[Buildroot] [PATCH v2 07/14] toolchain/toolchain-external: add BR2_TOOLCHAIN_EXTERNAL_HAS_NO_GDBSERVER option

[Thomas Petazzoni]

Some external toolchains do not have gdbserver available, but the
option BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY is always visible. And
when enabled, this option aborts with an error when gdbserver cannot
be found:

  Could not find gdbserver in external toolchain

Due to that, some random configurations fail to build when
BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY=y, for example with the Bootlin
toolchains for Microblaze or OpenRISC (because there's no GDB support
for those architectures).

One solution could be to make "Could not find gdbserver in external
toolchain" a warning instead of a hard error, but then nobody would
notice about this issue, in cases where it should legitimately abort
with a hard error.

So, the clean solution would be to add a
BR2_TOOLCHAIN_EXTERNAL_HAS_GDBSERVER. But that means all existing
external toolchains would have to be modified to select this option.

Instead, and as an exception, we chose to use inverted logic, and
create an option that is the opposite:
BR2_TOOLCHAIN_EXTERNAL_HAS_NO_GDBSERVER. By default, we assume
external toolchains have gdbserver. If
BR2_TOOLCHAIN_EXTERNAL_HAS_NO_GDBSERVER is enabled, we disallow the
BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY option.

Note that the case of custom external toolchain does not matter: by
definition they are not tested by the autobuilders, and by definition,
we cannot now in menuconfig if the custom toolchain has or does not
have gdbserver.

This will help fixing:

  http://autobuild.buildroot.net/results/6315ef7b66ee4ae8f870c92186bc674d65f62f2c/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
---
Note: if you want me to go with the positive logic option
BR2_TOOLCHAIN_EXTERNAL_HAS_GDBSERVER, I'll be happy to provide the
patches.
---
 toolchain/toolchain-external/Config.in | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/toolchain/toolchain-external/Config.in b/toolchain/toolchain-external/Config.in
index 2177e6a678..1a67e5645f 100644
--- a/toolchain/toolchain-external/Config.in
+++ b/toolchain/toolchain-external/Config.in
@@ -155,9 +155,13 @@ source "toolchain/toolchain-external/toolchain-external-bootlin/Config.in.option
 # Custom toolchains
 source "toolchain/toolchain-external/toolchain-external-custom/Config.in.options"
 
+config BR2_TOOLCHAIN_EXTERNAL_HAS_NO_GDBSERVER
+	bool
+
 config BR2_TOOLCHAIN_EXTERNAL_GDB_SERVER_COPY
 	bool "Copy gdb server to the Target"
 	depends on BR2_TOOLCHAIN_EXTERNAL
+	depends on !BR2_TOOLCHAIN_EXTERNAL_HAS_NO_GDBSERVER
 	help
 	  Copy the gdbserver provided by the external toolchain to the
 	  target.
-- 
2.35.3