[libc-commits] [libc] [libc] Add wasm support for some submodules in llvm-libc. (PR #154383)

[via libc-commits]

https://github.com/google-yfyang updated https://github.com/llvm/llvm-project/pull/154383

>From 50c3b0280355f300209929df06ec9879feef2ac2 Mon Sep 17 00:00:00 2001
From: google-yfyang <yfyang at google.com>
Date: Tue, 19 Aug 2025 12:39:39 -0400
Subject: [PATCH] [libc] Add wasm support for some submodules in llvm-libc

---
 libc/src/__support/StringUtil/platform_errors.h    |  2 +-
 .../src/__support/StringUtil/tables/posix_errors.h |  5 +++++
 libc/src/__support/StringUtil/tables/stdc_errors.h |  5 +++++
 .../__support/macros/properties/architectures.h    |  4 ++++
 libc/src/setjmp/wasm/sigsetjmp.cpp                 | 14 ++++++++++++++
 5 files changed, 29 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 32e8414b3e3de..5f83865482e72 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/StringUtil/tables/posix_errors.h b/libc/src/__support/StringUtil/tables/posix_errors.h
index b21f28f0b1321..d386a48c21d44 100644
--- a/libc/src/__support/StringUtil/tables/posix_errors.h
+++ b/libc/src/__support/StringUtil/tables/posix_errors.h
@@ -63,7 +63,12 @@ LIBC_INLINE_VAR constexpr MsgTable<76> POSIX_ERRORS = {
     MsgMapping(EPROTO, "Protocol error"),
     MsgMapping(EMULTIHOP, "Multihop attempted"),
     MsgMapping(EBADMSG, "Bad message"),
+#ifdef __EMSCRIPTEN__
+    // For now, match the musl string
+    MsgMapping(EOVERFLOW, "Value too large for data type"),
+#else
     MsgMapping(EOVERFLOW, "Value too large for defined data type"),
+#endif
     MsgMapping(ENOTSOCK, "Socket operation on non-socket"),
     MsgMapping(EDESTADDRREQ, "Destination address required"),
     MsgMapping(EMSGSIZE, "Message too long"),
diff --git a/libc/src/__support/StringUtil/tables/stdc_errors.h b/libc/src/__support/StringUtil/tables/stdc_errors.h
index a326616f20ef5..9a23d0718ea13 100644
--- a/libc/src/__support/StringUtil/tables/stdc_errors.h
+++ b/libc/src/__support/StringUtil/tables/stdc_errors.h
@@ -16,7 +16,12 @@
 namespace LIBC_NAMESPACE_DECL {
 
 LIBC_INLINE_VAR constexpr const MsgTable<4> STDC_ERRORS = {
+#ifdef __EMSCRIPTEN__
+    // For now, match the musl name for errno 0.
+    MsgMapping(0, "No error information"),
+#else
     MsgMapping(0, "Success"),
+#endif
     MsgMapping(EDOM, "Numerical argument out of domain"),
     MsgMapping(ERANGE, "Numerical result out of range"),
     MsgMapping(EILSEQ, "Invalid or incomplete multibyte or wide character"),
diff --git a/libc/src/__support/macros/properties/architectures.h b/libc/src/__support/macros/properties/architectures.h
index ecc93196be286..21e9bc4288cd7 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 0000000000000..809356d4577eb
--- /dev/null
+++ b/libc/src/setjmp/wasm/sigsetjmp.cpp
@@ -0,0 +1,14 @@
+#include "src/setjmp/sigsetjmp.h"
+#include "hdr/offsetof_macros.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+#if !defined(LIBC_TARGET_ARCH_IS_WASM)
+#error "Invalid file include"
+#endif
+
+namespace LIBC_NAMESPACE_DECL {
+[[gnu::returns_twice]] int sigsetjmp(jmp_buf sigjmp_buf, int savesigs) {
+    return setjmp(sigjmp_buf);
+}
+}