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glibc: Fix an edge case leading to duplicate stub symbols.

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Closes #20376.
Closes #21076.
This commit is contained in:
Alex Rønne Petersen
2024-08-24 22:42:57 +02:00
parent 1773a88ab1
commit 27c72c555a
1 changed files with 31 additions and 0 deletions
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31
src/glibc.zig
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@@ -854,6 +854,23 @@ pub fn buildSharedObjects(comp: *Compilation, prog_node: std.Progress.Node) !voi
var opt_symbol_name: ?[]const u8 = null;
var versions_buffer: [32]u8 = undefined;
var versions_len: usize = undefined;
// There can be situations where there are multiple inclusions for the same symbol with
// partially overlapping versions, due to different target lists. For example:
//
// lgammal:
// library: libm.so
// versions: 2.4 2.23
// targets: ... powerpc64-linux-gnu s390x-linux-gnu
// lgammal:
// library: libm.so
// versions: 2.2 2.23
// targets: sparc64-linux-gnu s390x-linux-gnu
//
// If we don't handle this, we end up writing the default `lgammal` symbol for version 2.33
// twice, which causes a "duplicate symbol" assembler error.
var versions_written = std.AutoArrayHashMap(Version, void).init(arena);
while (sym_i < fn_inclusions_len) : (sym_i += 1) {
const sym_name = opt_symbol_name orelse n: {
const name = mem.sliceTo(metadata.inclusions[inc_i..], 0);
@@ -907,6 +924,10 @@ pub fn buildSharedObjects(comp: *Compilation, prog_node: std.Progress.Node) !voi
}
}
}
versions_written.clearRetainingCapacity();
try versions_written.ensureTotalCapacity(versions_len);
{
var ver_buf_i: u8 = 0;
while (ver_buf_i < versions_len) : (ver_buf_i += 1) {
@@ -917,6 +938,9 @@ pub fn buildSharedObjects(comp: *Compilation, prog_node: std.Progress.Node) !voi
// _Exit_2_2_5:
const ver_index = versions_buffer[ver_buf_i];
const ver = metadata.all_versions[ver_index];
if (versions_written.getOrPutAssumeCapacity(ver).found_existing) continue;
// Default symbol version definition vs normal symbol version definition
const want_default = chosen_def_ver_index != 255 and ver_index == chosen_def_ver_index;
const at_sign_str: []const u8 = if (want_default) "@@" else "@";
@@ -1066,6 +1090,10 @@ pub fn buildSharedObjects(comp: *Compilation, prog_node: std.Progress.Node) !voi
}
}
}
versions_written.clearRetainingCapacity();
try versions_written.ensureTotalCapacity(versions_len);
{
var ver_buf_i: u8 = 0;
while (ver_buf_i < versions_len) : (ver_buf_i += 1) {
@@ -1077,6 +1105,9 @@ pub fn buildSharedObjects(comp: *Compilation, prog_node: std.Progress.Node) !voi
// environ_2_2_5:
const ver_index = versions_buffer[ver_buf_i];
const ver = metadata.all_versions[ver_index];
if (versions_written.getOrPutAssumeCapacity(ver).found_existing) continue;
// Default symbol version definition vs normal symbol version definition
const want_default = chosen_def_ver_index != 255 and ver_index == chosen_def_ver_index;
const at_sign_str: []const u8 = if (want_default) "@@" else "@";