Refactor load/save implementations for mod/pyc files

Author: czgdp1807

src/libasr/modfile.cpp

@@ -12,25 +12,8 @@ namespace LFortran {
 
 const std::string lfortran_modfile_type_string = "LFortran Modfile";
 
-// The save_modfile() and load_modfile() must stay consistent. What is saved
-// must be loaded in exactly the same order.
-
-/*
-    Saves the module into a binary stream.
-
-    That stream can be saved to a mod file by the caller.
-    The sections in the file/stream are saved using write_string(), so they
-    can be efficiently read by the loader and ignored if needed.
-
-    Comments below show some possible future improvements to the mod format.
-*/
-std::string save_modfile(const ASR::TranslationUnit_t &m) {
-    LFORTRAN_ASSERT(m.m_global_scope->get_scope().size()== 1);
-    for (auto &a : m.m_global_scope->get_scope()) {
-        LFORTRAN_ASSERT(ASR::is_a<ASR::Module_t>(*a.second));
-        if ((bool&)a) { } // Suppress unused warning in Release mode
-    }
-#ifdef WITH_LFORTRAN_BINARY_MODFILES
+inline void save_asr(const ASR::TranslationUnit_t &m, std::string& asr_string) {
+    #ifdef WITH_LFORTRAN_BINARY_MODFILES
     BinaryWriter b;
 #else
     TextWriter b;
@@ -54,39 +37,40 @@ std::string save_modfile(const ASR::TranslationUnit_t &m) {
     // Full ASR:
     b.write_string(serialize(m));
 
-    return b.get_str();
+    asr_string = b.get_str();
 }
 
-std::string save_pycfile(const ASR::TranslationUnit_t &m) {
-#ifdef WITH_LFORTRAN_BINARY_MODFILES
-    BinaryWriter b;
-#else
-    TextWriter b;
-#endif
-    // Header
-    b.write_string(lfortran_modfile_type_string);
-    b.write_string(LFORTRAN_VERSION);
+// The save_modfile() and load_modfile() must stay consistent. What is saved
+// must be loaded in exactly the same order.
 
-    // AST section: Original module source code:
-    // Currently empty.
-    // Note: in the future we can save here:
-    // * A path to the original source code
-    // * Hash of the orig source code
-    // * AST binary export of it (this AST only changes if the hash changes)
+/*
+    Saves the module into a binary stream.
 
-    // ASR section:
+    That stream can be saved to a mod file by the caller.
+    The sections in the file/stream are saved using write_string(), so they
+    can be efficiently read by the loader and ignored if needed.
 
-    // Export ASR:
-    // Currently empty.
+    Comments below show some possible future improvements to the mod format.
+*/
+std::string save_modfile(const ASR::TranslationUnit_t &m) {
+    LFORTRAN_ASSERT(m.m_global_scope->get_scope().size()== 1);
+    for (auto &a : m.m_global_scope->get_scope()) {
+        LFORTRAN_ASSERT(ASR::is_a<ASR::Module_t>(*a.second));
+        if ((bool&)a) { } // Suppress unused warning in Release mode
+    }
 
-    // Full ASR:
-    b.write_string(serialize(m));
+    std::string asr_string;
+    save_asr(m, asr_string);
+    return asr_string;
+}
 
-    return b.get_str();
+std::string save_pycfile(const ASR::TranslationUnit_t &m) {
+    std::string asr_string;
+    save_asr(m, asr_string);
+    return asr_string;
 }
 
-ASR::TranslationUnit_t* load_modfile(Allocator &al, const std::string &s,
-        bool load_symtab_id, SymbolTable &symtab) {
+inline void load_serialised_asr(const std::string &s, std::string& asr_binary) {
 #ifdef WITH_LFORTRAN_BINARY_MODFILES
     BinaryReader b(s);
 #else
@@ -100,7 +84,13 @@ ASR::TranslationUnit_t* load_modfile(Allocator &al, const std::string &s,
     if (version != LFORTRAN_VERSION) {
         throw LCompilersException("Incompatible format: LFortran Modfile was generated using version '" + version + "', but current LFortran version is '" + LFORTRAN_VERSION + "'");
     }
-    std::string asr_binary = b.read_string();
+    asr_binary = b.read_string();
+}
+
+ASR::TranslationUnit_t* load_modfile(Allocator &al, const std::string &s,
+        bool load_symtab_id, SymbolTable &symtab) {
+    std::string asr_binary;
+    load_serialised_asr(s, asr_binary);
     ASR::asr_t *asr = deserialize_asr(al, asr_binary, load_symtab_id, symtab);
 
     ASR::TranslationUnit_t *tu = ASR::down_cast2<ASR::TranslationUnit_t>(asr);
@@ -109,21 +99,8 @@ ASR::TranslationUnit_t* load_modfile(Allocator &al, const std::string &s,
 
 ASR::TranslationUnit_t* load_pycfile(Allocator &al, const std::string &s,
         bool load_symtab_id) {
-#ifdef WITH_LFORTRAN_BINARY_MODFILES
-    BinaryReader b(s);
-#else
-    TextReader b(s);
-#endif
-
-    std::string file_type = b.read_string();
-    if (file_type != lfortran_modfile_type_string) {
-        throw LCompilersException("LFortran Modfile format not recognized");
-    }
-    std::string version = b.read_string();
-    if (version != LFORTRAN_VERSION) {
-        throw LCompilersException("Incompatible format: LFortran Modfile was generated using version '" + version + "', but current LFortran version is '" + LFORTRAN_VERSION + "'");
-    }
-    std::string asr_binary = b.read_string();
+    std::string asr_binary;
+    load_serialised_asr(s, asr_binary);
     ASR::asr_t *asr = deserialize_asr(al, asr_binary, load_symtab_id);
 
     ASR::TranslationUnit_t *tu = ASR::down_cast2<ASR::TranslationUnit_t>(asr);