From 30a9a3a0894f19774f67279ed0224a17fa1a6f9b Mon Sep 17 00:00:00 2001
From: Mads Marquart <mads@marquart.dk>
Date: Sun, 10 Nov 2024 18:05:43 +0100
Subject: [PATCH 1/4] Properly disable PIC on WASM targets

CC https://github.com/rust-lang/cc-rs/issues/1240
---
 src/lib.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index f75b9511..3c165dc9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1994,11 +1994,15 @@ impl Build {
                     cmd.push_cc_arg("-fdata-sections".into());
                 }
                 // Disable generation of PIC on bare-metal for now: rust-lld doesn't support this yet
+                //
+                // `rustc` also defaults to disable PIC on WASM:
+                // <https://github.com/rust-lang/rust/blob/1.82.0/compiler/rustc_target/src/spec/base/wasm.rs#L101-L108>
                 if self.pic.unwrap_or(
                     target.os != "windows"
                         && target.os != "none"
                         && target.os != "uefi"
-                        && target.os != "wasi",
+                        && target.arch != "wasm32"
+                        && target.arch != "wasm64",
                 ) {
                     cmd.push_cc_arg("-fPIC".into());
                     // PLT only applies if code is compiled with PIC support,

From e61f4f6c92af948859e988ccec0fb9441a01976e Mon Sep 17 00:00:00 2001
From: Mads Marquart <mads@marquart.dk>
Date: Sun, 10 Nov 2024 18:09:19 +0100
Subject: [PATCH 2/4] Disable exceptions on all WASM targets

---
 src/lib.rs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 3c165dc9..4a3dd5a9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2013,10 +2013,17 @@ impl Build {
                         cmd.push_cc_arg("-fno-plt".into());
                     }
                 }
-                if target.os == "wasi" {
+                if target.arch == "wasm32" || target.arch == "wasm64" {
                     // WASI does not support exceptions yet.
                     // https://github.com/WebAssembly/exception-handling
+                    //
+                    // `rustc` also defaults to (currently) disable exceptions
+                    // on all WASM targets:
+                    // <https://github.com/rust-lang/rust/blob/1.82.0/compiler/rustc_target/src/spec/base/wasm.rs#L72-L77>
                     cmd.push_cc_arg("-fno-exceptions".into());
+                }
+
+                if target.os == "wasi" {
                     // Link clang sysroot
                     if let Ok(wasi_sysroot) = self.wasi_sysroot() {
                         cmd.push_cc_arg(

From 3fd85a8f3479e8190102c19fbce7f76a4ffa1d9a Mon Sep 17 00:00:00 2001
From: Mads Marquart <mads@marquart.dk>
Date: Sun, 10 Nov 2024 18:15:44 +0100
Subject: [PATCH 3/4] Default to compiling with Clang on all WASM targets

---
 src/lib.rs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 4a3dd5a9..f8544f01 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2715,12 +2715,10 @@ impl Build {
                         "{}-{}-{}-{}",
                         target.full_arch, target.vendor, target.os, traditional
                     )
-                } else if target.os == "wasi" {
-                    if self.cpp {
-                        "clang++".to_string()
-                    } else {
-                        "clang".to_string()
-                    }
+                } else if target.arch == "wasm32" || target.arch == "wasm64" {
+                    // Compiling WASM is not currently supported by GCC, so
+                    // let's default to Clang.
+                    clang.to_string()
                 } else if target.os == "vxworks" {
                     if self.cpp {
                         "wr-c++".to_string()

From e473a886fd3bd544fe87299807927abf6bfb2080 Mon Sep 17 00:00:00 2001
From: Mads Marquart <mads@marquart.dk>
Date: Sun, 10 Nov 2024 18:20:50 +0100
Subject: [PATCH 4/4] Find archiver on WASM64 as well

---
 src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index f8544f01..9ac535ec 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3103,7 +3103,7 @@ impl Build {
                         name = format!("em{}", tool).into();
                         Some(self.cmd(&name))
                     }
-                } else if target.arch == "wasm32" {
+                } else if target.arch == "wasm32" || target.arch == "wasm64" {
                     // Formally speaking one should be able to use this approach,
                     // parsing -print-search-dirs output, to cover all clang targets,
                     // including Android SDKs and other cross-compilation scenarios...