Bug 1501796 - Check for nasm in configure script. r=firefox-build-system-reviewers,mshal

Differential Revision: https://phabricator.services.mozilla.com/D9854

--HG--
extra : moz-landing-system : lando

build/moz.configure/toolchain.configure

@@ -128,6 +128,65 @@ set_config('HAVE_YASM', have_yasm)
 # Until the YASM variable is not necessary in old-configure.
 add_old_configure_assignment('YASM', have_yasm)
 
+# nasm detection
+# ==============================================================
+nasm = check_prog('NASM', ['nasm'], allow_missing=True)
+
+
+@depends_if(nasm)
+@checking('nasm version')
+def nasm_version(nasm):
+    version = check_cmd_output(
+        nasm, '-v',
+        onerror=lambda: die('Failed to get nasm version.')
+    ).splitlines()[0].split()[2]
+    return Version(version)
+
+
+@depends_if(nasm_version)
+def nasm_major_version(nasm_version):
+    return str(nasm_version.major)
+
+
+@depends_if(nasm_version)
+def nasm_minor_version(nasm_version):
+    return str(nasm_version.minor)
+
+
+set_config('NASM_MAJOR_VERSION', nasm_major_version)
+set_config('NASM_MINOR_VERSION', nasm_minor_version)
+
+
+@depends(nasm, target)
+def nasm_asflags(nasm, target):
+    if nasm:
+        asflags = {
+            ('OSX', 'x86'): ['-f', 'macho32'],
+            ('OSX', 'x86_64'): ['-f', 'macho64'],
+            ('WINNT', 'x86'): ['-f', 'win32'],
+            ('WINNT', 'x86_64'): ['-f', 'win64'],
+        }.get((target.os, target.cpu), None)
+        if asflags is None:
+            # We're assuming every x86 platform we support that's
+            # not Windows or Mac is ELF.
+            if target.cpu == 'x86':
+                asflags = ['-f', 'elf32']
+            elif target.cpu == 'x86_64':
+                asflags = ['-f', 'elf64']
+        return asflags
+
+
+set_config('NASM_ASFLAGS', nasm_asflags)
+
+
+@depends(nasm_asflags)
+def have_nasm(value):
+    if value:
+        return True
+
+
+set_config('HAVE_NASM', have_nasm)
+
 # Android NDK
 # ==============================================================