[PATCH] D47602: Correct aligment computation for shared object symbols

[Han Shen via Phabricator via llvm-commits]

shenhan updated this revision to Diff 149548.
shenhan marked 4 inline comments as done.

https://reviews.llvm.org/D47602

Files:
  ELF/InputFiles.cpp
  test/ELF/Inputs/copy-relocation-zero-abs-addr.s
  test/ELF/copy-relocation-zero-abs-addr.s


Index: test/ELF/copy-relocation-zero-abs-addr.s
===================================================================
--- /dev/null
+++ test/ELF/copy-relocation-zero-abs-addr.s
@@ -0,0 +1,44 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/copy-relocation-zero-abs-addr.s -o %t.o
+// RUN: ld.lld -shared -o %t2.so %t.o
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t3.o
+// RUN: ld.lld %t2.so %t3.o -o %t4
+// RUN: llvm-readobj -symbols %t2.so | FileCheck -check-prefix=ABSADDR %s
+// RUN: llvm-readobj -s -r --expand-relocs %t4 | FileCheck %s
+
+// This tests that symbols with absolute addresses are properly
+// handled. Normal DSO symbols are handled as usual.
+
+.text
+.globl _start
+_start:
+  movl $5, foo
+
+// ABSADDR:        Name: ver1
+// ABSADDR-NEXT:   Value: 0x0
+// ABSADDR-NEXT:   Size: 0
+// ABSADDR-NEXT:   Binding: Global
+// ABSADDR-NEXT:   Type: None
+// ABSADDR-NEXT:   Other: 0
+// ABSADDR-NEXT:   Section: Absolute (0xFFF1)
+// ABSADDR-NEXT: }
+// ABSADDR-NEXT: Symbol {
+// ABSADDR-NEXT:   Name: ver2
+// ABSADDR-NEXT:   Value: 0x0
+// ABSADDR-NEXT:   Size: 0
+// ABSADDR-NEXT:   Binding: Global
+// ABSADDR-NEXT:   Type: None
+// ABSADDR-NEXT:   Other: 0
+// ABSADDR-NEXT:   Section: Absolute (0xFFF1)
+// ABSADDR-NEXT: }
+
+// CHECK:      Relocations [
+// CHECK-NEXT:   Section (5) .rela.dyn {
+// CHECK-NEXT:     Relocation {
+// CHECK-NEXT:       Offset:
+// CHECK-NEXT:       Type: R_X86_64_COPY
+// CHECK-NEXT:       Symbol: foo
+// CHECK-NEXT:       Addend:
+// CHECK-NEXT:     }
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]
Index: test/ELF/Inputs/copy-relocation-zero-abs-addr.s
===================================================================
--- /dev/null
+++ test/ELF/Inputs/copy-relocation-zero-abs-addr.s
@@ -0,0 +1,7 @@
+.globl ver1
+.globl ver2
+ ver1 = 0x0
+ ver2 = 0x0
+
+.type foo, at object
+.comm foo,16,16
Index: ELF/InputFiles.cpp
===================================================================
--- ELF/InputFiles.cpp
+++ ELF/InputFiles.cpp
@@ -895,16 +895,13 @@
 template <class ELFT>
 uint32_t SharedFile<ELFT>::getAlignment(ArrayRef<Elf_Shdr> Sections,
                                         const Elf_Sym &Sym) {
-  uint64_t Ret = 1;
+  uint64_t Ret = UINT64_MAX;
   if (Sym.st_value)
     Ret = 1ULL << countTrailingZeros((uint64_t)Sym.st_value);
   if (0 < Sym.st_shndx && Sym.st_shndx < Sections.size())
     Ret = std::min<uint64_t>(Ret, Sections[Sym.st_shndx].sh_addralign);
 
-  if (Ret > UINT32_MAX)
-    error(toString(this) + ": alignment too large: " +
-          CHECK(Sym.getName(this->StringTable), this));
-  return Ret;
+  return (Ret > UINT32_MAX) ? 0 : Ret;
 }
 
 // Fully parse the shared object file. This must be called after parseSoName().


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