fixes for windows compilation (defining NOMINMAX)

installation-instructions for Windows/Visual Studio

.gitignore

@@ -42,6 +42,7 @@ Testing/Temporary
 CPackConfig.cmake
 CPackSourceConfig.cmake
 _CPack_Packages
+/CMakeSettings.json
 
 ## libraries
 *.a
@@ -68,6 +69,7 @@ src/lfortran/parser/tokenizer.cpp
 src/lfortran/parser/preprocessor.cpp
 src/lfortran/ast.h
 src/lfortran/asr.h
+src/libasr/asr.h
 src/lfortran/config.h
 share/jupyter/kernels/fortran/kernel.json
 src/runtime/*.o.empty.c 
@@ -141,6 +143,7 @@ MANIFEST
 
 ## Editor Files
 .vscode/
+.vs/
 
 ## Build Files
 */bin/lfortran

doc/src/installation.md

@@ -99,6 +99,38 @@ Run an interactive prompt:
 ./src/bin/lfortran
 ```
 
+## Build on Windows with Visual Studio
+
+Install Conda for example by installing the Miniconda installation by following instructions there for your platform. If not already done, activate the Conda-Installation (cf. Conda installation instructions).
+
+First, clone the repo to a local folder.
+
+Launch a Conda command interpreter and run the following commands:
+```bash
+conda update -q conda
+conda install -c conda-forge python=3.7 re2c m2-bison xonsh llvmdev=11.1.0 jupyter xeus=1.0.1 xtl nlohmann_json cppzmq jupyter_kernel_test pytest
+```
+Next, from the Conda prompt, launch an `xonsh`-shell:
+```bash
+xonsh
+```
+and `cd`` to the root of the repository and run
+```bash
+bash ci/version.sh
+python grammar/asdl_cpp.py
+python grammar/asdl_cpp.py grammar/ASR.asdl src/libasr/asr.h
+pushd src/lfortran/parser && re2c -W -b tokenizer.re -o tokenizer.cpp && popd
+pushd src/lfortran/parser && re2c -W -b preprocessor.re -o preprocessor.cpp && popd
+pushd src/lfortran/parser && bison -Wall -d -r all parser.yy && popd
+```
+
+Now, you can launch Visual Studio and open the LFortran folder.
+Before the first build you have to set up the `ZLib`-pathes: Go to the CMake-Settings (Project -> CMake Setttings for lfortran) and check `Show advanced variables`. Scroll to the `ZLIB_...` variables and set:
+- `ZLIB_INCLUDE_DIR` = \<Conda-Installation-Path\>\Library\include
+- `ZLIB_LIBRARY_[DEBUG|RELEASE]` = \<Conda-Installation-Path\>\Library\lib\zlib.lib
+
+Then you can generate the CMake-Cache and build the project.
+
 ## Enabling the Jupyter Kernel
 
 To install the Jupyter kernel, install the following Conda packages also:

src/bin/tpl/cpp-terminal/terminal_base.h

@@ -12,6 +12,9 @@
 #include <stdexcept>
 
 #ifdef _WIN32
+#    ifndef NOMINMAX
+#    define NOMINMAX
+#    endif // NOMINMAX
 #    include <conio.h>
 #    define _WINSOCKAPI_
 #    include <windows.h>

src/bin/tpl/whereami/whereami.cpp

@@ -47,7 +47,9 @@ extern "C" {
 #endif
 
 #if defined(_WIN32)
-
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif // NOMINMAX
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif

src/lfortran/utils.cpp

@@ -1,3 +1,10 @@
+#ifdef _WIN32
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif // NOMINMAX
+#include <windows.h>
+#endif
+
 #include <fstream>
 
 #include <bin/tpl/whereami/whereami.h>
@@ -57,5 +64,75 @@ std::string get_runtime_library_header_dir()
     return get_runtime_library_dir() + "/impure";
 }
 
+bool read_file(const std::string &filename, std::string &text)
+{
+    std::ifstream ifs(filename.c_str(), std::ios::in | std::ios::binary
+            | std::ios::ate);
+
+    std::ifstream::pos_type filesize = ifs.tellg();
+    if (filesize < 0) return false;
+
+    ifs.seekg(0, std::ios::beg);
+
+    std::vector<char> bytes(filesize);
+    ifs.read(&bytes[0], filesize);
+
+    text = std::string(&bytes[0], filesize);
+    return true;
+}
+
+bool present(Vec<char*> &v, const char* name) {
+    for (auto &a : v) {
+        if (std::string(a) == std::string(name)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+Platform get_platform()
+{
+#ifdef _WIN32
+    return Platform::Windows;
+#else
+#    ifdef __APPLE__
+#        ifdef __aarch64__
+    return Platform::macOS_ARM;
+#        else
+    return Platform::macOS_Intel;
+#        endif
+#    else
+#        ifdef __FreeBSD__
+    return Platform::FreeBSD;
+#        else
+    return Platform::Linux;
+#        endif
+#    endif
+#endif
+}
+
+// Platform-specific initialization
+// On Windows, enable colors in terminal. On other systems, does nothing.
+// Return value: 0 on success, negative number on failure.
+int initialize()
+{
+#ifdef _WIN32
+    HANDLE h_stdout = GetStdHandle(STD_OUTPUT_HANDLE);
+    if (h_stdout == INVALID_HANDLE_VALUE)
+        return -1;
+
+    DWORD mode;
+    if (! GetConsoleMode(h_stdout, &mode))
+        return -2;
+
+    mode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
+    if (! SetConsoleMode(h_stdout, mode))
+        return -3;
+
+    return 0;
+#else
+    return 0;
+#endif
+}
 
 }