From f6e8b26eab8324a60f437fdb3e88e5d5105c9845 Mon Sep 17 00:00:00 2001
From: google-yfyang <yfyang@google.com>
Date: Thu, 4 Sep 2025 11:26:21 -0400
Subject: [PATCH] [libc] Add wasm support for some submodules in llvm-libc.
 (#154383)

Introducing several emscripten-specific changes to the llvm-libc headers
as well as adding a wasm sigsetjmp.cpp.
---
 .../src/__support/StringUtil/platform_errors.h |  2 +-
 .../macros/properties/architectures.h          |  4 ++++
 libc/src/setjmp/wasm/sigsetjmp.cpp             | 18 ++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 libc/src/setjmp/wasm/sigsetjmp.cpp

diff --git a/libc/src/__support/StringUtil/platform_errors.h b/libc/src/__support/StringUtil/platform_errors.h
index 32e8414b3e3d..5f83865482e7 100644
--- a/libc/src/__support/StringUtil/platform_errors.h
+++ b/libc/src/__support/StringUtil/platform_errors.h
@@ -9,7 +9,7 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_STRINGUTIL_PLATFORM_ERRORS_H
 #define LLVM_LIBC_SRC___SUPPORT_STRINGUTIL_PLATFORM_ERRORS_H
 
-#if defined(__linux__) || defined(__Fuchsia__)
+#if defined(__linux__) || defined(__Fuchsia__) || defined(__EMSCRIPTEN__)
 #include "tables/linux_platform_errors.h"
 #else
 #include "tables/minimal_platform_errors.h"
diff --git a/libc/src/__support/macros/properties/architectures.h b/libc/src/__support/macros/properties/architectures.h
index ecc93196be28..21e9bc4288cd 100644
--- a/libc/src/__support/macros/properties/architectures.h
+++ b/libc/src/__support/macros/properties/architectures.h
@@ -41,6 +41,10 @@
 #define LIBC_TARGET_ARCH_IS_ARM
 #endif
 
+#if defined(__wasm__)
+#define LIBC_TARGET_ARCH_IS_WASM
+#endif
+
 #if defined(__aarch64__) || defined(__arm64__) || defined(_M_ARM64)
 #define LIBC_TARGET_ARCH_IS_AARCH64
 #endif
diff --git a/libc/src/setjmp/wasm/sigsetjmp.cpp b/libc/src/setjmp/wasm/sigsetjmp.cpp
new file mode 100644
index 000000000000..e9dfb3f837e7
--- /dev/null
+++ b/libc/src/setjmp/wasm/sigsetjmp.cpp
@@ -0,0 +1,18 @@
+//===-- Implementation of sigsetjmp ---------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/setjmp/sigsetjmp.h"
+#include "hdr/offsetof_macros.h"
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE_DECL {
+[[gnu::returns_twice]] int sigsetjmp(jmp_buf sigjmp_buf,
+                                     [[maybe_unused]] int savesigs) {
+  return setjmp(sigjmp_buf);
+}
+} // namespace LIBC_NAMESPACE_DECL