Delay the relocation scan.

We have to scan the relaxations after every symbol is defined.

This fixes pr25218.

llvm-svn: 250702

3 files changed, 48 insertions, 41 deletions

diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 65f57f38b9e..5be9afcce13 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -396,22 +396,6 @@ template <class ELFT> void Writer<ELFT>::createSections() {
   Map[{Out<ELFT>::Bss->getName(), Out<ELFT>::Bss->getType(),
        Out<ELFT>::Bss->getFlags()}] = Out<ELFT>::Bss;
 
-  // Declare linker generated symbols.
-  // This must be done before the relocation scan to make sure we can correctly
-  // decide if a dynamic relocation is needed or not.
-  // FIXME: Make this more declarative.
-  for (StringRef Name :
-       {"__preinit_array_start", "__preinit_array_end", "__init_array_start",
-        "__init_array_end", "__fini_array_start", "__fini_array_end"})
-    Symtab.addIgnoredSym(Name);
-
-  // __tls_get_addr is defined by the dynamic linker for dynamic ELFs. For
-  // static linking the linker is required to optimize away any references to
-  // __tls_get_addr, so it's not defined anywhere. Create a hidden definition
-  // to avoid the undefined symbol error.
-  if (!isOutputDynamic())
-    Symtab.addIgnoredSym("__tls_get_addr");
-
   std::vector<OutputSectionBase<ELFT> *> RegularSections;
 
   for (const std::unique_ptr<ObjectFile<ELFT>> &F : Symtab.getObjectFiles()) {
@@ -430,13 +414,9 @@ template <class ELFT> void Writer<ELFT>::createSections() {
         RegularSections.push_back(Sec);
       }
       Sec->addSection(C);
-      scanRelocs(*C);
     }
   }
 
-  for (OutputSectionBase<ELFT> *Sec : RegularSections)
-    addStartStopSymbols(Sec);
-
   Out<ELFT>::Dynamic->PreInitArraySec =
       Map.lookup({".preinit_array", SHT_PREINIT_ARRAY, SHF_WRITE | SHF_ALLOC});
   Out<ELFT>::Dynamic->InitArraySec =
@@ -449,6 +429,9 @@ template <class ELFT> void Writer<ELFT>::createSections() {
     if (OS) {
       Symtab.addSyntheticSym(Start, *OS, 0);
       Symtab.addSyntheticSym(End, *OS, OS->getSize());
+    } else {
+      Symtab.addIgnoredSym(Start);
+      Symtab.addIgnoredSym(End);
     }
   };
 
@@ -459,6 +442,23 @@ template <class ELFT> void Writer<ELFT>::createSections() {
   AddStartEnd("__fini_array_start", "__fini_array_end",
               Out<ELFT>::Dynamic->FiniArraySec);
 
+  for (OutputSectionBase<ELFT> *Sec : RegularSections)
+    addStartStopSymbols(Sec);
+
+  // __tls_get_addr is defined by the dynamic linker for dynamic ELFs. For
+  // static linking the linker is required to optimize away any references to
+  // __tls_get_addr, so it's not defined anywhere. Create a hidden definition
+  // to avoid the undefined symbol error.
+  if (!isOutputDynamic())
+    Symtab.addIgnoredSym("__tls_get_addr");
+
+  // Scan relocations. This must be done after every symbol is declared so that
+  // we can correctly decide if a dynamic relocation is needed.
+  for (const std::unique_ptr<ObjectFile<ELFT>> &F : Symtab.getObjectFiles())
+    for (InputSection<ELFT> *S : F->getSections())
+      if (S && S != &InputSection<ELFT>::Discarded)
+        scanRelocs(*S);
+
   // FIXME: Try to avoid the extra walk over all global symbols.
   std::vector<DefinedCommon<ELFT> *> CommonSymbols;
   for (auto &P : Symtab.getSymbols()) {
diff --git a/lld/test/elf2/pre_init_fini_array.s b/lld/test/elf2/pre_init_fini_array.s
index 5bee585691b..7d00bedc22b 100644
--- a/lld/test/elf2/pre_init_fini_array.s
+++ b/lld/test/elf2/pre_init_fini_array.s
@@ -67,7 +67,7 @@ _start:
 // CHECK-NEXT:   Size: 0
 // CHECK-NEXT:   Binding: Local
 // CHECK-NEXT:   Type: None
-// CHECK-NEXT:   Other: 2
+// CHECK-NEXT:   Other: 0
 // CHECK-NEXT:   Section: .fini_array
 // CHECK-NEXT: }
 // CHECK-NEXT: Symbol {
@@ -76,7 +76,7 @@ _start:
 // CHECK-NEXT:   Size: 0
 // CHECK-NEXT:   Binding: Local
 // CHECK-NEXT:   Type: None
-// CHECK-NEXT:   Other: 2
+// CHECK-NEXT:   Other: 0
 // CHECK-NEXT:   Section: .fini_array
 // CHECK-NEXT: }
 // CHECK-NEXT: Symbol {
@@ -85,7 +85,7 @@ _start:
 // CHECK-NEXT:   Size: 0
 // CHECK-NEXT:   Binding: Local
 // CHECK-NEXT:   Type: None
-// CHECK-NEXT:   Other: 2
+// CHECK-NEXT:   Other: 0
 // CHECK-NEXT:   Section: .init_array
 // CHECK-NEXT: }
 // CHECK-NEXT: Symbol {
@@ -94,7 +94,7 @@ _start:
 // CHECK-NEXT:   Size: 0
 // CHECK-NEXT:   Binding: Local
 // CHECK-NEXT:   Type: None
-// CHECK-NEXT:   Other: 2
+// CHECK-NEXT:   Other: 0
 // CHECK-NEXT:   Section: .init_array
 // CHECK-NEXT: }
 // CHECK-NEXT: Symbol {
@@ -103,7 +103,7 @@ _start:
 // CHECK-NEXT:   Size: 0
 // CHECK-NEXT:   Binding: Local
 // CHECK-NEXT:   Type: None
-// CHECK-NEXT:   Other: 2
+// CHECK-NEXT:   Other: 0
 // CHECK-NEXT:   Section: .preinit_array
 // CHECK-NEXT: }
 // CHECK-NEXT: Symbol {
@@ -112,7 +112,7 @@ _start:
 // CHECK-NEXT:   Size: 0
 // CHECK-NEXT:   Binding: Local
 // CHECK-NEXT:   Type: None
-// CHECK-NEXT:   Other: 2
+// CHECK-NEXT:   Other: 0
 // CHECK-NEXT:   Section: .preinit_array
 // CHECK-NEXT: }
 
diff --git a/lld/test/elf2/startstop.s b/lld/test/elf2/startstop.s
index 328468a7129..784c237bb31 100644
--- a/lld/test/elf2/startstop.s
+++ b/lld/test/elf2/startstop.s
@@ -1,41 +1,48 @@
 // REQUIRES: x86
 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
-// RUN: ld.lld2 %t -o %tout
+// RUN: ld.lld2 %t -o %tout -shared
 // RUN: llvm-objdump -d %tout | FileCheck -check-prefix=DISASM %s
-// RUN: llvm-readobj -symbols %tout | FileCheck -check-prefix=SYMBOL %s
+// RUN: llvm-readobj -symbols -r %tout | FileCheck -check-prefix=SYMBOL %s
 
 // DISASM: _start:
-// DISASM:    11000:       e8 0a 00 00 00  callq   10
-// DISASM:    11005:       e8 08 00 00 00  callq   8
-// DISASM:    1100a:       e8 03 00 00 00  callq   3
+// DISASM:    1000:       {{.*}}  callq   10
+// DISASM:    1005:       {{.*}}  callq   8
+// DISASM:    100a:       {{.*}}  callq   3
 // DISASM: Disassembly of section foo:
 // DISASM: __start_foo:
-// DISASM:    1100f:       90      nop
-// DISASM:    11010:       90      nop
-// DISASM:    11011:       90      nop
+// DISASM:    100f:       90      nop
+// DISASM:    1010:       90      nop
+// DISASM:    1011:       90      nop
 // DISASM: Disassembly of section bar:
 // DISASM: __start_bar:
-// DISASM:    11012:       90      nop
-// DISASM:    11013:       90      nop
-// DISASM:    11014:       90      nop
+// DISASM:    1012:       90      nop
+// DISASM:    1013:       90      nop
+// DISASM:    1014:       90      nop
+
+
+// SYMBOL: Relocations [
+// SYMBOL-NEXT: ]
 
 // SYMBOL: Symbol {
 // SYMBOL:   Name: __start_bar
-// SYMBOL:   Value: 0x11012
+// SYMBOL:   Value: 0x1012
 // SYMBOL:   Section: bar
 // SYMBOL: }
 // SYMBOL-NOT:   Section: __stop_bar
 // SYMBOL: Symbol {
 // SYMBOL:   Name: __start_foo
-// SYMBOL:   Value: 0x1100F
+// SYMBOL:   Value: 0x100F
 // SYMBOL:   Section: foo
 // SYMBOL: }
 // SYMBOL: Symbol {
 // SYMBOL:   Name: __stop_foo
-// SYMBOL:   Value: 0x11012
-// SYMBOL:   Section: foo (0x2)
+// SYMBOL:   Value: 0x1012
+// SYMBOL:   Section: foo
 // SYMBOL: }
 
+.hidden __start_foo
+.hidden __stop_foo
+.hidden __start_bar
 .global _start
 .text
 _start: