Subzero: Start writing out some relocation sections (text)

tests_lit/llvm2ice_tests/elf_container.ll

 ; Tests that we generate an ELF container with fields that make sense,
 ; cross-validating against llvm-mc.
 
 ; For the integrated ELF writer, we can't pipe the output because we need
 ; to seek backward and patch up the file headers. So, use a temporary file.
 ; RUN: %p2i -i %s --args -O2 --verbose none -elf-writer -o %t \
 ; RUN:   && llvm-readobj -file-headers -sections -section-data \
 ; RUN:       -relocations -symbols %t | FileCheck %s
 
 ; RUN: %p2i -i %s --args -O2 --verbose none \
@@ skipping 31 matching lines @@
   ret float %f
 }
 
 define internal double @returnDoubleConst() {
 entry:
   %d = fadd double 0x7FFFFFFFFFFFFFFFF, 0xFFF7FFFFFFFFFFFF
   %d2 = fadd double %d, 0xFFF8000000000003
   ret double %d2
 }
 
+; Test intrinsics that call out to external functions.
 define internal void @test_memcpy(i32 %iptr_dst, i32 %len) {
 entry:
   %dst = inttoptr i32 %iptr_dst to i8*
   %src = bitcast [7 x i8]* @bytes to i8*
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src,
                                        i32 %len, i32 1, i1 false)
   ret void
 }
 
 define internal void @test_memset(i32 %iptr_dst, i32 %wide_val, i32 %len) {
 entry:
   %val = trunc i32 %wide_val to i8
   %dst = inttoptr i32 %iptr_dst to i8*
   call void @llvm.memset.p0i8.i32(i8* %dst, i8 %val,
                                   i32 %len, i32 1, i1 false)
   ret void
 }
 
-; Test non-internal functions too.
+; Test calling internal functions (may be able to do the fixup,
+; without emitting a relocation).
+define internal float @test_call_internal() {
+  %f = call float @returnFloatConst()
+  ret float %f
+}
+
+; Test copying a function pointer, or a global data pointer.
+define internal i32 @test_ret_fp() {
+  %r = ptrtoint float ()* @returnFloatConst to i32
+  ret i32 %r
+}
+
+define internal i32 @test_ret_global_pointer() {
+  %r = ptrtoint [7 x i8]* @bytes to i32
+  ret i32 %r
+}
+
+; Test defining a non-internal function.
 define void @_start(i32) {
   %f = call float @returnFloatConst()
   %d = call double @returnDoubleConst()
   call void @test_memcpy(i32 0, i32 99)
   call void @test_memset(i32 0, i32 0, i32 99)
+  %f2 = call float @test_call_internal()
+  %p1 = call i32 @test_ret_fp()
+  %p2 = call i32 @test_ret_global_pointer()
   ret void
 }
 
-
 ; CHECK: ElfHeader {
 ; CHECK:   Ident {
 ; CHECK:     Magic: (7F 45 4C 46)
 ; CHECK:     Class: 32-bit
 ; CHECK:     DataEncoding: LittleEndian
 ; CHECK:     OS/ABI: SystemV (0x0)
 ; CHECK:     ABIVersion: 0
 ; CHECK:     Unused: (00 00 00 00 00 00 00)
 ; CHECK:   }
 ; CHECK:   Type: Relocatable (0x1)
@@ skipping 45 matching lines @@
 ; CHECK:     Info: 0
 ; CHECK:     AddressAlignment: 32
 ; CHECK:     EntrySize: 0
 ; CHECK:     SectionData (
 ;   There's probably halt padding (0xF4) in there somewhere.
 ; CHECK:       {{.*}}F4
 ; CHECK:     )
 ; CHECK:   }
 ; CHECK:   Section {
 ; CHECK:     Index: {{[1-9][0-9]*}}
+; CHECK:     Name: .rel.text
+; CHECK:     Type: SHT_REL
+; CHECK:     Flags [ (0x0)
+; CHECK:     ]
+; CHECK:     Address: 0x0
+; CHECK:     Offset: 0x{{[1-9A-F][0-9A-F]*}}
+; CHECK:     Size: {{[1-9][0-9]*}}
+; CHECK:     Link: [[SYMTAB_INDEX:[1-9][0-9]*]]
+; CHECK:     Info: {{[1-9][0-9]*}}
+; CHECK:     AddressAlignment: 4
+; CHECK:     EntrySize: 8
+; CHECK:     SectionData (
+; CHECK:     )
+; CHECK:   }
+; CHECK:   Section {
+; CHECK:     Index: {{[1-9][0-9]*}}
 ; CHECK:     Name: .rodata.cst4
 ; CHECK:     Type: SHT_PROGBITS
 ; CHECK:     Flags [ (0x12)
 ; CHECK:       SHF_ALLOC
 ; CHECK:       SHF_MERGE
 ; CHECK:     ]
 ; CHECK:     Address: 0x0
 ; CHECK:     Offset: 0x{{[1-9A-F][0-9A-F]*}}
 ; CHECK:     Size: 8
 ; CHECK:     Link: 0
@@ skipping 35 matching lines @@
 ; CHECK:     Size: {{[1-9][0-9]*}}
 ; CHECK:     Link: 0
 ; CHECK:     Info: 0
 ; CHECK:     AddressAlignment: 1
 ; CHECK:     EntrySize: 0
 ; CHECK:     SectionData (
 ; CHECK:       {{.*}}.text{{.*}}
 ; CHECK:     )
 ; CHECK:   }
 ; CHECK:   Section {
-; CHECK:     Index: {{[1-9][0-9]*}}
-; CHECK:     Name: .symtab
+; CHECK:     Index: [[SYMTAB_INDEX]]
+; CHECK-NEXT: Name: .symtab
 ; CHECK:     Type: SHT_SYMTAB
 ; CHECK:     Flags [ (0x0)
 ; CHECK:     ]
 ; CHECK:     Address: 0x0
 ; CHECK:     Offset: 0x{{[1-9A-F][0-9A-F]*}}
 ; CHECK:     Size: {{[1-9][0-9]*}}
 ; CHECK:     Link: [[STRTAB_INDEX:[1-9][0-9]*]]
 ; CHECK:     Info: [[GLOBAL_START_INDEX:[1-9][0-9]*]]
 ; CHECK:     AddressAlignment: 4
 ; CHECK:     EntrySize: 16
 ; CHECK:   }
 ; CHECK:   Section {
 ; CHECK:     Index: [[STRTAB_INDEX]]
-; CHECK:     Name: .strtab
+; CHECK-NEXT: Name: .strtab
 ; CHECK:     Type: SHT_STRTAB
 ; CHECK:     Flags [ (0x0)
 ; CHECK:     ]
 ; CHECK:     Address: 0x0
 ; CHECK:     Offset: 0x{{[1-9A-F][0-9A-F]*}}
 ; CHECK:     Size: {{[1-9][0-9]*}}
 ; CHECK:     Link: 0
 ; CHECK:     Info: 0
 ; CHECK:     AddressAlignment: 1
 ; CHECK:     EntrySize: 0
 ; CHECK:   }
 
 
 ; CHECK: Relocations [
-;  TODO: fill it out.
+; CHECK:   Section ({{[0-9]+}}) .rel.text {
+; CHECK:     0x4 R_386_32 .L$float$0 0x0
+; CHECK:     0xC R_386_32 .L$float$1 0x0
+; CHECK:     0x24 R_386_32 .L$double$0 0x0
+; CHECK:     0x2C R_386_32 .L$double$1 0x0
+; CHECK:     0x34 R_386_32 .L$double$2 0x0
+; The set of relocations between llvm-mc and integrated elf-writer
+; are different. The integrated elf-writer doesn't yet handle
+; global data and external/undef functions like memcpy.
+; Also, it does not resolve internal function calls and instead
+; writes out the relocation. However, there's probably some
+; function call so check for a PC32 relocation at least.
+; CHECK:     0x{{.*}} R_386_PC32
+; CHECK:   }
 ; CHECK: ]
 
 
 ; CHECK: Symbols [
 ; CHECK-NEXT:   Symbol {
 ; CHECK-NEXT:     Name: (0)
 ; CHECK-NEXT:     Value: 0x0
 ; CHECK-NEXT:     Size: 0
 ; CHECK-NEXT:     Binding: Local
 ; CHECK-NEXT:     Type: None
@@ skipping 68 matching lines @@
 ; CHECK:        Symbol {
 ; CHECK:          Name: _start
 ; CHECK-NEXT:     Value: 0x{{[1-9A-F][0-9A-F]*}}
 ; CHECK-NEXT:     Size: 0
 ; CHECK-NEXT:     Binding: Global
 ; CHECK-NEXT:     Type: Function
 ; CHECK-NEXT:     Other: 0
 ; CHECK-NEXT:     Section: .text
 ; CHECK-NEXT:   }
 ; CHECK: ]