From 966d3c72b561720446b827a3df436e6d10faafc3 Mon Sep 17 00:00:00 2001
From: StackOverflowExcept1on
 <109800286+StackOverflowExcept1on@users.noreply.github.com>
Date: Sat, 16 Aug 2025 14:46:15 +0300
Subject: [PATCH 1/2] fix: add `-mcpu=mvp` for `wasm32v1-none`

---
 src/lib.rs | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 6c41d3e6e..009081757 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2308,9 +2308,12 @@ impl Build {
                             None
                         };
 
-                    let clang_target =
-                        target.llvm_target(&self.get_raw_target()?, version.as_deref());
+                    let rustc_target = self.get_raw_target()?;
+                    let clang_target = target.llvm_target(&rustc_target, version.as_deref());
                     cmd.push_cc_arg(format!("--target={clang_target}").into());
+                    if rustc_target == "wasm32v1-none" {
+                        cmd.push_cc_arg("-mcpu=mvp".into());
+                    }
                 }
             }
             ToolFamily::Msvc { clang_cl } => {
@@ -2335,13 +2338,13 @@ impl Build {
                         // <https://github.com/microsoft/STL/pull/4741>.
                         cmd.push_cc_arg("-arch:SSE2".into());
                     } else {
+                        let rustc_target = self.get_raw_target()?;
                         cmd.push_cc_arg(
-                            format!(
-                                "--target={}",
-                                target.llvm_target(&self.get_raw_target()?, None)
-                            )
-                            .into(),
+                            format!("--target={}", target.llvm_target(&rustc_target, None)).into(),
                         );
+                        if rustc_target == "wasm32v1-none" {
+                            cmd.push_cc_arg("-mcpu=mvp".into());
+                        }
                     }
                 } else if target.full_arch == "i586" {
                     cmd.push_cc_arg("-arch:IA32".into());

From 22a0c295f743db8fadb47adcfba2fc1c3a1f23be Mon Sep 17 00:00:00 2001
From: StackOverflowExcept1on
 <109800286+StackOverflowExcept1on@users.noreply.github.com>
Date: Mon, 18 Aug 2025 11:50:49 +0300
Subject: [PATCH 2/2] fix review

---
 src/lib.rs | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 009081757..51bc39d7f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2308,12 +2308,9 @@ impl Build {
                             None
                         };
 
-                    let rustc_target = self.get_raw_target()?;
-                    let clang_target = target.llvm_target(&rustc_target, version.as_deref());
+                    let clang_target =
+                        target.llvm_target(&self.get_raw_target()?, version.as_deref());
                     cmd.push_cc_arg(format!("--target={clang_target}").into());
-                    if rustc_target == "wasm32v1-none" {
-                        cmd.push_cc_arg("-mcpu=mvp".into());
-                    }
                 }
             }
             ToolFamily::Msvc { clang_cl } => {
@@ -2338,13 +2335,13 @@ impl Build {
                         // <https://github.com/microsoft/STL/pull/4741>.
                         cmd.push_cc_arg("-arch:SSE2".into());
                     } else {
-                        let rustc_target = self.get_raw_target()?;
                         cmd.push_cc_arg(
-                            format!("--target={}", target.llvm_target(&rustc_target, None)).into(),
+                            format!(
+                                "--target={}",
+                                target.llvm_target(&self.get_raw_target()?, None)
+                            )
+                            .into(),
                         );
-                        if rustc_target == "wasm32v1-none" {
-                            cmd.push_cc_arg("-mcpu=mvp".into());
-                        }
                     }
                 } else if target.full_arch == "i586" {
                     cmd.push_cc_arg("-arch:IA32".into());
@@ -2534,6 +2531,13 @@ impl Build {
             }
         }
 
+        if raw_target == "wasm32v1-none" {
+            // `wasm32v1-none` target only exists in `rustc`, so we need to change the compilation flags:
+            // https://doc.rust-lang.org/rustc/platform-support/wasm32v1-none.html
+            cmd.push_cc_arg("-mcpu=mvp".into());
+            cmd.push_cc_arg("-mmutable-globals".into());
+        }
+
         if target.os == "solaris" || target.os == "illumos" {
             // On Solaris and illumos, multi-threaded C programs must be built with `_REENTRANT`
             // defined. This configures headers to define APIs appropriately for multi-threaded