[lldb/DWARF] Fix mixed v4+v5 location lists

Summary:
Our code was expecting that a single (symbol) file contains only one
kind of location lists. This is not correct (on non-apple platforms, at
least) as a file can compile units with different dwarf versions.

This patch moves the deteremination of location list flavour down to the
compile unit level, fixing this problem. I have also tried to rougly
align the code with the llvm DWARFUnit. Fully matching the API is not
possible because of how lldb's DWARFExpression lives separately from the
rest of the DWARF code, but this is at least a step in the right
direction.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: dblaikie, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71751

1 files changed, 154 insertions, 0 deletions

diff --git a/lldb/test/Shell/SymbolFile/DWARF/debug_loc_and_loclists.s b/lldb/test/Shell/SymbolFile/DWARF/debug_loc_and_loclists.s
new file mode 100644
index 00000000000..05bccbe78aa
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/debug_loc_and_loclists.s
@@ -0,0 +1,154 @@
+# Test that we can handle DWARF 4 and 5 location lists in the same object file
+# (but different compile units).
+
+# REQUIRES: x86
+
+# RUN: llvm-mc -triple=x86_64-pc-linux -filetype=obj %s > %t
+# RUN: %lldb %t -o "image lookup -v -s loc" -o "image lookup -v -s loclists" \
+# RUN:   -o exit | FileCheck %s
+
+
+# CHECK-LABEL: image lookup -v -s loc
+# CHECK: Variable: {{.*}}, name = "x0", type = "int", location = DW_OP_reg5 RDI,
+
+# CHECK-LABEL: image lookup -v -s loclists
+# CHECK: Variable: {{.*}}, name = "x1", type = "int", location = DW_OP_reg0 RAX,
+
+
+loc:
+        nop
+.Lloc_end:
+
+loclists:
+        nop
+.Lloclists_end:
+
+        .section        .debug_loc,"",@progbits
+.Lloc_list:
+        .quad loc-loc
+        .quad .Lloc_end-loc
+        .short 1
+        .byte   85                      # super-register DW_OP_reg5
+        .quad 0
+        .quad 0
+
+        .section        .debug_loclists,"",@progbits
+        .long   .Ldebug_loclist_table_end0-.Ldebug_loclist_table_start0 # Length
+.Ldebug_loclist_table_start0:
+        .short  5                       # Version
+        .byte   8                       # Address size
+        .byte   0                       # Segment selector size
+        .long   0                       # Offset entry count
+
+.Lloclists_list:
+        .byte   4                       # DW_LLE_offset_pair
+        .uleb128 loclists-loclists
+        .uleb128 .Lloclists_end-loclists
+        .uleb128 1
+        .byte   80                      # super-register DW_OP_reg0
+        .byte   0                       # DW_LLE_end_of_list
+.Ldebug_loclist_table_end0:
+
+        .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   8                       # DW_FORM_string
+        .byte   19                      # DW_AT_language
+        .byte   5                       # DW_FORM_data2
+        .byte   17                      # DW_AT_low_pc
+        .byte   1                       # DW_FORM_addr
+        .byte   18                      # DW_AT_high_pc
+        .byte   6                       # DW_FORM_data4
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   2                       # Abbreviation Code
+        .byte   46                      # DW_TAG_subprogram
+        .byte   1                       # DW_CHILDREN_yes
+        .byte   17                      # DW_AT_low_pc
+        .byte   1                       # DW_FORM_addr
+        .byte   18                      # DW_AT_high_pc
+        .byte   6                       # DW_FORM_data4
+        .byte   3                       # DW_AT_name
+        .byte   8                       # DW_FORM_string
+        .byte   73                      # DW_AT_type
+        .byte   16                      # DW_FORM_ref_addr
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   3                       # Abbreviation Code
+        .byte   5                       # DW_TAG_formal_parameter
+        .byte   0                       # DW_CHILDREN_no
+        .byte   2                       # DW_AT_location
+        .byte   23                      # DW_FORM_sec_offset
+        .byte   3                       # DW_AT_name
+        .byte   8                       # DW_FORM_string
+        .byte   73                      # DW_AT_type
+        .byte   16                      # DW_FORM_ref_addr
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   4                       # Abbreviation Code
+        .byte   36                      # DW_TAG_base_type
+        .byte   0                       # DW_CHILDREN_no
+        .byte   3                       # DW_AT_name
+        .byte   8                       # DW_FORM_string
+        .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
+        .long   .Lloc_cu_end-.Lloc_cu_start # Length of Unit
+.Lloc_cu_start:
+        .short  4                       # DWARF version number
+        .long   .debug_abbrev           # Offset Into Abbrev. Section
+        .byte   8                       # Address Size (in bytes)
+        .byte   1                       # Abbrev [1] 0xb:0x50 DW_TAG_compile_unit
+        .asciz  "Hand-written DWARF"    # DW_AT_producer
+        .short  12                      # DW_AT_language
+        .quad   loc                     # DW_AT_low_pc
+        .long   .Lloc_end-loc           # DW_AT_high_pc
+        .byte   2                       # Abbrev [2] 0x2a:0x29 DW_TAG_subprogram
+        .quad   loc                     # DW_AT_low_pc
+        .long   .Lloc_end-loc           # DW_AT_high_pc
+        .asciz  "loc"                   # DW_AT_name
+        .long   .Lint                   # DW_AT_type
+        .byte   3                       # Abbrev [3] DW_TAG_formal_parameter
+        .long   .Lloc_list              # DW_AT_location
+        .asciz  "x0"                    # DW_AT_name
+        .long   .Lint                   # DW_AT_type
+        .byte   0                       # End Of Children Mark
+.Lint:
+        .byte   4                       # Abbrev [4] 0x53:0x7 DW_TAG_base_type
+        .asciz  "int"                   # DW_AT_name
+        .byte   5                       # DW_AT_encoding
+        .byte   4                       # DW_AT_byte_size
+        .byte   0                       # End Of Children Mark
+.Lloc_cu_end:
+
+        .long   .Lloclists_cu_end-.Lloclists_cu_start # Length of Unit
+.Lloclists_cu_start:
+        .short  5                       # DWARF version number
+        .byte   1                       # DWARF Unit Type
+        .byte   8                       # Address Size (in bytes)
+        .long   .debug_abbrev           # Offset Into Abbrev. Section
+        .byte   1                       # Abbrev [1] 0xb:0x50 DW_TAG_compile_unit
+        .asciz  "Hand-written DWARF"    # DW_AT_producer
+        .short  12                      # DW_AT_language
+        .quad   loclists                # DW_AT_low_pc
+        .long   .Lloclists_end-loclists # DW_AT_high_pc
+        .byte   2                       # Abbrev [2] 0x2a:0x29 DW_TAG_subprogram
+        .quad   loclists                # DW_AT_low_pc
+        .long   .Lloclists_end-loclists # DW_AT_high_pc
+        .asciz  "loclists"              # DW_AT_name
+        .long   .Lint                   # DW_AT_type
+        .byte   3                       # Abbrev [3] DW_TAG_formal_parameter
+        .long   .Lloclists_list         # DW_AT_location
+        .asciz  "x1"                    # DW_AT_name
+        .long   .Lint                   # DW_AT_type
+        .byte   0                       # End Of Children Mark
+        .byte   0                       # End Of Children Mark
+.Lloclists_cu_end: