fix: function-like macro name not followed by parenthesis

2 files changed, 31 insertions, 1 deletions

diff --git a/src/preprocess.c b/src/preprocess.c
index b826bf2..b23ec4e 100644
--- a/src/preprocess.c
+++ b/src/preprocess.c
@@ -541,7 +541,9 @@ static MacroArgArray* pp_parse_macro_arguments(Preprocessor* pp, bool skip_newli
     MacroArgArray* args = macroargs_new();
 
     skip_whitespaces_or_newlines(pp, skip_newline);
-    expect_pp_token(pp, TokenKind_paren_l);
+    if (!consume_pp_token_if(pp, TokenKind_paren_l)) {
+        return NULL;
+    }
     skip_whitespaces_or_newlines(pp, skip_newline);
     Token* tok = peek_pp_token(pp);
     if (!skip_newline && tok->kind == TokenKind_newline) {
@@ -735,6 +737,10 @@ static int expand_macro(Preprocessor* pp, bool skip_newline, MacroExpansionConte
     if (macro->kind == MacroKind_func) {
         next_pp_token(pp);
         MacroArgArray* args = pp_parse_macro_arguments(pp, skip_newline);
+        if (!args) {
+            // If function-like macro name is not followed by opening parenthesis, it is not a macro invocation.
+            return pp->pos - macro_name_pos;
+        }
         token_count_before_expansion = pp->pos - macro_name_pos;
         replace_pp_tokens(pp, macro_name_pos, pp->pos, &macro->replacements);
 
diff --git a/tests/macros.sh b/tests/macros.sh
index 902f168..a6cf3df 100644
--- a/tests/macros.sh
+++ b/tests/macros.sh
@@ -422,3 +422,27 @@ int main() {
 #endif
 }
 EOF
+
+cat <<'EOF' > expected
+42
+EOF
+test_diff <<'EOF'
+int printf();
+
+#define m1(x) x
+
+int main() {
+    int m1 = 42;
+    printf("%d\n", m1);
+}
+EOF
+
+cat <<'EOF' > expected
+struct { int foo; } s;
+int x = ( ( 1) * 2);
+EOF
+test_cpp <<'EOF'
+#define foo(x) ((x) * 2)
+struct { int foo; } s;
+int x = foo(1);
+EOF