Handle shared symbols in the gnu hash construction.

They are special in that they they need to be in the hash table iff we
are linking an executable that preempts them.

llvm-svn: 316065

diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index e0ed162..617df3f 100644 (file)
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -1608,7 +1608,11 @@ void GnuHashTableSection::addSymbols(std::vector<SymbolTableEntry> &V) {
   // its type correctly.
   std::vector<SymbolTableEntry>::iterator Mid =
       std::stable_partition(V.begin(), V.end(), [](const SymbolTableEntry &S) {
-        return S.Symbol->isUndefined() || S.Symbol->isLazy();
+        // Shared symbols that this executable preempts are special. The dynamic
+        // linker has to look them up, so they have to be in the hash table.
+        if (auto *SS = dyn_cast<SharedSymbol>(S.Symbol))
+          return SS->CopyRelSec == nullptr && !SS->NeedsPltAddr;
+        return !S.Symbol->isInCurrentDSO();
       });
   if (Mid == V.end())
     return;

diff --git a/lld/test/ELF/gc-sections-shared.s b/lld/test/ELF/gc-sections-shared.s
index 21738e4..3bb8ff1 100644 (file)
--- a/lld/test/ELF/gc-sections-shared.s
+++ b/lld/test/ELF/gc-sections-shared.s
@@ -19,16 +19,16 @@
 # CHECK-NEXT:     Section: Undefined (0x0)
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: bar
+# CHECK-NEXT:     Name: bar2
 # CHECK-NEXT:     Value:
 # CHECK-NEXT:     Size:
 # CHECK-NEXT:     Binding: Global
 # CHECK-NEXT:     Type:
 # CHECK-NEXT:     Other:
-# CHECK-NEXT:     Section: .text
+# CHECK-NEXT:     Section: Undefined
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: foo
+# CHECK-NEXT:     Name: bar
 # CHECK-NEXT:     Value:
 # CHECK-NEXT:     Size:
 # CHECK-NEXT:     Binding: Global
@@ -37,13 +37,13 @@
 # CHECK-NEXT:     Section: .text
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Symbol {
-# CHECK-NEXT:     Name: bar2
+# CHECK-NEXT:     Name: foo
 # CHECK-NEXT:     Value:
 # CHECK-NEXT:     Size:
 # CHECK-NEXT:     Binding: Global
 # CHECK-NEXT:     Type:
 # CHECK-NEXT:     Other:
-# CHECK-NEXT:     Section: Undefined
+# CHECK-NEXT:     Section: .text
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 

diff --git a/lld/test/ELF/gnu-hash-table-copy.s b/lld/test/ELF/gnu-hash-table-copy.s
new file mode 100644 (file)
index 0000000..9d91163
--- /dev/null
+++ b/lld/test/ELF/gnu-hash-table-copy.s
@@ -0,0 +1,30 @@
+# REQUIRES: x86
+
+# RUN: echo ".global foo; .type foo, @object; .size foo, 4; foo:; .long 0" > %t.s
+# RUN: echo ".global bar; .type bar, @object; .size bar, 4; bar:; .long 0" >> %t.s
+# RUN: echo ".global zed; .type zed, @function; zed:" >> %t.s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %t.s -o %t1.o
+# RUN: ld.lld %t1.o -o %t1.so -shared
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t2.o
+# RUN: ld.lld --hash-style=gnu %t2.o %t1.so -o %t2
+
+# RUN: llvm-readelf --symbols --gnu-hash-table %t2 | FileCheck %s
+
+# CHECK:      Symbol table '.dynsym' contains 4 entries:
+# CHECK-NEXT:    Num:    Value          Size Type    Bind   Vis      Ndx   Name
+# CHECK-NEXT:      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND   @
+# CHECK-NEXT:      1: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  UND   foo@
+# CHECK-DAG:        : {{.*}}               4 OBJECT  GLOBAL DEFAULT {{.*}} bar@
+# CHECK-DAG:        : {{.*}}               0 FUNC    GLOBAL DEFAULT  UND   zed@
+
+# CHECK: First Hashed Symbol Index: 2
+
+.global _start
+_start:
+
+.quad bar
+.quad zed
+
+.data
+.quad foo

diff --git a/lld/test/ELF/gnu-hash-table.s b/lld/test/ELF/gnu-hash-table.s
index 6e322a4..7df8dfc 100644 (file)
--- a/lld/test/ELF/gnu-hash-table.s
+++ b/lld/test/ELF/gnu-hash-table.s
@@ -71,7 +71,7 @@
 # I386-NEXT:     ]
 # I386-NEXT:     Address:
 # I386-NEXT:     Offset:
-# I386-NEXT:     Size: 44
+# I386-NEXT:     Size: 32
 # I386-NEXT:     Link:
 # I386-NEXT:     Info: 0
 # I386-NEXT:     AddressAlignment: 4
@@ -89,6 +89,11 @@
 # I386:          Section: Undefined
 # I386:        }
 # I386:        Symbol {
+# I386:          Name: xyz@
+# I386:          Binding: Global
+# I386:          Section: Undefined
+# I386:        }
+# I386:        Symbol {
 # I386:          Name: zed@
 # I386:          Binding: Weak
 # I386:          Section: Undefined
@@ -103,20 +108,15 @@
 # I386:          Binding: Global
 # I386:          Section: .text
 # I386:        }
-# I386:        Symbol {
-# I386:          Name: xyz@
-# I386:          Binding: Global
-# I386:          Section: Undefined
-# I386:        }
 # I386:      ]
 # I386:      GnuHashTable {
-# I386-NEXT:   Num Buckets: 3
-# I386-NEXT:   First Hashed Symbol Index: 3
+# I386-NEXT:   Num Buckets: 1
+# I386-NEXT:   First Hashed Symbol Index: 4
 # I386-NEXT:   Num Mask Words: 1
 # I386-NEXT:   Shift Count: 5
-# I386-NEXT:   Bloom Filter: [0x14010A20]
-# I386-NEXT:   Buckets: [3, 0, 5]
-# I386-NEXT:   Values: [0xB8860BA, 0xB887389, 0xB88C171]
+# I386-NEXT:   Bloom Filter: [0x14000220]
+# I386-NEXT:   Buckets: [4]
+# I386-NEXT:   Values: [0xB8860BA, 0xB887389]
 # I386-NEXT: }
 
 # X86_64:      Format: ELF64-x86-64
@@ -130,7 +130,7 @@
 # X86_64-NEXT:     ]
 # X86_64-NEXT:     Address:
 # X86_64-NEXT:     Offset:
-# X86_64-NEXT:     Size: 48
+# X86_64-NEXT:     Size: 36
 # X86_64-NEXT:     Link:
 # X86_64-NEXT:     Info: 0
 # X86_64-NEXT:     AddressAlignment: 8
@@ -149,6 +149,11 @@
 # X86_64:          Section: Undefined
 # X86_64:        }
 # X86_64:        Symbol {
+# X86_64:          Name: xyz@
+# X86_64:          Binding: Global
+# X86_64:          Section: Undefined
+# X86_64:        }
+# X86_64:        Symbol {
 # X86_64:          Name: zed@
 # X86_64:          Binding: Weak
 # X86_64:          Section: Undefined
@@ -163,20 +168,15 @@
 # X86_64:          Binding: Global
 # X86_64:          Section: .text
 # X86_64:        }
-# X86_64:        Symbol {
-# X86_64:          Name: xyz@
-# X86_64:          Binding: Global
-# X86_64:          Section: Undefined
-# X86_64:        }
 # X86_64:      ]
 # X86_64:      GnuHashTable {
-# X86_64-NEXT:   Num Buckets: 3
-# X86_64-NEXT:   First Hashed Symbol Index: 3
+# X86_64-NEXT:   Num Buckets: 1
+# X86_64-NEXT:   First Hashed Symbol Index: 4
 # X86_64-NEXT:   Num Mask Words: 1
 # X86_64-NEXT:   Shift Count: 6
-# X86_64-NEXT:   Bloom Filter: [0x401000000004224]
-# X86_64-NEXT:   Buckets: [3, 0, 5]
-# X86_64-NEXT:   Values: [0xB8860BA, 0xB887389, 0xB88C171]
+# X86_64-NEXT:   Bloom Filter: [0x400000000004204]
+# X86_64-NEXT:   Buckets: [4]
+# X86_64-NEXT:   Values: [0xB8860BA, 0xB887389]
 # X86_64-NEXT: }
 
 # PPC64:      Format: ELF64-ppc64
@@ -190,7 +190,7 @@
 # PPC64-NEXT:     ]
 # PPC64-NEXT:     Address:
 # PPC64-NEXT:     Offset:
-# PPC64-NEXT:     Size: 48
+# PPC64-NEXT:     Size: 36
 # PPC64-NEXT:     Link:
 # PPC64-NEXT:     Info: 0
 # PPC64-NEXT:     AddressAlignment: 8
@@ -209,6 +209,11 @@
 # PPC64:          Section: Undefined
 # PPC64:        }
 # PPC64:        Symbol {
+# PPC64:          Name: xyz@
+# PPC64:          Binding: Global
+# PPC64:          Section: Undefined
+# PPC64:        }
+# PPC64:        Symbol {
 # PPC64:          Name: zed@
 # PPC64:          Binding: Weak
 # PPC64:          Section: Undefined
@@ -223,20 +228,15 @@
 # PPC64:          Binding: Global
 # PPC64:          Section: .text
 # PPC64:        }
-# PPC64:        Symbol {
-# PPC64:          Name: xyz@
-# PPC64:          Binding: Global
-# PPC64:          Section: Undefined
-# PPC64:        }
 # PPC64:      ]
 # PPC64:      GnuHashTable {
-# PPC64-NEXT:   Num Buckets: 3
-# PPC64-NEXT:   First Hashed Symbol Index: 3
+# PPC64-NEXT:   Num Buckets: 1
+# PPC64-NEXT:   First Hashed Symbol Index: 4
 # PPC64-NEXT:   Num Mask Words: 1
 # PPC64-NEXT:   Shift Count: 6
-# PPC64-NEXT:   Bloom Filter: [0x401000000004224]
-# PPC64-NEXT:   Buckets: [3, 0, 5]
-# PPC64-NEXT:   Values: [0xB8860BA, 0xB887389, 0xB88C171]
+# PPC64-NEXT:   Bloom Filter: [0x400000000004204]
+# PPC64-NEXT:   Buckets: [4]
+# PPC64-NEXT:   Values: [0xB8860BA, 0xB887389]
 # PPC64-NEXT: }
 
 .globl foo,bar,baz