Emit header files for ccallable

Author: Smit-create

src/libasr/codegen/asr_to_c.cpp

@@ -1,4 +1,5 @@
 #include <iostream>
+#include <fstream>
 #include <memory>
 
 #include <libasr/asr.h>
@@ -655,6 +656,7 @@ R"(
 #include <string.h>
 #include <lfortran_intrinsics.h>
 
+#ifndef ASSERT
 #define ASSERT(cond)                                                           \
     {                                                                          \
         if (!(cond)) {                                                         \
@@ -665,6 +667,9 @@ R"(
             exit(1);                                                           \
         }                                                                      \
     }
+#endif
+
+#ifndef ASSERT_MSG
 #define ASSERT_MSG(cond, msg)                                                  \
     {                                                                          \
         if (!(cond)) {                                                         \
@@ -677,6 +682,7 @@ R"(
             exit(1);                                                           \
         }                                                                      \
     }
+#endif
 
 )";
 
@@ -807,6 +813,24 @@ R"(
         }
         src = to_include + head + array_types_decls + unit_src +
               ds_funcs_defined + util_funcs_defined;
+        if (!emit_headers.empty()) {
+            std::string to_includes_1 = "";
+            for (auto &s: headers) {
+                to_includes_1 += "#include <" + s + ">\n";
+            }
+            for (auto &f_name: emit_headers) {
+                std::ofstream out_file;
+                std::string out_src = to_includes_1 + head + f_name.second;
+                std::string ifdefs = f_name.first.substr(0, f_name.first.length() - 2);
+                std::transform(ifdefs.begin(), ifdefs.end(), ifdefs.begin(), ::toupper);
+                ifdefs += "_H";
+                out_src = "#ifndef " + ifdefs + "\n#define " + ifdefs + "\n\n" + out_src;
+                out_src += "\n\n#endif\n";
+                out_file.open(f_name.first);
+                out_file << out_src;
+                out_file.close();
+            }
+        }
     }
 
     void visit_Module(const ASR::Module_t &x) {

src/libasr/codegen/asr_to_c_cpp.h

@@ -104,6 +104,7 @@ class BaseCCPPVisitor : public ASR::BaseVisitor<Struct>
     std::map<uint64_t, SymbolInfo> sym_info;
     std::map<uint64_t, std::string> const_var_names;
     std::map<int32_t, std::string> gotoid2name;
+    std::map<std::string, std::string> emit_headers;
 
     // Output configuration:
     // Use std::string or char*
@@ -622,6 +623,15 @@ R"(#include <stdio.h>
         }
         sub += "\n";
         src = sub;
+        if (f_type->m_abi == ASR::abiType::BindC
+            && f_type->m_deftype == ASR::deftypeType::Implementation) {
+            if (x.m_c_header) {
+                std::string header_name = std::string(x.m_c_header);
+                user_headers.insert(header_name);
+                emit_headers[header_name]+= "\n" + src;
+                src = "";
+            }
+        }
         current_scope = current_scope_copy;
     }