[PATCH] tests: Build correct sandbox configuration on 32bit

[Michal Suchanek]

Currently sandbox configuration defautls to 64bit and there is no
automation for building 32bit sandbox on 32bit hosts.

cpp does not know about target specification, code needs to be compiled
to determine integer width.

Add a test program that prints the integer width, and a make target that
aligns the sandbox configuration with the result.

Signed-off-by: Michal Suchanek <msuchanek at suse.de>
---

 Makefile              |  6 ++++++
 doc/arch/sandbox.rst  | 16 +++++++++++-----
 test/py/conftest.py   |  1 +
 tools/Makefile        |  2 ++
 tools/bits-per-long.c | 14 ++++++++++++++
 5 files changed, 34 insertions(+), 5 deletions(-)
 create mode 100644 tools/bits-per-long.c

diff --git a/Makefile b/Makefile
index 3866cc62f9..e5463573f3 100644
--- a/Makefile
+++ b/Makefile
@@ -2166,6 +2166,12 @@ tools-all: envtools tools ;
 cross_tools: export CROSS_BUILD_TOOLS=y
 cross_tools: tools ;
 
+PHONY += set_host_bits
+set_host_bits: tools
+	$(Q)sed -i -e /CONFIG_HOST_$$($(objtree)/tools/bits-per-long)BIT/d $(KCONFIG_CONFIG)
+	$(Q)sed -i -E -e "s/CONFIG_HOST_(..)BIT=y/# CONFIG_HOST_\1BIT is not set/" $(KCONFIG_CONFIG)
+	$(Q)echo CONFIG_HOST_$$($(objtree)/tools/bits-per-long)BIT=y >> $(KCONFIG_CONFIG)
+
 .PHONY : CHANGELOG
 CHANGELOG:
 	git log --no-merges U-Boot-1_1_5.. | \
diff --git a/doc/arch/sandbox.rst b/doc/arch/sandbox.rst
index 068d4a3be4..d751205eba 100644
--- a/doc/arch/sandbox.rst
+++ b/doc/arch/sandbox.rst
@@ -33,9 +33,11 @@ machines.
 
 There are two versions of the sandbox: One using 32-bit-wide integers, and one
 using 64-bit-wide integers. The 32-bit version can be build and run on either
-32 or 64-bit hosts by either selecting or deselecting CONFIG_SANDBOX_32BIT; by
-default, the sandbox it built for a 32-bit host. The sandbox using 64-bit-wide
-integers can only be built on 64-bit hosts.
+32 or 64-bit hosts by either selecting or deselecting HOST_64BIT; by
+default, the sandbox it built for a 64-bit host. The sandbox using 64-bit-wide
+integers can only be built on 64-bit hosts. There is no automation for ensuring
+32bit build on 32bit hosts - use ``make set_host_bits`` to adjust the sandbox
+config.
 
 Note that standalone/API support is not available at present.
 
@@ -51,7 +53,9 @@ Basic Operation
 
 To run sandbox U-Boot use something like::
 
-   make sandbox_defconfig all
+   make sandbox_defconfig
+   make set_host_bits
+   make all
    ./u-boot
 
 Note: If you get errors about 'sdl-config: Command not found' you may need to
@@ -59,7 +63,9 @@ install libsdl2.0-dev or similar to get SDL support. Alternatively you can
 build sandbox without SDL (i.e. no display/keyboard support) by removing
 the CONFIG_SANDBOX_SDL line in include/configs/sandbox.h or using::
 
-   make sandbox_defconfig all NO_SDL=1
+   make sandbox_defconfig
+   make set_host_bits
+   make all NO_SDL=1
    ./u-boot
 
 U-Boot will start on your computer, showing a sandbox emulation of the serial
diff --git a/test/py/conftest.py b/test/py/conftest.py
index 304e93164a..3d1fd6883a 100644
--- a/test/py/conftest.py
+++ b/test/py/conftest.py
@@ -104,6 +104,7 @@ def run_build(config, source_dir, build_dir, board_type, log):
             o_opt = ''
         cmds = (
             ['make', o_opt, '-s', board_type + '_defconfig'],
+            ['make', o_opt, '-s', 'set_host_bits'],
             ['make', o_opt, '-s', '-j{}'.format(os.cpu_count())],
         )
         name = 'make'
diff --git a/tools/Makefile b/tools/Makefile
index 34a1aa7a8b..d6b585953d 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -68,6 +68,8 @@ HOSTCFLAGS_img2srec.o := -pedantic
 hostprogs-$(CONFIG_XWAY_SWAP_BYTES) += xway-swap-bytes
 HOSTCFLAGS_xway-swap-bytes.o := -pedantic
 
+hostprogs-y += bits-per-long
+
 hostprogs-y += mkenvimage
 mkenvimage-objs := mkenvimage.o os_support.o lib/crc32.o
 
diff --git a/tools/bits-per-long.c b/tools/bits-per-long.c
new file mode 100644
index 0000000000..7630e1623f
--- /dev/null
+++ b/tools/bits-per-long.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+	unsigned long testvar = ~0UL;
+	unsigned int i;
+
+	for (i = 0; testvar; i++, testvar >>= 1)
+		;
+
+	return printf("%u\n", i);
+}
+
-- 
2.37.3