configure_file: Add output_format kwarg (#3636)

* configure_file: Add output_format kwarg

* docs: Reference-manual.md output_format was added in 0.47 [skip ci]

7 files changed, 129 insertions, 11 deletions

diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index 4e916fb55..0c54de0e0 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -208,6 +208,10 @@ the `@variable@` syntax.
   `@PLAINNAME@` or `@BASENAME@` substitutions). In configuration mode,
   the permissions of the input file (if it is specified) are copied to
   the output file.
+- `output_format` *(added 0.47.0)* the format of the output to generate when no input
+  was specified. It defaults to `c`, in which case preprocessor directives
+  will be prefixed with `#`, you can also use `nasm`, in which case the
+  prefix will be `%`.
 
 ### custom_target()
 
diff --git a/docs/markdown/snippets/configure_file_output_format.md b/docs/markdown/snippets/configure_file_output_format.md
new file mode 100644
index 000000000..e52288584
--- /dev/null
+++ b/docs/markdown/snippets/configure_file_output_format.md
@@ -0,0 +1,14 @@
+## New keyword argument `output_format` for configure_file()
+
+When called without an input file, `configure_file` generates a
+C header file by default. A keyword argument was added to allow
+specifying the output format, for example for use with nasm or yasm:
+
+```
+conf = configuration_data()
+conf.set('FOO', 1)
+
+configure_file('config.asm',
+  configuration: conf,
+  output_format: 'nasm')
+```
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index 4f2d45eae..d2238d754 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -1697,7 +1697,7 @@ permitted_kwargs = {'add_global_arguments': {'language'},
                     'add_test_setup': {'exe_wrapper', 'gdb', 'timeout_multiplier', 'env'},
                     'benchmark': {'args', 'env', 'should_fail', 'timeout', 'workdir', 'suite'},
                     'build_target': known_build_target_kwargs,
-                    'configure_file': {'input', 'output', 'configuration', 'command', 'copy', 'install_dir', 'capture', 'install', 'format'},
+                    'configure_file': {'input', 'output', 'configuration', 'command', 'copy', 'install_dir', 'capture', 'install', 'format', 'output_format'},
                     'custom_target': {'input', 'output', 'command', 'install', 'install_dir', 'build_always', 'capture', 'depends', 'depend_files', 'depfile', 'build_by_default'},
                     'dependency': {'default_options', 'fallback', 'language', 'main', 'method', 'modules', 'optional_modules', 'native', 'required', 'static', 'version', 'private_headers'},
                     'declare_dependency': {'include_directories', 'link_with', 'sources', 'dependencies', 'compile_args', 'link_args', 'link_whole', 'version'},
@@ -3196,6 +3196,16 @@ root and issuing %s.
         if fmt not in ('meson', 'cmake', 'cmake@'):
             raise InterpreterException('"format" possible values are "meson", "cmake" or "cmake@".')
 
+        if 'output_format' in kwargs:
+            output_format = kwargs['output_format']
+            if not isinstance(output_format, str):
+                raise InterpreterException('"output_format" keyword must be a string.')
+        else:
+            output_format = 'c'
+
+        if output_format not in ('c', 'nasm'):
+            raise InterpreterException('"format" possible values are "c" or "nasm".')
+
         # Validate input
         inputfile = None
         ifile_abs = None
@@ -3258,7 +3268,7 @@ root and issuing %s.
                         "present in the given configuration data." % (
                             var_list, inputfile), location=node)
             else:
-                mesonlib.dump_conf_header(ofile_abs, conf.held_object)
+                mesonlib.dump_conf_header(ofile_abs, conf.held_object, output_format)
             conf.mark_used()
         elif 'command' in kwargs:
             # We use absolute paths for input and output here because the cwd
diff --git a/mesonbuild/mesonlib.py b/mesonbuild/mesonlib.py
index fe426c574..6a38479d8 100644
--- a/mesonbuild/mesonlib.py
+++ b/mesonbuild/mesonlib.py
@@ -634,28 +634,46 @@ def do_conf_file(src, dst, confdata, format):
     replace_if_different(dst, dst_tmp)
     return missing_variables
 
-def dump_conf_header(ofilename, cdata):
-    ofilename_tmp = ofilename + '~'
-    with open(ofilename_tmp, 'w', encoding='utf-8') as ofile:
-        ofile.write('''/*
+CONF_C_PRELUDE = '''/*
  * Autogenerated by the Meson build system.
  * Do not edit, your changes will be lost.
  */
 
 #pragma once
 
-''')
+'''
+
+CONF_NASM_PRELUDE = '''; Autogenerated by the Meson build system.
+; Do not edit, your changes will be lost.
+
+'''
+
+def dump_conf_header(ofilename, cdata, output_format):
+    if output_format == 'c':
+        prelude = CONF_C_PRELUDE
+        prefix = '#'
+    elif output_format == 'nasm':
+        prelude = CONF_NASM_PRELUDE
+        prefix = '%'
+
+    ofilename_tmp = ofilename + '~'
+    with open(ofilename_tmp, 'w', encoding='utf-8') as ofile:
+        ofile.write(prelude)
         for k in sorted(cdata.keys()):
             (v, desc) = cdata.get(k)
             if desc:
-                ofile.write('/* %s */\n' % desc)
+                if output_format == 'c':
+                    ofile.write('/* %s */\n' % desc)
+                elif output_format == 'nasm':
+                    for line in desc.split('\n'):
+                        ofile.write('; %s\n' % line)
             if isinstance(v, bool):
                 if v:
-                    ofile.write('#define %s\n\n' % k)
+                    ofile.write('%sdefine %s\n\n' % (prefix, k))
                 else:
-                    ofile.write('#undef %s\n\n' % k)
+                    ofile.write('%sundef %s\n\n' % (prefix, k))
             elif isinstance(v, (int, str)):
-                ofile.write('#define %s %s\n\n' % (k, v))
+                ofile.write('%sdefine %s %s\n\n' % (prefix, k, v))
             else:
                 raise MesonException('Unknown data type in configuration file entry: ' + k)
     replace_if_different(ofilename, ofilename_tmp)
diff --git a/run_project_tests.py b/run_project_tests.py
index 3801432d4..2669a92c2 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -523,6 +523,7 @@ def detect_tests_to_run():
         ('python3', 'python3', backend is not Backend.ninja),
         ('fpga', 'fpga', shutil.which('yosys') is None),
         ('frameworks', 'frameworks', False),
+        ('nasm', 'nasm', False),
     ]
     gathered_tests = [(name, gather_tests(Path('test cases', subdir)), skip) for name, subdir, skip in all_tests]
     return gathered_tests
diff --git a/test cases/nasm/1 configure file/hello.asm b/test cases/nasm/1 configure file/hello.asm
new file mode 100644
index 000000000..4188b8dfe
--- /dev/null
+++ b/test cases/nasm/1 configure file/hello.asm
@@ -0,0 +1,27 @@
+;  hello.asm  a first program for nasm for Linux, Intel, gcc
+;
+; assemble:	nasm -f elf -l hello.lst  hello.asm
+; link:		gcc -o hello  hello.o
+; run:	        hello
+; output is:	Hello World
+
+%include "config.asm"
+
+	SECTION .data		; data section
+msg:	db "Hello World",10	; the string to print, 10=cr
+len:	equ $-msg		; "$" means "here"
+				; len is a value, not an address
+
+	SECTION .text		; code section
+        global main		; make label available to linker
+main:				; standard  gcc  entry point
+
+	mov	edx,len		; arg3, length of string to print
+	mov	ecx,msg		; arg2, pointer to string
+	mov	ebx,1		; arg1, where to write, screen
+	mov	eax,4		; write sysout command to int 80 hex
+	int	0x80		; interrupt 80 hex, call kernel
+
+	mov	ebx,HELLO	; exit code, 0=normal
+	mov	eax,1		; exit command to kernel
+	int	0x80		; interrupt 80 hex, call kernel
diff --git a/test cases/nasm/1 configure file/meson.build b/test cases/nasm/1 configure file/meson.build
new file mode 100644
index 000000000..213e11487
--- /dev/null
+++ b/test cases/nasm/1 configure file/meson.build
@@ -0,0 +1,44 @@
+project('nasm config file', 'c')
+
+if host_machine.cpu_family() == 'x86' and host_machine.system() == 'windows'
+  asm_format = 'win32'
+elif host_machine.cpu_family() == 'x86_64' and host_machine.system() == 'windows'
+  asm_format = 'win64'
+elif host_machine.cpu_family() == 'x86' and host_machine.system() == 'linux'
+  asm_format = 'elf32'
+elif host_machine.cpu_family() == 'x86_64' and host_machine.system() == 'linux'
+  asm_format = 'elf64'
+else
+  error('MESON_SKIP_TEST: skipping test on this platform')
+endif
+
+nasm = find_program('nasm', required: false)
+
+if not nasm.found()
+  error('MESON_SKIP_TEST: nasm not available')
+endif
+
+conf = configuration_data()
+
+conf.set('HELLO', 0)
+
+asm_gen = generator(nasm,
+  output : '@BASENAME@.o',
+  arguments : [
+    '-f', asm_format,
+    '-i', meson.current_source_dir() + '/',
+    '-i', join_paths(meson.current_source_dir(), ''),
+    '-P', join_paths(meson.current_build_dir(), 'config.asm'),
+    '@INPUT@',
+    '-o', '@OUTPUT@'])
+
+
+config_file = configure_file(
+  output: 'config.asm',
+  configuration: conf,
+  output_format: 'nasm',
+)
+
+exe = executable('hello', asm_gen.process('hello.asm'))
+
+test('test-nasm-configure-file', exe)