[PATCH] conformtest.py: Pass -dD to compiler

[H.J. Lu]

Since Clang doesn't support -dN, pass -dD to compiler.  Split and
reconstruct #define directives to "#define MACRO".

Tested with GCC 14.2 and Clang 19.1.5.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
 conform/conformtest.py | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/conform/conformtest.py b/conform/conformtest.py
index 8337afcdad..f3cd648ef8 100644
--- a/conform/conformtest.py
+++ b/conform/conformtest.py
@@ -620,7 +620,8 @@ class HeaderTests(object):
         out_file = os.path.join(self.temp_dir, 'namespace-out')
         with open(c_file, 'w') as c_file_out:
             c_file_out.write('#include <%s>\n' % self.header)
-        cmd = ('%s %s -E %s -P -Wp,-dN > %s'
+        # NB: Use -dD, instead of -dN, since Clang doesn't support -dN.
+        cmd = ('%s %s -E %s -P -Wp,-dD > %s'
                % (self.cc, self.cflags_namespace, c_file, out_file))
         subprocess.check_call(cmd, shell=True)
         bad_tokens = set()
@@ -629,6 +630,21 @@ class HeaderTests(object):
                 line = line.strip()
                 if not line:
                     continue
+                if line.startswith('#define'):
+                    # -dD outputs of #define directives are
+                    #   #define MACRO expression
+                    #   #define MACRO(arg...) expression
+                    # Split them to
+                    #   ['#define', 'MACRO', 'expression']
+                    #   ['#define', 'MACRO(arg...)', 'expression']
+                    line = line.split()
+                    # Split the second element to
+                    #   ['MACRO']
+                    #   ['MACRO', 'arg...)']
+                    macro = line[1].split("(")
+                    # Reconstruct the line to
+                    #   #define MACRO
+                    line = line[0] + ' ' + macro[0]
                 if re.match(r'# [1-9]', line):
                     continue
                 if line.startswith('#pragma GCC '):
-- 
2.47.1