[BOLT][DWARF] Fix handling of CUs without TU reference

When input is DWP with DWARF5 bolt wasn't handling correctly CUs that didn't
have TU references. Which resulted in a crash.

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D148589

3 files changed, 231 insertions, 1 deletions

diff --git a/bolt/lib/Rewrite/DWARFRewriter.cpp b/bolt/lib/Rewrite/DWARFRewriter.cpp
index 5b8a28465fd7..cffcde821379 100644
--- a/bolt/lib/Rewrite/DWARFRewriter.cpp
+++ b/bolt/lib/Rewrite/DWARFRewriter.cpp
@@ -1347,6 +1347,8 @@ static void extractTypesFromDWPDWARF5(
     MCStreamer &Streamer, StringRef Contents, uint64_t DWOId) {
   std::vector<const DWARFUnitIndex::Entry::SectionContribution *>
       TUContributions;
+  if (!TypeSignaturesPerCU.count(DWOId))
+    return;
   for (const uint64_t Val : TypeSignaturesPerCU.at(DWOId)) {
     const DWARFUnitIndex::Entry *TUE = TUIndex.getFromHash(Val);
     const DWARFUnitIndex::Entry::SectionContribution *C =
diff --git a/bolt/test/X86/Inputs/dwarf5-ftypes-split-dwarf-helper.s b/bolt/test/X86/Inputs/dwarf5-ftypes-split-dwarf-helper.s
new file mode 100644
index 000000000000..a1477c8d5e33
--- /dev/null
+++ b/bolt/test/X86/Inputs/dwarf5-ftypes-split-dwarf-helper.s
@@ -0,0 +1,226 @@
+# clang++ helper.cpp -g2 -gsplit-dwarf=split -gdwarf-5 -fdebug-types-section -S
+# int foo() {
+#   return 0;
+# }
+	.text
+	.file	"helper.cpp"
+	.globl	_Z3foov                         # -- Begin function _Z3foov
+	.p2align	4, 0x90
+	.type	_Z3foov,@function
+_Z3foov:                                # @_Z3foov
+.Lfunc_begin0:
+	.file	0 "." "helper.cpp" md5 0x95a4a33e7fe9423970d3c798fdf8ed43
+	.loc	0 1 0                           # helper.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
+.Ltmp0:
+	.loc	0 2 3 prologue_end              # helper.cpp:2:3
+	xorl	%eax, %eax
+	.loc	0 2 3 epilogue_begin is_stmt 0  # helper.cpp:2:3
+	popq	%rbp
+	.cfi_def_cfa %rsp, 8
+	retq
+.Ltmp1:
+.Lfunc_end0:
+	.size	_Z3foov, .Lfunc_end0-_Z3foov
+	.cfi_endproc
+                                        # -- End function
+	.section	.debug_abbrev,"",@progbits
+	.byte	1                               # Abbreviation Code
+	.byte	74                              # DW_TAG_skeleton_unit
+	.byte	0                               # DW_CHILDREN_no
+	.byte	16                              # DW_AT_stmt_list
+	.byte	23                              # DW_FORM_sec_offset
+	.byte	114                             # DW_AT_str_offsets_base
+	.byte	23                              # DW_FORM_sec_offset
+	.byte	27                              # DW_AT_comp_dir
+	.byte	37                              # DW_FORM_strx1
+	.ascii	"\264B"                         # DW_AT_GNU_pubnames
+	.byte	25                              # DW_FORM_flag_present
+	.byte	118                             # DW_AT_dwo_name
+	.byte	37                              # DW_FORM_strx1
+	.byte	17                              # DW_AT_low_pc
+	.byte	27                              # DW_FORM_addrx
+	.byte	18                              # DW_AT_high_pc
+	.byte	6                               # DW_FORM_data4
+	.byte	115                             # DW_AT_addr_base
+	.byte	23                              # DW_FORM_sec_offset
+	.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	5                               # DWARF version number
+	.byte	4                               # DWARF Unit Type
+	.byte	8                               # Address Size (in bytes)
+	.long	.debug_abbrev                   # Offset Into Abbrev. Section
+	.quad	-1360665163647638292
+	.byte	1                               # Abbrev [1] 0x14:0x14 DW_TAG_skeleton_unit
+	.long	.Lline_table_start0             # DW_AT_stmt_list
+	.long	.Lstr_offsets_base0             # DW_AT_str_offsets_base
+	.byte	0                               # DW_AT_comp_dir
+                                        # DW_AT_GNU_pubnames
+	.byte	1                               # DW_AT_dwo_name
+	.byte	0                               # DW_AT_low_pc
+	.long	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+	.long	.Laddr_table_base0              # DW_AT_addr_base
+.Ldebug_info_end0:
+	.section	.debug_str_offsets,"",@progbits
+	.long	12                              # Length of String Offsets Set
+	.short	5
+	.short	0
+.Lstr_offsets_base0:
+	.section	.debug_str,"MS",@progbits,1
+.Lskel_string0:
+	.asciz	"." # string offset=0
+.Lskel_string1:
+	.asciz	"helper.dwo"                    # string offset=50
+	.section	.debug_str_offsets,"",@progbits
+	.long	.Lskel_string0
+	.long	.Lskel_string1
+	.section	.debug_str_offsets.dwo,"e",@progbits
+	.long	28                              # Length of String Offsets Set
+	.short	5
+	.short	0
+	.section	.debug_str.dwo,"eMS",@progbits,1
+.Linfo_string0:
+	.asciz	"_Z3foov"                       # string offset=0
+.Linfo_string1:
+	.asciz	"foo"                           # string offset=8
+.Linfo_string2:
+	.asciz	"int"                           # string offset=12
+.Linfo_string3:
+	.asciz	"clang version 17.0.0 (https://github.com/llvm/llvm-project.git c8bb7c234c6814b80e2be27eba9718de7ab1ad79)" # string offset=16
+.Linfo_string4:
+	.asciz	"helper.cpp"                    # string offset=121
+.Linfo_string5:
+	.asciz	"helper.dwo"                    # string offset=132
+	.section	.debug_str_offsets.dwo,"e",@progbits
+	.long	0
+	.long	8
+	.long	12
+	.long	16
+	.long	121
+	.long	132
+	.section	.debug_info.dwo,"e",@progbits
+	.long	.Ldebug_info_dwo_end0-.Ldebug_info_dwo_start0 # Length of Unit
+.Ldebug_info_dwo_start0:
+	.short	5                               # DWARF version number
+	.byte	5                               # DWARF Unit Type
+	.byte	8                               # Address Size (in bytes)
+	.long	0                               # Offset Into Abbrev. Section
+	.quad	-1360665163647638292
+	.byte	1                               # Abbrev [1] 0x14:0x1b DW_TAG_compile_unit
+	.byte	3                               # DW_AT_producer
+	.short	33                              # DW_AT_language
+	.byte	4                               # DW_AT_name
+	.byte	5                               # DW_AT_dwo_name
+	.byte	2                               # Abbrev [2] 0x1a:0x10 DW_TAG_subprogram
+	.byte	0                               # DW_AT_low_pc
+	.long	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+	.byte	1                               # DW_AT_frame_base
+	.byte	86
+	.byte	0                               # DW_AT_linkage_name
+	.byte	1                               # DW_AT_name
+	.byte	0                               # DW_AT_decl_file
+	.byte	1                               # DW_AT_decl_line
+	.long	42                              # DW_AT_type
+                                        # DW_AT_external
+	.byte	3                               # Abbrev [3] 0x2a:0x4 DW_TAG_base_type
+	.byte	2                               # DW_AT_name
+	.byte	5                               # DW_AT_encoding
+	.byte	4                               # DW_AT_byte_size
+	.byte	0                               # End Of Children Mark
+.Ldebug_info_dwo_end0:
+	.section	.debug_abbrev.dwo,"e",@progbits
+	.byte	1                               # Abbreviation Code
+	.byte	17                              # DW_TAG_compile_unit
+	.byte	1                               # DW_CHILDREN_yes
+	.byte	37                              # DW_AT_producer
+	.byte	37                              # DW_FORM_strx1
+	.byte	19                              # DW_AT_language
+	.byte	5                               # DW_FORM_data2
+	.byte	3                               # DW_AT_name
+	.byte	37                              # DW_FORM_strx1
+	.byte	118                             # DW_AT_dwo_name
+	.byte	37                              # DW_FORM_strx1
+	.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	27                              # DW_FORM_addrx
+	.byte	18                              # DW_AT_high_pc
+	.byte	6                               # DW_FORM_data4
+	.byte	64                              # DW_AT_frame_base
+	.byte	24                              # DW_FORM_exprloc
+	.byte	110                             # DW_AT_linkage_name
+	.byte	37                              # DW_FORM_strx1
+	.byte	3                               # DW_AT_name
+	.byte	37                              # DW_FORM_strx1
+	.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	37                              # DW_FORM_strx1
+	.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_addr,"",@progbits
+	.long	.Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+	.short	5                               # DWARF version number
+	.byte	8                               # Address size
+	.byte	0                               # Segment selector size
+.Laddr_table_base0:
+	.quad	.Lfunc_begin0
+.Ldebug_addr_end0:
+	.section	.debug_gnu_pubnames,"",@progbits
+	.long	.LpubNames_end0-.LpubNames_start0 # Length of Public Names Info
+.LpubNames_start0:
+	.short	2                               # DWARF Version
+	.long	.Lcu_begin0                     # Offset of Compilation Unit Info
+	.long	40                              # Compilation Unit Length
+	.long	26                              # DIE offset
+	.byte	48                              # Attributes: FUNCTION, EXTERNAL
+	.asciz	"foo"                           # External Name
+	.long	0                               # End Mark
+.LpubNames_end0:
+	.section	.debug_gnu_pubtypes,"",@progbits
+	.long	.LpubTypes_end0-.LpubTypes_start0 # Length of Public Types Info
+.LpubTypes_start0:
+	.short	2                               # DWARF Version
+	.long	.Lcu_begin0                     # Offset of Compilation Unit Info
+	.long	40                              # Compilation Unit Length
+	.long	42                              # DIE offset
+	.byte	144                             # Attributes: TYPE, STATIC
+	.asciz	"int"                           # External Name
+	.long	0                               # End Mark
+.LpubTypes_end0:
+	.ident	"clang version 17.0.0 (https://github.com/llvm/llvm-project.git c8bb7c234c6814b80e2be27eba9718de7ab1ad79)"
+	.section	".note.GNU-stack","",@progbits
+	.addrsig
+	.section	.debug_line,"",@progbits
+.Lline_table_start0:
diff --git a/bolt/test/X86/dwarf5-ftypes-dwp-input-dwo-output.test b/bolt/test/X86/dwarf5-ftypes-dwp-input-dwo-output.test
index 4b928c4b1334..b59a3f056b22 100644
--- a/bolt/test/X86/dwarf5-ftypes-dwp-input-dwo-output.test
+++ b/bolt/test/X86/dwarf5-ftypes-dwp-input-dwo-output.test
@@ -4,7 +4,9 @@
 ; RUN: cd %t
 ; RUN: llvm-mc --split-dwarf-file=main.dwo --triple=x86_64-unknown-linux-gnu \
 ; RUN: --filetype=obj %p/Inputs/dwarf5-ftypes-split-dwarf.s -o=main.o
-; RUN: %clang %cflags -gdwarf-5 -gsplit-dwarf=split main.o -o main.exe
+; RUN: llvm-mc --split-dwarf-file=helper.dwo --triple=x86_64-unknown-linux-gnu \
+; RUN: --filetype=obj %p/Inputs/dwarf5-ftypes-split-dwarf-helper.s -o=helper.o
+; RUN: %clang %cflags -gdwarf-5 -gsplit-dwarf=split main.o helper.o -o main.exe
 ; RUN: llvm-dwp -e main.exe -o main.exe.dwp
 ; RUN: llvm-dwarfdump --show-form --verbose --debug-info main.exe.dwp | FileCheck -check-prefix=PRE-BOLT %s
 ; RUN: llvm-dwarfdump --show-form --verbose --debug-tu-index main.exe.dwp | FileCheck -check-prefix=PRE-BOLT-DWP-TU-INDEX %s