Support -c flag for generating object files

.github/workflows/CI.yml

@@ -67,3 +67,8 @@ jobs:
             ./src/bin/lc tests/array_01.cpp --backend=llvm --extra-arg="-Isrc/runtime/include" --
 
             ./src/bin/lc tests/array_02.cpp --backend=llvm --extra-arg="-Isrc/runtime/include" --
+
+            # Test generating object files
+            ./src/bin/lc examples/expr2.c --backend c --extra-arg="-Isrc/runtime/include" -o c_o -c --
+            ./src/bin/lc examples/expr2.c --backend llvm --extra-arg="-Isrc/runtime/include" -o llvm_o -c --
+            ls -1

src/bin/lc.cpp

@@ -53,6 +53,9 @@ static cl::opt<bool>
 static cl::opt<std::string>
     ArgO("o",
     cl::desc(Options.getOptionHelpText(options::OPT_o)), cl::cat(ClangCheckCategory));
+static cl::opt<bool>
+    ArgC("c",
+    cl::desc(Options.getOptionHelpText(options::OPT_c)), cl::cat(ClangCheckCategory));
 static cl::opt<bool>
     ShowWAT("show-wat",
     cl::desc("Show WAT (WebAssembly Text Format) and exit"), cl::cat(ClangCheckCategory));
@@ -373,6 +376,50 @@ int compile_to_binary_object(Allocator &al, const std::string &infile,
     return 0;
 }
 
+int compile_c_to_object_file(const std::string &infile,
+        const std::string &outfile) {
+
+    std::string CC = "cc";
+    char *env_CC = std::getenv("LFORTRAN_CC");
+    if (env_CC) CC = env_CC;
+    std::string options;
+    options += "-I" + LCompilers::LC::get_runtime_library_c_header_dir() + " ";
+    std::string cmd = CC + " " + options + " -o " + outfile + " -c " + infile;
+    int err = system(cmd.c_str());
+    if (err) {
+        std::cout << "The command '" + cmd + "' failed." << std::endl;
+        return 1;
+    }
+    return 0;
+}
+
+int compile_cpp_to_object_file(const std::string &infile,
+        const std::string &outfile) {
+
+    std::string CXX = "g++";
+    std::string options;
+    options += "-I" + LCompilers::LC::get_runtime_library_c_header_dir() + " ";
+    std::string cmd = CXX + " " + options + " -o " + outfile + " -c " + infile;
+    int err = system(cmd.c_str());
+    if (err) {
+        std::cout << "The command '" + cmd + "' failed." << std::endl;
+        return 1;
+    }
+    return 0;
+}
+
+int compile_fortran_to_object_file(const std::string &infile,
+        const std::string &outfile) {
+
+    std::string cmd = "gfortran -fno-backtrace -o " + outfile + " -c " + infile;
+    int err = system(cmd.c_str());
+    if (err) {
+        std::cout << "The command '" + cmd + "' failed." << std::endl;
+        return 1;
+    }
+    return 0;
+}
+
 // infile is an object file
 // outfile will become the executable
 int link_executable(const std::vector<std::string> &infiles,
@@ -698,7 +745,7 @@ int main(int argc, const char **argv) {
         tmp_file = outfile + "__generated__.f90";
         status = compile_to_fortran(al, infile, tmp_file, (LCompilers::ASR::TranslationUnit_t*)tu);
     } else if (backend == Backend::llvm) {
-        tmp_file = outfile + "__generated__.o";
+        tmp_file = ArgC ? outfile : (outfile + "__generated__.o");
         status = compile_to_binary_object(al, infile, tmp_file, (LCompilers::ASR::TranslationUnit_t*)tu);
     }
 
@@ -708,6 +755,19 @@ int main(int argc, const char **argv) {
 
     LCompilers::CompilerOptions co;
     co.arg_o = ArgO;
+
+    if (ArgC) {
+        // generate object file from source code
+        if (backend == Backend::c) {
+            status = compile_c_to_object_file(tmp_file, outfile);
+        } else if (backend == Backend::cpp) {
+            status = compile_cpp_to_object_file(tmp_file, outfile);
+        } else if (backend == Backend::fortran) {
+            status = compile_fortran_to_object_file(tmp_file, outfile);
+        }
+        return status;
+    }
+
     std::vector<std::string> infiles = {tmp_file};
     status = link_executable(infiles, outfile, LCompilers::LC::get_runtime_library_dir(), backend, false, false, true, co);
     return status;