[ELF] - Linkerscript: Implemented >> and <<

[grimar]

Summary

Found this operators used in the wild here:
https://searchcode.com/file/103745382/board/bf561-ezkit/u-boot.lds.S

__got2_entries = (_FIXUP_TABLE_ - _GOT2_TABLE_) >>2;
__fixup_entries = (. - _FIXUP_TABLE_)>>2;

[ruiu]

lld/trunk/ELF/LinkerScript.cpp

1084–1085

StringSwitch now has Cases function in addition to the existing Case for multiple choice cases. You can use it.

lld/trunk/ELF/LinkerScript.cpp

if (!Cmd) {
         Cmd = readOutputSectionDescription(Tok);
     }
     Opt.Commands.emplace_back(Cmd);
   }
 }
 
 static int precedence(StringRef Op) {
   return StringSwitch<int>(Op)
-      .Case("*", 4)
-      .Case("/", 4)
-      .Case("+", 3)
-      .Case("-", 3)
+      .Case("*", 5)
+      .Case("/", 5)
+      .Case("+", 4)
+      .Case("-", 4)
+      .Case("<<", 3)
+      .Case(">>", 3)
       .Case("<", 2)
       .Case(">", 2)
       .Case(">=", 2)
       .Case("<=", 2)
       .Case("==", 2)
       .Case("!=", 2)
       .Case("&", 1)
       .Case("|", 1)
return [=](uint64_t Dot) -> uint64_t {
       }
       return L(Dot) / RHS;
     };
   }
   if (Op == "+")
     return [=](uint64_t Dot) { return L(Dot) + R(Dot); };
   if (Op == "-")
     return [=](uint64_t Dot) { return L(Dot) - R(Dot); };
+  if (Op == "<<")
+    return [=](uint64_t Dot) { return L(Dot) << R(Dot); };
+  if (Op == ">>")
+    return [=](uint64_t Dot) { return L(Dot) >> R(Dot); };
   if (Op == "<")
     return [=](uint64_t Dot) { return L(Dot) < R(Dot); };
   if (Op == ">")
     return [=](uint64_t Dot) { return L(Dot) > R(Dot); };
   if (Op == ">=")
     return [=](uint64_t Dot) { return L(Dot) >= R(Dot); };
   if (Op == "<=")
     return [=](uint64_t Dot) { return L(Dot) <= R(Dot); };

lld/trunk/test/ELF/linkerscript/locationcounter.s

 # RUN:  . = DATA_SEGMENT_ALIGN (CONSTANT (MAXPAGESIZE), CONSTANT (COMMONPAGESIZE)); \
 # RUN:  .datasegmentalign : { *(.datasegmentalign) } \
 # RUN:  . = DATA_SEGMENT_END (.); \
 # RUN:  . = 0x27000; \
 # RUN:  . += 0x1000; \
 # RUN:  .plusassign : { *(.plusassign) } \
 # RUN:  . = ((. + 0x1fff) & ~(0x1000 + -1)); \
 # RUN:  .unary : { *(.unary) } \
+# RUN:  . = 0x30000 + (1 + 1 << 5); \
+# RUN:  .shiftl : { *(.shiftl) } \
+# RUN:  . = 0x30000 + (1 + 1023 >> 2); \
+# RUN:  .shiftr : { *(.shiftr) } \
+
 # RUN: }" > %t.script
 # RUN: ld.lld %t --script %t.script -o %t2
 # RUN: llvm-objdump -section-headers %t2 | FileCheck %s
 
 # CHECK: .plus             {{.*}} 0000000000010000
 # CHECK: .minus            {{.*}} 0000000000011000
 # CHECK: .div              {{.*}} 0000000000012000
 # CHECK: .mul              {{.*}} 0000000000013000
 # CHECK: .bracket          {{.*}} 0000000000014000
 # CHECK: .and              {{.*}} 0000000000015000
 # CHECK: .ternary1         {{.*}} 0000000000016000
 # CHECK: .ternary2         {{.*}} 0000000000017000
 # CHECK: .less             {{.*}} 0000000000018000
 # CHECK: .lesseq           {{.*}} 0000000000019000
 # CHECK: .great            {{.*}} 0000000000020000
 # CHECK: .greateq          {{.*}} 0000000000021000
 # CHECK: .eq               {{.*}} 0000000000022000
 # CHECK: .neq              {{.*}} 0000000000023000
 # CHECK: .maxpagesize      {{.*}} 0000000004800000
 # CHECK: .commonpagesize   {{.*}} 0000000000025000
 # CHECK: .datasegmentalign {{.*}} 0000000000200000
 # CHECK: .plusassign       {{.*}} 0000000000028000
 # CHECK: .unary            {{.*}} 000000000002a000
+# CHECK: .shiftl           {{.*}} 0000000000030040
+# CHECK: .shiftr           {{.*}} 0000000000030100
 
 ## Mailformed number error.
 # RUN: echo "SECTIONS { \
 # RUN:  . = 0x12Q41; \
 # RUN: }" > %t.script
 # RUN: not ld.lld %t --script %t.script -o %t2 2>&1 | \
 # RUN:  FileCheck --check-prefix=NUMERR %s
 # NUMERR: malformed number: 0x12Q41

 .section .datasegmentalign, "a"
 .quad 0
 
 .section .plusassign, "a"
 .quad 0
 
 .section .unary, "a"
 .quad 0
+
+.section .shiftl, "a"
+.quad 0
+
+.section .shiftr, "a"
+.quad 0