feat: support function calls via function pointers

The two-pass parsing of function pointer declaration is referenced from chibicc:
https://github.com/rui314/chibicc

2 files changed, 20 insertions, 1 deletions

diff --git a/tests/cli.sh b/tests/cli.sh
index fc8a481..2c6ac72 100644
--- a/tests/cli.sh
+++ b/tests/cli.sh
@@ -45,8 +45,9 @@ int main(int argc, char** argv) {
 EOF
 
 # compile errors
+# TODO: report as "undefined function"
 cat <<'EOF' > expected
-main.c:2: undefined function: f
+main.c:2: undefined variable: f
 EOF
 test_compile_error <<'EOF'
 int main() {
diff --git a/tests/functions.c b/tests/functions.c
index b5ffecb..eef9496 100644
--- a/tests/functions.c
+++ b/tests/functions.c
@@ -95,6 +95,10 @@ int f9(int select, int a, int b, int c, int d, S e, int f, int g) {
     }
 }
 
+int f10() {
+    return 12345;
+}
+
 // recursive functions
 int fib(int n) {
     if (n <= 1) {
@@ -136,6 +140,20 @@ int main() {
     ASSERT_EQ(7, f9(6, 1, 2, 3, 4, s, 7, 8));
     ASSERT_EQ(8, f9(7, 1, 2, 3, 4, s, 7, 8));
 
+    // function pointers
+    ASSERT_EQ(12345, (f10)());
+    ASSERT_EQ(12345, (*f10)());
+    ASSERT_EQ(12345, (**f10)());
+
+    int (*fp1)() = f10;
+    ASSERT_EQ(12345, fp1());
+    int (*fp2)(int, int, int, int, int, int) = f;
+    ASSERT_EQ(1, fp2(1, 2, 3, 4, 5, 6));
+    int (*fp3)(int, int, int, int, int, int) = f6;
+    ASSERT_EQ(6, fp3(1, 2, 3, 4, 5, 6));
+    int (*fp4)(int, int, int, int, int, int, int, int, int, int, int) = f7;
+    ASSERT_EQ(7, fp4(6, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+
     // recursive functions
     ASSERT_EQ(89, fib(10));
 }