[PATCH v2 3/3] target: Wrap linker flags into `-largs'/`-margs' for Ada

[Maciej W. Rozycki]

Unrecognized `gnatmake' switches are not implicitly passed on to the 
linker, so just pasting board `ldflags' and any other linker flags 
verbatim into `add_flags' to use for the invocation line of `gnatmake' 
will make them ignored at best.

For example in a GCC test environment that has:

set_board_info ldflags 
"-Wl,-dynamic-linker,.../sysroot/lib/ld-linux-riscv64-lp64d.so.1 
-Wl,-rpath,.../sysroot/lib64/lp64d -Wl,-rpath,.../sysroot/usr/lib64/lp64d"

so that sysroot paths are correctly embedded with the binaries linked 
for use with the dynamic loader and shared library dependencies, the 
setting will be ignored for the GNAT test suite making all the execution 
tests fail, e.g.:

PASS: gnat.dg/abstract_with_anonymous_result.adb (test for excess errors)
spawn qemu-riscv64 ./abstract_with_anonymous_result.exe
/lib/ld-linux-riscv64-lp64d.so.1: No such file or directory
FAIL: gnat.dg/abstract_with_anonymous_result.adb execution test

For `gnatmake' to pass switches on to the linker the `-largs' switch has 
to be used, which affects all the switches that follow until a switch is 
seen that changes the selection, like `-margs', which resets to the 
initial state of the switch interpretation machine.

Wrap linker flags into `-largs'/`-margs' for Ada then, carefully 
preserving the place these flags are placed within `add_flags', as 
surely someone will have depended on that, correcting test failures like 
above:

PASS: gnat.dg/abstract_with_anonymous_result.adb (test for excess errors)
spawn qemu-riscv64 ./abstract_with_anonymous_result.exe
PASS: gnat.dg/abstract_with_anonymous_result.adb execution test

and progressing GCC 10 gnat testsuite user mode QEMU emulation results 
from:

                === gnat Summary ===

# of expected passes            2179
# of unexpected failures        719
# of expected failures          23
# of unsupported tests          28

to:

                === gnat Summary ===

# of expected passes            3235
# of unexpected failures        6
# of expected failures          23
# of unsupported tests          28

with the `riscv64-linux-gnu' target and the `x86_64-linux-gnu' host.


        * lib/target.exp (default_target_compile): Wrap linker flags into 
        `-largs'/`-margs' for Ada.

Signed-off-by: Maciej W. Rozycki <address@hidden>
---
Hi,

 This is a repost of a change originally proposed as a part of a series: 
<https://lists.gnu.org/archive/html/dejagnu/2019-05/msg00001.html> for an 
issue where additional linker flags are defined in the target board have 
not been correctly passed to `gnatmake'.  The GCC pieces of the series 
have all been since included upstream.

 Jacob, please let me know if you want this issue resolved differently.

 Otherwise, Rob, please apply this change.

  Maciej 

Changes from v1:

- commit description updated with test results now that complementing GCC 
  changes went upstream.
---
 lib/target.exp |   24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

dejagnu-target-ada-ldflags.diff
Index: dejagnu/lib/target.exp
===================================================================
--- dejagnu.orig/lib/target.exp
+++ dejagnu/lib/target.exp
@@ -518,11 +518,12 @@ proc default_target_compile {source dest
     }
 
     if { $type eq "executable" } {
+       set extra_ldflags ""
        if {[board_info $dest exists ldflags]} {
-           append add_flags " [board_info $dest ldflags]"
+           append extra_ldflags " [board_info $dest ldflags]"
        }
        if { $compiler_type eq "c++" } {
-           append add_flags " [g++_link_flags]"
+           append extra_ldflags " [g++_link_flags]"
        }
        if {[isnative]} {
            # This is a lose.
@@ -530,16 +531,23 @@ proc default_target_compile {source dest
            if { $tmp ne "" } {
                if {[regexp ".*solaris2.*" $target_triplet]} {
                    # Solaris 2
-                   append add_flags " -R$tool_root_dir/libstdc++"
+                   append extra_ldflags " -R$tool_root_dir/libstdc++"
                } elseif {[regexp ".*(osf|irix5|linux).*" $target_triplet]} {
                    # OSF/1 or IRIX 5
-                   append add_flags " -Wl,-rpath,$tool_root_dir/libstdc++"
+                   append extra_ldflags " -Wl,-rpath,$tool_root_dir/libstdc++"
                } elseif {[regexp ".*hppa.*" $target_triplet]} {
                    # HP-UX
-                   append add_flags " -Wl,-a,shared_archive"
+                   append extra_ldflags " -Wl,-a,shared_archive"
                }
            }
        }
+       if { $extra_ldflags ne "" } {
+           if { $compiler_type eq "ada" } {
+               append add_flags " -largs $extra_ldflags -margs"
+           } else {
+               append add_flags " $extra_ldflags"
+           }
+       }
     }
 
     if {![info exists ldscript]} {
@@ -561,7 +569,11 @@ proc default_target_compile {source dest
     }
 
     if { $type eq "executable" } {
-       append add_flags " $ldflags"
+       if { $compiler_type eq "ada" } {
+           append add_flags " -largs $ldflags -margs"
+       } else {
+           append add_flags " $ldflags"
+       }
        foreach x $libs {
            if {[file exists $x]} {
                append source " $x"