[patch,avr]: Part2: Fix various problems with specs and specs file generation.

[Georg-Johann Lay]

Am 04/06/2015 um 11:54 AM schrieb Sivanupandi, Pitchumani:
> Hi Johann,
>
> Did you try running g++ tests?
> It seems xgcc is invoked to get multilibs (from gcc/testsuite/lib/g++.exp) which failed to find specs file.


This is because libgloss.exp:get_multilibs (used from g++_init) runs xgcc 
($compiler) without -B, i.e. without any prefix.  Without prefix there is no 
way to determine where the specs files are located.

Patching driver_self_specs to read a specs file by means of -specs= is, well, 
not very common.  I don't know any other target which does that.

As a work-around you can run the tests against the installed compiler.

Denis, what do you think?  I could add yet another fixme to avr backend like 
the following; that way there's no need to change dejagnu:


Johann

Index: config/avr/driver-avr.c
===================================================================
--- config/avr/driver-avr.c     (revision 221602)
+++ config/avr/driver-avr.c     (working copy)
@@ -80,6 +80,20 @@ avr_devicespecs_file (int argc, const ch
        return X_NODEVLIB;

      case 1:
+      if (0 == strcmp ("device-specs", argv[0]))
+        {
+          /* FIXME:  This means "device-specs%s" from avr.h:DRIVER_SELF_SPECS
+             has not been resolved to a path.  That case can occur when the
+             c++ testsuite is run from the build directory.  DejaGNU's
+             libgloss.exp:get_multilibs runs $compiler without -B, i.e.runs
+             xgcc without specifying a prefix.  Without any prefix, there is
+             no means to find out where the specs files might be located.
+             get_multilibs runs xgcc --print-multi-lib, hence we don't
+             actually need information form a specs file and may skip it
+             altogether.  */
+          return X_NODEVLIB;
+        }
+
        mmcu = AVR_MMCU_DEFAULT;
        break;

g