From 3d5afab3393064e563305bc27264fde5a7598635 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Wed, 22 Apr 2020 08:09:45 +0200 Subject: [PATCH] [gdb/symtab] Don't create duplicate psymtab for forward-imported CU Consider the executable generated for test-case gdb.dwarf2/imported-unit.exp. When loading the executable using various tracing: ... $ gdb \ outputs/gdb.dwarf2/imported-unit/imported-unit \ -batch \ -iex "set verbose on" \ -iex "set debug symtab-create 1" ... Created psymtab 0x213f380 for module @0xc7. Created psymtab 0x20e7b00 for module imported_unit.c. Created psymtab 0x215da20 for module imported_unit.c. Created psymtab 0x2133630 for module elf-init.c. Created psymtab 0x215b910 for module ../sysdeps/x86_64/crtn.S. ... we notice that there are two psymtabs generated for imported_unit.c. This is due to the following: in dwarf2_build_psymtabs_hard we loop over CUs and generate partial symtabs for those, and if we encounter an import of another CU, we also generate a partial symtab for that one, unless already created. This works well with backward import references: - the imported CU is read - then the importing CU is read - the import is encountered, but the imported CU is already read, so we're done. But with forward import references, we have instead: - the importing CU is read - the import is encountered, and the imported CU is read - the imported CU is read once more Fix this by skipping already created psymtabs in the loop in dwarf2_build_psymtabs_hard. Tested on x86_64-linux, with native and target board unix/-flto/-O0/-flto-partition=none/-ffat-lto-objects. This causes this regression with the target board: ... FAIL: gdb.ada/dgopt.exp: list x.adb:16, 16 ... which I consider a seperate PR, filed as PR25801 - "Filename of shared psymtab is ignored". gdb/ChangeLog: 2020-04-22 Tom de Vries PR symtab/25700 * dwarf2/read.c (dwarf2_build_psymtabs_hard): Don't create psymtab for CU if already created. gdb/testsuite/ChangeLog: 2020-04-22 Tom de Vries PR symtab/25700 * gdb.dwarf2/imported-unit.exp: Verify that there's only one partial symtab for imported_unit.c. --- gdb/ChangeLog | 6 ++++++ gdb/dwarf2/read.c | 7 ++++++- gdb/testsuite/ChangeLog | 6 ++++++ gdb/testsuite/gdb.dwarf2/imported-unit.exp | 18 ++++++++++++++++++ 4 files changed, 36 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 89940c658e7..3f1cce59e7d 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2020-04-22 Tom de Vries + + PR symtab/25700 + * dwarf2/read.c (dwarf2_build_psymtabs_hard): Don't create psymtab for + CU if already created. + 2020-04-21 Tankut Baris Aktemur * infrun.c (displaced_step_fixup): Switch to the event_thread diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 41db511c851..450c53b5196 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -7779,7 +7779,12 @@ dwarf2_build_psymtabs_hard (struct dwarf2_per_objfile *dwarf2_per_objfile) addrmap_create_mutable (&temp_obstack)); for (dwarf2_per_cu_data *per_cu : dwarf2_per_objfile->all_comp_units) - process_psymtab_comp_unit (per_cu, false, language_minimal); + { + if (per_cu->v.psymtab != NULL) + /* In case a forward DW_TAG_imported_unit has read the CU already. */ + continue; + process_psymtab_comp_unit (per_cu, false, language_minimal); + } /* This has to wait until we read the CUs, we need the list of DWOs. */ process_skeletonless_type_units (dwarf2_per_objfile); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 10c2a01b4b9..f6c52c8e425 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2020-04-22 Tom de Vries + + PR symtab/25700 + * gdb.dwarf2/imported-unit.exp: Verify that there's only one partial + symtab for imported_unit.c. + 2020-04-21 Gary Benson * gdb.base/advance.c (func): New argument, to match call site. diff --git a/gdb/testsuite/gdb.dwarf2/imported-unit.exp b/gdb/testsuite/gdb.dwarf2/imported-unit.exp index 41a75054594..d7b3d4c5398 100644 --- a/gdb/testsuite/gdb.dwarf2/imported-unit.exp +++ b/gdb/testsuite/gdb.dwarf2/imported-unit.exp @@ -168,6 +168,24 @@ if { $psymtabs_p } { } else { unsupported $test } + +# Verify that there's only one partial symtab for imported_unit.c. Test-case +# for PR25700. +set test "no duplicate psymtab for imported_unit.c" +if { $psymtabs_p } { + set line "Partial symtab for source file imported_unit.c" + gdb_test_multiple "maint print psymbols" $test { + -re -wrap "$line.*$line.*" { + fail $gdb_test_name + } + -re -wrap "$line.*" { + pass $gdb_test_name + } + } +} else { + unsupported $test +} + # Sanity check gdb_test "ptype main" "= int \\(void\\)" -- 2.30.2