ASM_NASM: Improve support for standalone usage

* Add tests for standalone NASM usage

* Change generic ASM_NASM executable linker to <CMAKE_LINKER>

* Use CMAKE_SYSTEM_PROCESSOR to determine output format when used
  without a C/CXX compiler

.gitlab/ci/configure_debian12_ninja.cmake

@@ -1,2 +1,4 @@
+set(CMake_TEST_ASM_NASM "ON" CACHE BOOL "")
+
 include("${CMAKE_CURRENT_LIST_DIR}/configure_debian12_ninja_common.cmake")
 set(CMake_TEST_UseSWIG "ON" CACHE BOOL "")

.gitlab/ci/configure_fedora39_makefiles.cmake

@@ -6,6 +6,7 @@ if (NOT "$ENV{CMAKE_CI_NIGHTLY}" STREQUAL "")
   set(CMake_TEST_CTestUpdate_P4 "ON" CACHE BOOL "")
 endif()
 
+set(CMake_TEST_ASM_NASM "ON" CACHE BOOL "")
 set(CMake_TEST_FindALSA "ON" CACHE BOOL "")
 set(CMake_TEST_FindBLAS "All;static=1;Generic" CACHE STRING "")
 set(CMake_TEST_FindBoost "ON" CACHE BOOL "")

Modules/CMakeASM_NASMInformation.cmake

@@ -12,6 +12,8 @@ if(NOT CMAKE_ASM_NASM_OBJECT_FORMAT)
       set(CMAKE_ASM_NASM_OBJECT_FORMAT win64)
     elseif(DEFINED CMAKE_CXX_SIZEOF_DATA_PTR AND CMAKE_CXX_SIZEOF_DATA_PTR EQUAL 8)
       set(CMAKE_ASM_NASM_OBJECT_FORMAT win64)
+    elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+      set(CMAKE_ASM_NASM_OBJECT_FORMAT win64)
     else()
       set(CMAKE_ASM_NASM_OBJECT_FORMAT win32)
     endif()
@@ -20,6 +22,8 @@ if(NOT CMAKE_ASM_NASM_OBJECT_FORMAT)
       set(CMAKE_ASM_NASM_OBJECT_FORMAT macho64)
     elseif(DEFINED CMAKE_CXX_SIZEOF_DATA_PTR AND CMAKE_CXX_SIZEOF_DATA_PTR EQUAL 8)
       set(CMAKE_ASM_NASM_OBJECT_FORMAT macho64)
+    elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+      set(CMAKE_ASM_NASM_OBJECT_FORMAT macho64)
     else()
       set(CMAKE_ASM_NASM_OBJECT_FORMAT macho)
     endif()
@@ -28,6 +32,8 @@ if(NOT CMAKE_ASM_NASM_OBJECT_FORMAT)
       set(CMAKE_ASM_NASM_OBJECT_FORMAT elf64)
     elseif(DEFINED CMAKE_CXX_SIZEOF_DATA_PTR AND CMAKE_CXX_SIZEOF_DATA_PTR EQUAL 8)
       set(CMAKE_ASM_NASM_OBJECT_FORMAT elf64)
+    elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+      set(CMAKE_ASM_NASM_OBJECT_FORMAT elf64)
     else()
       set(CMAKE_ASM_NASM_OBJECT_FORMAT elf)
     endif()
@@ -38,6 +44,11 @@ if(NOT CMAKE_ASM_NASM_COMPILE_OBJECT)
   set(CMAKE_ASM_NASM_COMPILE_OBJECT "<CMAKE_ASM_NASM_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -f ${CMAKE_ASM_NASM_OBJECT_FORMAT} -o <OBJECT> <SOURCE>")
 endif()
 
+if(NOT CMAKE_ASM_NASM_LINK_EXECUTABLE)
+  set(CMAKE_ASM_NASM_LINK_EXECUTABLE
+    "<CMAKE_LINKER> <CMAKE_ASM_NASM_LINK_FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
+endif()
+
 if(CMAKE_ASM_NASM_COMPILER_ID STREQUAL "NASM")
   set(CMAKE_DEPFILE_FLAGS_ASM_NASM "-MD <DEP_FILE> -MT <DEP_TARGET>")
 

Tests/CMakeLists.txt

@@ -498,6 +498,10 @@ if(BUILD_TESTING)
   ADD_TEST_MACRO(ReturnTest ReturnTest)
   ADD_TEST_MACRO(Properties Properties)
   ADD_TEST_MACRO(Assembler HelloAsm)
+  # relies on Linux syscall interface
+  if(CMake_TEST_ASM_NASM AND CMAKE_SYSTEM_NAME MATCHES "Linux" AND CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64")
+    ADD_TEST_MACRO(NasmOnly NasmOnly)
+  endif()
   ADD_TEST_MACRO(SourceGroups SourceGroups)
   ADD_TEST_MACRO(Preprocess Preprocess)
   set(ExportImport_BUILD_OPTIONS -DCMake_TEST_NESTED_MAKE_PROGRAM:FILEPATH=${CMake_TEST_EXPLICIT_MAKE_PROGRAM}

Tests/NasmOnly/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.28)
+
+project(NasmOnly LANGUAGES ASM_NASM)
+
+add_library(testnasm1 STATIC libnasm1.nasm)
+add_executable(NasmOnly nasmonly.nasm)
+target_link_libraries(NasmOnly testnasm1)

Tests/NasmOnly/libnasm1.nasm

@@ -0,0 +1,6 @@
+global LibNasm1Func
+
+section .text
+LibNasm1Func:
+  mov rax, 1
+  ret

Tests/NasmOnly/nasmonly.nasm

@@ -0,0 +1,19 @@
+global _start
+
+extern LibNasm1Func
+
+section .text
+_start:
+  xor rax, rax
+  call LibNasm1Func
+  cmp rax, 1
+  jne err
+
+  mov rax, 60
+  xor rdi, rdi
+  syscall
+
+err:
+  mov rax, 60
+  mov rdi, 1
+  syscall