[lld] r306522 - [ELF] Consolidate .ARM.extab.* sections into .ARM.extab

[Peter Smith via llvm-commits]

Author: psmith
Date: Wed Jun 28 02:12:38 2017
New Revision: 306522

URL: http://llvm.org/viewvc/llvm-project?rev=306522&view=rev
Log:
[ELF] Consolidate .ARM.extab.* sections into .ARM.extab

When -ffunction-sections and ARM C++ exceptions are used each .text.suffix
section will have at least one .ARM.exidx.suffix section and may have an
additional .ARM.extab.suffix section if the unwinding instructions are too
large to inline into the .ARM.exidx table entry. For a large program without
a linker script this can lead to a large number of section header table
entries that can increase the size of the ELF file.

This change introduces a default rule for .ARM.extab.* to be placed in
a single output section called .ARM.extab . This follows the behavior of
ld.gold and ld.bfd.

fixes pr33407

Differential Revision: https://reviews.llvm.org/D34678


Modified:
    lld/trunk/ELF/Writer.cpp
    lld/trunk/test/ELF/arm-exidx-canunwind.s
    lld/trunk/test/ELF/arm-exidx-gc.s
    lld/trunk/test/ELF/arm-exidx-shared.s

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=306522&r1=306521&r2=306522&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Wed Jun 28 02:12:38 2017
@@ -104,7 +104,7 @@ StringRef elf::getOutputSectionName(Stri
   for (StringRef V :
        {".text.", ".rodata.", ".data.rel.ro.", ".data.", ".bss.rel.ro.",
         ".bss.", ".init_array.", ".fini_array.", ".ctors.", ".dtors.", ".tbss.",
-        ".gcc_except_table.", ".tdata.", ".ARM.exidx."}) {
+        ".gcc_except_table.", ".tdata.", ".ARM.exidx.", ".ARM.extab."}) {
     StringRef Prefix = V.drop_back();
     if (Name.startswith(V) || Name == Prefix)
       return Prefix;

Modified: lld/trunk/test/ELF/arm-exidx-canunwind.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/arm-exidx-canunwind.s?rev=306522&r1=306521&r2=306522&view=diff
==============================================================================
--- lld/trunk/test/ELF/arm-exidx-canunwind.s (original)
+++ lld/trunk/test/ELF/arm-exidx-canunwind.s Wed Jun 28 02:12:38 2017
@@ -72,7 +72,7 @@ _start:
 // CHECK-EXIDX-NEXT: 100d4 380f0000 08849780 340f0000 0c000000
 // 100e4 + f30 = 11014 = terminate = func2 + sizeof(func2)
 // CHECK-EXIDX-NEXT: 100e4 300f0000 01000000
-// CHECK-EXIDX-NEXT: Contents of section .ARM.extab.text.func2:
+// CHECK-EXIDX-NEXT: Contents of section .ARM.extab:
 // 100ec + f28 = 11014 = __gxx_personality_v0
 // CHECK-EXIDX-NEXT: 100ec 280f0000 b0b0b000 00000000
 

Modified: lld/trunk/test/ELF/arm-exidx-gc.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/arm-exidx-gc.s?rev=306522&r1=306521&r2=306522&view=diff
==============================================================================
--- lld/trunk/test/ELF/arm-exidx-gc.s (original)
+++ lld/trunk/test/ELF/arm-exidx-gc.s Wed Jun 28 02:12:38 2017
@@ -110,16 +110,15 @@ _start:
 // CHECK-NOT: unusedfunc2
 // CHECK-NOT: __gxx_personality_v1
 
-// CHECK-EXIDX-NOT: Contents of section .ARM.extab.text.unusedfunc2:
 // CHECK-EXIDX: Contents of section .ARM.exidx:
 // 100d4 + f38 = 1100c = func1
-// 100dc + f34 = 11010 = func2 (100e0 + 1c = 100fc = .ARM.extab.text.func2)
+// 100dc + f34 = 11010 = func2 (100e0 + 1c = 100fc = .ARM.extab)
 // CHECK-EXIDX-NEXT: 100d4 380f0000 08849780 340f0000 1c000000
 // 100e4 + f30 = 11014 = __gxx_personality_v0
 // 100ec + f2c = 11018 = __aeabi_unwind_cpp_pr0
 // CHECK-EXIDX-NEXT: 100e4 300f0000 01000000 2c0f0000 01000000
 // 100f4 + f28 = 1101c = __aeabi_unwind_cpp_pr0 + sizeof(__aeabi_unwind_cpp_pr0)
 // CHECK-EXIDX-NEXT: 100f4 280f0000 01000000
-// CHECK-EXIDX-NEXT: Contents of section .ARM.extab.text.func2:
+// CHECK-EXIDX-NEXT: Contents of section .ARM.extab:
 // 100fc + f18 = 11014 = __gxx_personality_v0
 // CHECK-EXIDX-NEXT: 100fc 180f0000 b0b0b000

Modified: lld/trunk/test/ELF/arm-exidx-shared.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/arm-exidx-shared.s?rev=306522&r1=306521&r2=306522&view=diff
==============================================================================
--- lld/trunk/test/ELF/arm-exidx-shared.s (original)
+++ lld/trunk/test/ELF/arm-exidx-shared.s Wed Jun 28 02:12:38 2017
@@ -40,6 +40,6 @@ __aeabi_unwind_cpp_pr0:
 // CHECK-NEXT:   Section (6) .rel.plt {
 // CHECK-NEXT:     0x200C R_ARM_JUMP_SLOT __gxx_personality_v0
 
-// CHECK-EXTAB: Contents of section .ARM.extab.text.func2:
+// CHECK-EXTAB: Contents of section .ARM.extab:
 // 014c + 0ed8 = 0x1024 = __gxx_personality_v0(PLT)
 // CHECK-EXTAB-NEXT:  014c d80e0000 b0b0b000 00000000