Revert "Merge pull request #1702 from Kelimion/filename_generation"

This reverts commit a40a53b10447c9223c24cccf565a95f1773d3922, reversing
changes made to 5422a3b17eae821df4adf869960995e922eb0e76.

21 files changed, 434 insertions, 697 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d72775636..3cc4283b0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,9 +39,7 @@ jobs:
           make
         timeout-minutes: 10
       - name: Odin issues tests
-        run: |
-          cd tests/issues
-          ./run.sh
+        run: tests/issues/run.sh
         timeout-minutes: 10
       - name: Odin check examples/all for Linux i386
         run: ./odin check examples/all -vet -strict-style -target:linux_i386
@@ -93,9 +91,7 @@ jobs:
           make
         timeout-minutes: 10
       - name: Odin issues tests
-        run: |
-          cd tests/issues
-          ./run.sh
+        run: tests/issues/run.sh
         timeout-minutes: 10
       - name: Odin check examples/all for Darwin arm64
         run: ./odin check examples/all -vet -strict-style -target:darwin_arm64
@@ -167,8 +163,7 @@ jobs:
         shell: cmd
         run: |
           call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat
-          cd tests\issues
-          call run.bat
+          call tests\issues\run.bat
         timeout-minutes: 10
       - name: Odin check examples/all for Windows 32bits
         shell: cmd
diff --git a/.gitignore b/.gitignore
index d03a86fd7..e8b3d3050 100644
--- a/.gitignore
+++ b/.gitignore
@@ -269,7 +269,6 @@ bin/
 # - Linux/MacOS
 odin
 odin.dSYM
-*.bin
 
 # shared collection
 shared/
diff --git a/Makefile b/Makefile
index 1a1c93180..82150c6a2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
-all: debug
+all: debug demo
 
 demo:
-	./odin run examples/demo
+	./odin run examples/demo/demo.odin
 
 report:
 	./odin report
diff --git a/build_odin.sh b/build_odin.sh
index 4810cafd2..aef3f2836 100755
--- a/build_odin.sh
+++ b/build_odin.sh
@@ -102,7 +102,7 @@ build_odin() {
 }
 
 run_demo() {
-	./odin run examples/demo
+	./odin run examples/demo/demo.odin -file
 }
 
 case $OS in
@@ -147,4 +147,4 @@ if [[ $# -eq 1 ]]; then
 	exit 0
 else
 	panic "Too many arguments!"
-fi
\ No newline at end of file
+fi
diff --git a/core/crypto/util/util.odin b/core/crypto/util/util.odin
index 83b07e546..6273a232e 100644
--- a/core/crypto/util/util.odin
+++ b/core/crypto/util/util.odin
@@ -11,7 +11,6 @@ package util
 */
 
 import "core:mem"
-_ :: mem
 
 // @note(bp): this can replace the other two
 cast_slice :: #force_inline proc "contextless" ($D: typeid/[]$DE, src: $S/[]$SE) -> D {
diff --git a/src/build_settings.cpp b/src/build_settings.cpp
index 212ded5c8..2f3eb03a5 100644
--- a/src/build_settings.cpp
+++ b/src/build_settings.cpp
@@ -3,6 +3,7 @@
 #include <sys/sysctl.h>
 #endif
 
+
 // #if defined(GB_SYSTEM_WINDOWS)
 // #define DEFAULT_TO_THREADED_CHECKER
 // #endif
@@ -197,22 +198,6 @@ enum RelocMode : u8 {
 	RelocMode_DynamicNoPIC,
 };
 
-enum BuildPath : u8 {
-	BuildPath_Main_Package,     // Input  Path to the package directory (or file) we're building.
-	BuildPath_RC,               // Input  Path for .rc  file, can be set with `-resource:`.
-	BuildPath_RES,              // Output Path for .res file, generated from previous.
-	BuildPath_Win_SDK_Root,     // windows_sdk_root
-	BuildPath_Win_SDK_UM_Lib,   // windows_sdk_um_library_path
-	BuildPath_Win_SDK_UCRT_Lib, // windows_sdk_ucrt_library_path
-	BuildPath_VS_EXE,           // vs_exe_path
-	BuildPath_VS_LIB,           // vs_library_path
-
-	BuildPath_Output,           // Output Path for .exe, .dll, .so, etc. Can be overridden with `-out:`.
-	BuildPath_PDB,              // Output Path for .pdb file, can be overridden with `-pdb-name:`.
-
-	BuildPathCOUNT,
-};
-
 // This stores the information for the specify architecture of this build
 struct BuildContext {
 	// Constants
@@ -241,13 +226,9 @@ struct BuildContext {
 
 	bool show_help;
 
-	Array<Path> build_paths;   // Contains `Path` objects to output filename, pdb, resource and intermediate files.
-	                           // BuildPath enum contains the indices of paths we know *before* the work starts.
-
 	String out_filepath;
 	String resource_filepath;
 	String pdb_filepath;
-
 	bool   has_resource;
 	String link_flags;
 	String extra_linker_flags;
@@ -319,6 +300,8 @@ struct BuildContext {
 
 };
 
+
+
 gb_global BuildContext build_context = {0};
 
 bool global_warnings_as_errors(void) {
@@ -622,6 +605,28 @@ bool allow_check_foreign_filepath(void) {
 // is_abs_path
 // has_subdir
 
+enum TargetFileValidity : u8 {
+	TargetFileValidity_Invalid,
+
+	TargetFileValidity_Writable_File,
+	TargetFileValidity_No_Write_Permission,
+	TargetFileValidity_Directory,
+
+	TargetTargetFileValidity_COUNT,
+};
+
+TargetFileValidity set_output_filename(void) {
+	// Assembles the output filename from build_context information.
+	// Returns `true`  if it doesn't exist or is a file.
+	// Returns `false` if a directory or write-protected file.
+
+
+
+
+	return TargetFileValidity_Writable_File;
+}
+
+
 String const WIN32_SEPARATOR_STRING = {cast(u8 *)"\\", 1};
 String const NIX_SEPARATOR_STRING   = {cast(u8 *)"/",  1};
 
@@ -968,6 +973,7 @@ char *token_pos_to_string(TokenPos const &pos) {
 	return s;
 }
 
+
 void init_build_context(TargetMetrics *cross_target) {
 	BuildContext *bc = &build_context;
 
@@ -1146,166 +1152,8 @@ void init_build_context(TargetMetrics *cross_target) {
 
 	bc->optimization_level = gb_clamp(bc->optimization_level, 0, 3);
 
+
+
 	#undef LINK_FLAG_X64
 	#undef LINK_FLAG_386
 }
-
-#if defined(GB_SYSTEM_WINDOWS)
-// NOTE(IC): In order to find Visual C++ paths without relying on environment variables.
-// NOTE(Jeroen): No longer needed in `main.cpp -> linker_stage`. We now resolve those paths in `init_build_paths`.
-#include "microsoft_craziness.h"
-#endif
-
-// NOTE(Jeroen): Set/create the output and other paths and report an error as appropriate.
-// We've previously called `parse_build_flags`, so `out_filepath` should be set.
-bool init_build_paths(String init_filename) {
-	gbAllocator   ha = heap_allocator();
-	BuildContext *bc = &build_context;
-
-	// NOTE(Jeroen): We're pre-allocating BuildPathCOUNT slots so that certain paths are always at the same enumerated index.
-	array_init(&bc->build_paths, permanent_allocator(), BuildPathCOUNT);
-
-	// [BuildPathMainPackage] Turn given init path into a `Path`, which includes normalizing it into a full path.
-	bc->build_paths[BuildPath_Main_Package] = path_from_string(ha, init_filename);
-
-	bool produces_output_file = false;
-	if (bc->command_kind == Command_doc && bc->cmd_doc_flags & CmdDocFlag_DocFormat) {
-		produces_output_file = true;
-	} else if (bc->command_kind & Command__does_build) {
-		produces_output_file = true;
-	}
-
-	if (!produces_output_file) {
-		// Command doesn't produce output files. We're done.
-		return true;
-	}
-
-	#if defined(GB_SYSTEM_WINDOWS)
-		if (bc->resource_filepath.len > 0) {
-			bc->build_paths[BuildPath_RC]      = path_from_string(ha, bc->resource_filepath);
-			bc->build_paths[BuildPath_RES]     = path_from_string(ha, bc->resource_filepath);
-			bc->build_paths[BuildPath_RC].ext  = copy_string(ha, STR_LIT("rc"));
-			bc->build_paths[BuildPath_RES].ext = copy_string(ha, STR_LIT("res"));
-		}
-
-		if (bc->pdb_filepath.len > 0) {
-			bc->build_paths[BuildPath_PDB]          = path_from_string(ha, bc->pdb_filepath);
-		}
-
-		if ((bc->command_kind & Command__does_build) && (!bc->ignore_microsoft_magic)) {
-			// NOTE(ic): It would be nice to extend this so that we could specify the Visual Studio version that we want instead of defaulting to the latest.
-			Find_Result_Utf8 find_result = find_visual_studio_and_windows_sdk_utf8();
-
-			if (find_result.windows_sdk_version == 0) {
-				gb_printf_err("Windows SDK not found.\n");
-				return false;
-			}
-
-			GB_ASSERT(find_result.windows_sdk_um_library_path.len > 0);
-			GB_ASSERT(find_result.windows_sdk_ucrt_library_path.len > 0);
-
-			if (find_result.windows_sdk_root.len > 0) {
-				bc->build_paths[BuildPath_Win_SDK_Root]     = path_from_string(ha, find_result.windows_sdk_root);
-			}
-
-			if (find_result.windows_sdk_um_library_path.len > 0) {
-				bc->build_paths[BuildPath_Win_SDK_UM_Lib]   = path_from_string(ha, find_result.windows_sdk_um_library_path);
-			}
-
-			if (find_result.windows_sdk_ucrt_library_path.len > 0) {
-				bc->build_paths[BuildPath_Win_SDK_UCRT_Lib] = path_from_string(ha, find_result.windows_sdk_ucrt_library_path);
-			}
-
-			if (find_result.vs_exe_path.len > 0) {
-				bc->build_paths[BuildPath_VS_EXE]           = path_from_string(ha, find_result.vs_exe_path);
-			}
-
-			if (find_result.vs_library_path.len > 0) {
-				bc->build_paths[BuildPath_VS_LIB]           = path_from_string(ha, find_result.vs_library_path);
-			}
-
-			gb_free(ha, find_result.windows_sdk_root.text);
-			gb_free(ha, find_result.windows_sdk_um_library_path.text);
-			gb_free(ha, find_result.windows_sdk_ucrt_library_path.text);
-			gb_free(ha, find_result.vs_exe_path.text);
-			gb_free(ha, find_result.vs_library_path.text);
-
-		}
-	#endif
-
-	// All the build targets and OSes.
-	String output_extension;
-
-	if (bc->command_kind == Command_doc && bc->cmd_doc_flags & CmdDocFlag_DocFormat) {
-		output_extension = STR_LIT("odin-doc");
-	} else if (is_arch_wasm()) {
-		output_extension = STR_LIT("wasm");
-	} else if (build_context.build_mode == BuildMode_Executable) {
-		// By default use a .bin executable extension.
-		output_extension = STR_LIT("bin");
-
-		if (build_context.metrics.os == TargetOs_windows) {
-			output_extension = STR_LIT("exe");
-		} else if (build_context.cross_compiling && selected_target_metrics->metrics == &target_essence_amd64) {
-			output_extension = make_string(nullptr, 0);
-		}
-	} else if (build_context.build_mode == BuildMode_DynamicLibrary) {
-		// By default use a .so shared library extension.
-		output_extension = STR_LIT("so");
-
-		if (build_context.metrics.os == TargetOs_windows) {
-			output_extension = STR_LIT("dll");
-		} else if (build_context.metrics.os == TargetOs_darwin) {
-			output_extension = STR_LIT("dylib");
-		}
-	} else if (build_context.build_mode == BuildMode_Object) {
-		// By default use a .o object extension.
-		output_extension = STR_LIT("o");
-
-		if (build_context.metrics.os == TargetOs_windows) {
-			output_extension = STR_LIT("obj");
-		}
-	} else if (build_context.build_mode == BuildMode_Assembly) {
-		// By default use a .S asm extension.
-		output_extension = STR_LIT("S");
-	} else if (build_context.build_mode == BuildMode_LLVM_IR) {
-		output_extension = STR_LIT("ll");
-	} else {
-		GB_PANIC("Unhandled build mode/target combination.\n");
-	}
-
-	if (bc->out_filepath.len > 0) {
-		bc->build_paths[BuildPath_Output] = path_from_string(ha, bc->out_filepath);
-	} else {
-		String output_name = remove_directory_from_path(init_filename);
-		output_name        = remove_extension_from_path(output_name);
-		output_name        = copy_string(ha, string_trim_whitespace(output_name));
-
-		Path output_path = path_from_string(ha, output_name);
-
-		// Replace extension.
-		if (output_path.ext.len > 0) {
-			gb_free(ha, output_path.ext.text);
-		}
-		output_path.ext  = copy_string(ha, output_extension);
-
-		bc->build_paths[BuildPath_Output] = output_path;
-	}
-
-	// Do we have an extension? We might not if the output filename was supplied.
-	if (bc->build_paths[BuildPath_Output].ext.len == 0) {
-		if (build_context.metrics.os == TargetOs_windows || build_context.build_mode != BuildMode_Executable) {
-			bc->build_paths[BuildPath_Output].ext = copy_string(ha, output_extension);
-		}
-	}
-
-	// Check if output path is a directory.
-	if (path_is_directory(bc->build_paths[BuildPath_Output])) {
-		String output_file = path_to_string(ha, bc->build_paths[BuildPath_Output]);
-		defer (gb_free(ha, output_file.text));
-		gb_printf_err("Output path %.*s is a directory.\n", LIT(output_file));
-		return false;
-	}
-
-	return true;
-}
\ No newline at end of file
diff --git a/src/common.cpp b/src/common.cpp
index 94248fb62..aaacda04b 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -675,7 +675,262 @@ wchar_t **command_line_to_wargv(wchar_t *cmd_line, int *_argc) {
 
 #endif
 
-#include "path.cpp"
+
+#if defined(GB_SYSTEM_WINDOWS)
+	bool path_is_directory(String path) {
+		gbAllocator a = heap_allocator();
+		String16 wstr = string_to_string16(a, path);
+		defer (gb_free(a, wstr.text));
+
+		i32 attribs = GetFileAttributesW(wstr.text);
+		if (attribs < 0) return false;
+
+		return (attribs & FILE_ATTRIBUTE_DIRECTORY) != 0;
+	}
+
+#else
+	bool path_is_directory(String path) {
+		gbAllocator a = heap_allocator();
+		char *copy = cast(char *)copy_string(a, path).text;
+		defer (gb_free(a, copy));
+
+		struct stat s;
+		if (stat(copy, &s) == 0) {
+			return (s.st_mode & S_IFDIR) != 0;
+		}
+		return false;
+	}
+#endif
+
+
+String path_to_full_path(gbAllocator a, String path) {
+	gbAllocator ha = heap_allocator();
+	char *path_c = gb_alloc_str_len(ha, cast(char *)path.text, path.len);
+	defer (gb_free(ha, path_c));
+
+	char *fullpath = gb_path_get_full_name(a, path_c);
+	String res = string_trim_whitespace(make_string_c(fullpath));
+#if defined(GB_SYSTEM_WINDOWS)
+	for (isize i = 0; i < res.len; i++) {
+		if (res.text[i] == '\\') {
+			res.text[i] = '/';
+		}
+	}
+#endif
+	return res;
+}
+
+
+
+struct FileInfo {
+	String name;
+	String fullpath;
+	i64    size;
+	bool   is_dir;
+};
+
+enum ReadDirectoryError {
+	ReadDirectory_None,
+
+	ReadDirectory_InvalidPath,
+	ReadDirectory_NotExists,
+	ReadDirectory_Permission,
+	ReadDirectory_NotDir,
+	ReadDirectory_Empty,
+	ReadDirectory_Unknown,
+
+	ReadDirectory_COUNT,
+};
+
+i64 get_file_size(String path) {
+	char *c_str = alloc_cstring(heap_allocator(), path);
+	defer (gb_free(heap_allocator(), c_str));
+
+	gbFile f = {};
+	gbFileError err = gb_file_open(&f, c_str);
+	defer (gb_file_close(&f));
+	if (err != gbFileError_None) {
+		return -1;
+	}
+	return gb_file_size(&f);
+}
+
+
+#if defined(GB_SYSTEM_WINDOWS)
+ReadDirectoryError read_directory(String path, Array<FileInfo> *fi) {
+	GB_ASSERT(fi != nullptr);
+
+	gbAllocator a = heap_allocator();
+
+	while (path.len > 0) {
+		Rune end = path[path.len-1];
+		if (end == '/') {
+			path.len -= 1;
+		} else if (end == '\\') {
+			path.len -= 1;
+		} else {
+			break;
+		}
+	}
+
+	if (path.len == 0) {
+		return ReadDirectory_InvalidPath;
+	}
+	{
+		char *c_str = alloc_cstring(a, path);
+		defer (gb_free(a, c_str));
+
+		gbFile f = {};
+		gbFileError file_err = gb_file_open(&f, c_str);
+		defer (gb_file_close(&f));
+
+		switch (file_err) {
+		case gbFileError_Invalid:    return ReadDirectory_InvalidPath;
+		case gbFileError_NotExists:  return ReadDirectory_NotExists;
+		// case gbFileError_Permission: return ReadDirectory_Permission;
+		}
+	}
+
+	if (!path_is_directory(path)) {
+		return ReadDirectory_NotDir;
+	}
+
+
+	char *new_path = gb_alloc_array(a, char, path.len+3);
+	defer (gb_free(a, new_path));
+
+	gb_memmove(new_path, path.text, path.len);
+	gb_memmove(new_path+path.len, "/*", 2);
+	new_path[path.len+2] = 0;
+
+	String np = make_string(cast(u8 *)new_path, path.len+2);
+	String16 wstr = string_to_string16(a, np);
+	defer (gb_free(a, wstr.text));
+
+	WIN32_FIND_DATAW file_data = {};
+	HANDLE find_file = FindFirstFileW(wstr.text, &file_data);
+	if (find_file == INVALID_HANDLE_VALUE) {
+		return ReadDirectory_Unknown;
+	}
+	defer (FindClose(find_file));
+
+	array_init(fi, a, 0, 100);
+
+	do {
+		wchar_t *filename_w = file_data.cFileName;
+		i64 size = cast(i64)file_data.nFileSizeLow;
+		size |= (cast(i64)file_data.nFileSizeHigh) << 32;
+		String name = string16_to_string(a, make_string16_c(filename_w));
+		if (name == "." || name == "..") {
+			gb_free(a, name.text);
+			continue;
+		}
+
+		String filepath = {};
+		filepath.len = path.len+1+name.len;
+		filepath.text = gb_alloc_array(a, u8, filepath.len+1);
+		defer (gb_free(a, filepath.text));
+		gb_memmove(filepath.text, path.text, path.len);
+		gb_memmove(filepath.text+path.len, "/", 1);
+		gb_memmove(filepath.text+path.len+1, name.text, name.len);
+
+		FileInfo info = {};
+		info.name = name;
+		info.fullpath = path_to_full_path(a, filepath);
+		info.size = size;
+		info.is_dir = (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
+		array_add(fi, info);
+	} while (FindNextFileW(find_file, &file_data));
+
+	if (fi->count == 0) {
+		return ReadDirectory_Empty;
+	}
+
+	return ReadDirectory_None;
+}
+#elif defined(GB_SYSTEM_LINUX) || defined(GB_SYSTEM_OSX) || defined(GB_SYSTEM_FREEBSD) || defined(GB_SYSTEM_OPENBSD)
+
+#include <dirent.h>
+
+ReadDirectoryError read_directory(String path, Array<FileInfo> *fi) {
+	GB_ASSERT(fi != nullptr);
+
+	gbAllocator a = heap_allocator();
+
+	char *c_path = alloc_cstring(a, path);
+	defer (gb_free(a, c_path));
+
+	DIR *dir = opendir(c_path);
+	if (!dir) {
+		switch (errno) {
+		case ENOENT:
+			return ReadDirectory_NotExists;
+		case EACCES:
+			return ReadDirectory_Permission;
+		case ENOTDIR:
+			return ReadDirectory_NotDir;
+		default:
+			// ENOMEM: out of memory
+			// EMFILE: per-process limit on open fds reached
+			// ENFILE: system-wide limit on total open files reached
+			return ReadDirectory_Unknown;
+		}
+		GB_PANIC("unreachable");
+	}
+
+	array_init(fi, a, 0, 100);
+
+	for (;;) {
+		struct dirent *entry = readdir(dir);
+		if (entry == nullptr) {
+			break;
+		}
+
+		String name = make_string_c(entry->d_name);
+		if (name == "." || name == "..") {
+			continue;
+		}
+
+		String filepath = {};
+		filepath.len = path.len+1+name.len;
+		filepath.text = gb_alloc_array(a, u8, filepath.len+1);
+		defer (gb_free(a, filepath.text));
+		gb_memmove(filepath.text, path.text, path.len);
+		gb_memmove(filepath.text+path.len, "/", 1);
+		gb_memmove(filepath.text+path.len+1, name.text, name.len);
+		filepath.text[filepath.len] = 0;
+
+
+		struct stat dir_stat = {};
+
+		if (stat((char *)filepath.text, &dir_stat)) {
+			continue;
+		}
+
+		if (S_ISDIR(dir_stat.st_mode)) {
+			continue;
+		}
+
+		i64 size = dir_stat.st_size;
+
+		FileInfo info = {};
+		info.name = name;
+		info.fullpath = path_to_full_path(a, filepath);
+		info.size = size;
+		array_add(fi, info);
+	}
+
+	if (fi->count == 0) {
+		return ReadDirectory_Empty;
+	}
+
+	return ReadDirectory_None;
+}
+#else
+#error Implement read_directory
+#endif
+
+
 
 struct LoadedFile {
 	void *handle;
diff --git a/src/gb/gb.h b/src/gb/gb.h
index 3b2d6434c..b72a893f7 100644
--- a/src/gb/gb.h
+++ b/src/gb/gb.h
@@ -6273,44 +6273,20 @@ char *gb_path_get_full_name(gbAllocator a, char const *path) {
 #else
 	char *p, *result, *fullpath = NULL;
 	isize len;
-	fullpath = realpath(path, NULL);
-
-	if (fullpath == NULL) {
-		// NOTE(Jeroen): Path doesn't exist.
-		if (gb_strlen(path) > 0 && path[0] == '/') {
-			// But it is an absolute path, so return as-is.
-
-			fullpath = (char *)path;
-			len      = gb_strlen(fullpath) + 1;
-			result   = gb_alloc_array(a, char, len + 1);
-
-			gb_memmove(result, fullpath, len);
-			result[len] = 0;
-
-		} else {
-			// Appears to be a relative path, so construct an absolute one relative to <cwd>.
-			char cwd[4096];
-			getcwd(&cwd[0], 4096);
-
-			isize path_len = gb_strlen(path);
-			isize cwd_len  = gb_strlen(cwd);
-			len            = cwd_len + 1 + path_len + 1;
-			result         = gb_alloc_array(a, char, len);
+	p = realpath(path, NULL);
+	fullpath = p;
+	if (p == NULL) {
+		// NOTE(bill): File does not exist
+		fullpath = cast(char *)path;
+	}
 
-			gb_memmove(result, (void *)cwd, cwd_len);
-			result[cwd_len] = '/';
+	len = gb_strlen(fullpath);
 
-			gb_memmove(result + cwd_len + 1, (void *)path, gb_strlen(path));
-			result[len] = 0;
+	result = gb_alloc_array(a, char, len + 1);
+	gb_memmove(result, fullpath, len);
+	result[len] = 0;
+	free(p);
 
-		}
-	} else {
-		len      = gb_strlen(fullpath) + 1;
-		result   = gb_alloc_array(a, char, len + 1);
-		gb_memmove(result, fullpath, len);
-		result[len] = 0;
-		free(fullpath);
-	}
 	return result;
 #endif
 }
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 7781997f7..f5cb84785 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -967,12 +967,7 @@ lbProcedure *lb_create_main_procedure(lbModule *m, lbProcedure *startup_runtime)
 }
 
 String lb_filepath_ll_for_module(lbModule *m) {
-	String path = concatenate3_strings(permanent_allocator(),
-		build_context.build_paths[BuildPath_Output].basename,
-		STR_LIT("/"),
-		build_context.build_paths[BuildPath_Output].name
-	);
-
+	String path = m->gen->output_base;
 	if (m->pkg) {
 		path = concatenate3_strings(permanent_allocator(), path, STR_LIT("-"), m->pkg->name);
 	} else if (USE_SEPARATE_MODULES) {
@@ -983,12 +978,7 @@ String lb_filepath_ll_for_module(lbModule *m) {
 	return path;
 }
 String lb_filepath_obj_for_module(lbModule *m) {
-	String path = concatenate3_strings(permanent_allocator(),
-		build_context.build_paths[BuildPath_Output].basename,
-		STR_LIT("/"),
-		build_context.build_paths[BuildPath_Output].name
-	);
-
+	String path = m->gen->output_base;
 	if (m->pkg) {
 		path = concatenate3_strings(permanent_allocator(), path, STR_LIT("-"), m->pkg->name);
 	}
diff --git a/src/llvm_backend_general.cpp b/src/llvm_backend_general.cpp
index 1a431a4ac..330059622 100644
--- a/src/llvm_backend_general.cpp
+++ b/src/llvm_backend_general.cpp
@@ -87,6 +87,7 @@ bool lb_init_generator(lbGenerator *gen, Checker *c) {
 		return false;
 	}
 
+
 	String init_fullpath = c->parser->init_fullpath;
 
 	if (build_context.out_filepath.len == 0) {
diff --git a/src/main.cpp b/src/main.cpp
index 7b0364149..fc8792ceb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -46,6 +46,7 @@ gb_global Timings global_timings = {0};
 #include "checker.cpp"
 #include "docs.cpp"
 
+
 #include "llvm_backend.cpp"
 
 #if defined(GB_SYSTEM_OSX)
@@ -56,8 +57,16 @@ gb_global Timings global_timings = {0};
 #endif
 
 #include "query_data.cpp"
+
+
+#if defined(GB_SYSTEM_WINDOWS)
+// NOTE(IC): In order to find Visual C++ paths without relying on environment variables.
+#include "microsoft_craziness.h"
+#endif
+
 #include "bug_report.cpp"
 
+
 // NOTE(bill): 'name' is used in debugging and profiling modes
 i32 system_exec_command_line_app(char const *name, char const *fmt, ...) {
 	isize const cmd_cap = 64<<20; // 64 MiB should be more than enough
@@ -121,35 +130,34 @@ i32 system_exec_command_line_app(char const *name, char const *fmt, ...) {
 }
 
 
+
+
 i32 linker_stage(lbGenerator *gen) {
 	i32 result = 0;
 	Timings *timings = &global_timings;
 
-	String output_filename = path_to_string(heap_allocator(), build_context.build_paths[BuildPath_Output]);
-	debugf("Linking %.*s\n", LIT(output_filename));
-
-	// TOOD(Jeroen): Make a `build_paths[BuildPath_Object] to avoid `%.*s.o`.
+	String output_base = gen->output_base;
 
 	if (is_arch_wasm()) {
 		timings_start_section(timings, str_lit("wasm-ld"));
 
 	#if defined(GB_SYSTEM_WINDOWS)
 		result = system_exec_command_line_app("wasm-ld",
-			"\"%.*s\\bin\\wasm-ld\" \"%.*s.o\" -o \"%.*s\" %.*s %.*s",
+			"\"%.*s\\bin\\wasm-ld\" \"%.*s.wasm.o\" -o \"%.*s.wasm\" %.*s %.*s",
 			LIT(build_context.ODIN_ROOT),
-			LIT(output_filename), LIT(output_filename), LIT(build_context.link_flags), LIT(build_context.extra_linker_flags));
+			LIT(output_base), LIT(output_base), LIT(build_context.link_flags), LIT(build_context.extra_linker_flags));
 	#else
 		result = system_exec_command_line_app("wasm-ld",
-			"wasm-ld \"%.*s.o\" -o \"%.*s\" %.*s %.*s",
-			LIT(output_filename), LIT(output_filename), LIT(build_context.link_flags), LIT(build_context.extra_linker_flags));
+			"wasm-ld \"%.*s.wasm.o\" -o \"%.*s.wasm\" %.*s %.*s",
+			LIT(output_base), LIT(output_base), LIT(build_context.link_flags), LIT(build_context.extra_linker_flags));
 	#endif
 		return result;
 	}
 
 	if (build_context.cross_compiling && selected_target_metrics->metrics == &target_essence_amd64) {
-#if defined(GB_SYSTEM_UNIX) 
+#ifdef GB_SYSTEM_UNIX
 		result = system_exec_command_line_app("linker", "x86_64-essence-gcc \"%.*s.o\" -o \"%.*s\" %.*s %.*s",
-			LIT(output_filename), LIT(output_filename), LIT(build_context.link_flags), LIT(build_context.extra_linker_flags));
+			LIT(output_base), LIT(output_base), LIT(build_context.link_flags), LIT(build_context.extra_linker_flags));
 #else
 		gb_printf_err("Linking for cross compilation for this platform is not yet supported (%.*s %.*s)\n",
 			LIT(target_os_names[build_context.metrics.os]),
@@ -173,11 +181,28 @@ i32 linker_stage(lbGenerator *gen) {
 		gbString lib_str = gb_string_make(heap_allocator(), "");
 		defer (gb_string_free(lib_str));
 
+		char const *output_ext = "exe";
 		gbString link_settings = gb_string_make_reserve(heap_allocator(), 256);
 		defer (gb_string_free(link_settings));
 
+
+		// NOTE(ic): It would be nice to extend this so that we could specify the Visual Studio version that we want instead of defaulting to the latest.
+		Find_Result_Utf8 find_result = find_visual_studio_and_windows_sdk_utf8();
+
+		if (find_result.windows_sdk_version == 0) {
+			gb_printf_err("Windows SDK not found.\n");
+			exit(1);
+		}
+
+		if (build_context.ignore_microsoft_magic) {
+			find_result = {};
+		}
+
 		// Add library search paths.
-		if (build_context.build_paths[BuildPath_VS_LIB].basename.len > 0) {
+		if (find_result.vs_library_path.len > 0) {
+			GB_ASSERT(find_result.windows_sdk_um_library_path.len > 0);
+			GB_ASSERT(find_result.windows_sdk_ucrt_library_path.len > 0);
+
 			String path = {};
 			auto add_path = [&](String path) {
 				if (path[path.len-1] == '\\') {
@@ -185,9 +210,9 @@ i32 linker_stage(lbGenerator *gen) {
 				}
 				link_settings = gb_string_append_fmt(link_settings, " /LIBPATH:\"%.*s\"", LIT(path));
 			};
-			add_path(build_context.build_paths[BuildPath_Win_SDK_UM_Lib].basename);
-			add_path(build_context.build_paths[BuildPath_Win_SDK_UCRT_Lib].basename);
-			add_path(build_context.build_paths[BuildPath_VS_LIB].basename);
+			add_path(find_result.windows_sdk_um_library_path);
+			add_path(find_result.windows_sdk_ucrt_library_path);
+			add_path(find_result.vs_library_path);
 		}
 
 
@@ -227,14 +252,14 @@ i32 linker_stage(lbGenerator *gen) {
 
 
 		if (build_context.build_mode == BuildMode_DynamicLibrary) {
+			output_ext = "dll";
 			link_settings = gb_string_append_fmt(link_settings, " /DLL");
 		} else {
 			link_settings = gb_string_append_fmt(link_settings, " /ENTRY:mainCRTStartup");
 		}
 
 		if (build_context.pdb_filepath != "") {
-			String pdb_path = path_to_string(heap_allocator(), build_context.build_paths[BuildPath_PDB]);
-			link_settings = gb_string_append_fmt(link_settings, " /PDB:%.*s", LIT(pdb_path));
+			link_settings = gb_string_append_fmt(link_settings, " /PDB:%.*s", LIT(build_context.pdb_filepath));
 		}
 
 		if (build_context.no_crt) {
@@ -275,21 +300,13 @@ i32 linker_stage(lbGenerator *gen) {
 			object_files = gb_string_append_fmt(object_files, "\"%.*s\" ", LIT(object_path));
 		}
 
-		String vs_exe_path = path_to_string(heap_allocator(), build_context.build_paths[BuildPath_VS_EXE]);
-		defer (gb_free(heap_allocator(), vs_exe_path.text));
-
 		char const *subsystem_str = build_context.use_subsystem_windows ? "WINDOWS" : "CONSOLE";
 		if (!build_context.use_lld) { // msvc
 			if (build_context.has_resource) {
-				String rc_path  = path_to_string(heap_allocator(), build_context.build_paths[BuildPath_RC]);
-				String res_path = path_to_string(heap_allocator(), build_context.build_paths[BuildPath_RES]);
-				defer (gb_free(heap_allocator(), rc_path.text));
-				defer (gb_free(heap_allocator(), res_path.text));
-
 				result = system_exec_command_line_app("msvc-link",
-					"\"rc.exe\" /nologo /fo \"%.*s\" \"%.*s\"",
-					LIT(res_path),
-					LIT(rc_path)
+					"\"rc.exe\" /nologo /fo \"%.*s.res\" \"%.*s.rc\"",
+					LIT(output_base),
+					LIT(build_context.resource_filepath)
 				);
 
 				if (result) {
@@ -297,13 +314,13 @@ i32 linker_stage(lbGenerator *gen) {
 				}
 
 				result = system_exec_command_line_app("msvc-link",
-					"\"%.*slink.exe\" %s \"%.*s\" -OUT:\"%.*s\" %s "
+					"\"%.*slink.exe\" %s \"%.*s.res\" -OUT:\"%.*s.%s\" %s "
 					"/nologo /incremental:no /opt:ref /subsystem:%s "
 					" %.*s "
 					" %.*s "
 					" %s "
 					"",
-					LIT(vs_exe_path), object_files, LIT(res_path), LIT(output_filename),
+					LIT(find_result.vs_exe_path), object_files, LIT(output_base), LIT(output_base), output_ext,
 					link_settings,
 					subsystem_str,
 					LIT(build_context.link_flags),
@@ -312,13 +329,13 @@ i32 linker_stage(lbGenerator *gen) {
 				  );
 			} else {
 				result = system_exec_command_line_app("msvc-link",
-					"\"%.*slink.exe\" %s -OUT:\"%.*s\" %s "
+					"\"%.*slink.exe\" %s -OUT:\"%.*s.%s\" %s "
 					"/nologo /incremental:no /opt:ref /subsystem:%s "
 					" %.*s "
 					" %.*s "
 					" %s "
 					"",
-					LIT(vs_exe_path), object_files, LIT(output_filename),
+					LIT(find_result.vs_exe_path), object_files, LIT(output_base), output_ext,
 					link_settings,
 					subsystem_str,
 					LIT(build_context.link_flags),
@@ -333,13 +350,13 @@ i32 linker_stage(lbGenerator *gen) {
 
 		} else { // lld
 			result = system_exec_command_line_app("msvc-lld-link",
-				"\"%.*s\\bin\\lld-link\" %s -OUT:\"%.*s\" %s "
+				"\"%.*s\\bin\\lld-link\" %s -OUT:\"%.*s.%s\" %s "
 				"/nologo /incremental:no /opt:ref /subsystem:%s "
 				" %.*s "
 				" %.*s "
 				" %s "
 				"",
-				LIT(build_context.ODIN_ROOT), object_files, LIT(output_filename),
+				LIT(build_context.ODIN_ROOT), object_files, LIT(output_base),output_ext,
 				link_settings,
 				subsystem_str,
 				LIT(build_context.link_flags),
@@ -398,7 +415,7 @@ i32 linker_stage(lbGenerator *gen) {
 				} else if (string_ends_with(lib, str_lit(".so"))) {
 					// dynamic lib, relative path to executable
 					// NOTE(vassvik): it is the user's responsibility to make sure the shared library files are visible
-					//                at runtime to the executable
+					//                at runtimeto the executable
 					lib_str = gb_string_append_fmt(lib_str, " -l:\"%s/%.*s\" ", cwd, LIT(lib));
 				} else {
 					// dynamic or static system lib, just link regularly searching system library paths
@@ -414,6 +431,9 @@ i32 linker_stage(lbGenerator *gen) {
 			object_files = gb_string_append_fmt(object_files, "\"%.*s\" ", LIT(object_path));
 		}
 
+		// Unlike the Win32 linker code, the output_ext includes the dot, because
+		// typically executable files on *NIX systems don't have extensions.
+		String output_ext = {};
 		gbString link_settings = gb_string_make_reserve(heap_allocator(), 32);
 
 		if (build_context.no_crt) {
@@ -441,12 +461,26 @@ i32 linker_stage(lbGenerator *gen) {
 			// correctly this way since all the other dependencies provided implicitly
 			// by the compiler frontend are still needed and most of the command
 			// line arguments prepared previously are incompatible with ld.
+			//
+			// Shared libraries are .dylib on MacOS and .so on Linux.
+			if (build_context.metrics.os == TargetOs_darwin) {
+				output_ext = STR_LIT(".dylib");
+			} else {
+				output_ext = STR_LIT(".so");
+			}
 			link_settings = gb_string_appendc(link_settings, "-Wl,-init,'_odin_entry_point' ");
 			link_settings = gb_string_appendc(link_settings, "-Wl,-fini,'_odin_exit_point' ");
 		} else if (build_context.metrics.os != TargetOs_openbsd) {
 			// OpenBSD defaults to PIE executable. do not pass -no-pie for it.
 			link_settings = gb_string_appendc(link_settings, "-no-pie ");
 		}
+		if (build_context.out_filepath.len > 0) {
+			//NOTE(thebirk): We have a custom -out arguments, so we should use the extension from that
+			isize pos = string_extension_position(build_context.out_filepath);
+			if (pos > 0) {
+				output_ext = substring(build_context.out_filepath, pos, build_context.out_filepath.len);
+			}
+		}
 
 		gbString platform_lib_str = gb_string_make(heap_allocator(), "");
 		defer (gb_string_free(platform_lib_str));
@@ -473,7 +507,7 @@ i32 linker_stage(lbGenerator *gen) {
 		defer (gb_string_free(link_command_line));
 
 		link_command_line = gb_string_appendc(link_command_line, object_files);
-		link_command_line = gb_string_append_fmt(link_command_line, " -o \"%.*s\" ", LIT(output_filename));
+		link_command_line = gb_string_append_fmt(link_command_line, " -o \"%.*s%.*s\" ", LIT(output_base), LIT(output_ext));
 		link_command_line = gb_string_append_fmt(link_command_line, " %s ", platform_lib_str);
 		link_command_line = gb_string_append_fmt(link_command_line, " %s ", lib_str);
 		link_command_line = gb_string_append_fmt(link_command_line, " %.*s ", LIT(build_context.link_flags));
@@ -490,7 +524,9 @@ i32 linker_stage(lbGenerator *gen) {
 		if (build_context.ODIN_DEBUG) {
 			// NOTE: macOS links DWARF symbols dynamically. Dsymutil will map the stubs in the exe
 			// to the symbols in the object file
-			result = system_exec_command_line_app("dsymutil", "dsymutil %.*s", LIT(output_filename));
+			result = system_exec_command_line_app("dsymutil",
+				"dsymutil %.*s%.*s", LIT(output_base), LIT(output_ext)
+			);
 
 			if (result) {
 				return result;
@@ -1490,10 +1526,6 @@ bool parse_build_flags(Array<String> args) {
 									gb_printf_err("Invalid -resource path %.*s, missing .rc\n", LIT(path));
 									bad_flags = true;
 									break;
-								} else if (!gb_file_exists((const char *)path.text)) {
-									gb_printf_err("Invalid -resource path %.*s, file does not exist.\n", LIT(path));
-									bad_flags = true;
-									break;
 								}
 								build_context.resource_filepath = substring(path, 0, string_extension_position(path));
 								build_context.has_resource = true;
@@ -1508,11 +1540,6 @@ bool parse_build_flags(Array<String> args) {
 							String path = value.value_string;
 							path = string_trim_whitespace(path);
 							if (is_build_flag_path_valid(path)) {
-								if (path_is_directory(path)) {
-									gb_printf_err("Invalid -pdb-name path. %.*s, is a directory.\n", LIT(path));
-									bad_flags = true;
-									break;									
-								}
 								// #if defined(GB_SYSTEM_WINDOWS)
 								// 	String ext = path_extension(path);
 								// 	if (ext != ".pdb") {
@@ -2639,8 +2666,6 @@ int main(int arg_count, char const **arg_ptr) {
 		return 1;
 	}
 
-	init_filename = copy_string(permanent_allocator(), init_filename);
-
 	if (init_filename == "-help" ||
 	    init_filename == "--help") {
 		build_context.show_help = true;
@@ -2663,12 +2688,6 @@ int main(int arg_count, char const **arg_ptr) {
 				gb_printf_err("Did you mean `%.*s %.*s %.*s -file`?\n", LIT(args[0]), LIT(command), LIT(init_filename));
 				gb_printf_err("The `-file` flag tells it to treat a file as a self-contained package.\n");
 				return 1;
-			} else {
-				String const ext = str_lit(".odin");
-				if (!string_ends_with(init_filename, ext)) {
-					gb_printf_err("Expected either a directory or a .odin file, got '%.*s'\n", LIT(init_filename));
-					return 1;
-				}
 			}
 		}
 	}
@@ -2690,24 +2709,13 @@ int main(int arg_count, char const **arg_ptr) {
 			get_fullpath_relative(heap_allocator(), odin_root_dir(), str_lit("shared")));
 	}
 
+
 	init_build_context(selected_target_metrics ? selected_target_metrics->metrics : nullptr);
 	// if (build_context.word_size == 4 && build_context.metrics.os != TargetOs_js) {
 	// 	print_usage_line(0, "%.*s 32-bit is not yet supported for this platform", LIT(args[0]));
 	// 	return 1;
 	// }
 
-	// Set and check build paths...
-	if (!init_build_paths(init_filename)) {
-		return 1;
-	}
-
-	if (build_context.show_debug_messages) {
-		for_array(i, build_context.build_paths) {
-			String build_path = path_to_string(heap_allocator(), build_context.build_paths[i]);
-			debugf("build_paths[%ld]: %.*s\n", i, LIT(build_path));
-		}		
-	}
-
 	init_global_thread_pool();
 	defer (thread_pool_destroy(&global_thread_pool));
 
@@ -2724,8 +2732,6 @@ int main(int arg_count, char const **arg_ptr) {
 	}
 	defer (destroy_parser(parser));
 
-	// TODO(jeroen): Remove the `init_filename` param.
-	// Let's put that on `build_context.build_paths[0]` instead.
 	if (parse_packages(parser, init_filename) != ParseFile_None) {
 		return 1;
 	}
@@ -2804,14 +2810,16 @@ int main(int arg_count, char const **arg_ptr) {
 	}
 
 	if (run_output) {
-		String exe_name = path_to_string(heap_allocator(), build_context.build_paths[BuildPath_Output]);
-		defer (gb_free(heap_allocator(), exe_name.text));
-
 	#if defined(GB_SYSTEM_WINDOWS)
-		return system_exec_command_line_app("odin run", "%.*s %.*s", LIT(exe_name), LIT(run_args_string));
+		return system_exec_command_line_app("odin run", "%.*s.exe %.*s", LIT(gen->output_base), LIT(run_args_string));
 	#else
-		return system_exec_command_line_app("odin run", "\"%.*s\" %.*s", LIT(exe_name), LIT(run_args_string));
+		//NOTE(thebirk): This whole thing is a little leaky
+		String output_ext = {};
+		String complete_path = concatenate_strings(permanent_allocator(), gen->output_base, output_ext);
+		complete_path = path_to_full_path(permanent_allocator(), complete_path);
+		return system_exec_command_line_app("odin run", "\"%.*s\" %.*s", LIT(complete_path), LIT(run_args_string));
 	#endif
 	}
+
 	return 0;
 }
diff --git a/src/parser.cpp b/src/parser.cpp
index df7f908a6..767119aa8 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -5751,7 +5751,7 @@ ParseFileError parse_packages(Parser *p, String init_filename) {
 			}
 		}
 	}
-
+	
 
 	{ // Add these packages serially and then process them parallel
 		mutex_lock(&p->wait_mutex);
diff --git a/src/path.cpp b/src/path.cpp
deleted file mode 100644
index 8d8e532b8..000000000
--- a/src/path.cpp
+++ /dev/null
@@ -1,333 +0,0 @@
-/*

-	Path handling utilities.

-*/

-

-#if defined(GB_SYSTEM_WINDOWS)

-	bool path_is_directory(String path) {

-		gbAllocator a = heap_allocator();

-		String16 wstr = string_to_string16(a, path);

-		defer (gb_free(a, wstr.text));

-

-		i32 attribs = GetFileAttributesW(wstr.text);

-		if (attribs < 0) return false;

-

-		return (attribs & FILE_ATTRIBUTE_DIRECTORY) != 0;

-	}

-

-#else

-	bool path_is_directory(String path) {

-		gbAllocator a = heap_allocator();

-		char *copy = cast(char *)copy_string(a, path).text;

-		defer (gb_free(a, copy));

-

-		struct stat s;

-		if (stat(copy, &s) == 0) {

-			return (s.st_mode & S_IFDIR) != 0;

-		}

-		return false;

-	}

-#endif

-

-

-String path_to_full_path(gbAllocator a, String path) {

-	gbAllocator ha = heap_allocator();

-	char *path_c = gb_alloc_str_len(ha, cast(char *)path.text, path.len);

-	defer (gb_free(ha, path_c));

-

-	char *fullpath = gb_path_get_full_name(a, path_c);

-	String res = string_trim_whitespace(make_string_c(fullpath));

-#if defined(GB_SYSTEM_WINDOWS)

-	for (isize i = 0; i < res.len; i++) {

-		if (res.text[i] == '\\') {

-			res.text[i] = '/';

-		}

-	}

-#endif

-	return copy_string(a, res);

-}

-

-struct Path {

-	String basename;

-	String name;

-	String ext;

-};

-

-// NOTE(Jeroen): Naively turns a Path into a string.

-String path_to_string(gbAllocator a, Path path) {

-	if (path.basename.len + path.name.len + path.ext.len == 0) {

-		return make_string(nullptr, 0);

-	}

-

-	isize len = path.basename.len + 1 + path.name.len + 1;

-	if (path.ext.len > 0) {

-		 len += path.ext.len + 1;

-	}

-

-	u8 *str = gb_alloc_array(a, u8, len);

-

-	isize i = 0;

-	gb_memmove(str+i, path.basename.text, path.basename.len); i += path.basename.len;

-	gb_memmove(str+i, "/", 1);                                i += 1;

-	gb_memmove(str+i, path.name.text,     path.name.len);     i += path.name.len;

-	if (path.ext.len > 0) {

-		gb_memmove(str+i, ".", 1);                            i += 1;

-		gb_memmove(str+i, path.ext.text,  path.ext.len);      i += path.ext.len;

-	}

-	str[i] = 0;

-

-	String res = make_string(str, i);

-	res        = string_trim_whitespace(res);

-	return res;

-}

-

-// NOTE(Jeroen): Naively turns a Path into a string, then normalizes it using `path_to_full_path`.

-String path_to_full_path(gbAllocator a, Path path) {

-	String temp = path_to_string(heap_allocator(), path);

-	defer (gb_free(heap_allocator(), temp.text));

-

-	return path_to_full_path(a, temp);

-}

-

-// NOTE(Jeroen): Takes a path like "odin" or "W:\Odin", turns it into a full path,

-// and then breaks it into its components to make a Path.

-Path path_from_string(gbAllocator a, String const &path) {

-	Path res = {};

-

-	if (path.len == 0) return res;

-

-	String fullpath = path_to_full_path(a, path);

-	defer (gb_free(heap_allocator(), fullpath.text));

-

-	res.basename     = directory_from_path(fullpath);

-	res.basename     = copy_string(a, res.basename);

-

-	if (string_ends_with(fullpath, '/')) {

-		// It's a directory. We don't need to tinker with the name and extension.

-		return res;

-	}

-

-	isize name_start = (res.basename.len > 0) ? res.basename.len + 1 : res.basename.len;

-	res.name         = substring(fullpath, name_start, fullpath.len);

-	res.name         = remove_extension_from_path(res.name);

-	res.name         = copy_string(a, res.name);

-

-	res.ext          = path_extension(fullpath, false); // false says not to include the dot.

-	res.ext          = copy_string(a, res.ext);

-	return res;

-}

-

-bool path_is_directory(Path path) {

-	String path_string = path_to_full_path(heap_allocator(), path);

-	defer (gb_free(heap_allocator(), path_string.text));

-

-	return path_is_directory(path_string);

-}

-

-struct FileInfo {

-	String name;

-	String fullpath;

-	i64    size;

-	bool   is_dir;

-};

-

-enum ReadDirectoryError {

-	ReadDirectory_None,

-

-	ReadDirectory_InvalidPath,

-	ReadDirectory_NotExists,

-	ReadDirectory_Permission,

-	ReadDirectory_NotDir,

-	ReadDirectory_Empty,

-	ReadDirectory_Unknown,

-

-	ReadDirectory_COUNT,

-};

-

-i64 get_file_size(String path) {

-	char *c_str = alloc_cstring(heap_allocator(), path);

-	defer (gb_free(heap_allocator(), c_str));

-

-	gbFile f = {};

-	gbFileError err = gb_file_open(&f, c_str);

-	defer (gb_file_close(&f));

-	if (err != gbFileError_None) {

-		return -1;

-	}

-	return gb_file_size(&f);

-}

-

-

-#if defined(GB_SYSTEM_WINDOWS)

-ReadDirectoryError read_directory(String path, Array<FileInfo> *fi) {

-	GB_ASSERT(fi != nullptr);

-

-	gbAllocator a = heap_allocator();

-

-	while (path.len > 0) {

-		Rune end = path[path.len-1];

-		if (end == '/') {

-			path.len -= 1;

-		} else if (end == '\\') {

-			path.len -= 1;

-		} else {

-			break;

-		}

-	}

-

-	if (path.len == 0) {

-		return ReadDirectory_InvalidPath;

-	}

-	{

-		char *c_str = alloc_cstring(a, path);

-		defer (gb_free(a, c_str));

-

-		gbFile f = {};

-		gbFileError file_err = gb_file_open(&f, c_str);

-		defer (gb_file_close(&f));

-

-		switch (file_err) {

-		case gbFileError_Invalid:    return ReadDirectory_InvalidPath;

-		case gbFileError_NotExists:  return ReadDirectory_NotExists;

-		// case gbFileError_Permission: return ReadDirectory_Permission;

-		}

-	}

-

-	if (!path_is_directory(path)) {

-		return ReadDirectory_NotDir;

-	}

-

-

-	char *new_path = gb_alloc_array(a, char, path.len+3);

-	defer (gb_free(a, new_path));

-

-	gb_memmove(new_path, path.text, path.len);

-	gb_memmove(new_path+path.len, "/*", 2);

-	new_path[path.len+2] = 0;

-

-	String np = make_string(cast(u8 *)new_path, path.len+2);

-	String16 wstr = string_to_string16(a, np);

-	defer (gb_free(a, wstr.text));

-

-	WIN32_FIND_DATAW file_data = {};

-	HANDLE find_file = FindFirstFileW(wstr.text, &file_data);

-	if (find_file == INVALID_HANDLE_VALUE) {

-		return ReadDirectory_Unknown;

-	}

-	defer (FindClose(find_file));

-

-	array_init(fi, a, 0, 100);

-

-	do {

-		wchar_t *filename_w = file_data.cFileName;

-		i64 size = cast(i64)file_data.nFileSizeLow;

-		size |= (cast(i64)file_data.nFileSizeHigh) << 32;

-		String name = string16_to_string(a, make_string16_c(filename_w));

-		if (name == "." || name == "..") {

-			gb_free(a, name.text);

-			continue;

-		}

-

-		String filepath = {};

-		filepath.len = path.len+1+name.len;

-		filepath.text = gb_alloc_array(a, u8, filepath.len+1);

-		defer (gb_free(a, filepath.text));

-		gb_memmove(filepath.text, path.text, path.len);

-		gb_memmove(filepath.text+path.len, "/", 1);

-		gb_memmove(filepath.text+path.len+1, name.text, name.len);

-

-		FileInfo info = {};

-		info.name = name;

-		info.fullpath = path_to_full_path(a, filepath);

-		info.size = size;

-		info.is_dir = (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;

-		array_add(fi, info);

-	} while (FindNextFileW(find_file, &file_data));

-

-	if (fi->count == 0) {

-		return ReadDirectory_Empty;

-	}

-

-	return ReadDirectory_None;

-}

-#elif defined(GB_SYSTEM_LINUX) || defined(GB_SYSTEM_OSX) || defined(GB_SYSTEM_FREEBSD) || defined(GB_SYSTEM_OPENBSD)

-

-#include <dirent.h>

-

-ReadDirectoryError read_directory(String path, Array<FileInfo> *fi) {

-	GB_ASSERT(fi != nullptr);

-

-	gbAllocator a = heap_allocator();

-

-	char *c_path = alloc_cstring(a, path);

-	defer (gb_free(a, c_path));

-

-	DIR *dir = opendir(c_path);

-	if (!dir) {

-		switch (errno) {

-		case ENOENT:

-			return ReadDirectory_NotExists;

-		case EACCES:

-			return ReadDirectory_Permission;

-		case ENOTDIR:

-			return ReadDirectory_NotDir;

-		default:

-			// ENOMEM: out of memory

-			// EMFILE: per-process limit on open fds reached

-			// ENFILE: system-wide limit on total open files reached

-			return ReadDirectory_Unknown;

-		}

-		GB_PANIC("unreachable");

-	}

-

-	array_init(fi, a, 0, 100);

-

-	for (;;) {

-		struct dirent *entry = readdir(dir);

-		if (entry == nullptr) {

-			break;

-		}

-

-		String name = make_string_c(entry->d_name);

-		if (name == "." || name == "..") {

-			continue;

-		}

-

-		String filepath = {};

-		filepath.len = path.len+1+name.len;

-		filepath.text = gb_alloc_array(a, u8, filepath.len+1);

-		defer (gb_free(a, filepath.text));

-		gb_memmove(filepath.text, path.text, path.len);

-		gb_memmove(filepath.text+path.len, "/", 1);

-		gb_memmove(filepath.text+path.len+1, name.text, name.len);

-		filepath.text[filepath.len] = 0;

-

-

-		struct stat dir_stat = {};

-

-		if (stat((char *)filepath.text, &dir_stat)) {

-			continue;

-		}

-

-		if (S_ISDIR(dir_stat.st_mode)) {

-			continue;

-		}

-

-		i64 size = dir_stat.st_size;

-

-		FileInfo info = {};

-		info.name = name;

-		info.fullpath = path_to_full_path(a, filepath);

-		info.size = size;

-		array_add(fi, info);

-	}

-

-	if (fi->count == 0) {

-		return ReadDirectory_Empty;

-	}

-

-	return ReadDirectory_None;

-}

-#else

-#error Implement read_directory

-#endif

-

diff --git a/src/string.cpp b/src/string.cpp
index 3515df48e..d3dbc6904 100644
--- a/src/string.cpp
+++ b/src/string.cpp
@@ -245,14 +245,15 @@ gb_inline isize string_extension_position(String const &str) {
 	return dot_pos;
 }
 
-String path_extension(String const &str, bool include_dot = true) {
+String path_extension(String const &str) {
 	isize pos = string_extension_position(str);
 	if (pos < 0) {
 		return make_string(nullptr, 0);
 	}
-	return substring(str, include_dot ? pos : pos + 1, str.len);
+	return substring(str, pos, str.len);
 }
 
+
 String string_trim_whitespace(String str) {
 	while (str.len > 0 && rune_is_whitespace(str[str.len-1])) {
 		str.len--;
@@ -327,10 +328,7 @@ String directory_from_path(String const &s) {
 			break;
 		}
 	}
-	if (i >= 0) {
-		return substring(s, 0, i);	
-	}
-	return substring(s, 0, 0);
+	return substring(s, 0, i);
 }
 
 String concatenate_strings(gbAllocator a, String const &x, String const &y) {
diff --git a/tests/core/Makefile b/tests/core/Makefile
index 9bb622633..6a92b4efb 100644
--- a/tests/core/Makefile
+++ b/tests/core/Makefile
@@ -1,6 +1,5 @@
 ODIN=../../odin
 PYTHON=$(shell which python3)
-OUT_FILE=test_binary.bin
 
 all: download_test_assets image_test compress_test strings_test hash_test crypto_test noise_test encoding_test \
 	 math_test linalg_glsl_math_test filepath_test reflect_test os_exit_test
@@ -9,39 +8,39 @@ download_test_assets:
 	$(PYTHON) download_assets.py
 
 image_test:
-	$(ODIN) run image/test_core_image.odin -out=$(OUT_FILE) -file
+	$(ODIN) run image/test_core_image.odin -file
 
 compress_test:
-	$(ODIN) run compress/test_core_compress.odin -out=$(OUT_FILE) -file
+	$(ODIN) run compress/test_core_compress.odin -file
 
 strings_test:
-	$(ODIN) run strings/test_core_strings.odin -out=$(OUT_FILE) -file
+	$(ODIN) run strings/test_core_strings.odin -file
 
 hash_test:
-	$(ODIN) run hash -out=$(OUT_FILE) -o:speed -no-bounds-check
+	$(ODIN) run hash -out=test_hash -o:speed -no-bounds-check
 
 crypto_test:
-	$(ODIN) run crypto -out=$(OUT_FILE) -o:speed -no-bounds-check
+	$(ODIN) run crypto -out=test_crypto_hash -o:speed -no-bounds-check
 
 noise_test:
-	$(ODIN) run math/noise -out=$(OUT_FILE)
+	$(ODIN) run math/noise -out=test_noise
 
 encoding_test:
-	$(ODIN) run encoding/hxa -out=$(OUT_FILE) -collection:tests=..
-	$(ODIN) run encoding/json -out=$(OUT_FILE)
-	$(ODIN) run encoding/varint -out=$(OUT_FILE)
+	$(ODIN) run encoding/hxa -out=test_hxa -collection:tests=..
+	$(ODIN) run encoding/json -out=test_json
+	$(ODIN) run encoding/varint -out=test_varint
 
 math_test:
-	$(ODIN) run math/test_core_math.odin -out=$(OUT_FILE) -file -collection:tests=..
+	$(ODIN) run math/test_core_math.odin -out=test_core_math -file -collection:tests=..
 
 linalg_glsl_math_test:
-	$(ODIN) run math/linalg/glsl/test_linalg_glsl_math.odin -file -out=$(OUT_FILE) -collection:tests=..
+	$(ODIN) run math/linalg/glsl/test_linalg_glsl_math.odin -file -out=test_linalg_glsl_math -collection:tests=..
 
 filepath_test:
-	$(ODIN) run path/filepath/test_core_filepath.odin -file -out=$(OUT_FILE) -collection:tests=..
+	$(ODIN) run path/filepath/test_core_filepath.odin -file -out=test_core_filepath -collection:tests=..
 
 reflect_test:
-	$(ODIN) run reflect/test_core_reflect.odin -file -out=$(OUT_FILE) -collection:tests=..
+	$(ODIN) run reflect/test_core_reflect.odin -file -out=test_core_reflect -collection:tests=..
 
 os_exit_test:
-	$(ODIN) run os/test_core_os_exit.odin -file -out=$(OUT_FILE) && exit 1 || exit 0
+	$(ODIN) run os/test_core_os_exit.odin -file -out=test_core_os_exit && exit 1 || exit 0
diff --git a/tests/core/build.bat b/tests/core/build.bat
index 331a473aa..2f9ba672e 100644
--- a/tests/core/build.bat
+++ b/tests/core/build.bat
@@ -1,8 +1,6 @@
 @echo off

-set OUT_FILE=test_binary.exe

-set COMMON=-show-timings -no-bounds-check -vet -strict-style -collection:tests=.. -out:%OUT_FILE%

+set COMMON=-show-timings -no-bounds-check -vet -strict-style -collection:tests=..

 set PATH_TO_ODIN==..\..\odin

-

 python3 download_assets.py

 echo ---

 echo Running core:image tests

@@ -37,14 +35,14 @@ echo ---
 echo ---

 echo Running core:encoding tests

 echo ---

-%PATH_TO_ODIN% run encoding/hxa    %COMMON%

-%PATH_TO_ODIN% run encoding/json   %COMMON%

+%PATH_TO_ODIN% run encoding/hxa %COMMON%

+%PATH_TO_ODIN% run encoding/json %COMMON%

 %PATH_TO_ODIN% run encoding/varint %COMMON%

 

 echo ---

 echo Running core:math/noise tests

 echo ---

-%PATH_TO_ODIN% run math/noise      %COMMON%

+%PATH_TO_ODIN% run math/noise %COMMON%

 

 echo ---

 echo Running core:math tests

diff --git a/tests/core/math/big/build.bat b/tests/core/math/big/build.bat
index ad199d775..16bdbc8ca 100644
--- a/tests/core/math/big/build.bat
+++ b/tests/core/math/big/build.bat
@@ -4,7 +4,7 @@ set PATH_TO_ODIN==..\..\..\..\odin
 set TEST_ARGS=-fast-tests

 set TEST_ARGS=-no-random

 set TEST_ARGS=

-set OUT_NAME=math_big_test_library.dll

+set OUT_NAME=math_big_test_library

 set COMMON=-build-mode:shared -show-timings -no-bounds-check -define:MATH_BIG_EXE=false -vet -strict-style

 echo ---

 echo Running core:math/big tests

diff --git a/tests/issues/run.bat b/tests/issues/run.bat
index a936bd896..a652d9694 100644
--- a/tests/issues/run.bat
+++ b/tests/issues/run.bat
@@ -1,12 +1,17 @@
 @echo off
-set PATH_TO_ODIN==..\..\odin
-set COMMON=-collection:tests=.. -out:build\test_issue
-if not exist "build" mkdir build
 
-%PATH_TO_ODIN% build test_issue_829.odin %COMMON% -file
-build\test_issue
+if not exist "tests\issues\build\" mkdir tests\issues\build
 
-%PATH_TO_ODIN% build test_issue_1592.odin %COMMON% -file
-build\test_issue
+set COMMON=-collection:tests=tests -out:tests\issues\build\test_issue
 
-rmdir /S /Q build
+@echo on
+
+.\odin build tests\issues\test_issue_829.odin %COMMON% -file
+tests\issues\build\test_issue
+
+.\odin build tests\issues\test_issue_1592.odin %COMMON% -file
+tests\issues\build\test_issue
+
+@echo off
+
+rmdir /S /Q tests\issues\build
diff --git a/tests/issues/run.sh b/tests/issues/run.sh
index ec6d7130d..117a9a5f1 100755
--- a/tests/issues/run.sh
+++ b/tests/issues/run.sh
@@ -1,17 +1,18 @@
 #!/bin/bash
-ODIN=../../odin
-COMMON="-collection:tests=.. -out:build/test_issue.bin"
-
 set -eu
-mkdir -p build
+
+mkdir -p tests/issues/build
+
+COMMON="-collection:tests=tests -out:tests/issues/build/test_issue"
+
 set -x
 
-$ODIN build test_issue_829.odin $COMMON -file
-build/test_issue.bin
+./odin build tests/issues/test_issue_829.odin $COMMON -file
+tests/issues/build/test_issue
 
-$ODIN build test_issue_1592.odin $COMMON -file
-build/test_issue.bin
+./odin build tests/issues/test_issue_1592.odin $COMMON -file
+tests/issues/build/test_issue
 
 set +x
 
-rm -rf build
+rm -rf tests/issues/build
diff --git a/tests/vendor/Makefile b/tests/vendor/Makefile
index 380e64e09..341067c6e 100644
--- a/tests/vendor/Makefile
+++ b/tests/vendor/Makefile
@@ -1,6 +1,5 @@
 ODIN=../../odin
 ODINFLAGS=
-OUT_FILE=test_binary.bin
 
 OS=$(shell uname)
 
@@ -11,4 +10,4 @@ endif
 all: botan_test
 
 botan_test:
-	$(ODIN) run botan -out=$(OUT_FILE) -o:speed -no-bounds-check $(ODINFLAGS)
+	$(ODIN) run botan -out=botan_hash -o:speed -no-bounds-check $(ODINFLAGS)
diff --git a/tests/vendor/build.bat b/tests/vendor/build.bat
index 4bd9a6496..e70d9f1d5 100644
--- a/tests/vendor/build.bat
+++ b/tests/vendor/build.bat
@@ -1,6 +1,5 @@
 @echo off

-set OUT_FILE=test_binary.exe

-set COMMON=-show-timings -no-bounds-check -vet -strict-style -out:%OUT_FILE%

+set COMMON=-show-timings -no-bounds-check -vet -strict-style

 set PATH_TO_ODIN==..\..\odin

 

 echo ---