[BOLT][DWARF] Fix how DW_AT_high_pc [DW_FORM_udata] is handled

We were not handling correctly conversion from DW_AT_high_pc into DW_AT_ranges,
when size of DW_AT_high_pc is not 4/8 bytes.

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D120528

3 files changed, 188 insertions, 1 deletions

diff --git a/bolt/include/bolt/Core/DebugData.h b/bolt/include/bolt/Core/DebugData.h
index 75fdbb4c5eaf..c3463782f7fc 100644
--- a/bolt/include/bolt/Core/DebugData.h
+++ b/bolt/include/bolt/Core/DebugData.h
@@ -490,6 +490,7 @@ public:
     PatchBaseClass,
     PatchValue32,
     PatchValue64to32,
+    PatchValue32GenericSize,
     PatchValue64,
     PatchValueVariable,
     ReferencePatchValue,
@@ -536,6 +537,22 @@ public:
     uint32_t Value;
   };
 
+  /// Patch for 4 byte entry, where original entry size is not 4 bytes or 8
+  /// bytes.
+  struct DebugPatch32GenericSize : public Patch {
+    DebugPatch32GenericSize(uint32_t O, uint32_t V, uint32_t OVS)
+        : Patch(O, DebugPatchKind::PatchValue32GenericSize) {
+      Value = V;
+      OldValueSize = OVS;
+    }
+
+    static bool classof(const Patch *Writer) {
+      return Writer->getKind() == DebugPatchKind::PatchValue32GenericSize;
+    }
+    uint32_t Value;
+    uint32_t OldValueSize;
+  };
+
   struct DebugPatch64 : public Patch {
     DebugPatch64(uint32_t O, uint64_t V)
         : Patch(O, DebugPatchKind::PatchValue64) {
@@ -693,6 +710,9 @@ private:
       case DebugPatchKind::PatchValue64to32:
         delete reinterpret_cast<DebugPatch64to32 *>(P);
         break;
+      case DebugPatchKind::PatchValue32GenericSize:
+        delete reinterpret_cast<DebugPatch32GenericSize *>(P);
+        break;
       case DebugPatchKind::PatchValue64:
         delete reinterpret_cast<DebugPatch64 *>(P);
         break;
diff --git a/bolt/lib/Core/DebugData.cpp b/bolt/lib/Core/DebugData.cpp
index 24e188df5744..ba6a653cb88b 100644
--- a/bolt/lib/Core/DebugData.cpp
+++ b/bolt/lib/Core/DebugData.cpp
@@ -486,8 +486,11 @@ void DebugInfoBinaryPatcher::addLE32Patch(uint64_t Offset, uint32_t NewValue,
   std::lock_guard<std::mutex> Lock(WriterMutex);
   if (OldValueSize == 4)
     DebugPatches.emplace_back(new DebugPatch32(Offset, NewValue));
-  else
+  else if (OldValueSize == 8)
     DebugPatches.emplace_back(new DebugPatch64to32(Offset, NewValue));
+  else
+    DebugPatches.emplace_back(
+        new DebugPatch32GenericSize(Offset, NewValue, OldValueSize));
 }
 
 void SimpleBinaryPatcher::addBinaryPatch(uint64_t Offset,
@@ -578,6 +581,12 @@ CUOffsetMap DebugInfoBinaryPatcher::computeNewOffsets(DWARFContext &DWCtx,
       PreviousChangeInSize -= 4;
       break;
     }
+    case DebugPatchKind::PatchValue32GenericSize: {
+      DebugPatch32GenericSize *DPVS =
+          reinterpret_cast<DebugPatch32GenericSize *>(P);
+      PreviousChangeInSize += 4 - DPVS->OldValueSize;
+      break;
+    }
     case DebugPatchKind::PatchValueVariable: {
       DebugPatchVariableSize *DPV =
           reinterpret_cast<DebugPatchVariableSize *>(P);
@@ -691,6 +700,14 @@ std::string DebugInfoBinaryPatcher::patchBinary(StringRef BinaryContents) {
       ByteSequence = encodeLE(4, P64to32->Value);
       break;
     }
+    case DebugPatchKind::PatchValue32GenericSize: {
+      DebugPatch32GenericSize *DPVS =
+          reinterpret_cast<DebugPatch32GenericSize *>(P);
+      Offset = DPVS->Offset;
+      OldValueSize = DPVS->OldValueSize;
+      ByteSequence = encodeLE(4, DPVS->Value);
+      break;
+    }
     case DebugPatchKind::PatchValueVariable: {
       DebugPatchVariableSize *PV =
           reinterpret_cast<DebugPatchVariableSize *>(P);
diff --git a/bolt/test/X86/high_pc_udata.s b/bolt/test/X86/high_pc_udata.s
new file mode 100644
index 000000000000..18db02a5ad8d
--- /dev/null
+++ b/bolt/test/X86/high_pc_udata.s
@@ -0,0 +1,150 @@
+# REQUIRES: system-linux
+
+# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt -update-debug-sections
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.exe | FileCheck --check-prefix=PRECHECK %s
+# RUN: llvm-dwarfdump --show-form --verbose --debug-info %t.bolt | FileCheck --check-prefix=POSTCHECK %s
+
+# PRECHECK: DW_AT_high_pc [DW_FORM_udata]	(15)
+# PRECHECK-NEXT: DW_AT_name [DW_FORM_strp]
+# PRECHECK-SAME: "main.cpp"
+
+# POSTCHECK: DW_AT_ranges [DW_FORM_sec_offset]
+# POSTCHECK-NEXT: [
+# POSTCHECK-NEXT: DW_AT_name [DW_FORM_strp]
+# POSTCHECK-SAME: "main.cpp"
+
+# Testing that BOLT transforms DW_AT_high_pc of form DW_FORM_udata correctly into DW_AT_ranges.
+# Manually changed so that DW_AT_high_pc is DW_FORM_udata, and that DW_AT_name is after it.
+# int main() {
+#    return 0;
+# }
+.text
+	.file	"main.cpp"
+	.globl	main                            # -- Begin function main
+	.p2align	4, 0x90
+	.type	main,@function
+main:                                   # @main
+.Lfunc_begin0:
+	.file	1 "" "main.cpp"
+	.loc	1 1 0                           # main.cpp:1:0
+	.cfi_startproc
+# %bb.0:                                # %entry
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset %rbp, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register %rbp
+	movl	$0, -4(%rbp)
+.Ltmp0:
+	.loc	1 2 1 prologue_end              # main.cpp:2:1
+	xorl	%eax, %eax
+	popq	%rbp
+	.cfi_def_cfa %rsp, 8
+	retq
+.Ltmp1:
+.Lfunc_end0:
+	.size	main, .Lfunc_end0-main
+	.cfi_endproc
+                                        # -- End function
+	.section	.debug_abbrev,"",@progbits
+	.byte	1                               # Abbreviation Code
+	.byte	17                              # DW_TAG_compile_unit
+	.byte	1                               # DW_CHILDREN_yes
+	.byte	37                              # DW_AT_producer
+	.byte	14                              # DW_FORM_strp
+	.byte	19                              # DW_AT_language
+	.byte	5                               # DW_FORM_data2
+	.byte	16                              # DW_AT_stmt_list
+	.byte	23                              # DW_FORM_sec_offset
+	.byte	27                              # DW_AT_comp_dir
+	.byte	14                              # DW_FORM_strp
+	.byte	17                              # DW_AT_low_pc
+	.byte	1                               # DW_FORM_addr
+	.byte	18                              # DW_AT_high_pc
+	.byte	15                              # DW_FORM_udata
+	.byte	3                               # DW_AT_name
+	.byte	14                              # DW_FORM_strp
+	.byte	0                               # EOM(1)
+	.byte	0                               # EOM(2)
+	.byte	2                               # Abbreviation Code
+	.byte	46                              # DW_TAG_subprogram
+	.byte	0                               # DW_CHILDREN_no
+	.byte	17                              # DW_AT_low_pc
+	.byte	1                               # DW_FORM_addr
+	.byte	18                              # DW_AT_high_pc
+	.byte	6                               # DW_FORM_data4
+	.byte	64                              # DW_AT_frame_base
+	.byte	24                              # DW_FORM_exprloc
+	.byte	3                               # DW_AT_name
+	.byte	14                              # DW_FORM_strp
+	.byte	58                              # DW_AT_decl_file
+	.byte	11                              # DW_FORM_data1
+	.byte	59                              # DW_AT_decl_line
+	.byte	11                              # DW_FORM_data1
+	.byte	73                              # DW_AT_type
+	.byte	19                              # DW_FORM_ref4
+	.byte	63                              # DW_AT_external
+	.byte	25                              # DW_FORM_flag_present
+	.byte	0                               # EOM(1)
+	.byte	0                               # EOM(2)
+	.byte	3                               # Abbreviation Code
+	.byte	36                              # DW_TAG_base_type
+	.byte	0                               # DW_CHILDREN_no
+	.byte	3                               # DW_AT_name
+	.byte	14                              # DW_FORM_strp
+	.byte	62                              # DW_AT_encoding
+	.byte	11                              # DW_FORM_data1
+	.byte	11                              # DW_AT_byte_size
+	.byte	11                              # DW_FORM_data1
+	.byte	0                               # EOM(1)
+	.byte	0                               # EOM(2)
+	.byte	0                               # EOM(3)
+	.section	.debug_info,"",@progbits
+.Lcu_begin0:
+	.long	.Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+	.short	4                               # DWARF version number
+	.long	.debug_abbrev                   # Offset Into Abbrev. Section
+	.byte	8                               # Address Size (in bytes)
+	.byte	1                               # Abbrev [1] 0xb:0x40 DW_TAG_compile_unit
+	.long	.Linfo_string0                  # DW_AT_producer
+	.short	33                              # DW_AT_language
+	.long	.Lline_table_start0             # DW_AT_stmt_list
+	.long	.Linfo_string2                  # DW_AT_comp_dir
+	.quad	.Lfunc_begin0                   # DW_AT_low_pc
+	.byte	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+	.long	.Linfo_string1                  # DW_AT_name
+	.byte	2                               # Abbrev [2] 0x2a:0x19 DW_TAG_subprogram
+	.quad	.Lfunc_begin0                   # DW_AT_low_pc
+	.long	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+	.byte	1                               # DW_AT_frame_base
+	.byte	86
+	.long	.Linfo_string3                  # DW_AT_name
+	.byte	1                               # DW_AT_decl_file
+	.byte	1                               # DW_AT_decl_line
+	.long	67                              # DW_AT_type
+                                        # DW_AT_external
+	.byte	3                               # Abbrev [3] 0x43:0x7 DW_TAG_base_type
+	.long	.Linfo_string4                  # DW_AT_name
+	.byte	5                               # DW_AT_encoding
+	.byte	4                               # DW_AT_byte_size
+	.byte	0                               # End Of Children Mark
+.Ldebug_info_end0:
+	.section	.debug_str,"MS",@progbits,1
+.Linfo_string0:
+	.asciz	"clang" # string offset=0
+.Linfo_string1:
+	.asciz	"main.cpp"                      # string offset=134
+.Linfo_string2:
+	.asciz	"test" # string offset=143
+.Linfo_string3:
+	.asciz	"main"                          # string offset=186
+.Linfo_string4:
+	.asciz	"int"                           # string offset=191
+	.ident	"clang"
+	.section	".note.GNU-stack","",@progbits
+	.addrsig
+	.section	.debug_line,"",@progbits
+.Lline_table_start0: