naked functions: respect function_sections on windows

For `gnu` function_sections is off by default.

Author: folkertdev

compiler/rustc_codegen_ssa/src/mir/naked_asm.rs

@@ -127,6 +127,8 @@ fn prefix_and_suffix<'tcx>(
 
     let is_arm = tcx.sess.target.arch == Arch::Arm;
     let is_thumb = tcx.sess.unstable_target_features.contains(&sym::thumb_mode);
+    let function_sections =
+        tcx.sess.opts.unstable_opts.function_sections.unwrap_or(tcx.sess.target.function_sections);
 
     let attrs = tcx.codegen_instance_attrs(instance.def);
     let link_section = attrs.link_section.map(|symbol| symbol.as_str().to_string());
@@ -256,8 +258,11 @@ fn prefix_and_suffix<'tcx>(
             }
         }
         BinaryFormat::Coff => {
-            let section = link_section.unwrap_or_else(|| format!(".text.{asm_name}"));
-            writeln!(begin, ".pushsection {},\"xr\"", section).unwrap();
+            if let Some(section) = &link_section {
+                writeln!(begin, ".pushsection {section},\"xr\"").unwrap()
+            } else if function_sections {
+                writeln!(begin, ".pushsection .text${asm_name},\"xr\"").unwrap()
+            }
             writeln!(begin, ".balign {align_bytes}").unwrap();
             write_linkage(&mut begin).unwrap();
             writeln!(begin, ".def {asm_name}").unwrap();
@@ -268,7 +273,9 @@ fn prefix_and_suffix<'tcx>(
 
             writeln!(end).unwrap();
             writeln!(end, ".Lfunc_end_{asm_name}:").unwrap();
-            writeln!(end, ".popsection").unwrap();
+            if link_section.is_some() || function_sections {
+                writeln!(end, ".popsection").unwrap();
+            }
             if !arch_suffix.is_empty() {
                 writeln!(end, "{}", arch_suffix).unwrap();
             }

tests/codegen-llvm/naked-fn/naked-functions.rs

@@ -1,12 +1,14 @@
 //@ add-minicore
-//@ revisions: linux win_x86 win_i686 macos thumb
+//@ revisions: linux win_x86_msvc win_x86_gnu win_i686_gnu macos thumb
 //
 //@[linux] compile-flags: --target x86_64-unknown-linux-gnu
 //@[linux] needs-llvm-components: x86
-//@[win_x86] compile-flags: --target x86_64-pc-windows-gnu
-//@[win_x86] needs-llvm-components: x86
-//@[win_i686] compile-flags: --target i686-pc-windows-gnu
-//@[win_i686] needs-llvm-components: x86
+//@[win_x86_gnu] compile-flags: --target x86_64-pc-windows-gnu
+//@[win_x86_gnu] needs-llvm-components: x86
+//@[win_x86_msvc] compile-flags: --target x86_64-pc-windows-msvc
+//@[win_x86_msvc] needs-llvm-components: x86
+//@[win_i686_gnu] compile-flags: --target i686-pc-windows-gnu
+//@[win_i686_gnu] needs-llvm-components: x86
 //@[macos] compile-flags: --target aarch64-apple-darwin
 //@[macos] needs-llvm-components: aarch64
 //@[thumb] compile-flags: --target thumbv7em-none-eabi
@@ -23,8 +25,9 @@ use minicore::*;
 //
 // linux:    .pushsection .text.naked_empty,\22ax\22, @progbits
 // macos:    .pushsection __TEXT,__text,regular,pure_instructions
-// win_x86:  .pushsection .text.naked_empty,\22xr\22
-// win_i686: .pushsection .text._naked_empty,\22xr\22
+// win_x86_msvc:     .pushsection .text$naked_empty,\22xr\22
+// win_x86_gnu-NOT:  .pushsection
+// win_i686_gnu-NOT: .pushsection
 // thumb:    .pushsection .text.naked_empty,\22ax\22, %progbits
 //
 // CHECK: .balign 4
@@ -37,12 +40,12 @@ use minicore::*;
 //
 // linux: .type naked_empty, @function
 //
-// win_x86:  .def naked_empty
-// win_i686: .def _naked_empty
+// win_x86_msvc,win_x86_gnu:  .def naked_empty
+// win_i686_gnu: .def _naked_empty
 //
-// win_x86,win_i686: .scl 2
-// win_x86,win_i686: .type 32
-// win_x86,win_i686: .endef
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .scl 2
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .type 32
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .endef
 //
 // thumb: .type naked_empty, %function
 // thumb: .thumb
@@ -53,7 +56,8 @@ use minicore::*;
 // linux,macos,win: ret
 // thumb: bx lr
 //
-// CHECK: .popsection
+// linux,windows,win_x86_msvc,thumb: .popsection
+// win_x86_gnu-NOT,win_i686_gnu-NOT: .popsection
 //
 // thumb: .thumb
 //
@@ -73,8 +77,9 @@ pub extern "C" fn naked_empty() {
 //
 // linux:    .pushsection .text.naked_with_args_and_return,\22ax\22, @progbits
 // macos:    .pushsection __TEXT,__text,regular,pure_instructions
-// win_x86:  .pushsection .text.naked_with_args_and_return,\22xr\22
-// win_i686: .pushsection .text._naked_with_args_and_return,\22xr\22
+// win_x86_msvc:     .pushsection .text$naked_with_args_and_return,\22xr\22
+// win_x86_gnu-NOT:  .pushsection
+// win_i686_gnu-NOT: .pushsection
 // thumb:    .pushsection .text.naked_with_args_and_return,\22ax\22, %progbits
 //
 // CHECK: .balign 4
@@ -87,27 +92,28 @@ pub extern "C" fn naked_empty() {
 //
 // linux: .type naked_with_args_and_return, @function
 //
-// win_x86:  .def naked_with_args_and_return
-// win_i686: .def _naked_with_args_and_return
+// win_x86_msvc,win_x86_gnu:  .def naked_with_args_and_return
+// win_i686_gnu: .def _naked_with_args_and_return
 //
-// win_x86,win_i686: .scl 2
-// win_x86,win_i686: .type 32
-// win_x86,win_i686: .endef
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .scl 2
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .type 32
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .endef
 //
 // thumb: .type naked_with_args_and_return, %function
 // thumb: .thumb
 // thumb: .thumb_func
 //
 // CHECK-LABEL: naked_with_args_and_return:
 //
-// linux, win_x86,win_i686: lea rax, [rdi + rsi]
+// linux,win_x86_msvc,win_x86_gnu,win_i686_gnu: lea rax, [rdi + rsi]
 // macos: add x0, x0, x1
 // thumb: adds r0, r0, r1
 //
 // linux,macos,win: ret
 // thumb: bx lr
 //
-// CHECK: .popsection
+// linux,windows,win_x86_msvc,thumb: .popsection
+// win_x86_gnu-NOT,win_i686_gnu-NOT: .popsection
 //
 // thumb: .thumb
 //
@@ -134,7 +140,7 @@ pub extern "C" fn naked_with_args_and_return(a: isize, b: isize) -> isize {
 
 // linux:            .pushsection .text.some_different_name,\22ax\22, @progbits
 // macos:            .pushsection .text.some_different_name,regular,pure_instructions
-// win_x86,win_i686: .pushsection .text.some_different_name,\22xr\22
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .pushsection .text.some_different_name,\22xr\22
 // thumb:            .pushsection .text.some_different_name,\22ax\22, %progbits
 // CHECK-LABEL: test_link_section:
 #[no_mangle]
@@ -148,15 +154,15 @@ pub extern "C" fn test_link_section() {
     naked_asm!("bx lr");
 }
 
-// win_x86:  .def fastcall_cc
-// win_i686: .def @fastcall_cc@4
+// win_x86_msvc,win_x86_gnu:  .def fastcall_cc
+// win_i686_gnu: .def @fastcall_cc@4
 //
-// win_x86,win_i686: .scl 2
-// win_x86,win_i686: .type 32
-// win_x86,win_i686: .endef
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .scl 2
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .type 32
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .endef
 //
-// win_x86-LABEL: fastcall_cc:
-// win_i686-LABEL: @fastcall_cc@4:
+// win_x86_msvc-LABEL,win_x86_gnu-LABEL: fastcall_cc:
+// win_i686_gnu-LABEL: @fastcall_cc@4:
 #[cfg(target_os = "windows")]
 #[no_mangle]
 #[unsafe(naked)]