From 522ae4cb3f9032e7a2f092932a2c49277ddc2bec Mon Sep 17 00:00:00 2001
From: Ansh Rai <anshrai331@gmail.com>
Date: Sun, 19 Jul 2026 06:58:36 +0000
Subject: [PATCH] tools/Zig.defs: Fix Zig builds on sim:x86_64

Building Zig applications on sim:x86_64 with Zig 0.13.0 fails because
the generated target "x86_64-freestanding-sysv" is not recognized by
Zig. Introduce a Zig-specific ABI mapping that translates "sysv" to
"gnu" without affecting other toolchains.

After correcting the target ABI, linking still fails due to unresolved
references to __zig_probe_stack. Add -fcompiler-rt so Zig includes the
required compiler runtime during linking.

Verified on sim:nsh with CONFIG_EXAMPLES_HELLO_ZIG=y:

  nsh> hello_zig
  [sim]: Hello, Zig!

Fixes #19475

Signed-off-by: Ansh Rai <anshrai331@gmail.com>
---
 tools/Zig.defs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/Zig.defs b/tools/Zig.defs
index 6feabe72e22..18f7424c995 100644
--- a/tools/Zig.defs
+++ b/tools/Zig.defs
@@ -36,7 +36,13 @@ else ifeq ($(CONFIG_ARCH_RISCV),y)
   ZIGFLAGS += -mcmodel=medium
 
 else 
-  ZIGFLAGS := -target $(LLVM_ARCHTYPE)-freestanding-$(LLVM_ABITYPE)
+  ifeq ($(LLVM_ABITYPE),sysv)
+    ZIG_ABITYPE := gnu
+  else
+    ZIG_ABITYPE := $(LLVM_ABITYPE)
+  endif
+
+  ZIGFLAGS := -target $(LLVM_ARCHTYPE)-freestanding-$(ZIG_ABITYPE)
 endif
 
 # Convert cortex-xxx/sifive-exx to cortex_xxx/sifive_exx
@@ -44,3 +50,5 @@ endif
 ifneq ($(LLVM_CPUTYPE),)
 ZIGFLAGS += -mcpu $(subst -,_,$(LLVM_CPUTYPE))
 endif
+
+ZIGFLAGS += -fcompiler-rt