[ELF][test] Improve flag propagation when an output section does not contain input sections

Author: MaskRay

lld/test/ELF/linkerscript/Inputs/extend-pt-load.s

@@ -1,3 +1,6 @@
 nop
 .section .data.rel.ro, "aw"
 .byte 0
+
+.section .rodata,"a"
+.byte 0

lld/test/ELF/linkerscript/extend-pt-load1.test

@@ -11,6 +11,7 @@ SECTIONS {
   .dynsym : {}
   .hash : {}
   .dynstr : {}
+  .rodata : { *(.rodata) }
   .text : { *(.text) }
   . = ALIGN(0x1000);
   .data.rel.ro : { *(.data.rel.ro) }
@@ -19,5 +20,6 @@ SECTIONS {
 # CHECK:      .text        PROGBITS 00000000000001f4 0001f4 000001 00 AX
 # CHECK-NEXT: .data.rel.ro PROGBITS 0000000000001000 001000 000001 00 WA
 
-# CHECK:      LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0001f1 0x0001f1 R   0x1000
+# CHECK:      LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0001f2 0x0001f2 R   0x1000
 # CHECK-NEXT: LOAD 0x0001f4 0x00000000000001f4 0x00000000000001f4 0x000001 0x000001 R E 0x1000
+# CHECK-NEXT: LOAD 0x001000 0x0000000000001000 0x0000000000001000 0x000068 0x000068 RW  0x1000

lld/test/ELF/linkerscript/extend-pt-load2.test

@@ -11,15 +11,20 @@ SECTIONS {
   .dynsym : {}
   .hash : {}
   .dynstr : {}
+  .rodata : { *(.rodata) }
+  foo : { sym = .; }
+
   .text : { *(.text) }
   bar : { . = ALIGN(0x1000); }
   .data.rel.ro : { *(.data.rel.ro) }
 }
 
-# CHECK:      .text        PROGBITS 00000000000001f4 0001f4 000001 00 AX
-# CHECK-NEXT: bar          PROGBITS 00000000000001f5 0001f5 000e0b 00 AX
-# CHECK-NEXT: .data.rel.ro PROGBITS 0000000000001000 001000 000001 00 WA
+# CHECK:      .rodata      PROGBITS 0000000000000215 000215 000001 00 A  0
+# CHECK-NEXT: foo          PROGBITS 0000000000000216 000216 000000 00 A  0
+# CHECK-NEXT: .text        PROGBITS 0000000000000218 000218 000001 00 AX 0
+# CHECK-NEXT: bar          PROGBITS 0000000000000219 000219 000de7 00 AX 0
+# CHECK-NEXT: .data.rel.ro PROGBITS 0000000000001000 001000 000001 00 WA 0
 
-# CHECK:      LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0001f1 0x0001f1 R   0x1000
-# CHECK:      LOAD 0x0001f4 0x00000000000001f4 0x00000000000001f4 0x000e0c 0x000e0c R E 0x1000
+# CHECK:      LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x000216 0x000216 R   0x1000
+# CHECK:      LOAD 0x000218 0x0000000000000218 0x0000000000000218 0x000de8 0x000de8 R E 0x1000
 # CHECK-NEXT: LOAD 0x001000 0x0000000000001000 0x0000000000001000 0x000068 0x000068 RW  0x1000

lld/test/ELF/linkerscript/extend-pt-load3.test

@@ -11,15 +11,17 @@ SECTIONS {
   .dynsym : {}
   .hash : {}
   .dynstr : {}
+  .rodata : { *(.rodata) }
   .text : { *(.text) }
   . = ALIGN(0x1000);
   HIDDEN(bar_sym = .);
   .data.rel.ro : { *(.data.rel.ro) }
 }
 
-# CHECK:      .text        PROGBITS 00000000000001f4 0001f4 000001 00 AX
-# CHECK-NEXT: .data.rel.ro PROGBITS 0000000000001000 001000 000001 00 WA
+# CHECK:      .rodata      PROGBITS 00000000000001f1 0001f1 000001 00 A  0
+# CHECK:      .text        PROGBITS 00000000000001f4 0001f4 000001 00 AX 0
+# CHECK-NEXT: .data.rel.ro PROGBITS 0000000000001000 001000 000001 00 WA 0
 
-# CHECK:      LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0001f1 0x0001f1 R   0x1000
+# CHECK:      LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0001f2 0x0001f2 R   0x1000
 # CHECK-NEXT: LOAD 0x0001f4 0x00000000000001f4 0x00000000000001f4 0x000001 0x000001 R E 0x1000
 # CHECK-NEXT: LOAD 0x001000 0x0000000000001000 0x0000000000001000 0x000068 0x000068 RW  0x1000