Merge pull request #96785 from akien-mga/scons-lto-use-thinlto-llvm

SCons: Make `lto=auto` prefer ThinLTO over full LTO for LLVM targets

platform/linuxbsd/detect.py

@@ -184,8 +184,8 @@ def configure(env: "SConsEnvironment"):
 
     # LTO
 
-    if env["lto"] == "auto":  # Full LTO for production.
-        env["lto"] = "full"
+    if env["lto"] == "auto":  # Enable LTO for production.
+        env["lto"] = "thin" if env["use_llvm"] else "full"
 
     if env["lto"] != "none":
         if env["lto"] == "thin":

platform/web/detect.py

@@ -117,8 +117,8 @@ def configure(env: "SConsEnvironment"):
 
     # LTO
 
-    if env["lto"] == "auto":  # Full LTO for production.
-        env["lto"] = "full"
+    if env["lto"] == "auto":  # Enable LTO for production.
+        env["lto"] = "thin"
 
     if env["lto"] != "none":
         if env["lto"] == "thin":

platform/windows/detect.py

@@ -762,8 +762,8 @@ def configure_mingw(env: "SConsEnvironment"):
 
     ## LTO
 
-    if env["lto"] == "auto":  # Full LTO for production with MinGW.
-        env["lto"] = "full"
+    if env["lto"] == "auto":  # Enable LTO for production with MinGW.
+        env["lto"] = "thin" if env["use_llvm"] else "full"
 
     if env["lto"] != "none":
         if env["lto"] == "thin":