[PATCH v7 07/14] kernel: Disable ccache when kernel rust support is enabled

[Harish.Sadineni@windriver.com]

From: Harish Sadineni <Harish.Sadineni@windriver.com>

Currently, a ccache enabled build fails with:
  |   HOSTRUSTC scripts/generate_rust_target
  |   HOSTCC  scripts/kallsyms
  |   HOSTCC  scripts/sorttable
  |   HOSTCC  scripts/asn1_compiler
  |   TOUCH   include/generated/gcc-plugins.h
  |   DESCEND objtool
  | error: multiple input filenames provided (first two filenames are gcc and
.../tmp/work-shared/qemux86-64/kernel-source/scripts/generate_rust_target.rs)

Linux rust build infrastructure does not currently support ccache (Opened bug[0]).

Quick summary: There are 2 issues: $HOSTCC is not escaped and rustc
expect a path (and not a command)

Disable ccache if KERNEL_RUST_SUPPORT is 'True' for kernel and kernel module builds, including
auxiliary tooling such as make-mod-scripts.

More details in: https://lists.openembedded.org/g/openembedded-core/message/229336

[0]: https://github.com/Rust-for-Linux/linux/issues/1224

Co-developed-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: El Mehdi YOUNES <elmehdi.younes@smile.fr>
Cc: Alban MOIZAN <alban.moizan@smile.fr>
Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Harish Sadineni <Harish.Sadineni@windriver.com>
---
 meta/classes-recipe/kernel-yocto-rust.bbclass              | 7 +++++++
 .../make-mod-scripts/make-mod-scripts_1.0.bb               | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/meta/classes-recipe/kernel-yocto-rust.bbclass b/meta/classes-recipe/kernel-yocto-rust.bbclass
index fd9ee91c79..608ccc4609 100644
--- a/meta/classes-recipe/kernel-yocto-rust.bbclass
+++ b/meta/classes-recipe/kernel-yocto-rust.bbclass
@@ -16,3 +16,10 @@ do_kernel_configme[depends] += "${RUST_KERNEL_TASK_DEPENDS}"
 do_kernel_configme:append () {
         oe_runmake -C ${S} O=${B} rustavailable
 }
+
+# Linux rust build infrastructure does not currently support ccache
+# see https://github.com/Rust-for-Linux/linux/issues/1224
+# Quick summary: There are 2 issues: $HOSTCC is not escaped and rustc expect a path (and not a command)
+# More details in: https://lists.openembedded.org/g/openembedded-core/message/229336
+# Disable ccache for kernel build if kernel rust support is enabled to workaround this.
+CCACHE_DISABLE ?= "1"
diff --git a/meta/recipes-kernel/make-mod-scripts/make-mod-scripts_1.0.bb b/meta/recipes-kernel/make-mod-scripts/make-mod-scripts_1.0.bb
index 874e16e642..6226382001 100644
--- a/meta/recipes-kernel/make-mod-scripts/make-mod-scripts_1.0.bb
+++ b/meta/recipes-kernel/make-mod-scripts/make-mod-scripts_1.0.bb
@@ -36,3 +36,10 @@ do_configure() {
 		-C ${STAGING_KERNEL_DIR} O=${STAGING_KERNEL_BUILDDIR} $t
 	done
 }
+
+# Linux rust build infrastructure does not currently support ccache
+# see https://github.com/Rust-for-Linux/linux/issues/1224
+# Quick summary: There are 2 issues: $HOSTCC is not escaped and rustc expect a path (and not a command)
+# More details in: https://lists.openembedded.org/g/openembedded-core/message/229336
+# Disable ccache for kernel build if kernel rust support is enabled to workaround this
+CCACHE_DISABLE ?= "${@bb.utils.contains('KERNEL_RUST_SUPPORT', 'True', '1', '0', d)}"
-- 
2.49.0