Author: labath
Date: Mon Oct 14 05:49:06 2019
New Revision: 374769
URL: http://llvm.org/viewvc/llvm-project?rev=374769&view=rev
Log:
DWARFExpression: Fix/add support for (v4) debug_loc base address selection
entries
The DWARFExpression is parsing the location lists in about five places.
Of those, only one actually had proper support for base address
selection entries.
Since r374600, llvm has started to produce location expressions with
base address selection entries more aggresively, which caused some tests
to fail.
This patch adds support for these entries to the places which had it
missing, fixing the failing tests. It also adds a targeted test for the
two of the three fixes, which should continue testing this functionality
even if the llvm output changes. I am not aware of a way to write a
targeted test for the third fix (DWARFExpression::Evaluate).
Modified:
lldb/trunk/source/Expression/DWARFExpression.cpp
lldb/trunk/test/Shell/SymbolFile/DWARF/debug_loc.s
Modified: lldb/trunk/source/Expression/DWARFExpression.cpp
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Expression/DWARFExpression.cpp?rev=374769&r1=374768&r2=374769&view=diff
==============================================================================
--- lldb/trunk/source/Expression/DWARFExpression.cpp (original)
+++ lldb/trunk/source/Expression/DWARFExpression.cpp Mon Oct 14 05:49:06 2019
@@ -636,6 +636,11 @@ bool DWARFExpression::LocationListContai
if (lo_pc == 0 && hi_pc == 0)
break;
+ if ((m_data.GetAddressByteSize() == 4 && (lo_pc == UINT32_MAX)) ||
+ (m_data.GetAddressByteSize() == 8 && (lo_pc == UINT64_MAX))) {
+ loclist_base_addr = hi_pc + m_loclist_slide;
+ continue;
+ }
lo_pc += loclist_base_addr - m_loclist_slide;
hi_pc += loclist_base_addr - m_loclist_slide;
@@ -671,6 +676,12 @@ bool DWARFExpression::GetLocation(addr_t
if (lo_pc == 0 && hi_pc == 0)
break;
+ if ((m_data.GetAddressByteSize() == 4 && (lo_pc == UINT32_MAX)) ||
+ (m_data.GetAddressByteSize() == 8 && (lo_pc == UINT64_MAX))) {
+ curr_base_addr = hi_pc + m_loclist_slide;
+ continue;
+ }
+
lo_pc += curr_base_addr - m_loclist_slide;
hi_pc += curr_base_addr - m_loclist_slide;
@@ -967,6 +978,13 @@ bool DWARFExpression::Evaluate(Execution
if (lo_pc == 0 && hi_pc == 0)
break;
+ if ((m_data.GetAddressByteSize() == 4 &&
+ (lo_pc == UINT32_MAX)) ||
+ (m_data.GetAddressByteSize() == 8 &&
+ (lo_pc == UINT64_MAX))) {
+ curr_loclist_base_load_addr = hi_pc + m_loclist_slide;
+ continue;
+ }
lo_pc += curr_loclist_base_load_addr - m_loclist_slide;
hi_pc += curr_loclist_base_load_addr - m_loclist_slide;
Modified: lldb/trunk/test/Shell/SymbolFile/DWARF/debug_loc.s
URL:
http://llvm.org/viewvc/llvm-project/lldb/trunk/test/Shell/SymbolFile/DWARF/debug_loc.s?rev=374769&r1=374768&r2=374769&view=diff
==============================================================================
--- lldb/trunk/test/Shell/SymbolFile/DWARF/debug_loc.s (original)
+++ lldb/trunk/test/Shell/SymbolFile/DWARF/debug_loc.s Mon Oct 14 05:49:06 2019
@@ -17,14 +17,22 @@
# CHECK: Variable: {{.*}}, name = "x0", type = "int", location = DW_OP_reg0
RAX,
# CHECK: Variable: {{.*}}, name = "x1", type = "int", location = ,
# CHECK: Variable: {{.*}}, name = "x2", type = "int", location = ,
+# CHECK: Variable: {{.*}}, name = "x3", type = "int", location = DW_OP_reg1
RDX,
.type f,@function
f: # @f
.Lfunc_begin0:
- movl %edi, %eax
+ nop
.Ltmp0:
- retq
+ nop
.Ltmp1:
+ nop
+.Ltmp2:
+ nop
+.Ltmp3:
+ nop
+.Ltmp4:
+ nop
.Lfunc_end0:
.size f, .Lfunc_end0-f
@@ -35,12 +43,6 @@ f:
.asciz "f"
.Linfo_string4:
.asciz "int"
-.Lx0:
- .asciz "x0"
-.Lx1:
- .asciz "x1"
-.Lx2:
- .asciz "x2"
.section .debug_loc,"",@progbits
.Ldebug_loc0:
@@ -54,6 +56,17 @@ f:
.byte 80 # super-register DW_OP_reg0
.quad 0
.quad 0
+
+.Ldebug_loc3:
+ .quad -1 # Select base address
+ .quad .Ltmp1
+ .quad .Ltmp1-.Ltmp1
+ .quad .Ltmp2-.Ltmp1
+ .short 1 # Loc expr size
+ .byte 81 # super-register DW_OP_reg1
+ .quad 0
+ .quad 0
+
.Ldebug_loc2:
.quad .Lfunc_begin0-.Lfunc_begin0
.quad .Lfunc_end0-.Lfunc_begin0
@@ -88,7 +101,7 @@ f:
.byte 2 # DW_AT_location
.byte 23 # DW_FORM_sec_offset
.byte 3 # DW_AT_name
- .byte 14 # DW_FORM_strp
+ .byte 8 # DW_FORM_string
.byte 73 # DW_AT_type
.byte 19 # DW_FORM_ref4
.byte 0 # EOM(1)
@@ -123,15 +136,19 @@ f:
.long .Lint # DW_AT_type
.byte 3 # Abbrev [3] DW_TAG_formal_parameter
.long .Ldebug_loc0 # DW_AT_location
- .long .Lx0 # DW_AT_name
+ .asciz "x0" # DW_AT_name
.long .Lint-.Lcu_begin0 # DW_AT_type
.byte 3 # Abbrev [3] DW_TAG_formal_parameter
.long 0xdeadbeef # DW_AT_location
- .long .Lx1 # DW_AT_name
+ .asciz "x1" # DW_AT_name
.long .Lint-.Lcu_begin0 # DW_AT_type
.byte 3 # Abbrev [3] DW_TAG_formal_parameter
.long .Ldebug_loc2 # DW_AT_location
- .long .Lx2 # DW_AT_name
+ .asciz "x2" # DW_AT_name
+ .long .Lint-.Lcu_begin0 # DW_AT_type
+ .byte 3 # Abbrev [3] DW_TAG_formal_parameter
+ .long .Ldebug_loc3 # DW_AT_location
+ .asciz "x3" # DW_AT_name
.long .Lint-.Lcu_begin0 # DW_AT_type
.byte 0 # End Of Children Mark
.Lint:
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