From 6ca8fde226e907db13bc538e721af8724f0e92d0 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Wed, 24 Nov 2021 23:17:13 -0800
Subject: [PATCH] [ELF] Emit DF_STATIC_TLS only for -shared

This matches GNU ld and saves 2 words for executables.
---
 lld/ELF/SyntheticSections.cpp          |  2 +-
 lld/test/ELF/i386-tls-opt-iele-nopic.s | 12 ++++++------
 lld/test/ELF/x86-64-static-tls-model.s | 10 +++++++---
 lld/test/ELF/x86-64-tls-ie.s           | 16 ++++++++--------
 4 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index a47b8d7..78d41e5 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -1382,7 +1382,7 @@ template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
   }
   if (!config->zText)
     dtFlags |= DF_TEXTREL;
-  if (config->hasTlsIe)
+  if (config->hasTlsIe && config->shared)
     dtFlags |= DF_STATIC_TLS;
 
   if (dtFlags)
diff --git a/lld/test/ELF/i386-tls-opt-iele-nopic.s b/lld/test/ELF/i386-tls-opt-iele-nopic.s
index 641552d..8dd0cf6 100644
--- a/lld/test/ELF/i386-tls-opt-iele-nopic.s
+++ b/lld/test/ELF/i386-tls-opt-iele-nopic.s
@@ -14,8 +14,8 @@
 // GOTREL-NEXT:     SHF_ALLOC
 // GOTREL-NEXT:     SHF_WRITE
 // GOTREL-NEXT:   ]
-// GOTREL-NEXT:   Address:  0x402258
-// GOTREL-NEXT:   Offset: 0x258
+// GOTREL-NEXT:   Address:  0x402250
+// GOTREL-NEXT:   Offset: 0x250
 // GOTREL-NEXT:   Size: 8
 // GOTREL-NEXT:   Link: 0
 // GOTREL-NEXT:   Info: 0
@@ -24,8 +24,8 @@
 // GOTREL-NEXT: }
 // GOTREL:      Relocations [
 // GOTREL-NEXT: Section ({{.*}}) .rel.dyn {
-// GOTREL-NEXT:   0x402258 R_386_TLS_TPOFF tlsshared0
-// GOTREL-NEXT:   0x40225C R_386_TLS_TPOFF tlsshared1
+// GOTREL-NEXT:   0x402250 R_386_TLS_TPOFF tlsshared0
+// GOTREL-NEXT:   0x402254 R_386_TLS_TPOFF tlsshared1
 // GOTREL-NEXT:  }
 // GOTREL-NEXT: ]
 
@@ -45,10 +45,10 @@
 // DISASM-NEXT:               addl $0xfffffffc, %ecx
 // DISASM-NEXT:               movl %gs:(%ecx), %eax
 /// &.got[0]
-// DISASM-NEXT:               movl 0x402258, %ecx
+// DISASM-NEXT:               movl 0x402250, %ecx
 // DISASM-NEXT:               movl %gs:(%ecx), %eax
 /// &.got[1]
-// DISASM-NEXT:               addl 0x40225c, %ecx
+// DISASM-NEXT:               addl 0x402254, %ecx
 // DISASM-NEXT:               movl %gs:(%ecx), %eax
 
 .type tlslocal0,@object
diff --git a/lld/test/ELF/x86-64-static-tls-model.s b/lld/test/ELF/x86-64-static-tls-model.s
index 997def3..0908462 100644
--- a/lld/test/ELF/x86-64-static-tls-model.s
+++ b/lld/test/ELF/x86-64-static-tls-model.s
@@ -1,15 +1,19 @@
 # REQUIRES: x86
 
 ## In this test R_X86_64_GOTTPOFF is a IE relocation (static TLS model),
-## test check we add STATIC_TLS flag.
+## test check we add STATIC_TLS flag for -shared.
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
-# RUN: ld.lld %t.o -o %t1 -shared
-# RUN: llvm-readobj --dynamic-table %t1 | FileCheck %s
+# RUN: ld.lld %t.o -o %t.so -shared
+# RUN: llvm-readobj --dynamic-table %t.so | FileCheck %s
+# RUN: ld.lld %t.o -o %t -pie
+# RUN: llvm-readobj --dynamic-table %t | FileCheck %s --check-prefix=EXE
 
 # CHECK: DynamicSection [
 # CHECK: FLAGS STATIC_TLS
 
+# EXE-NOT: FLAGS STATIC_TLS
+
 .section ".tdata", "awT", @progbits
 .globl var
 var:
diff --git a/lld/test/ELF/x86-64-tls-ie.s b/lld/test/ELF/x86-64-tls-ie.s
index 9dd7010..e5510f8 100644
--- a/lld/test/ELF/x86-64-tls-ie.s
+++ b/lld/test/ELF/x86-64-tls-ie.s
@@ -15,7 +15,7 @@
 // CHECK-NEXT:   SHF_WRITE
 // CHECK-NEXT: ]
 // CHECK-NEXT: Address: [[ADDR:.*]]
-// CHECK-NEXT: Offset: 0x3C0
+// CHECK-NEXT: Offset: 0x3B0
 // CHECK-NEXT: Size: 16
 // CHECK-NEXT: Link: 0
 // CHECK-NEXT: Info: 0
@@ -26,21 +26,21 @@
 // CHECK:      Relocations [
 // CHECK-NEXT:   Section (5) .rela.dyn {
 // CHECK-NEXT:     [[ADDR]] R_X86_64_TPOFF64 tls1 0x0
-// CHECK-NEXT:     0x2023C8 R_X86_64_TPOFF64 tls0 0x0
+// CHECK-NEXT:     0x2023B8 R_X86_64_TPOFF64 tls0 0x0
 // CHECK-NEXT:   }
 // CHECK-NEXT: ]
 
-// 0x2012d0 + 4329 + 7 = 0x2023C0
-// 0x2012dA + 4327 + 7 = 0x2023C8
-// 0x2012e4 + 4317 + 7 = 0x2023C8
+// 0x2012d0 + 4313 + 7 = 0x2023B0
+// 0x2012dA + 4311 + 7 = 0x2023B8
+// 0x2012e4 + 4301 + 7 = 0x2023B8
 // DISASM:      Disassembly of section .text:
 // DISASM-EMPTY:
 // DISASM-NEXT: <main>:
-// DISASM-NEXT: 2012d0: {{.*}} movq 4329(%rip), %rax
+// DISASM-NEXT: 2012d0: {{.*}} movq 4313(%rip), %rax
 // DISASM-NEXT: 2012d7: {{.*}} movl %fs:(%rax), %eax
-// DISASM-NEXT: 2012da: {{.*}} movq 4327(%rip), %rax
+// DISASM-NEXT: 2012da: {{.*}} movq 4311(%rip), %rax
 // DISASM-NEXT: 2012e1: {{.*}} movl %fs:(%rax), %eax
-// DISASM-NEXT: 2012e4: {{.*}} movq 4317(%rip), %rax
+// DISASM-NEXT: 2012e4: {{.*}} movq 4301(%rip), %rax
 // DISASM-NEXT: 2012eb: {{.*}} movl %fs:(%rax), %eax
 // DISASM-NEXT: 2012ee: {{.*}} retq
 
-- 
2.7.4