Merge commit '38b632c16e0f' from llvm.org/master into apple/main

Author: git apple-llvm automerger

lld/ELF/SyntheticSections.cpp

@@ -2914,7 +2914,8 @@ void GdbIndexSection::writeTo(uint8_t *buf) {
   uint32_t cuOff = 0;
   for (GdbChunk &chunk : chunks) {
     for (AddressEntry &e : chunk.addressAreas) {
-      uint64_t baseAddr = e.section->getVA(0);
+      // In the case of ICF there may be duplicate address range entries.
+      const uint64_t baseAddr = e.section->repl->getVA(0);
       write64le(buf, baseAddr + e.lowAddress);
       write64le(buf + 8, baseAddr + e.highAddress);
       write32le(buf + 16, e.cuIndex + cuOff);

lld/test/ELF/gdb-index-icf.s

@@ -0,0 +1,67 @@
+# REQUIRES: x86
+## Test that the address range contributed by an ICF folded function is identical
+## to that of the folded-in function. Not considering ICF may lead to an address
+## range whose low address equals the start address of the output section.
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
+# RUN: ld.lld --gdb-index --icf=all -Ttext=0x1000 %t.o -o %t
+# RUN: llvm-dwarfdump --gdb-index %t | FileCheck %s
+
+# CHECK:      Address area offset = 0x38, has 2 entries:
+# CHECK-NEXT:   Low/High address = [0x1001, 0x1002) (Size: 0x1), CU id = 0
+# CHECK-NEXT:   Low/High address = [0x1001, 0x1002) (Size: 0x1), CU id = 1
+
+.text
+nop
+
+.section .text.0,"ax"
+.Lfunc_begin0:
+  ret
+.Lfunc_end0:
+
+.section .text.1,"ax"
+.Lfunc_begin1:
+  ret
+.Lfunc_end1:
+
+.section  .debug_abbrev,"",@progbits
+  .byte  1                         # Abbreviation Code
+  .byte  65                        # DW_TAG_type_unit
+  .byte  0                         # DW_CHILDREN_no
+  .byte  0                         # EOM(1)
+  .byte  0                         # EOM(2)
+
+  .byte  2                         # Abbreviation Code
+  .byte  17                        # DW_TAG_compile_unit
+  .byte  0                         # DW_CHILDREN_no
+  .byte  17                        # DW_AT_low_pc
+  .byte  1                         # DW_FORM_addr
+  .byte  18                        # DW_AT_high_pc
+  .byte  6                         # DW_FORM_data4
+  .byte  0                         # EOM(1)
+  .byte  0                         # EOM(2)
+
+  .byte  0                         # EOM(3)
+
+.section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Lcu_end0-.Lcu_begin0-4    # Length of Unit
+  .short 5                         # DWARF version number
+  .byte  1                         # DWARF Unit Type
+  .byte  8                         # Address Size
+  .long  .debug_abbrev             # Offset Into Abbrev. Section
+  .byte  2                         # Abbrev [2] DW_TAG_compile_unit
+  .quad  .Lfunc_begin0             # DW_AT_low_pc
+  .long  .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
+.Lcu_end0:
+
+.Lcu_begin1:
+  .long .Lcu_end1-.Lcu_begin1-4    # Length of Unit
+  .short 5                         # DWARF version number
+  .byte  1                         # DWARF Unit Type
+  .byte  8                         # Address Size
+  .long  .debug_abbrev             # Offset Into Abbrev. Section
+  .byte  2                         # Abbrev [2] DW_TAG_compile_unit
+  .quad  .Lfunc_begin1             # DW_AT_low_pc
+  .long  .Lfunc_end1-.Lfunc_begin1 # DW_AT_high_pc
+.Lcu_end1: