Skip to content

zig: expose linker options and include '-z notext' #10056

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 29, 2021
Merged

zig: expose linker options and include '-z notext' #10056

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions lib/std/build.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1489,6 +1489,9 @@ pub const LibExeObjStep = struct {

linker_allow_shlib_undefined: ?bool = null,

/// Permit read-only relocations in read-only segments. Disallowed by default.
link_z_notext: bool = false,

/// Uses system Wine installation to run cross compiled Windows build artifacts.
enable_wine: bool = false,

Expand Down Expand Up @@ -2354,6 +2357,10 @@ pub const LibExeObjStep = struct {
if (self.linker_allow_shlib_undefined) |x| {
try zig_args.append(if (x) "-fallow-shlib-undefined" else "-fno-allow-shlib-undefined");
}
if (self.link_z_notext) {
try zig_args.append("-z");
try zig_args.append("notext");
}
if (self.single_threaded) {
try zig_args.append("--single-threaded");
}
Expand Down
2 changes: 2 additions & 0 deletions src/Compilation.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -718,6 +718,7 @@ pub const InitOptions = struct {
each_lib_rpath: ?bool = null,
disable_c_depfile: bool = false,
linker_z_nodelete: bool = false,
linker_z_notext: bool = false,
linker_z_defs: bool = false,
linker_z_origin: bool = false,
linker_z_noexecstack: bool = false,
Expand Down Expand Up @@ -1400,6 +1401,7 @@ pub fn create(gpa: *Allocator, options: InitOptions) !*Compilation {
.allow_shlib_undefined = options.linker_allow_shlib_undefined,
.bind_global_refs_locally = options.linker_bind_global_refs_locally orelse false,
.z_nodelete = options.linker_z_nodelete,
.z_notext = options.linker_z_notext,
.z_defs = options.linker_z_defs,
.z_origin = options.linker_z_origin,
.z_noexecstack = options.linker_z_noexecstack,
Expand Down
1 change: 1 addition & 0 deletions src/link.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -72,6 +72,7 @@ pub const Options = struct {
emit_relocs: bool,
rdynamic: bool,
z_nodelete: bool,
z_notext: bool,
z_defs: bool,
z_origin: bool,
z_noexecstack: bool,
Expand Down
5 changes: 5 additions & 0 deletions src/link/Elf.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1332,6 +1332,7 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
man.hash.add(self.base.options.each_lib_rpath);
man.hash.add(self.base.options.skip_linker_dependencies);
man.hash.add(self.base.options.z_nodelete);
man.hash.add(self.base.options.z_notext);
man.hash.add(self.base.options.z_defs);
man.hash.add(self.base.options.z_origin);
man.hash.add(self.base.options.z_noexecstack);
Expand Down Expand Up @@ -1470,6 +1471,10 @@ fn linkWithLLD(self: *Elf, comp: *Compilation) !void {
try argv.append("-z");
try argv.append("nodelete");
}
if (self.base.options.z_notext) {
try argv.append("-z");
try argv.append("notext");
}
if (self.base.options.z_defs) {
try argv.append("-z");
try argv.append("defs");
Expand Down
35 changes: 35 additions & 0 deletions src/main.zig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -401,6 +401,14 @@ const usage_build_generic =
\\ -fno-allow-shlib-undefined Disallows undefined symbols in shared libraries
\\ --eh-frame-hdr Enable C++ exception handling by passing --eh-frame-hdr to linker
\\ --emit-relocs Enable output of relocation sections for post build tools
\\ -z [arg] Append linker arguments
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hmm, -z <arg> seems specific to ELF linkers; would it make more sense to expose each flag of interest separately with -fnotext or something similar? Also, we should definitely point out these are ELF-specific. @andrewrk I'd appreciate your look at this too!

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

-z specifies an extension flag. wasm-ld supports them as well and we actually already make use of it to set the stack size for executables. So if we go with this, perhaps those should be supported too.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
\\ -z [arg] Append linker arguments
\\ -z [arg] Set linker extension flags

\\ nodelete Indicate that the object cannot be deleted from a process
\\ notext Permit read-only relocations in read-only segments
\\ defs Force a fatal error if any undefined symbols remain
\\ origin Indicate that the object must have its origin processed
\\ noexecstack Indicate that the object requires an executable stack
\\ now Force all relocations to be processed on load
\\ relro Force all relocations to be resolved and be read-only on load
\\ -dynamic Force output to be dynamically linked
\\ -static Force output to be statically linked
\\ -Bsymbolic Bind global references locally
Expand Down Expand Up @@ -595,6 +603,7 @@ fn buildOutputType(
var linker_allow_shlib_undefined: ?bool = null;
var linker_bind_global_refs_locally: ?bool = null;
var linker_z_nodelete = false;
var linker_z_notext = false;
var linker_z_defs = false;
var linker_z_origin = false;
var linker_z_noexecstack = false;
Expand Down Expand Up @@ -1086,6 +1095,29 @@ fn buildOutputType(
linker_allow_shlib_undefined = true;
} else if (mem.eql(u8, arg, "-fno-allow-shlib-undefined")) {
linker_allow_shlib_undefined = false;
} else if (mem.eql(u8, arg, "-z")) {
i += 1;
if (i >= args.len) {
fatal("expected linker arg after '{s}'", .{arg});
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
fatal("expected linker arg after '{s}'", .{arg});
fatal("expected linker extension flag after '{s}'", .{arg});

}
const z_arg = args[i];
if (mem.eql(u8, z_arg, "nodelete")) {
linker_z_nodelete = true;
} else if (mem.eql(u8, z_arg, "notext")) {
linker_z_notext = true;
} else if (mem.eql(u8, z_arg, "defs")) {
linker_z_defs = true;
} else if (mem.eql(u8, z_arg, "origin")) {
linker_z_origin = true;
} else if (mem.eql(u8, z_arg, "noexecstack")) {
linker_z_noexecstack = true;
} else if (mem.eql(u8, z_arg, "now")) {
linker_z_now = true;
} else if (mem.eql(u8, z_arg, "relro")) {
linker_z_relro = true;
} else {
warn("unsupported linker arg: -z {s}", .{z_arg});
}
} else if (mem.eql(u8, arg, "-Bsymbolic")) {
linker_bind_global_refs_locally = true;
} else if (mem.eql(u8, arg, "--debug-compile-errors")) {
Expand Down Expand Up @@ -1422,6 +1454,8 @@ fn buildOutputType(
const z_arg = linker_args.items[i];
if (mem.eql(u8, z_arg, "nodelete")) {
linker_z_nodelete = true;
} else if (mem.eql(u8, z_arg, "notext")) {
linker_z_notext = true;
} else if (mem.eql(u8, z_arg, "defs")) {
linker_z_defs = true;
} else if (mem.eql(u8, z_arg, "origin")) {
Expand Down Expand Up @@ -2108,6 +2142,7 @@ fn buildOutputType(
.linker_allow_shlib_undefined = linker_allow_shlib_undefined,
.linker_bind_global_refs_locally = linker_bind_global_refs_locally,
.linker_z_nodelete = linker_z_nodelete,
.linker_z_notext = linker_z_notext,
.linker_z_defs = linker_z_defs,
.linker_z_origin = linker_z_origin,
.linker_z_noexecstack = linker_z_noexecstack,
Expand Down