From 4631503b28f63cfa66a363008d714a94c2c71e06 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 31 May 2021 12:33:31 -0400 Subject: [PATCH] gdb: move dwarf2_per_cu_data and signatured_type up Move them up before dwarf2_per_bfd, this will allow adding and using signatured_type_up in the next patch. gdb/ChangeLog: * dwarf2/read.h (signatured_type, dwarf2_per_cu_data): Move up. Change-Id: I85acad4476c8236930b6f9e53ddb8bbbad009e5e --- gdb/ChangeLog | 4 + gdb/dwarf2/read.h | 432 +++++++++++++++++++++++----------------------- 2 files changed, 221 insertions(+), 215 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7f52c280c1..a570dfef8c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,7 @@ +2021-05-31 Simon Marchi + + * dwarf2/read.h (signatured_type, dwarf2_per_cu_data): Move up. + 2021-05-30 Tom Tromey * dwarf2/read.c (dwarf2_per_bfd::allocate_signatured_type): Set diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h index 07fbb36c41..44ba1a624c 100644 --- a/gdb/dwarf2/read.h +++ b/gdb/dwarf2/read.h @@ -47,7 +47,9 @@ struct tu_stats struct dwarf2_cu; struct dwarf2_debug_sections; +struct dwarf2_per_bfd; struct dwarf2_per_cu_data; +struct dwarf2_psymtab; struct mapped_index; struct mapped_debug_names; struct signatured_type; @@ -88,6 +90,221 @@ struct dwarf2_per_cu_data_deleter typedef std::unique_ptr dwarf2_per_cu_data_up; +/* Persistent data held for a compilation unit, even when not + processing it. We put a pointer to this structure in the + psymtab. */ + +struct dwarf2_per_cu_data +{ + dwarf2_per_cu_data () + : queued (false), + is_debug_types (false), + is_dwz (false), + reading_dwo_directly (false), + tu_read (false), + m_header_read_in (false), + unit_type {}, + lang (language_unknown) + { + } + + /* The start offset and length of this compilation unit. + NOTE: Unlike comp_unit_head.length, this length includes + initial_length_size. + If the DIE refers to a DWO file, this is always of the original die, + not the DWO file. */ + sect_offset sect_off {}; + unsigned int length = 0; + + /* DWARF standard version this data has been read from (such as 4 or 5). */ + unsigned char dwarf_version = 0; + + /* Flag indicating this compilation unit will be read in before + any of the current compilation units are processed. */ + unsigned int queued : 1; + + /* Non-zero if this CU is from .debug_types. + Struct dwarf2_per_cu_data is contained in struct signatured_type iff + this is non-zero. */ + unsigned int is_debug_types : 1; + + /* Non-zero if this CU is from the .dwz file. */ + unsigned int is_dwz : 1; + + /* Non-zero if reading a TU directly from a DWO file, bypassing the stub. + This flag is only valid if is_debug_types is true. + We can't read a CU directly from a DWO file: There are required + attributes in the stub. */ + unsigned int reading_dwo_directly : 1; + + /* Non-zero if the TU has been read. + This is used to assist the "Stay in DWO Optimization" for Fission: + When reading a DWO, it's faster to read TUs from the DWO instead of + fetching them from random other DWOs (due to comdat folding). + If the TU has already been read, the optimization is unnecessary + (and unwise - we don't want to change where gdb thinks the TU lives + "midflight"). + This flag is only valid if is_debug_types is true. */ + unsigned int tu_read : 1; + + /* True if HEADER has been read in. + + Don't access this field directly. It should be private, but we can't make + it private at the moment. */ + mutable bool m_header_read_in : 1; + + /* The unit type of this CU. */ + ENUM_BITFIELD (dwarf_unit_type) unit_type : 8; + + /* The language of this CU. */ + ENUM_BITFIELD (language) lang : LANGUAGE_BITS; + + /* Our index in the unshared "symtabs" vector. */ + unsigned index = 0; + + /* The section this CU/TU lives in. + If the DIE refers to a DWO file, this is always the original die, + not the DWO file. */ + struct dwarf2_section_info *section = nullptr; + + /* Backlink to the owner of this. */ + dwarf2_per_bfd *per_bfd = nullptr; + + /* DWARF header of this CU. Note that dwarf2_cu reads its own version of the + header, which may differ from this one, since it may pass rcuh_kind::TYPE + to read_comp_unit_head, whereas for dwarf2_per_cu_data we always pass + rcuh_kind::COMPILE. + + Don't access this field directly, use the get_header method instead. It + should be private, but we can't make it private at the moment. */ + mutable comp_unit_head m_header {}; + + /* When dwarf2_per_bfd::using_index is true, the 'quick' field + is active. Otherwise, the 'psymtab' field is active. */ + union + { + /* The partial symbol table associated with this compilation unit, + or NULL for unread partial units. */ + dwarf2_psymtab *psymtab; + + /* Data needed by the "quick" functions. */ + struct dwarf2_per_cu_quick_data *quick; + } v {}; + + /* The CUs we import using DW_TAG_imported_unit. This is filled in + while reading psymtabs, used to compute the psymtab dependencies, + and then cleared. Then it is filled in again while reading full + symbols, and only deleted when the objfile is destroyed. + + This is also used to work around a difference between the way gold + generates .gdb_index version <=7 and the way gdb does. Arguably this + is a gold bug. For symbols coming from TUs, gold records in the index + the CU that includes the TU instead of the TU itself. This breaks + dw2_lookup_symbol: It assumes that if the index says symbol X lives + in CU/TU Y, then one need only expand Y and a subsequent lookup in Y + will find X. Alas TUs live in their own symtab, so after expanding CU Y + we need to look in TU Z to find X. Fortunately, this is akin to + DW_TAG_imported_unit, so we just use the same mechanism: For + .gdb_index version <=7 this also records the TUs that the CU referred + to. Concurrently with this change gdb was modified to emit version 8 + indices so we only pay a price for gold generated indices. + http://sourceware.org/bugzilla/show_bug.cgi?id=15021. + + This currently needs to be a public member due to how + dwarf2_per_cu_data is allocated and used. Ideally in future things + could be refactored to make this private. Until then please try to + avoid direct access to this member, and instead use the helper + functions above. */ + std::vector *imported_symtabs = nullptr; + + /* Return true of IMPORTED_SYMTABS is empty or not yet allocated. */ + bool imported_symtabs_empty () const + { + return (imported_symtabs == nullptr || imported_symtabs->empty ()); + } + + /* Push P to the back of IMPORTED_SYMTABS, allocated IMPORTED_SYMTABS + first if required. */ + void imported_symtabs_push (dwarf2_per_cu_data *p) + { + if (imported_symtabs == nullptr) + imported_symtabs = new std::vector ; + imported_symtabs->push_back (p); + } + + /* Return the size of IMPORTED_SYMTABS if it is allocated, otherwise + return 0. */ + size_t imported_symtabs_size () const + { + if (imported_symtabs == nullptr) + return 0; + return imported_symtabs->size (); + } + + /* Delete IMPORTED_SYMTABS and set the pointer back to nullptr. */ + void imported_symtabs_free () + { + delete imported_symtabs; + imported_symtabs = nullptr; + } + + /* Get the header of this per_cu, reading it if necessary. */ + const comp_unit_head *get_header () const; + + /* Return the address size given in the compilation unit header for + this CU. */ + int addr_size () const; + + /* Return the offset size given in the compilation unit header for + this CU. */ + int offset_size () const; + + /* Return the DW_FORM_ref_addr size given in the compilation unit + header for this CU. */ + int ref_addr_size () const; + + /* Return DWARF version number of this CU. */ + short version () const + { + return dwarf_version; + } + + /* A type unit group has a per_cu object that is recognized by + having no section. */ + bool type_unit_group_p () const + { + return section == nullptr; + } +}; + +/* Entry in the signatured_types hash table. */ + +struct signatured_type : public dwarf2_per_cu_data +{ + /* The type's signature. */ + ULONGEST signature = 0; + + /* Offset in the TU of the type's DIE, as read from the TU header. + If this TU is a DWO stub and the definition lives in a DWO file + (specified by DW_AT_GNU_dwo_name), this value is unusable. */ + cu_offset type_offset_in_tu {}; + + /* Offset in the section of the type's DIE. + If the definition lives in a DWO file, this is the offset in the + .debug_types.dwo section. + The value is zero until the actual value is known. + Zero is otherwise not a valid section offset. */ + sect_offset type_offset_in_section {}; + + /* Type units are grouped by their DW_AT_stmt_list entry so that they + can share them. This points to the containing symtab. */ + struct type_unit_group *type_unit_group = nullptr; + + /* Containing DWO unit. + This field is valid iff per_cu.reading_dwo_directly. */ + struct dwo_unit *dwo_unit = nullptr; +}; + /* Some DWARF data can be shared across objfiles who share the same BFD, this data is stored in this object. @@ -402,221 +619,6 @@ struct dwarf2_psymtab : public partial_symtab struct dwarf2_per_cu_data *per_cu_data; }; -/* Persistent data held for a compilation unit, even when not - processing it. We put a pointer to this structure in the - psymtab. */ - -struct dwarf2_per_cu_data -{ - dwarf2_per_cu_data () - : queued (false), - is_debug_types (false), - is_dwz (false), - reading_dwo_directly (false), - tu_read (false), - m_header_read_in (false), - unit_type {}, - lang (language_unknown) - { - } - - /* The start offset and length of this compilation unit. - NOTE: Unlike comp_unit_head.length, this length includes - initial_length_size. - If the DIE refers to a DWO file, this is always of the original die, - not the DWO file. */ - sect_offset sect_off {}; - unsigned int length = 0; - - /* DWARF standard version this data has been read from (such as 4 or 5). */ - unsigned char dwarf_version = 0; - - /* Flag indicating this compilation unit will be read in before - any of the current compilation units are processed. */ - unsigned int queued : 1; - - /* Non-zero if this CU is from .debug_types. - Struct dwarf2_per_cu_data is contained in struct signatured_type iff - this is non-zero. */ - unsigned int is_debug_types : 1; - - /* Non-zero if this CU is from the .dwz file. */ - unsigned int is_dwz : 1; - - /* Non-zero if reading a TU directly from a DWO file, bypassing the stub. - This flag is only valid if is_debug_types is true. - We can't read a CU directly from a DWO file: There are required - attributes in the stub. */ - unsigned int reading_dwo_directly : 1; - - /* Non-zero if the TU has been read. - This is used to assist the "Stay in DWO Optimization" for Fission: - When reading a DWO, it's faster to read TUs from the DWO instead of - fetching them from random other DWOs (due to comdat folding). - If the TU has already been read, the optimization is unnecessary - (and unwise - we don't want to change where gdb thinks the TU lives - "midflight"). - This flag is only valid if is_debug_types is true. */ - unsigned int tu_read : 1; - - /* True if HEADER has been read in. - - Don't access this field directly. It should be private, but we can't make - it private at the moment. */ - mutable bool m_header_read_in : 1; - - /* The unit type of this CU. */ - ENUM_BITFIELD (dwarf_unit_type) unit_type : 8; - - /* The language of this CU. */ - ENUM_BITFIELD (language) lang : LANGUAGE_BITS; - - /* Our index in the unshared "symtabs" vector. */ - unsigned index = 0; - - /* The section this CU/TU lives in. - If the DIE refers to a DWO file, this is always the original die, - not the DWO file. */ - struct dwarf2_section_info *section = nullptr; - - /* Backlink to the owner of this. */ - dwarf2_per_bfd *per_bfd = nullptr; - - /* DWARF header of this CU. Note that dwarf2_cu reads its own version of the - header, which may differ from this one, since it may pass rcuh_kind::TYPE - to read_comp_unit_head, whereas for dwarf2_per_cu_data we always pass - rcuh_kind::COMPILE. - - Don't access this field directly, use the get_header method instead. It - should be private, but we can't make it private at the moment. */ - mutable comp_unit_head m_header {}; - - /* When dwarf2_per_bfd::using_index is true, the 'quick' field - is active. Otherwise, the 'psymtab' field is active. */ - union - { - /* The partial symbol table associated with this compilation unit, - or NULL for unread partial units. */ - dwarf2_psymtab *psymtab; - - /* Data needed by the "quick" functions. */ - struct dwarf2_per_cu_quick_data *quick; - } v {}; - - /* The CUs we import using DW_TAG_imported_unit. This is filled in - while reading psymtabs, used to compute the psymtab dependencies, - and then cleared. Then it is filled in again while reading full - symbols, and only deleted when the objfile is destroyed. - - This is also used to work around a difference between the way gold - generates .gdb_index version <=7 and the way gdb does. Arguably this - is a gold bug. For symbols coming from TUs, gold records in the index - the CU that includes the TU instead of the TU itself. This breaks - dw2_lookup_symbol: It assumes that if the index says symbol X lives - in CU/TU Y, then one need only expand Y and a subsequent lookup in Y - will find X. Alas TUs live in their own symtab, so after expanding CU Y - we need to look in TU Z to find X. Fortunately, this is akin to - DW_TAG_imported_unit, so we just use the same mechanism: For - .gdb_index version <=7 this also records the TUs that the CU referred - to. Concurrently with this change gdb was modified to emit version 8 - indices so we only pay a price for gold generated indices. - http://sourceware.org/bugzilla/show_bug.cgi?id=15021. - - This currently needs to be a public member due to how - dwarf2_per_cu_data is allocated and used. Ideally in future things - could be refactored to make this private. Until then please try to - avoid direct access to this member, and instead use the helper - functions above. */ - std::vector *imported_symtabs = nullptr; - - /* Return true of IMPORTED_SYMTABS is empty or not yet allocated. */ - bool imported_symtabs_empty () const - { - return (imported_symtabs == nullptr || imported_symtabs->empty ()); - } - - /* Push P to the back of IMPORTED_SYMTABS, allocated IMPORTED_SYMTABS - first if required. */ - void imported_symtabs_push (dwarf2_per_cu_data *p) - { - if (imported_symtabs == nullptr) - imported_symtabs = new std::vector ; - imported_symtabs->push_back (p); - } - - /* Return the size of IMPORTED_SYMTABS if it is allocated, otherwise - return 0. */ - size_t imported_symtabs_size () const - { - if (imported_symtabs == nullptr) - return 0; - return imported_symtabs->size (); - } - - /* Delete IMPORTED_SYMTABS and set the pointer back to nullptr. */ - void imported_symtabs_free () - { - delete imported_symtabs; - imported_symtabs = nullptr; - } - - /* Get the header of this per_cu, reading it if necessary. */ - const comp_unit_head *get_header () const; - - /* Return the address size given in the compilation unit header for - this CU. */ - int addr_size () const; - - /* Return the offset size given in the compilation unit header for - this CU. */ - int offset_size () const; - - /* Return the DW_FORM_ref_addr size given in the compilation unit - header for this CU. */ - int ref_addr_size () const; - - /* Return DWARF version number of this CU. */ - short version () const - { - return dwarf_version; - } - - /* A type unit group has a per_cu object that is recognized by - having no section. */ - bool type_unit_group_p () const - { - return section == nullptr; - } -}; - -/* Entry in the signatured_types hash table. */ - -struct signatured_type : public dwarf2_per_cu_data -{ - /* The type's signature. */ - ULONGEST signature = 0; - - /* Offset in the TU of the type's DIE, as read from the TU header. - If this TU is a DWO stub and the definition lives in a DWO file - (specified by DW_AT_GNU_dwo_name), this value is unusable. */ - cu_offset type_offset_in_tu {}; - - /* Offset in the section of the type's DIE. - If the definition lives in a DWO file, this is the offset in the - .debug_types.dwo section. - The value is zero until the actual value is known. - Zero is otherwise not a valid section offset. */ - sect_offset type_offset_in_section {}; - - /* Type units are grouped by their DW_AT_stmt_list entry so that they - can share them. This points to the containing symtab. */ - struct type_unit_group *type_unit_group = nullptr; - - /* Containing DWO unit. - This field is valid iff per_cu.reading_dwo_directly. */ - struct dwo_unit *dwo_unit = nullptr; -}; - /* Return the type of the DIE at DIE_OFFSET in the CU named by PER_CU. */ -- 2.34.1