commit 3dddb881bfefbcd64aae7775ed72c42e37503674 (tree)
parent 852e7e24b5f15b489463bdabb0039e2a424e5ee6
Author: Jakub Konka <kubkon@jakubkonka.com>
Date: Mon, 15 Jan 2024 07:37:09 +0100
Merge pull request #18560 from ziglang/elf-report-dupes
elf: report duplicate symbol definitions
Diffstat:
5 files changed, 131 insertions(+), 50 deletions(-)
diff --git a/lib/std/Build/Step/Compile.zig b/lib/std/Build/Step/Compile.zig
@@ -1077,9 +1077,8 @@ fn make(step: *Step, prog_node: *std.Progress.Node) !void {
.exe => return step.fail("cannot link with an executable build artifact", .{}),
.@"test" => return step.fail("cannot link with a test", .{}),
.obj => {
- const included_in_lib = !my_responsibility and
- compile.kind == .lib and other.kind == .obj;
- if (!already_linked and !included_in_lib) {
+ const included_in_lib_or_obj = !my_responsibility and (compile.kind == .lib or compile.kind == .obj);
+ if (!already_linked and !included_in_lib_or_obj) {
try zig_args.append(other.getEmittedBin().getPath(b));
total_linker_objects += 1;
}
diff --git a/src/link/Elf.zig b/src/link/Elf.zig
@@ -1302,6 +1302,11 @@ pub fn flushModule(self: *Elf, arena: Allocator, prog_node: *std.Progress.Node)
}
}
+ self.checkDuplicates() catch |err| switch (err) {
+ error.HasDuplicates => return error.FlushFailure,
+ else => |e| return e,
+ };
+
try self.initOutputSections();
try self.addLinkerDefinedSymbols();
self.claimUnresolved();
@@ -3428,6 +3433,27 @@ fn allocateLinkerDefinedSymbols(self: *Elf) void {
}
}
+fn checkDuplicates(self: *Elf) !void {
+ const gpa = self.base.comp.gpa;
+
+ var dupes = std.AutoArrayHashMap(Symbol.Index, std.ArrayListUnmanaged(File.Index)).init(gpa);
+ defer {
+ for (dupes.values()) |*list| {
+ list.deinit(gpa);
+ }
+ dupes.deinit();
+ }
+
+ if (self.zigObjectPtr()) |zig_object| {
+ try zig_object.checkDuplicates(&dupes, self);
+ }
+ for (self.objects.items) |index| {
+ try self.file(index).?.object.checkDuplicates(&dupes, self);
+ }
+
+ try self.reportDuplicates(dupes);
+}
+
fn initOutputSections(self: *Elf) !void {
for (self.objects.items) |index| {
try self.file(index).?.object.initOutputSections(self);
@@ -6101,6 +6127,36 @@ fn reportUndefinedSymbols(self: *Elf, undefs: anytype) !void {
}
}
+fn reportDuplicates(self: *Elf, dupes: anytype) error{ HasDuplicates, OutOfMemory }!void {
+ const max_notes = 3;
+ var has_dupes = false;
+ var it = dupes.iterator();
+ while (it.next()) |entry| {
+ const sym = self.symbol(entry.key_ptr.*);
+ const notes = entry.value_ptr.*;
+ const nnotes = @min(notes.items.len, max_notes) + @intFromBool(notes.items.len > max_notes);
+
+ var err = try self.addErrorWithNotes(nnotes + 1);
+ try err.addMsg(self, "duplicate symbol definition: {s}", .{sym.name(self)});
+ try err.addNote(self, "defined by {}", .{sym.file(self).?.fmtPath()});
+
+ var inote: usize = 0;
+ while (inote < @min(notes.items.len, max_notes)) : (inote += 1) {
+ const file_ptr = self.file(notes.items[inote]).?;
+ try err.addNote(self, "defined by {}", .{file_ptr.fmtPath()});
+ }
+
+ if (notes.items.len > max_notes) {
+ const remaining = notes.items.len - max_notes;
+ try err.addNote(self, "defined {d} more times", .{remaining});
+ }
+
+ has_dupes = true;
+ }
+
+ if (has_dupes) return error.HasDuplicates;
+}
+
fn reportMissingLibraryError(
self: *Elf,
checked_paths: []const []const u8,
diff --git a/src/link/Elf/Object.zig b/src/link/Elf/Object.zig
@@ -581,30 +581,30 @@ pub fn markEhFrameAtomsDead(self: Object, elf_file: *Elf) void {
}
}
-pub fn checkDuplicates(self: *Object, elf_file: *Elf) void {
+pub fn checkDuplicates(self: *Object, dupes: anytype, elf_file: *Elf) error{OutOfMemory}!void {
const first_global = self.first_global orelse return;
for (self.globals(), 0..) |index, i| {
- const sym_idx = @as(u32, @intCast(first_global + i));
- const this_sym = self.symtab.items[sym_idx];
+ const sym_idx = first_global + i;
+ const sym = self.symtab.items[sym_idx];
const global = elf_file.symbol(index);
- const global_file = global.getFile(elf_file) orelse continue;
+ const global_file = global.file(elf_file) orelse continue;
- if (self.index == global_file.getIndex() or
- this_sym.st_shndx == elf.SHN_UNDEF or
- this_sym.st_bind() == elf.STB_WEAK or
- this_sym.st_shndx == elf.SHN_COMMON) continue;
+ if (self.index == global_file.index() or
+ sym.st_shndx == elf.SHN_UNDEF or
+ sym.st_bind() == elf.STB_WEAK or
+ sym.st_shndx == elf.SHN_COMMON) continue;
- if (this_sym.st_shndx != elf.SHN_ABS) {
- const atom_index = self.atoms.items[this_sym.st_shndx];
+ if (sym.st_shndx != elf.SHN_ABS) {
+ const atom_index = self.atoms.items[sym.st_shndx];
const atom = elf_file.atom(atom_index) orelse continue;
if (!atom.flags.alive) continue;
}
- elf_file.base.fatal("multiple definition: {}: {}: {s}", .{
- self.fmtPath(),
- global_file.fmtPath(),
- global.getName(elf_file),
- });
+ const gop = try dupes.getOrPut(index);
+ if (!gop.found_existing) {
+ gop.value_ptr.* = .{};
+ }
+ try gop.value_ptr.append(elf_file.base.comp.gpa, self.index);
}
}
diff --git a/src/link/Elf/ZigObject.zig b/src/link/Elf/ZigObject.zig
@@ -451,6 +451,32 @@ pub fn markLive(self: *ZigObject, elf_file: *Elf) void {
}
}
+pub fn checkDuplicates(self: *ZigObject, dupes: anytype, elf_file: *Elf) error{OutOfMemory}!void {
+ for (self.globals(), 0..) |index, i| {
+ const esym = self.global_esyms.items(.elf_sym)[i];
+ const shndx = self.global_esyms.items(.shndx)[i];
+ const global = elf_file.symbol(index);
+ const global_file = global.file(elf_file) orelse continue;
+
+ if (self.index == global_file.index() or
+ esym.st_shndx == elf.SHN_UNDEF or
+ esym.st_bind() == elf.STB_WEAK or
+ esym.st_shndx == elf.SHN_COMMON) continue;
+
+ if (esym.st_shndx == SHN_ATOM) {
+ const atom_index = self.atoms.items[shndx];
+ const atom = elf_file.atom(atom_index) orelse continue;
+ if (!atom.flags.alive) continue;
+ }
+
+ const gop = try dupes.getOrPut(index);
+ if (!gop.found_existing) {
+ gop.value_ptr.* = .{};
+ }
+ try gop.value_ptr.append(elf_file.base.comp.gpa, self.index);
+ }
+}
+
/// This is just a temporary helper function that allows us to re-read what we wrote to file into a buffer.
/// We need this so that we can write to an archive.
/// TODO implement writing ZigObject data directly to a buffer instead.
diff --git a/test/link/elf.zig b/test/link/elf.zig
@@ -695,41 +695,41 @@ fn testDsoUndef(b: *Build, opts: Options) *Step {
fn testEmitRelocatable(b: *Build, opts: Options) *Step {
const test_step = addTestStep(b, "emit-relocatable", opts);
- const obj1 = addObject(b, opts, .{
- .name = "obj1",
- .zig_source_bytes =
- \\const std = @import("std");
- \\extern var bar: i32;
- \\export fn foo() i32 {
- \\ return bar;
- \\}
- \\export fn printFoo() void {
- \\ std.debug.print("foo={d}\n", .{foo()});
- \\}
- ,
- .c_source_bytes =
- \\#include <stdio.h>
- \\int bar = 42;
- \\void printBar() {
- \\ fprintf(stderr, "bar=%d\n", bar);
- \\}
- ,
+ const a_o = addObject(b, opts, .{ .name = "a", .zig_source_bytes =
+ \\const std = @import("std");
+ \\extern var bar: i32;
+ \\export fn foo() i32 {
+ \\ return bar;
+ \\}
+ \\export fn printFoo() void {
+ \\ std.debug.print("foo={d}\n", .{foo()});
+ \\}
});
- obj1.linkLibC();
+ a_o.linkLibC();
- const exe = addExecutable(b, opts, .{
- .name = "test",
- .zig_source_bytes =
- \\const std = @import("std");
- \\extern fn printFoo() void;
- \\extern fn printBar() void;
- \\pub fn main() void {
- \\ printFoo();
- \\ printBar();
- \\}
- ,
+ const b_o = addObject(b, opts, .{ .name = "b", .c_source_bytes =
+ \\#include <stdio.h>
+ \\int bar = 42;
+ \\void printBar() {
+ \\ fprintf(stderr, "bar=%d\n", bar);
+ \\}
});
- exe.addObject(obj1);
+ b_o.linkLibC();
+
+ const c_o = addObject(b, opts, .{ .name = "c" });
+ c_o.addObject(a_o);
+ c_o.addObject(b_o);
+
+ const exe = addExecutable(b, opts, .{ .name = "test", .zig_source_bytes =
+ \\const std = @import("std");
+ \\extern fn printFoo() void;
+ \\extern fn printBar() void;
+ \\pub fn main() void {
+ \\ printFoo();
+ \\ printBar();
+ \\}
+ });
+ exe.addObject(c_o);
exe.linkLibC();
const run = addRunArtifact(exe);
