From eb3b93d14ad1c163a862098f1cbcd7c293985712 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Fri, 12 Jan 2024 12:21:20 -0700
Subject: [PATCH] Define strtold in C until Rust and cbindgen can use f128

---
 Cargo.lock            | 14 ++++++++++++--
 Cargo.toml            |  3 +++
 build.rs              | 38 ++++++++++++++++++++++++++++++++++++++
 include/bits/stdlib.h |  4 +---
 src/c/stdlib.c        |  5 +++++
 5 files changed, 59 insertions(+), 5 deletions(-)
 create mode 100644 build.rs
 create mode 100644 src/c/stdlib.c

diff --git a/Cargo.lock b/Cargo.lock
index e3a5979b18..f4af0254dd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -23,6 +23,15 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "cc"
+version = "1.0.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1174fb0b6ec23863f8b971027804a42614e347eafb0a95bf0b12cdae21fc4d0"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crt0"
 version = "0.1.0"
@@ -56,9 +65,9 @@ version = "0.1.0"
 
 [[package]]
 name = "libc"
-version = "0.2.151"
+version = "0.2.152"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "302d7ab3130588088d277783b1e2d2e10c9e9e4a16dd9050e6ec93fb3e7048f4"
+checksum = "13e3bf6590cbc649f4d1a3eefc9d5d6eb746f5200ffb04e5e142700b8faa56e7"
 
 [[package]]
 name = "log"
@@ -225,6 +234,7 @@ version = "0.2.5"
 dependencies = [
  "bitflags",
  "cbitset",
+ "cc",
  "dlmalloc",
  "goblin",
  "libc",
diff --git a/Cargo.toml b/Cargo.toml
index 9ac37b223b..66ea8f2454 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,9 @@ crate-type = ["staticlib"]
 members = ["src/crt0", "src/crti", "src/crtn", "src/ld_so", "src/platform/redox/redox-exec"]
 exclude = ["ralloc", "tests", "dlmalloc-rs"]
 
+[build-dependencies]
+cc = "1"
+
 [dependencies]
 bitflags = "2"
 cbitset = "0.2"
diff --git a/build.rs b/build.rs
new file mode 100644
index 0000000000..154c0527c6
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,38 @@
+extern crate cc;
+
+use std::{env, fs};
+
+fn get_target() -> String {
+    env::var("TARGET").unwrap_or(
+        option_env!("TARGET").map_or("x86_64-unknown-redox".to_string(), |x| x.to_string()),
+    )
+}
+
+fn main() {
+    let crate_dir = env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR not set");
+    let target = get_target();
+
+    println!("cargo:rerun-if-changed=src/c");
+
+    let mut cc_builder = &mut cc::Build::new();
+
+    cc_builder = cc_builder
+        .flag("-nostdinc")
+        .flag("-nostdlib");
+
+    if target.starts_with("aarch64") {
+        cc_builder = cc_builder.flag("-mno-outline-atomics")
+    }
+
+    cc_builder
+        .flag("-fno-stack-protector")
+        .flag("-Wno-expansion-to-defined")
+        .files(
+            fs::read_dir("src/c")
+                .expect("src/c directory missing")
+                .map(|res| res.expect("read_dir error").path()),
+        )
+        .compile("relibc_c");
+
+    println!("cargo:rustc-link-lib=static=relibc_c");
+}
diff --git a/include/bits/stdlib.h b/include/bits/stdlib.h
index 45bb7a37e8..8d639cef38 100644
--- a/include/bits/stdlib.h
+++ b/include/bits/stdlib.h
@@ -5,9 +5,7 @@
 extern "C" {
 #endif
 
-long double strtold(const char *nptr, char **endptr) {
-  return (long double)strtod(nptr, endptr);
-}
+long double strtold(const char *nptr, char **endptr);
 
 #ifdef __cplusplus
 } // extern "C"
diff --git a/src/c/stdlib.c b/src/c/stdlib.c
new file mode 100644
index 0000000000..39e4fb0f44
--- /dev/null
+++ b/src/c/stdlib.c
@@ -0,0 +1,5 @@
+double strtod(const char *nptr, char **endptr);
+
+long double strtold(const char *nptr, char **endptr) {
+    return (long double)strtod(nptr, endptr);
+}