From 100a6034c923f16ad083ce839ebcf6f971661bcf Mon Sep 17 00:00:00 2001
From: Carter Canedy <cartercanedy42@gmail.com>
Date: Sat, 23 Aug 2025 21:54:21 -0700
Subject: [PATCH] specify windows-msvc compiler flags

---
 Cargo.lock             |  4 ++--
 turbojpeg-sys/build.rs | 31 +++++++++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1f6f660..eaf35ee 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "adler2"
@@ -602,7 +602,7 @@ dependencies = [
 
 [[package]]
 name = "turbojpeg"
-version = "1.3.3"
+version = "1.3.4-pre"
 dependencies = [
  "anyhow",
  "clap",
diff --git a/turbojpeg-sys/build.rs b/turbojpeg-sys/build.rs
index 254d5c6..751ea47 100644
--- a/turbojpeg-sys/build.rs
+++ b/turbojpeg-sys/build.rs
@@ -153,6 +153,35 @@ fn build_vendor(link_kind: LinkKind) -> Result<Library> {
         cmake.configure_arg("-DREQUIRE_SIMD=ON");
     }
 
+    let is_msvc = env("CARGO_CFG_TARGET_ENV").unwrap() == "msvc";
+
+    #[cfg(target_os = "windows")] {
+        // add missing msvc-specific flags
+        if is_msvc {
+            let opt_level = env("OPT_LEVEL")
+                .map(|s| s
+                    .to_string_lossy()
+                    .chars()
+                    .nth(0)
+                    .unwrap()
+                )
+                .unwrap();
+
+            let compiler_flags: &[&str] = match opt_level {
+                's' => &["/O1", "/Ob1"], // min size + no opt + min inlining
+                'z' => &["/O1", "/Ob0"], // min size + no opt + no inlining
+                '1' | '2' => &["/O1"],   // min opt
+                '3' => &["/O2", "/Ob3"], // max opt + max inlining
+                '0' => &["/Od"], // no opt
+                _ => panic!("unknown optimization level: '{opt_level}'")
+            };
+
+            for flag in compiler_flags {
+                cmake.cflag(flag);
+            }
+        }
+    }
+
     let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
     if target_os == "android" {
         let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
@@ -171,8 +200,6 @@ fn build_vendor(link_kind: LinkKind) -> Result<Library> {
     let lib_path = dst_path.join("lib");
     let include_path = dst_path.join("include");
 
-    let is_msvc = env("CARGO_CFG_TARGET_ENV").unwrap() == "msvc";
-
     println!("cargo:rustc-link-search=native={}", lib_path.display());
     println!("cargo:rustc-link-lib={}=turbojpeg{}", match link_kind {
         LinkKind::Static | LinkKind::Default => "static",