[lld] 21dbfd4 - [ELF] --gc-sections: Change startwith(".init") (and ".fini") to exact match

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2021-12-15T01:16:26-08:00
New Revision: 21dbfd430021cc8f4270daaec15897b023a5cacc

URL: https://github.com/llvm/llvm-project/commit/21dbfd430021cc8f4270daaec15897b023a5cacc
DIFF: https://github.com/llvm/llvm-project/commit/21dbfd430021cc8f4270daaec15897b023a5cacc.diff

LOG: [ELF] --gc-sections: Change startwith(".init") (and ".fini") to exact match

GNU ld's internal linker script keeps `.init`, but not other sections starting
with `.init`. .fini is similar.

Added: 
    

Modified: 
    lld/ELF/MarkLive.cpp
    lld/test/ELF/gc-sections.s

Removed: 
    


################################################################################
diff  --git a/lld/ELF/MarkLive.cpp b/lld/ELF/MarkLive.cpp
index 48ef87bb7bb3e..a040de09acb68 100644
--- a/lld/ELF/MarkLive.cpp
+++ b/lld/ELF/MarkLive.cpp
@@ -178,9 +178,8 @@ static bool isReserved(InputSectionBase *sec) {
     return !sec->nextInSectionGroup;
   default:
     StringRef s = sec->name;
-    return s.startswith(".ctors") || s.startswith(".dtors") ||
-           s.startswith(".init") || s.startswith(".fini") ||
-           s.startswith(".jcr");
+    return s == ".init" || s == ".fini" || s.startswith(".ctors") ||
+           s.startswith(".dtors") || s.startswith(".jcr");
   }
 }
 

diff  --git a/lld/test/ELF/gc-sections.s b/lld/test/ELF/gc-sections.s
index a98696d41a002..4e3dd5324f571 100644
--- a/lld/test/ELF/gc-sections.s
+++ b/lld/test/ELF/gc-sections.s
@@ -3,7 +3,7 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 # RUN: ld.lld %t -o %t2
 # RUN: llvm-readobj --sections --symbols %t2 | FileCheck -check-prefix=NOGC %s
-# RUN: ld.lld --gc-sections %t -o %t2
+# RUN: ld.lld --gc-sections --print-gc-sections %t -o %t2 | FileCheck --check-prefix=GC1-DISCARD %s
 # RUN: llvm-readobj --sections --symbols %t2 | FileCheck -check-prefix=GC1 %s
 # RUN: ld.lld --export-dynamic --gc-sections %t -o %t2
 # RUN: llvm-readobj --sections --symbols %t2 | FileCheck -check-prefix=GC2 %s
@@ -11,6 +11,7 @@
 # NOGC: Name: .eh_frame
 # NOGC: Name: .text
 # NOGC: Name: .init
+# NOGC: Name: .init_x
 # NOGC: Name: .fini
 # NOGC: Name: .tdata
 # NOGC: Name: .tbss
@@ -29,6 +30,14 @@
 # NOGC: Name: y
 # NOGC: Name: d
 
+# GC1-DISCARD:      removing unused section {{.*}}:(.text.d)
+# GC1-DISCARD-NEXT: removing unused section {{.*}}:(.text.x)
+# GC1-DISCARD-NEXT: removing unused section {{.*}}:(.text.y)
+# GC1-DISCARD-NEXT: removing unused section {{.*}}:(.tbss.f)
+# GC1-DISCARD-NEXT: removing unused section {{.*}}:(.tdata.h)
+# GC1-DISCARD-NEXT: removing unused section {{.*}}:(.init_x)
+# GC1-DISCARD-EMPTY:
+
 # GC1:     Name: .eh_frame
 # GC1:     Name: .text
 # GC1:     Name: .init
@@ -124,10 +133,13 @@ h:
 .section .dtors,"aw", at progbits
   .quad 0
 
-.section .init,"aw", at init_array
+.section .init,"ax"
+  .quad 0
+
+.section .init_x,"ax"
   .quad 0
 
-.section .fini,"aw", at fini_array
+.section .fini,"ax"
   .quad 0
 
 .section .preinit_array,"aw", at preinit_array