Introduce llvm-enable-rtti option

config.toml.example

@@ -148,6 +148,9 @@ changelog-seen = 2
 # The value specified here will be passed as `-DLLVM_USE_LINKER` to CMake.
 #use-linker = <none> (path)
 
+# Whether or not to specify `-DLLVM_ENABLE_RTTI=YES`
+#enable-rtti = false
+
 # Whether or not to specify `-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=YES`
 #allow-old-toolchain = false
 

src/bootstrap/config.rs

@@ -105,6 +105,7 @@ pub struct Config {
     pub llvm_version_suffix: Option<String>,
     pub llvm_use_linker: Option<String>,
     pub llvm_allow_old_toolchain: bool,
+    pub llvm_enable_rtti: bool,
     pub llvm_polly: bool,
     pub llvm_clang: bool,
     pub llvm_from_ci: bool,
@@ -474,6 +475,7 @@ derive_merge! {
         use_libcxx: Option<bool>,
         use_linker: Option<String>,
         allow_old_toolchain: Option<bool>,
+        enable_rtti: Option<bool>,
         polly: Option<bool>,
         clang: Option<bool>,
         download_ci_llvm: Option<StringOrBool>,
@@ -805,6 +807,7 @@ impl Config {
             set(&mut config.llvm_use_libcxx, llvm.use_libcxx);
             config.llvm_use_linker = llvm.use_linker.clone();
             config.llvm_allow_old_toolchain = llvm.allow_old_toolchain.unwrap_or(false);
+            config.llvm_enable_rtti = llvm.enable_rtti.unwrap_or(false);
             config.llvm_polly = llvm.polly.unwrap_or(false);
             config.llvm_clang = llvm.clang.unwrap_or(false);
             config.llvm_from_ci = match llvm.download_ci_llvm {
@@ -874,6 +877,7 @@ impl Config {
                 check_ci_llvm!(llvm.use_libcxx);
                 check_ci_llvm!(llvm.use_linker);
                 check_ci_llvm!(llvm.allow_old_toolchain);
+                check_ci_llvm!(llvm.enable_rtti);
                 check_ci_llvm!(llvm.polly);
                 check_ci_llvm!(llvm.clang);
                 check_ci_llvm!(llvm.plugins);

src/bootstrap/configure.py

@@ -73,6 +73,7 @@ def v(*args):
 o("optimize", "rust.optimize", "build optimized rust code")
 o("optimize-llvm", "llvm.optimize", "build optimized LLVM")
 o("llvm-assertions", "llvm.assertions", "build LLVM with assertions")
+o("llvm-enable-rtti", "llvm.enable-rtti", "build LLVM with using C++’s built in RTTI")
 o("llvm-plugins", "llvm.plugins", "build LLVM with plugin interface")
 o("debug-assertions", "rust.debug-assertions", "build with debugging assertions")
 o("debug-assertions-std", "rust.debug-assertions-std", "build the standard library with debugging assertions")

src/bootstrap/native.rs

@@ -351,6 +351,10 @@ impl Step for Llvm {
             cfg.define("LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN", "YES");
         }
 
+        if builder.config.llvm_enable_rtti {
+            cfg.define("LLVM_ENABLE_RTTI", "YES");
+        }
+
         configure_cmake(builder, target, &mut cfg, true);
 
         // FIXME: we don't actually need to build all LLVM tools and all LLVM