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Merge commit '7b346357db30' from llvm.org/main into next
2 parents d15b70a + 7b34635 commit 915b452

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4 files changed

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‎lld/ELF/Writer.cpp

Lines changed: 16 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -935,27 +935,32 @@ findOrphanPos(SmallVectorImpl<SectionCommand *>::iterator b,
935935
return i;
936936
}
937937

938-
// Find the first element that has as close a rank as possible.
939-
if (b == e)
940-
return e;
941-
int proximity = getRankProximity(sec, *b);
942-
auto i = b;
943-
for (auto j = b; ++j != e;) {
938+
// Find the most similar output section as the anchor. Rank Proximity is a
939+
// value in the range [-1, 32] where [0, 32] indicates potential anchors (0:
940+
// least similar; 32: identical). -1 means not an anchor.
941+
//
942+
// In the event of proximity ties, we select the first or last section
943+
// depending on whether the orphan's rank is smaller.
944+
int maxP = 0;
945+
auto i = e;
946+
for (auto j = b; j != e; ++j) {
944947
int p = getRankProximity(sec, *j);
945-
if (p > proximity) {
946-
proximity = p;
948+
if (p > maxP ||
949+
(p == maxP && cast<OutputDesc>(*j)->osec.sortRank <= sec->sortRank)) {
950+
maxP = p;
947951
i = j;
948952
}
949953
}
950-
if (!isa<OutputDesc>(*i))
954+
if (i == e)
951955
return e;
952956

953957
auto isOutputSecWithInputSections = [](SectionCommand *cmd) {
954958
auto *osd = dyn_cast<OutputDesc>(cmd);
955959
return osd && osd->osec.hasInputSections;
956960
};
957961

958-
// If i's rank is larger, the orphan section can be placed before i.
962+
// Then, scan backward or forward through the script for a suitable insertion
963+
// point. If i's rank is larger, the orphan section can be placed before i.
959964
//
960965
// However, don't do this if custom program headers are defined. Otherwise,
961966
// adding the orphan to a previous segment can change its flags, for example,
@@ -967,7 +972,7 @@ findOrphanPos(SmallVectorImpl<SectionCommand *>::iterator b,
967972
for (auto j = ++i; j != e; ++j) {
968973
if (!isOutputSecWithInputSections(*j))
969974
continue;
970-
if (getRankProximity(sec, *j) != proximity)
975+
if (getRankProximity(sec, *j) != maxP)
971976
break;
972977
i = j + 1;
973978
}

‎lld/test/ELF/linkerscript/orphan.s

Lines changed: 22 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -65,6 +65,18 @@
6565
# RW-TEXT-NEXT: .text PROGBITS 0000000000001{{...}} 0
6666
# RW-TEXT-NEXT: .mytext PROGBITS 0000000000001{{...}} 0
6767

68+
# RUN: ld.lld a.o -T rw-text-rw.lds -o rw-text-rw
69+
# RUN: llvm-readelf -S rw-text-rw | FileCheck %s --check-prefix=RW-TEXT-RW
70+
# RW-TEXT-RW: .jcr PROGBITS 00000000000002{{..}} 0
71+
# RW-TEXT-RW-NEXT: .rw1 PROGBITS 00000000000002{{..}} 0
72+
# RW-TEXT-RW-NEXT: .interp PROGBITS 00000000000002{{..}} 0
73+
# RW-TEXT-RW-NEXT: .note.my NOTE 00000000000002{{..}} 0
74+
# RW-TEXT-RW-NEXT: .text PROGBITS 0000000000001{{...}} 0
75+
# RW-TEXT-RW-NEXT: .mytext PROGBITS 0000000000001{{...}} 0
76+
# RW-TEXT-RW-NEXT: .rw2 PROGBITS 0000000000002{{...}} 0
77+
# RW-TEXT-RW-NEXT: .rw3 PROGBITS 0000000000002{{...}} 0
78+
# RW-TEXT-RW-NEXT: .bss NOBITS 0000000000002{{...}} 0
79+
6880
#--- a.s
6981
.section .rw1, "aw"; .byte 0
7082
.section .rw2, "aw"; .byte 0
@@ -112,3 +124,13 @@ SECTIONS {
112124
. = ALIGN(CONSTANT(MAXPAGESIZE));
113125
.text : { *(.text) }
114126
}
127+
128+
#--- rw-text-rw.lds
129+
SECTIONS {
130+
. = SIZEOF_HEADERS;
131+
.rw1 : { *(.rw1) }
132+
. = ALIGN(CONSTANT(MAXPAGESIZE));
133+
.text : { *(.text) }
134+
. = ALIGN(CONSTANT(MAXPAGESIZE));
135+
.rw2 : { *(.rw2) }
136+
}

‎lld/test/ELF/linkerscript/sections-nonalloc.s

Lines changed: 17 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -14,15 +14,16 @@
1414
# CHECK-NEXT: [ 0] NULL 0000000000000000 000000 000000 00 0
1515
# CHECK-NEXT: [ 1] .bss NOBITS 0000000000000000 001000 000001 00 WA 0
1616
# CHECK-NEXT: [ 2] data1 PROGBITS 0000000000000001 001001 000001 00 WA 0
17-
# CHECK-NEXT: [ 3] data3 PROGBITS 0000000000000002 001002 000001 00 WA 0
18-
# CHECK-NEXT: [ 4] other1 PROGBITS 0000000000000000 001008 000001 00 0
19-
# CHECK-NEXT: [ 5] other2 PROGBITS 0000000000000000 001010 000001 00 0
17+
# CHECK-NEXT: [ 3] other1 PROGBITS 0000000000000000 001008 000001 00 0
18+
# CHECK-NEXT: [ 4] other2 PROGBITS 0000000000000000 001010 000001 00 0
2019
## Orphan placement places other3, .symtab, .shstrtab and .strtab after other2.
21-
# CHECK-NEXT: [ 6] other3 PROGBITS 0000000000000000 001020 000001 00 0
22-
# CHECK-NEXT: [ 7] .symtab SYMTAB 0000000000000000 001028 000030 18 9
23-
# CHECK-NEXT: [ 8] .shstrtab STRTAB 0000000000000000 001058 00004d 00 0
24-
# CHECK-NEXT: [ 9] .strtab STRTAB 0000000000000000 0010a5 000008 00 0
25-
# CHECK-NEXT: [10] data2 PROGBITS 0000000000000003 001003 000001 00 WA 0
20+
# CHECK-NEXT: [ 5] other3 PROGBITS 0000000000000000 001020 000001 00 0
21+
# CHECK-NEXT: [ 6] .symtab SYMTAB 0000000000000000 001028 000030 18 8
22+
# CHECK-NEXT: [ 7] .shstrtab STRTAB 0000000000000000 001058 00004d 00 0
23+
# CHECK-NEXT: [ 8] .strtab STRTAB 0000000000000000 0010a5 000008 00 0
24+
# CHECK-NEXT: [ 9] data2 PROGBITS 0000000000000002 001002 000001 00 WA 0
25+
## max{sortRank(data1),sortRank(data2)} <= sortRank(data3). data3 is placed after the latter.
26+
# CHECK-NEXT: [10] data3 PROGBITS 0000000000000003 001003 000001 00 WA 0
2627
# CHECK-NEXT: [11] .text PROGBITS 0000000000000004 001004 000001 00 AX 0
2728

2829
# CHECK: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
@@ -38,14 +39,14 @@
3839
# CHECK1-NEXT: [ 1] .text PROGBITS 00000000000000b0 0000b0 000001 00 AX 0
3940
# CHECK1-NEXT: [ 2] .bss NOBITS 00000000000000b1 0000b1 000001 00 WA 0
4041
# CHECK1-NEXT: [ 3] data1 PROGBITS 00000000000000b2 0000b2 000001 00 WA 0
41-
# CHECK1-NEXT: [ 4] data3 PROGBITS 00000000000000b3 0000b3 000001 00 WA 0
42-
# CHECK1-NEXT: [ 5] other1 PROGBITS 0000000000000000 0000b8 000001 00 0
43-
# CHECK1-NEXT: [ 6] other2 PROGBITS 0000000000000000 0000c0 000001 00 0
44-
# CHECK1-NEXT: [ 7] other3 PROGBITS 0000000000000000 0000d0 000001 00 0
45-
# CHECK1-NEXT: [ 8] .symtab SYMTAB 0000000000000000 0000d8 000030 18 10
46-
# CHECK1-NEXT: [ 9] .shstrtab STRTAB 0000000000000000 000108 00004d 00 0
47-
# CHECK1-NEXT: [10] .strtab STRTAB 0000000000000000 000155 000008 00 0
48-
# CHECK1-NEXT: [11] data2 PROGBITS 00000000000000b4 0000b4 000001 00 WA 0
42+
# CHECK1-NEXT: [ 4] other1 PROGBITS 0000000000000000 0000b8 000001 00 0
43+
# CHECK1-NEXT: [ 5] other2 PROGBITS 0000000000000000 0000c0 000001 00 0
44+
# CHECK1-NEXT: [ 6] other3 PROGBITS 0000000000000000 0000d0 000001 00 0
45+
# CHECK1-NEXT: [ 7] .symtab SYMTAB 0000000000000000 0000d8 000030 18 9
46+
# CHECK1-NEXT: [ 8] .shstrtab STRTAB 0000000000000000 000108 00004d 00 0
47+
# CHECK1-NEXT: [ 9] .strtab STRTAB 0000000000000000 000155 000008 00 0
48+
# CHECK1-NEXT: [10] data2 PROGBITS 00000000000000b3 0000b3 000001 00 WA 0
49+
# CHECK1-NEXT: [11] data3 PROGBITS 00000000000000b4 0000b4 000001 00 WA 0
4950
# CHECK1: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
5051
# CHECK1-NEXT: LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0000b5 0x0000b5 RWE 0x1000
5152
# CHECK1-NEXT: 0x60000000 0x0000b8 0x0000000000000000 0x0000000000000000 0x000009 0x000001 0x8

‎lld/test/ELF/linkerscript/sections.s

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -78,13 +78,13 @@
7878
# SEP-BY-NONALLOC: [Nr] Name Type Address Off Size ES Flg
7979
# SEP-BY-NONALLOC: [ 1] .text PROGBITS 0000000000000000 001000 00000e 00 AX
8080
# SEP-BY-NONALLOC-NEXT: [ 2] .data PROGBITS 000000000000000e 00100e 000020 00 WA
81-
# SEP-BY-NONALLOC-NEXT: [ 3] .bss NOBITS 000000000000002e 00102e 000002 00 WA
82-
# SEP-BY-NONALLOC-NEXT: [ 4] .comment PROGBITS 0000000000000000 001033 000008 01 MS
83-
# SEP-BY-NONALLOC: [ 8] other PROGBITS 0000000000000030 001030 000003 00 WA
81+
# SEP-BY-NONALLOC-NEXT: [ 3] .comment PROGBITS 0000000000000000 001031 000008 01 MS
82+
# SEP-BY-NONALLOC: [ 7] other PROGBITS 000000000000002e 00102e 000003 00 WA
83+
# SEP-BY-NONALLOC-NEXT: [ 8] .bss NOBITS 0000000000000031 001031 000002 00 WA
8484

8585
# SEP-BY-NONALLOC: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
8686
# SEP-BY-NONALLOC-NEXT: LOAD 0x001000 0x0000000000000000 0x0000000000000000 0x00000e 0x00000e R E 0x1000
87-
# SEP-BY-NONALLOC-NEXT: LOAD 0x00100e 0x000000000000000e 0x000000000000000e 0x000025 0x000025 RW 0x1000
87+
# SEP-BY-NONALLOC-NEXT: LOAD 0x00100e 0x000000000000000e 0x000000000000000e 0x000023 0x000025 RW 0x1000
8888
# SEP-BY-NONALLOC-NEXT: GNU_STACK 0x000000 0x0000000000000000 0x0000000000000000 0x000000 0x000000 RW 0
8989

9090
# Input section pattern contains additional semicolon.

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