Commit f9ae1f808b9e8c1d9a0394505be222f8becf4259 | zig

author	Jacob Young <jacobly@ziglang.org> 2026-08-30 06:24:21-04:00
committer	Jacob Young <jacobly@ziglang.org> 2026-09-03 12:59:38-04:00
log	f9ae1f808b9e8c1d9a0394505be222f8becf4259
tree	974c16daf179bb5382149969d516008f1f1dd137
parent	eecbd183ccca14f904eada0b909b70812a2c9cb8

Elf2: replace `trimStart` calls with an unconditional padding node

The trim strategy came from the old dwarf impl, but it does not work
with the overaligned section node optimization.

2 files changed, 9 insertions(+), 34 deletions(-)

src
- link
  - Elf2.zig
  - MappedFile.zig

src/link/Elf2.zig+9-17

 @@ -7189,7 +7189,6 @@ fn prelinkInner(elf: *Elf) Error!void {
         }) |debug_shndx| {
             if (debug_shndx == .UNDEF) continue;
             const debug_ni = debug_shndx.get(elf).ni;
-            _ = debug_ni.last(&elf.mf).unwrap() orelse continue;
             const frame_format = debug_shndx.debugFrameFormat(elf);
             const unit_padding_ni = elf.addNodeAssumeCapacity(
                 try debug_ni.addFloatingChild(gpa, &elf.mf, .{
 @@ -8941,7 +8940,6 @@ fn updateFuncInner(
                     .debug_frame => elf.shndx.debug_frame,
                     .eh_frame => elf.shndx.eh_frame,
                 }.get(elf).ni;
-                try frame_ni.trimStart(gpa, &elf.mf);
                 switch (wip_nav.frame_format) {
                     .debug_frame => {},
                     .eh_frame => {
 @@ -8953,11 +8951,6 @@ fn updateFuncInner(
             },
             .dwarf2 => |debug| {
                 try debug.finishFunc(func_length);
-                for ([3]Section.Index{
-                    elf.shndx.debug_info,
-                    elf.shndx.debug_line,
-                    elf.shndx.debug_rnglists,
-                }) |debug_shndx| try debug_shndx.get(elf).ni.trimStart(gpa, &elf.mf);
                 const unit = debug.wip_nav.unit.get(debug.wip_nav.dwarf);
                 {
                     const debug_info_ni = unit.debug_info_ni.unwrap().?;
 @@ -10928,19 +10921,21 @@ pub fn printNode(
             const zcu = elf.base.comp.zcu.?;
             const ip = &zcu.intern_pool;
             const nav = ip.getNav(gi.nav(&elf.dwarf));
-            try w.print("({f}, {f})", .{
+            try w.writeByte('(');
-                Type.fromInterned(nav.resolved.?.type).fmt(.{ .zcu = zcu, .tid = tid }),
+            if (nav.resolved) |resolved| try w.print("{f}, ", .{
-                nav.fqn.fmt(ip),
+                Type.fromInterned(resolved.type).fmt(.{ .zcu = zcu, .tid = tid }),
             });
+            try w.print("{f})", .{nav.fqn.fmt(ip)});
         },
         .func_frame_fde, .func_debug_info, .func_debug_line => |fi| {
             const zcu = elf.base.comp.zcu.?;
             const ip = &zcu.intern_pool;
             const nav = ip.getNav(fi.nav(&elf.dwarf));
-            try w.print("({f}, {f})", .{
+            try w.writeByte('(');
-                Type.fromInterned(nav.resolved.?.type).fmt(.{ .zcu = zcu, .tid = tid }),
+            if (nav.resolved) |resolved| try w.print("{f}, ", .{
-                nav.fqn.fmt(ip),
+                Type.fromInterned(resolved.type).fmt(.{ .zcu = zcu, .tid = tid }),
             });
+            try w.print("{f})", .{nav.fqn.fmt(ip)});
         },
         .decl_debug_info => |di| {
             const comp = elf.base.comp;
 @@ -10948,10 +10943,7 @@ pub fn printNode(
             const ip = &zcu.intern_pool;
             const src_inst = di.srcInst(&elf.dwarf);
             try w.print("({f}, ", .{zcu.fileByIndex(src_inst.resolveFile(ip)).path.fmt(comp)});
-            if (src_inst.resolve(ip)) |inst|
+            if (src_inst.resolve(ip)) |inst| try w.print("%{d}", .{inst}) else try w.writeAll("lost");
-                try w.print("%{d}", .{inst})
-            else
-                try w.writeAll("lost");
             try w.writeByte(')');
         },
     }

src/link/MappedFile.zig-17

...	@@ -664,23 +664,6 @@ pub const Node = extern struct {	...	@@ -664,23 +664,6 @@ pub const Node = extern struct {
664	return true;	664	return true;
665	}	665	}
666		666
667	pub fn trimStart(ni: Node.Index, gpa: Allocator, mf: *MappedFile) Allocator.Error!void {
668	mf.nodes_lock.assertUnlocked();
669	const node = ni.get(mf);
670	const first_ni = node.first.unwrap() orelse return;
671	const shift, _ = first_ni.location(mf).resolve(mf);
672	if (shift == 0) return;
673	const offset, const size = node.location().resolve(mf);
674	try ni.setLocation(gpa, mf, offset + shift, size - shift);
675	var child_oni = node.first;
676	while (child_oni.unwrap()) \|child_ni\| {
677	const child_node = child_ni.get(mf);
678	const child_offset, const child_size = child_node.location().resolve(mf);
679	try child_ni.setLocation(gpa, mf, child_offset - shift, child_size);
680	child_oni = child_node.next;
681	}
682	}
683
684	/// Ensures that the size of `ni` is at least `min_size`. Valid for any node.	667	/// Ensures that the size of `ni` is at least `min_size`. Valid for any node.
685	///	668	///
686	/// Applies `growth_factor` if necessary (so the caller should not apply `growth_factor`).	669	/// Applies `growth_factor` if necessary (so the caller should not apply `growth_factor`).