Refine build system

[jserv]

• Remove duplicate git submodule initialization from Makefile header
• Consolidate submodule init logic into $(KCONFIGLIB) target with proper error handling

---

Summary by cubic

Refined the build system by moving Kconfig submodule init into the KCONFIGLIB target with clear error handling, and fixed small toolchain/linker issues to prevent build failures.

• Refactors

  • Consolidated Kconfig submodule init into $(KCONFIGLIB) with a .git check and explicit error on missing repo.

• Bug Fixes

  • Added missing space in _cmd_link_so.cxx.host to avoid merged flags.
  • Simplified clang++ resolution: derive CXX by substituting in CC.
  • Corrected HOSTOBJCOPY typo (objcpy -> objcopy).

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (all 1 issues)

Understand the root cause of the following 1 issues and fix them.


<file name="mk/toolchain.mk">

<violation number="1" location="mk/toolchain.mk:28">
Substituting &quot;clang&quot; across the full CC path rewrites directory components (e.g. `/usr/local/clang+llvm/bin/clang` becomes `/usr/local/clang+++llvm/bin/clang++`), so clang++ cannot be located on such installations; please limit the substitution to the basename.</violation>
</file>

_{React with 👍 or 👎 to teach cubic. Mention @cubic-dev-ai to give feedback, ask questions, or re-run the review.}

[cubic-dev-ai]

Substituting "clang" across the full CC path rewrites directory components (e.g. /usr/local/clang+llvm/bin/clang becomes /usr/local/clang+++llvm/bin/clang++), so clang++ cannot be located on such installations; please limit the substitution to the basename.

Prompt for AI agents

Address the following comment on mk/toolchain.mk at line 28:

<comment>Substituting &quot;clang&quot; across the full CC path rewrites directory components (e.g. `/usr/local/clang+llvm/bin/clang` becomes `/usr/local/clang+++llvm/bin/clang++`), so clang++ cannot be located on such installations; please limit the substitution to the basename.</comment>

<file context>
@@ -25,7 +25,7 @@ ifndef CXX
 endif
 ifeq (&quot;$(CC_IS_CLANG)&quot;, &quot;1&quot;)
-override CXX := $(dir $(CC))$(subst clang,clang++,$(notdir $(CC)))
+override CXX := $(subst clang,clang++,$(CC))
 endif
 
</file context>

Suggested change

	override CXX := $(subst clang,clang++,$(CC))
	override CXX := $(dir $(CC))$(subst clang,clang++,$(notdir $(CC)))