Compiler: Add early error for output path being a directory.

- Introduce new `Path` type and an array of build paths on the build context.
- Resolve input and output paths/files early (before parsing).
- Error early if inputs are missing or outputs are directories.
- Plumb new file path generation into linker stage instead of its adhoc method.

TODO:
- Remove more adhoc file path generation in parser and linker stage.
- Make intermediate object file generation use new path system.
- Round out and robustify Path helper functions.

1 files changed, 12 insertions, 2 deletions

diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index f5cb84785..7781997f7 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -967,7 +967,12 @@ lbProcedure *lb_create_main_procedure(lbModule *m, lbProcedure *startup_runtime)
 }
 
 String lb_filepath_ll_for_module(lbModule *m) {
-	String path = m->gen->output_base;
+	String path = concatenate3_strings(permanent_allocator(),
+		build_context.build_paths[BuildPath_Output].basename,
+		STR_LIT("/"),
+		build_context.build_paths[BuildPath_Output].name
+	);
+
 	if (m->pkg) {
 		path = concatenate3_strings(permanent_allocator(), path, STR_LIT("-"), m->pkg->name);
 	} else if (USE_SEPARATE_MODULES) {
@@ -978,7 +983,12 @@ String lb_filepath_ll_for_module(lbModule *m) {
 	return path;
 }
 String lb_filepath_obj_for_module(lbModule *m) {
-	String path = m->gen->output_base;
+	String path = concatenate3_strings(permanent_allocator(),
+		build_context.build_paths[BuildPath_Output].basename,
+		STR_LIT("/"),
+		build_context.build_paths[BuildPath_Output].name
+	);
+
 	if (m->pkg) {
 		path = concatenate3_strings(permanent_allocator(), path, STR_LIT("-"), m->pkg->name);
 	}