm_configure_build_target, we
> forgot to handle cases when the mode is changed via attributes (either
> in the source code, or via -mflip-thumb).
>
> This patch adds the same error message when trying to apply the
> "thumb" attribute and the target does not support Thumb-2 (only if we
> are in FDPIC mode, of course).
>
> OK?

OK.

Ramana
>
> Thanks,
>
> Christophe

[PATCH][PR91749][arm] FDPIC: Handle -mflip-thumb

[Christophe Lyon]

[Re-sending in plain text-mode, sorry for the duplicates]

Hi,

In PR91749, we have ICEs because -mflip-thumb switches to Thumb-1 (the
default target cpu does not support Thumb-2).

Although we already filter this in arm_configure_build_target, we
forgot to handle cases when the mode is changed via attributes (either
in the source code, or via -mflip-thumb).

This patch adds the same error message when trying to apply the
"thumb" attribute and the target does not support Thumb-2 (only if we
are in FDPIC mode, of course).

OK?

Thanks,

Christophe
gcc/ChangeLog:

2019-09-16  Christophe Lyon  

PR target/91749
* config/arm/arm.c (arm_valid_target_attribute_rec): Make sure the
mode attributed is supported by FDPIC.

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index c452771..ceabe0a 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -31175,7 +31175,11 @@ arm_valid_target_attribute_rec (tree args, struct 
gcc_options *opts)
 {
   argstr = NULL;
   if (!strcmp (q, "thumb"))
-   opts->x_target_flags |= MASK_THUMB;
+   {
+ opts->x_target_flags |= MASK_THUMB;
+ if (TARGET_FDPIC && !arm_arch_thumb2)
+   sorry ("FDPIC mode is not supported in Thumb-1 mode");
+   }
 
   else if (!strcmp (q, "arm"))
opts->x_target_flags &= ~MASK_THUMB;