rustc_target: Introduce msvc_base

and inherit both `windows_msvc_base` and `uefi_msvc_base` from it.

Author: petrochenkov

src/librustc_target/spec/i686_unknown_uefi.rs

@@ -23,11 +23,6 @@ pub fn target() -> TargetResult {
     // arguments, thus giving you access to full MMX/SSE acceleration.
     base.features = "-mmx,-sse,+soft-float".to_string();
 
-    // UEFI mirrors the calling-conventions used on windows. In case of i686 this means small
-    // structs will be returned as int. This shouldn't matter much, since the restrictions placed
-    // by the UEFI specifications forbid any ABI to return structures.
-    base.abi_return_struct_as_int = true;
-
     // Use -GNU here, because of the reason below:
     // Background and Problem:
     //   If we use i686-unknown-windows, the LLVM IA32 MSVC generates compiler intrinsic

src/librustc_target/spec/mod.rs

@@ -59,6 +59,7 @@ mod l4re_base;
 mod linux_base;
 mod linux_kernel_base;
 mod linux_musl_base;
+mod msvc_base;
 mod netbsd_base;
 mod openbsd_base;
 mod redox_base;

src/librustc_target/spec/msvc_base.rs

@@ -0,0 +1,38 @@
+use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, TargetOptions};
+
+pub fn opts() -> TargetOptions {
+    let pre_link_args_msvc = vec![
+        // Suppress the verbose logo and authorship debugging output, which would needlessly
+        // clog any log files.
+        "/NOLOGO".to_string(),
+        // Tell the compiler that non-code sections can be marked as non-executable,
+        // including stack pages.
+        // UEFI is fully compatible to non-executable data pages.
+        // In fact, firmware might enforce this, so we better let the linker know about this,
+        // so it will fail if the compiler ever tries placing code on the stack
+        // (e.g., trampoline constructs and alike).
+        "/NXCOMPAT".to_string(),
+    ];
+    let mut pre_link_args = LinkArgs::new();
+    pre_link_args.insert(LinkerFlavor::Msvc, pre_link_args_msvc.clone());
+    pre_link_args.insert(LinkerFlavor::Lld(LldFlavor::Link), pre_link_args_msvc);
+
+    TargetOptions {
+        executables: true,
+        is_like_windows: true,
+        is_like_msvc: true,
+        // set VSLANG to 1033 can prevent link.exe from using
+        // language packs, and avoid generating Non-UTF-8 error
+        // messages if a link error occurred.
+        link_env: vec![("VSLANG".to_string(), "1033".to_string())],
+        lld_flavor: LldFlavor::Link,
+        pre_link_args,
+        // UEFI mirrors the calling-conventions used on windows. In case of x86-64 and i686 this
+        // means small structs will be returned as int. This shouldn't matter much, since the
+        // restrictions placed by the UEFI specifications forbid any ABI to return structures.
+        abi_return_struct_as_int: true,
+        emit_debug_gdb_scripts: false,
+
+        ..Default::default()
+    }
+}

src/librustc_target/spec/uefi_msvc_base.rs

@@ -9,19 +9,12 @@
 // the timer-interrupt. Device-drivers are required to use polling-based models. Furthermore, all
 // code runs in the same environment, no process separation is supported.
 
-use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, PanicStrategy, TargetOptions};
+use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy, TargetOptions};
 
 pub fn opts() -> TargetOptions {
+    let mut base = super::msvc_base::opts();
+
     let pre_link_args_msvc = vec![
-        // Suppress the verbose logo and authorship debugging output, which would needlessly
-        // clog any log files.
-        "/NOLOGO".to_string(),
-        // UEFI is fully compatible to non-executable data pages. Tell the compiler that
-        // non-code sections can be marked as non-executable, including stack pages. In fact,
-        // firmware might enforce this, so we better let the linker know about this, so it
-        // will fail if the compiler ever tries placing code on the stack (e.g., trampoline
-        // constructs and alike).
-        "/NXCOMPAT".to_string(),
         // Non-standard subsystems have no default entry-point in PE+ files. We have to define
         // one. "efi_main" seems to be a common choice amongst other implementations and the
         // spec.
@@ -37,25 +30,29 @@ pub fn opts() -> TargetOptions {
         // exit (default for applications).
         "/subsystem:efi_application".to_string(),
     ];
-    let mut pre_link_args = LinkArgs::new();
-    pre_link_args.insert(LinkerFlavor::Msvc, pre_link_args_msvc.clone());
-    pre_link_args.insert(LinkerFlavor::Lld(LldFlavor::Link), pre_link_args_msvc);
+    base.pre_link_args.get_mut(&LinkerFlavor::Msvc).unwrap().extend(pre_link_args_msvc.clone());
+    base.pre_link_args
+        .get_mut(&LinkerFlavor::Lld(LldFlavor::Link))
+        .unwrap()
+        .extend(pre_link_args_msvc);
 
     TargetOptions {
-        dynamic_linking: false,
-        executables: true,
         disable_redzone: true,
         exe_suffix: ".efi".to_string(),
         allows_weak_linkage: false,
         panic_strategy: PanicStrategy::Abort,
         stack_probes: true,
         singlethread: true,
-        emit_debug_gdb_scripts: false,
-
         linker: Some("rust-lld".to_string()),
-        lld_flavor: LldFlavor::Link,
-        pre_link_args,
+        // FIXME: This should likely be `true` inherited from `msvc_base`
+        // because UEFI follows Windows ABI and uses PE/COFF.
+        // The `false` is probably causing ABI bugs right now.
+        is_like_windows: false,
+        // FIXME: This should likely be `true` inherited from `msvc_base`
+        // because UEFI follows Windows ABI and uses PE/COFF.
+        // The `false` is probably causing ABI bugs right now.
+        is_like_msvc: false,
 
-        ..Default::default()
+        ..base
     }
 }

src/librustc_target/spec/windows_msvc_base.rs

@@ -1,33 +1,18 @@
-use crate::spec::{LinkArgs, LinkerFlavor, LldFlavor, TargetOptions};
+use crate::spec::TargetOptions;
 
 pub fn opts() -> TargetOptions {
-    let pre_link_args_msvc = vec!["/NOLOGO".to_string(), "/NXCOMPAT".to_string()];
-    let mut pre_link_args = LinkArgs::new();
-    pre_link_args.insert(LinkerFlavor::Msvc, pre_link_args_msvc.clone());
-    pre_link_args.insert(LinkerFlavor::Lld(LldFlavor::Link), pre_link_args_msvc);
+    let base = super::msvc_base::opts();
 
     TargetOptions {
-        function_sections: true,
         dynamic_linking: true,
-        executables: true,
         dll_prefix: String::new(),
         dll_suffix: ".dll".to_string(),
         exe_suffix: ".exe".to_string(),
         staticlib_prefix: String::new(),
         staticlib_suffix: ".lib".to_string(),
         target_family: Some("windows".to_string()),
-        is_like_windows: true,
-        is_like_msvc: true,
-        // set VSLANG to 1033 can prevent link.exe from using
-        // language packs, and avoid generating Non-UTF-8 error
-        // messages if a link error occurred.
-        link_env: vec![("VSLANG".to_string(), "1033".to_string())],
-        lld_flavor: LldFlavor::Link,
-        pre_link_args,
         crt_static_allows_dylibs: true,
         crt_static_respected: true,
-        abi_return_struct_as_int: true,
-        emit_debug_gdb_scripts: false,
         requires_uwtable: true,
         // Currently we don't pass the /NODEFAULTLIB flag to the linker on MSVC
         // as there's been trouble in the past of linking the C++ standard
@@ -40,6 +25,6 @@ pub fn opts() -> TargetOptions {
         // not ever be possible for us to pass this flag.
         no_default_libraries: false,
 
-        ..Default::default()
+        ..base
     }
 }

src/librustc_target/spec/x86_64_unknown_uefi.rs

@@ -28,11 +28,6 @@ pub fn target() -> TargetResult {
     // places no locality-restrictions, so it fits well here.
     base.code_model = Some("large".to_string());
 
-    // UEFI mirrors the calling-conventions used on windows. In case of x86-64 this means small
-    // structs will be returned as int. This shouldn't matter much, since the restrictions placed
-    // by the UEFI specifications forbid any ABI to return structures.
-    base.abi_return_struct_as_int = true;
-
     Ok(Target {
         llvm_target: "x86_64-unknown-windows".to_string(),
         target_endian: "little".to_string(),