Merge #1375

1375: backend: properly handles foreign ABIs r=philberty a=liushuyu

- Properly handles foreign (`extern` functions) ABIs


Co-authored-by: liushuyu <liushuyu011@gmail.com>

4 files changed, 44 insertions, 6 deletions

diff --git a/gcc/rust/backend/rust-compile-base.cc b/gcc/rust/backend/rust-compile-base.cc
index 3e6e370..5bf64cc 100644
--- a/gcc/rust/backend/rust-compile-base.cc
+++ b/gcc/rust/backend/rust-compile-base.cc
@@ -17,17 +17,20 @@
 // <http://www.gnu.org/licenses/>.
 
 #include "rust-compile-base.h"
+#include "rust-abi.h"
 #include "rust-compile-item.h"
 #include "rust-compile-stmt.h"
 #include "rust-compile-fnparam.h"
 #include "rust-compile-var-decl.h"
 
+#include "rust-diagnostics.h"
 #include "rust-expr.h"	// for AST::AttrInputLiteral
 #include "rust-macro.h" // for AST::MetaNameValueStr
 
 #include "fold-const.h"
 #include "stringpool.h"
 #include "attribs.h"
+#include "tree.h"
 
 namespace Rust {
 namespace Compile {
@@ -293,6 +296,8 @@ HIRCompileBase::handle_must_use_attribute_on_fndecl (tree fndecl,
 void
 HIRCompileBase::setup_abi_options (tree fndecl, ABI abi)
 {
+  tree abi_tree = NULL_TREE;
+
   switch (abi)
     {
     case Rust::ABI::RUST:
@@ -301,22 +306,34 @@ HIRCompileBase::setup_abi_options (tree fndecl, ABI abi)
     case Rust::ABI::CDECL:
       DECL_ATTRIBUTES (fndecl)
 	= tree_cons (get_identifier ("cdecl"), NULL, DECL_ATTRIBUTES (fndecl));
-      break;
+
+      return;
 
     case Rust::ABI::STDCALL:
-      DECL_ATTRIBUTES (fndecl) = tree_cons (get_identifier ("stdcall"), NULL,
-					    DECL_ATTRIBUTES (fndecl));
+      abi_tree = get_identifier ("stdcall");
+
       break;
 
     case Rust::ABI::FASTCALL:
-      DECL_ATTRIBUTES (fndecl) = tree_cons (get_identifier ("fastcall"), NULL,
-					    DECL_ATTRIBUTES (fndecl));
+      abi_tree = get_identifier ("fastcall");
+
+      break;
+
+    case Rust::ABI::SYSV64:
+      abi_tree = get_identifier ("sysv_abi");
+
+      break;
+
+    case Rust::ABI::WIN64:
+      abi_tree = get_identifier ("ms_abi");
 
       break;
 
     default:
       break;
     }
+
+  decl_attributes (&fndecl, build_tree_list (abi_tree, NULL_TREE), 0);
 }
 
 // ported from gcc/c/c-typecheck.c
@@ -497,7 +514,7 @@ HIRCompileBase::compile_function (
 
   setup_fndecl (fndecl, is_main_fn, fntype->has_subsititions_defined (),
 		visibility, qualifiers, outer_attrs);
-  setup_abi_options (fndecl, fntype->get_abi ());
+  setup_abi_options (fndecl, qualifiers.get_abi ());
 
   // conditionally mangle the function name
   bool should_mangle = should_mangle_item (fndecl);
diff --git a/gcc/rust/util/rust-abi.cc b/gcc/rust/util/rust-abi.cc
index 4739887..6477c37 100644
--- a/gcc/rust/util/rust-abi.cc
+++ b/gcc/rust/util/rust-abi.cc
@@ -33,6 +33,10 @@ get_abi_from_string (const std::string &abi)
     return Rust::ABI::STDCALL;
   else if (abi.compare ("fastcall") == 0)
     return Rust::ABI::FASTCALL;
+  else if (abi.compare ("sysv64") == 0)
+    return Rust::ABI::SYSV64;
+  else if (abi.compare ("win64") == 0)
+    return Rust::ABI::WIN64;
 
   return Rust::ABI::UNKNOWN;
 }
@@ -54,6 +58,10 @@ get_string_from_abi (Rust::ABI abi)
       return "stdcall";
     case Rust::ABI::FASTCALL:
       return "fastcall";
+    case Rust::ABI::SYSV64:
+      return "sysv64";
+    case Rust::ABI::WIN64:
+      return "win64";
 
     case Rust::ABI::UNKNOWN:
       return "unknown";
diff --git a/gcc/rust/util/rust-abi.h b/gcc/rust/util/rust-abi.h
index 2bd5ff0..d794cc3 100644
--- a/gcc/rust/util/rust-abi.h
+++ b/gcc/rust/util/rust-abi.h
@@ -30,6 +30,8 @@ enum ABI
   CDECL,
   STDCALL,
   FASTCALL,
+  WIN64,
+  SYSV64
 };
 
 extern Rust::ABI
diff --git a/gcc/testsuite/rust/debug/win64-abi.rs b/gcc/testsuite/rust/debug/win64-abi.rs
new file mode 100644
index 0000000..9d8de40
--- /dev/null
+++ b/gcc/testsuite/rust/debug/win64-abi.rs
@@ -0,0 +1,11 @@
+pub extern "win64" fn square(num: i32) -> i32 {
+    num * num
+}
+
+fn main() {
+    // { dg-do compile { target { x86_64-*-* } } }
+    // { dg-options "-gdwarf-5 -dA -w -O1" }
+    // MS ABI dictates that the first argument is ecx instead of edi from the sysv world
+    // { dg-final { scan-assembler "%ecx, %ecx" } }
+    square(1);
+}