[PATCH] D82433: [ELF] -r: don't parse @ (symbol versioning) for .symver inline asm in bitcode

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: grimar, psmith, ruiu.
Herald added subscribers: llvm-commits, dmgreen, dexonsmith, steven_wu, hiraditya, arichardson, emaste.
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MaskRay updated this revision to Diff 272917.
MaskRay added a comment.

Fix a comment and improve test


Fixes PR46420
Similar to D43307 <https://reviews.llvm.org/D43307> for non-LTO.

Module-level inline assembly can use .symver to create a symbol with `@` in the name.
For relocatable output, @ should be retained in the symbol name. `@ver` should
not be parsed and dropped.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D82433

Files:
  lld/ELF/Driver.cpp
  lld/test/ELF/lto/version-script2.ll


Index: lld/test/ELF/lto/version-script2.ll
===================================================================
--- lld/test/ELF/lto/version-script2.ll
+++ lld/test/ELF/lto/version-script2.ll
@@ -1,18 +1,30 @@
 ; REQUIRES: x86
 
-;; Test we parse symbol versions before LTO, otherwise we may get a symbol
-;; named "foo@@VER1", but not "foo" with the version VER1.
+;; For non-relocatable output, Test we parse symbol versions after LTO,
+;; otherwise we may get a symbol named "foo@@VER1", but not "foo" with the
+;; version VER1.
 
 ; RUN: llvm-as %s -o %t.o
 ; RUN: echo "VER1 {};" > %t.script
 ; RUN: ld.lld %t.o -o %t.so -shared --version-script %t.script
-; RUN: llvm-readobj --dyn-syms %t.so | FileCheck %s
+; RUN: llvm-readelf --dyn-syms %t.so | FileCheck %s
 
-; CHECK: Name: foo@@VER1 (
+;; For non-relocatable output, @ in symbol names has no effect on undefined symbols.
+; CHECK:      UND         bar{{$}}
+; CHECK-NEXT: [[#SHNDX:]] foo@@VER1
+
+;; For relocatable output, @ should be retained in the symbol name.
+;; Don't parse and drop `@VER1`.
+; RUN: ld.lld %t.o -o %t.ro -r --version-script %t.script
+; RUN: llvm-readelf -s %t.ro | FileCheck %s --check-prefix=RELOCATABLE
+
+; RELOCATABLE:      [[#SHNDX:]] foo@@VER1
+; RELOCATABLE-NEXT: UND         bar at VER1
 
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 module asm ".global foo"
-module asm "foo:"
+module asm "foo: call bar"
 module asm ".symver foo,foo@@@VER1"
+module asm ".symver bar,bar@@@VER1"
Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -1717,8 +1717,11 @@
   for (InputFile *file : lto->compile()) {
     auto *obj = cast<ObjFile<ELFT>>(file);
     obj->parse(/*ignoreComdats=*/true);
-    for (Symbol *sym : obj->getGlobalSymbols())
-      sym->parseSymbolVersion();
+
+    // Parse '@' in symbol names for non-relocatable output.
+    if (!config->relocatable)
+      for (Symbol *sym : obj->getGlobalSymbols())
+        sym->parseSymbolVersion();
     objectFiles.push_back(file);
   }
 }


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