[JITLink][ELF][x86-64] Add support for R_X86_64_32 relocation.

Author: lhames

llvm/lib/ExecutionEngine/JITLink/ELF_x86_64.cpp

@@ -108,6 +108,7 @@ class ELFLinkGraphBuilder_x86_64 : public ELFLinkGraphBuilder<object::ELF64LE> {
 
   enum ELFX86RelocationKind : Edge::Kind {
     Branch32 = Edge::FirstRelocation,
+    Pointer32,
     Pointer32Signed,
     Pointer64,
     PCRel32,
@@ -123,6 +124,8 @@ class ELFLinkGraphBuilder_x86_64 : public ELFLinkGraphBuilder<object::ELF64LE> {
 
   static Expected<ELFX86RelocationKind> getRelocationKind(const uint32_t Type) {
     switch (Type) {
+    case ELF::R_X86_64_32:
+      return ELFX86RelocationKind::Pointer32;
     case ELF::R_X86_64_32S:
       return ELFX86RelocationKind::Pointer32Signed;
     case ELF::R_X86_64_PC32:
@@ -207,6 +210,9 @@ class ELFLinkGraphBuilder_x86_64 : public ELFLinkGraphBuilder<object::ELF64LE> {
     case Delta64:
       Kind = x86_64::Delta64;
       break;
+    case Pointer32:
+      Kind = x86_64::Pointer32;
+      break;
     case Pointer32Signed:
       Kind = x86_64::Pointer32Signed;
       break;

llvm/test/ExecutionEngine/JITLink/X86/ELF_R_X86_64_32.yaml

@@ -0,0 +1,83 @@
+# Check success and failure cases of R_X86_64_32 handling.
+# This file contains a single R_X86_64_32 relocation. We expect the relocation
+# to apply successfully when we assign x an address in the low 32-bits of the
+# address space, and fail if we assign x an address outside that range.
+
+# RUN: yaml2obj -o %t.o %s
+# RUN: llvm-jitlink -abs x=0x12345678 -noexec -check=%s %t.o
+# RUN: not llvm-jitlink -abs x=0x123456789 -noexec %t.o 2>&1 | \
+# RUN:   FileCheck -check-prefix=CHECK-ERROR %s
+
+# jitlink-check: *{8}xptr = x
+
+# CHECK-ERROR: relocation target "x" {{.*}} is out of range of Pointer32 fixup
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+  SectionHeaderStringTable: .strtab
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x10
+    Content:         31C0C3
+  - Name:            .data
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:    0x8
+    Content:         '0000000000000000'
+  - Name:            .comment
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_MERGE, SHF_STRINGS ]
+    AddressAlign:    0x1
+    EntSize:         0x1
+    Content:         00636C616E672076657273696F6E2031372E302E302028676974406769746875622E636F6D3A6C6C766D2F6C6C766D2D70726F6A6563742E67697420393361303461303539316331393538643533343466333534313135376662643862386666373337302900
+  - Name:            .note.GNU-stack
+    Type:            SHT_PROGBITS
+    AddressAlign:    0x1
+  - Name:            .rela.data
+    Type:            SHT_RELA
+    Flags:           [ SHF_INFO_LINK ]
+    Link:            .symtab
+    AddressAlign:    0x8
+    Info:            .data
+    Relocations:
+      - Symbol:          x
+        Type:            R_X86_64_32
+  - Name:            .llvm_addrsig
+    Type:            SHT_LLVM_ADDRSIG
+    Flags:           [ SHF_EXCLUDE ]
+    Link:            .symtab
+    AddressAlign:    0x1
+    Symbols:         [ x ]
+  - Type:            SectionHeaderTable
+    Sections:
+      - Name:            .strtab
+      - Name:            .text
+      - Name:            .data
+      - Name:            .rela.data
+      - Name:            .comment
+      - Name:            .note.GNU-stack
+      - Name:            .llvm_addrsig
+      - Name:            .symtab
+Symbols:
+  - Name:            testcase.c
+    Type:            STT_FILE
+    Index:           SHN_ABS
+  - Name:            main
+    Type:            STT_FUNC
+    Section:         .text
+    Binding:         STB_GLOBAL
+    Size:            0x3
+  - Name:            xptr
+    Type:            STT_OBJECT
+    Section:         .data
+    Binding:         STB_GLOBAL
+    Size:            0x8
+  - Name:            x
+    Binding:         STB_GLOBAL
+...