test: added regression test for #774

Author: gnikit

ci/run_tests.sh

@@ -122,6 +122,10 @@ pushd c_main
 "$fpm" run
 popd
 
+pushd c_main_preprocess
+"$fpm" build --c-flag "-DVAL"
+popd
+
 pushd app_with_c
 "$fpm" run
 popd

example_packages/c_main_preprocess/app/main.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+#include "val.h"
+
+int main() {
+    printf("%d\n", variable);
+}

example_packages/c_main_preprocess/fpm.toml

@@ -0,0 +1,7 @@
+name = "c_main_preprocess"
+[library]
+include-dir = ["src"]
+
+[[executable]]
+name="main-c"
+main="main.c"

example_packages/c_main_preprocess/src/val.h

@@ -0,0 +1,7 @@
+#ifndef _VAL_H_
+#define _VAL_H_
+
+#ifdef VAL
+const int variable = 1;
+#endif
+#endif