Commit bda5180b2ccfed22da04dd0b7a48d60beda03538 | zig

author	Jakub Konka <kubkon@jakubkonka.com> 2022-12-09 12:40:53+01:00
committer	Jakub Konka <kubkon@jakubkonka.com> 2022-12-09 14:16:44+01:00
log	bda5180b2ccfed22da04dd0b7a48d60beda03538
tree	560aa602784b1fc88d6f18a69cae4d40c7727eb2
parent	d88eb75a69d27ef50635f9aa1caf2a7177d99ead

llvm: resolve all relative paths when creating DIFiles

This will make stack traces and debugging experience more consistent
in the sense that the presence of source lines in stack traces will
not be dependent on the current working directory of the running process.

1 files changed, 25 insertions(+), 19 deletions(-)

src
- codegen
  - llvm.zig

src/codegen/llvm.zig+25-19

 @@ -443,20 +443,19 @@ pub const Object = struct {
             });
             defer gpa.free(producer);
-            // For macOS stack traces, we want to avoid having to parse the compilation unit debug
+            // We fully resolve all paths at this point to avoid lack of source line info in stack
-            // info. As long as each debug info file has a path independent of the compilation unit
+            // traces or lack of debugging information which, if relative paths were used, would
-            // directory (DW_AT_comp_dir), then we never have to look at the compilation unit debug
+            // be very location dependent.
-            // info. If we provide an absolute path to LLVM here for the compilation unit debug
+            // TODO: the only concern I have with this is WASI as either host or target, should
-            // info, LLVM will emit DWARF info that depends on DW_AT_comp_dir. To avoid this, we
+            // we leave the paths as relative then?
-            // pass "." for the compilation unit directory. This forces each debug file to have a
+            var buf: [std.fs.MAX_PATH_BYTES]u8 = undefined;
-            // directory rather than be relative to DW_AT_comp_dir. According to DWARF 5, debug
+            const compile_unit_dir = blk: {
-            // files will no longer reference DW_AT_comp_dir, for the purpose of being able to
+                const path = d: {
-            // support the common practice of stripping all but the line number sections from an
+                    const mod = options.module orelse break :d ".";
-            // executable.
+                    break :d mod.root_pkg.root_src_directory.path orelse ".";
-            const compile_unit_dir = d: {
+                };
-                if (options.target.isDarwin()) break :d ".";
+                if (std.fs.path.isAbsolute(path)) break :blk path;
-                const mod = options.module orelse break :d ".";
+                break :blk std.os.realpath(path, &buf) catch path; // If realpath fails, fallback to whatever path was
-                break :d mod.root_pkg.root_src_directory.path orelse ".";
             };
             const compile_unit_dir_z = try gpa.dupeZ(u8, compile_unit_dir);
             defer gpa.free(compile_unit_dir_z);
 @@ -1389,13 +1388,20 @@ pub const Object = struct {
         if (gop.found_existing) {
             return @ptrCast(*llvm.DIFile, gop.value_ptr.*);
         }
-        const dir_path = file.pkg.root_src_directory.path orelse ".";
+        const dir_path_z = d: {
+            var buffer: [std.fs.MAX_PATH_BYTES]u8 = undefined;
+            const dir_path = file.pkg.root_src_directory.path orelse ".";
+            const resolved_dir_path = if (std.fs.path.isAbsolute(dir_path))
+                dir_path
+            else
+                std.os.realpath(dir_path, &buffer) catch dir_path; // If realpath fails, fallback to whatever dir_path was
+            break :d try std.fs.path.joinZ(gpa, &.{
+                resolved_dir_path, std.fs.path.dirname(file.sub_file_path) orelse "",
+            });
+        };
+        defer gpa.free(dir_path_z);
         const sub_file_path_z = try gpa.dupeZ(u8, std.fs.path.basename(file.sub_file_path));
         defer gpa.free(sub_file_path_z);
-        const dir_path_z = try std.fs.path.joinZ(gpa, &.{
-            dir_path, std.fs.path.dirname(file.sub_file_path) orelse "",
-        });
-        defer gpa.free(dir_path_z);
         const di_file = o.di_builder.?.createFile(sub_file_path_z, dir_path_z);
         gop.value_ptr.* = di_file.toNode();
         return di_file;