dblaikie created this revision.
dblaikie added a reviewer: labath.
dblaikie requested review of this revision.
Herald added a reviewer: jdoerfert.
Herald added subscribers: lldb-commits, sstefan1.
Herald added a project: LLDB.
gcc already produces debug info with this form
-freorder-block-and-partition
clang produces this sort of thing with -fbasic-block-sections and with a
coming-soon tweak to use ranges in DWARFv5 where they can allow greater
reuse of debug_addr than the low/high_pc forms.
This fixes the case of breaking on a function name, but leaves broken
printing a variable - a follow-up commit will add that and improve the
test case to match.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D94063
Files:
lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h
lldb/test/Shell/SymbolFile/DWARF/Inputs/subprogram_ranges.s
lldb/test/Shell/SymbolFile/DWARF/subprogram_ranges.test
Index: lldb/test/Shell/SymbolFile/DWARF/subprogram_ranges.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/SymbolFile/DWARF/subprogram_ranges.test
@@ -0,0 +1,29 @@
+# UNSUPPORTED: system-windows
+# RUN: %clang_host -g -O0 %S/Inputs/subprogram_ranges.s -o %t.out
+# RUN: not %lldb -b -s %s %t.out 2>&1 | FileCheck %s
+
+# Test breaking on symbols and printing variables when a DW_TAG_subprogram uses
+# DW_AT_ranges instead of DW_AT_low_pc/DW_AT_high_pc. While the assembly here
+# is a bit unrealistic - it's a single-entry range using DWARFv4 which isn't
+# useful for anything (a single-entry range with DWARFv5 can reduce address
+# relocations, and multi-entry ranges can be used for function sections), but
+# it's the simplest thing to test. If anyone's updating this test at some
+# point, feel free to replace it with another equivalent test if it's
+# especially useful, but don't dismiss it as pointless just because it's a bit
+# weird.
+
+b main
+# CHECK: (lldb) b main
+# CHECK-NEXT: Breakpoint 1: where = subprogram_ranges.test.tmp.out`main + 6 at main.c:2:7
+
+run
+# Stopping inside of the stop hook range
+# CHECK: (lldb) run
+
+print var
+# Check that local variable names can be looked up
+# FIXME: This should be: (int) $0 = {{.*}}
+# CHECK: (lldb) print var
+# CHECK-NEXT: error: <user expression 0>:1:1: use of undeclared identifier 'var'
+
+q
Index: lldb/test/Shell/SymbolFile/DWARF/Inputs/subprogram_ranges.s
===================================================================
--- /dev/null
+++ lldb/test/Shell/SymbolFile/DWARF/Inputs/subprogram_ranges.s
@@ -0,0 +1,159 @@
+ .text
+ .file "main.c"
+ .globl main # -- Begin function main
+ .p2align 4, 0x90
+ .type main,@function
+main: # @main
+.Lfunc_begin0:
+ .file 1 "/usr/local/google/home/blaikie/dev/scratch" "main.c"
+ .loc 1 1 0 # main.c: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
+ xorl %eax, %eax
+.Ltmp0:
+ .loc 1 2 7 prologue_end # main.c:2:7
+ movl $3, -4(%rbp)
+ .loc 1 3 1 # main.c:3:1
+ 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 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .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 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 85 # DW_AT_ranges
+ .byte 23 # DW_FORM_sec_offset
+ .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 52 # DW_TAG_variable
+ .byte 0 # DW_CHILDREN_no
+ .byte 2 # DW_AT_location
+ .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 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 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:0x47 DW_TAG_compile_unit
+ .long .Linfo_string0 # DW_AT_producer
+ .short 12 # DW_AT_language
+ .long .Linfo_string1 # DW_AT_name
+ .long .Lline_table_start0 # DW_AT_stmt_list
+ .long .Linfo_string2 # DW_AT_comp_dir
+ .quad .Lfunc_begin0 # DW_AT_low_pc
+ .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
+ .byte 2 # Abbrev [2] 0x2a:0x20 DW_TAG_subprogram
+ .long .Ldebug_ranges0 # DW_AT_ranges
+ .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 74 # DW_AT_type
+ # DW_AT_external
+ .byte 3 # Abbrev [3] 0x3b:0xe DW_TAG_variable
+ .byte 2 # DW_AT_location
+ .byte 145
+ .byte 124
+ .long .Linfo_string5 # DW_AT_name
+ .byte 1 # DW_AT_decl_file
+ .byte 2 # DW_AT_decl_line
+ .long 74 # DW_AT_type
+ .byte 0 # End Of Children Mark
+ .byte 4 # Abbrev [4] 0x4a: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_ranges,"",@progbits
+.Ldebug_ranges0:
+ .quad .Lfunc_begin0-.Lfunc_begin0
+ .quad .Lfunc_end0-.Lfunc_begin0
+ .quad 0
+ .quad 0
+ .section .debug_str,"MS",@progbits,1
+.Linfo_string0:
+ .asciz "clang version 12.0.0 ([email protected]:llvm/llvm-project.git 1c15aa171b2f67d9198a8498945cbdb936c0cd3b)" # string offset=0
+.Linfo_string1:
+ .asciz "main.c" # string offset=101
+.Linfo_string2:
+ .asciz "/usr/local/google/home/blaikie/dev/scratch" # string offset=108
+.Linfo_string3:
+ .asciz "main" # string offset=151
+.Linfo_string4:
+ .asciz "int" # string offset=156
+.Linfo_string5:
+ .asciz "var" # string offset=160
+ .ident "clang version 12.0.0 ([email protected]:llvm/llvm-project.git 1c15aa171b2f67d9198a8498945cbdb936c0cd3b)"
+ .section ".note.GNU-stack","",@progbits
+ .addrsig
+ .section .debug_line,"",@progbits
+.Lline_table_start0:
+
Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h
@@ -42,7 +42,7 @@
bool operator==(const DWARFDebugInfoEntry &rhs) const;
bool operator!=(const DWARFDebugInfoEntry &rhs) const;
- void BuildFunctionAddressRangeTable(const DWARFUnit *cu,
+ void BuildFunctionAddressRangeTable(DWARFUnit *cu,
DWARFDebugAranges *debug_aranges) const;
bool Extract(const lldb_private::DWARFDataExtractor &data,
Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
@@ -687,13 +687,15 @@
/// table, except that the actual DIE offset for the function is placed in the
/// table instead of the compile unit offset.
void DWARFDebugInfoEntry::BuildFunctionAddressRangeTable(
- const DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
+ DWARFUnit *cu, DWARFDebugAranges *debug_aranges) const {
if (m_tag) {
if (m_tag == DW_TAG_subprogram) {
- dw_addr_t lo_pc = LLDB_INVALID_ADDRESS;
- dw_addr_t hi_pc = LLDB_INVALID_ADDRESS;
- if (GetAttributeAddressRange(cu, lo_pc, hi_pc, LLDB_INVALID_ADDRESS)) {
- debug_aranges->AppendRange(GetOffset(), lo_pc, hi_pc);
+ DWARFRangeList ranges;
+ GetAttributeAddressRanges(cu, ranges,
+ /*check_hi_lo_pc=*/true);
+ for (const auto &r : ranges) {
+ debug_aranges->AppendRange(GetOffset(), r.GetRangeBase(),
+ r.GetRangeEnd());
}
}
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