gdb: Make dwarf support optional at compile time
This commit allows a user to enable or disable dwarf support at
compilation time. To do that, a new configure option is introduced, in
the form of --enable-gdb-dwarf-support (and the accompanying --disable
version). By default, dwarf support is enabled, so no behavior changes
occur if a user doesn't use the new feature. If support is disabled, no
.c files inside the dwarf2/ subfolder will be compiled into the final
binary.
To achieve this, this commit also introduces the new macro
DWARF_FORMAT_AVAILABLE, which guards the definitions of functions
exported from the dwarf reader. If the macro is not defined, there are a
couple behaviors that exported functions may have:
* no-ops: several functions are used to register things at
initialization time, like unwinders. These are turned into no-ops
because the user hasn't attempted to read DWARF yet, there's no point
in warning that DWARF is unavailable.
* warnings: similar to the previous commit, if dwarf would be read or
used, the funciton will emit the warning "No dwarf support available."
* throw exceptions: If the code that calls a function expects an
exceptin in case of errors, and has a try-catch block, an error with
the previous message is thrown.
I believe that the changed functions should probalby be moved to the
dwarf2/public.h header, but that require a much larger refactor, so it
is left as a future improvement.
Finally, the --enable-gdb-compile configure option has been slightly
changed, since compile requires dwarf support. If compile was requested
and dwarf was disabled, configure will throw an error. If the option was
not used, support will follow what was requested for dwarf (warning the
user of what is decided).
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Andrew Burgess <aburgess@redhat.com>
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index a3760c6..998203c 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1092,36 +1092,6 @@
disasm.c \
displaced-stepping.c \
dummy-frame.c \
- dwarf2/abbrev.c \
- dwarf2/abbrev-table-cache.c \
- dwarf2/ada-imported.c \
- dwarf2/aranges.c \
- dwarf2/attribute.c \
- dwarf2/cooked-index.c \
- dwarf2/cooked-index-entry.c \
- dwarf2/cooked-index-shard.c \
- dwarf2/cooked-index-worker.c \
- dwarf2/cooked-indexer.c \
- dwarf2/cu.c \
- dwarf2/die.c \
- dwarf2/dwz.c \
- dwarf2/expr.c \
- dwarf2/frame-tailcall.c \
- dwarf2/frame.c \
- dwarf2/index-cache.c \
- dwarf2/index-common.c \
- dwarf2/index-write.c \
- dwarf2/leb.c \
- dwarf2/line-header.c \
- dwarf2/loc.c \
- dwarf2/macro.c \
- dwarf2/parent-map.c \
- dwarf2/read.c \
- dwarf2/read-debug-names.c \
- dwarf2/read-gdb-index.c \
- dwarf2/section.c \
- dwarf2/stringify.c \
- dwarf2/unit-head.c \
extract-store-integer.c \
eval.c \
event-top.c \
@@ -1911,6 +1881,40 @@
$(CONFIG_SRCS)
TAGFILES_WITH_SRCDIR = $(HFILES_WITH_SRCDIR)
+# Files that are used to support certain debuginfo formats
+DWARF2_SRCS = \
+ dwarf2/abbrev.c \
+ dwarf2/abbrev-table-cache.c \
+ dwarf2/ada-imported.c \
+ dwarf2/aranges.c \
+ dwarf2/attribute.c \
+ dwarf2/cooked-index.c \
+ dwarf2/cooked-index-entry.c \
+ dwarf2/cooked-index-shard.c \
+ dwarf2/cooked-index-worker.c \
+ dwarf2/cooked-indexer.c \
+ dwarf2/cu.c \
+ dwarf2/die.c \
+ dwarf2/dwz.c \
+ dwarf2/expr.c \
+ dwarf2/frame-tailcall.c \
+ dwarf2/frame.c \
+ dwarf2/index-cache.c \
+ dwarf2/index-common.c \
+ dwarf2/index-write.c \
+ dwarf2/leb.c \
+ dwarf2/line-header.c \
+ dwarf2/loc.c \
+ dwarf2/macro.c \
+ dwarf2/parent-map.c \
+ dwarf2/read.c \
+ dwarf2/read-debug-names.c \
+ dwarf2/read-gdb-index.c \
+ dwarf2/section.c \
+ dwarf2/stringify.c \
+ dwarf2/unit-head.c
+DWARF2_OBS = $(patsubst %.c,%.o, $(DWARF2_SRCS))
+
COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
mi/mi-common.o \
version.o \
diff --git a/gdb/NEWS b/gdb/NEWS
index 5efe456..ec71d89 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -209,6 +209,10 @@
subsystem to be disabled at configure time, in the form of
--disable-gdb-compile.
+* A new configure option was added, allowing support for DWARF debug
+ information to be disabled at configure time. The flag is
+ --disable-gdb-dwarf-support.
+
* A new configure option was added, allowing support for mdebug/ecoff
debug information to be disabled at configure time. The flag to do
that is --disable-gdb-mdebug-support.
diff --git a/gdb/README b/gdb/README
index ae331a4..eca4181c 100644
--- a/gdb/README
+++ b/gdb/README
@@ -443,7 +443,11 @@
supported).
`--disable-gdb-compile'
- Build GDB without support for the 'compile' command.
+ Build GDB without support for the 'compile' command. DWARF support
+ is required for this feature.
+
+`--disable-gdb-dwarf-support'
+ Build GDB without support for reading DWARF debug information.
`--disable-gdb-mdebug-support'
Build GDB without support for reading mdebug debug information.
diff --git a/gdb/config.in b/gdb/config.in
index db55ad6..c0a050c 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -39,6 +39,9 @@
/* Define to BFD's default target vector. */
#undef DEFAULT_BFD_VEC
+/* defined if dwarf format was requested. */
+#undef DWARF_FORMAT_AVAILABLE
+
/* Handle .ctf type-info sections */
#undef ENABLE_LIBCTF
diff --git a/gdb/configure b/gdb/configure
index 01db0d0..d0fb74d 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -933,6 +933,7 @@
with_auto_load_safe_path
enable_targets
enable_gdb_mdebug_support
+enable_gdb_dwarf_support
with_amd_dbgapi
enable_tui
enable_gdbtk
@@ -1647,6 +1648,9 @@
--enable-gdb-mdebug-support
Enable support for the mdebug debuginfo format
(default 'yes')
+ --enable-gdb-dwarf-support
+ Enable support for the dwarf debuginfo format
+ (default 'yes')
--enable-tui enable full-screen terminal user interface (TUI)
--enable-gdbtk enable gdbtk graphical user interface (GUI)
--enable-profiling enable profiling of GDB
@@ -11503,7 +11507,7 @@
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11506 "configure"
+#line 11510 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -11609,7 +11613,7 @@
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11612 "configure"
+#line 11616 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -24904,6 +24908,31 @@
fi
+# Check whether to support dwarf debug information
+# Check whether --enable-gdb-dwarf-support was given.
+if test "${enable_gdb_dwarf_support+set}" = set; then :
+ enableval=$enable_gdb_dwarf_support;
+ case $enableval in
+ yes | no)
+ ;;
+ *)
+ as_fn_error $? "bad value $enableval for --enable-gdb-dwarf-support" "$LINENO" 5
+ ;;
+ esac
+
+else
+ enable_gdb_dwarf_support=yes
+fi
+
+
+if test "x${enable_gdb_dwarf_support}" != "xno"; then
+
+$as_echo "#define DWARF_FORMAT_AVAILABLE 1" >>confdefs.h
+
+ CONFIG_SRCS="$CONFIG_SRCS \$(DWARF2_SRCS)"
+ CONFIG_OBS="$CONFIG_OBS \$(DWARF2_OBS)"
+fi
+
# See whether 64-bit bfd lib has been enabled.
OLD_CPPFLAGS=$CPPFLAGS
# Put the old CPPFLAGS last, in case the user's CPPFLAGS point somewhere
@@ -28973,21 +29002,37 @@
esac
else
- enable_gdb_compile=yes
+ enable_gdb_compile=default
fi
-if test "${enable_gdb_compile}" = yes; then
-
-$as_echo "#define HAVE_COMPILE 1" >>confdefs.h
-
- CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_GCC_COMPILE_OBS)"
-else
+case ${enable_gdb_compile}-${enable_gdb_dwarf_support} in
+ yes-no)
+ as_fn_error $? "enabling gdb compile requires dwarf support" "$LINENO" 5
+ ;;
+ default-no)
+ { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Defaulting compile support to 'no'" >&5
+$as_echo "$as_me: WARNING: Defaulting compile support to 'no'" >&2;}
+ # Fallthrough.
+ ;&
+ no-*)
# Even if compile support is not enabled, we need this file to define
# the "compile" command.
CONFIG_OBS="$CONFIG_OBS compile/compile.o"
CONFIG_SRCS="$CONFIG_SRCS compile/compile.c"
-fi
+ ;;
+ default-yes)
+ { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Defaulting compile support to 'yes'" >&5
+$as_echo "$as_me: WARNING: Defaulting compile support to 'yes'" >&2;}
+ # Fallthrough.
+ ;&
+ yes-*)
+
+$as_echo "#define HAVE_COMPILE 1" >>confdefs.h
+
+ CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_GCC_COMPILE_OBS)"
+ ;;
+esac
# ---------------------------- #
# Check for source highlight. #
diff --git a/gdb/configure.ac b/gdb/configure.ac
index e8ce421..9e41882 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -206,6 +206,20 @@
[defined if mdebug format was requested.])
fi
+# Check whether to support dwarf debug information
+AC_ARG_ENABLE(gdb-dwarf-support,
+AS_HELP_STRING([--enable-gdb-dwarf-support],
+ [Enable support for the dwarf debuginfo format (default 'yes')]),
+[GDB_CHECK_YES_NO_VAL([$enableval], [--enable-gdb-dwarf-support])],
+[enable_gdb_dwarf_support=yes])
+
+if test "x${enable_gdb_dwarf_support}" != "xno"; then
+ AC_DEFINE(DWARF_FORMAT_AVAILABLE, 1,
+ [defined if dwarf format was requested.])
+ CONFIG_SRCS="$CONFIG_SRCS \$(DWARF2_SRCS)"
+ CONFIG_OBS="$CONFIG_OBS \$(DWARF2_OBS)"
+fi
+
BFD_64_BIT
# Provide defaults for some variables set by the per-host and per-target
@@ -1234,17 +1248,31 @@
AS_HELP_STRING([--enable-gdb-compile],
[enable support for the compile subsystem, default 'yes']),
[GDB_CHECK_YES_NO_VAL([$enableval], [--enable-gdb-compile])],
- [enable_gdb_compile=yes])
+ [enable_gdb_compile=default])
-if test "${enable_gdb_compile}" = yes; then
- AC_DEFINE(HAVE_COMPILE, 1, [Define if compiling support to gdb compile.])
- CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_GCC_COMPILE_OBS)"
-else
+case ${enable_gdb_compile}-${enable_gdb_dwarf_support} in
+ yes-no)
+ AC_MSG_ERROR([enabling gdb compile requires dwarf support])
+ ;;
+ default-no)
+ AC_MSG_WARN([Defaulting compile support to 'no'])
+ # Fallthrough.
+ ;&
+ no-*)
# Even if compile support is not enabled, we need this file to define
# the "compile" command.
CONFIG_OBS="$CONFIG_OBS compile/compile.o"
CONFIG_SRCS="$CONFIG_SRCS compile/compile.c"
-fi
+ ;;
+ default-yes)
+ AC_MSG_WARN([Defaulting compile support to 'yes'])
+ # Fallthrough.
+ ;&
+ yes-*)
+ AC_DEFINE(HAVE_COMPILE, 1, [Define if compiling support to gdb compile.])
+ CONFIG_OBS="$CONFIG_OBS \$(SUBDIR_GCC_COMPILE_OBS)"
+ ;;
+esac
# ---------------------------- #
# Check for source highlight. #
diff --git a/gdb/dwarf2/frame.h b/gdb/dwarf2/frame.h
index f8fd8e8..9357cc1 100644
--- a/gdb/dwarf2/frame.h
+++ b/gdb/dwarf2/frame.h
@@ -198,6 +198,15 @@ struct dwarf2_frame_state
bool armcc_cfa_offsets_reversed = false;
};
+/* If DWARF supoprt was requested, create the real prototype for the
+ append_unwinders function. Otherwise, create a fake inline function.
+
+ There is no need to emit a warning for some of these, because they aren't
+ actively reading DWARF when this is called, they're just initializing GDB.
+
+ These should probably be moved to dwarf2/public.h. */
+#if defined(DWARF_FORMAT_AVAILABLE)
+
/* Set the architecture-specific register state initialization
function for GDBARCH to INIT_REG. */
@@ -287,4 +296,56 @@ extern void *dwarf2_frame_get_fn_data (const frame_info_ptr &this_frame,
void **this_cache,
fn_prev_register cookie);
+#else /* DWARF_FORMAT_AVAILABLE */
+
+static inline void dwarf2_append_unwinders (struct gdbarch *gdbarch) { }
+
+static inline void dwarf2_frame_set_init_reg (
+ gdbarch *gdbarch, void (*init_reg) (struct gdbarch *,int,
+ dwarf2_frame_state_reg *,
+ const frame_info_ptr &)) { }
+
+static inline const struct frame_base *
+ dwarf2_frame_base_sniffer (const frame_info_ptr &this_frame)
+{
+ warning (_("No dwarf support available."));
+ return nullptr;
+}
+
+static inline void dwarf2_frame_set_signal_frame_p
+ (gdbarch *gdbarch, int (*signal_frame_p) (struct gdbarch *,
+ const frame_info_ptr &)) { }
+
+static inline void *dwarf2_frame_get_fn_data (const frame_info_ptr &this_frame,
+ void **this_cache,
+ fn_prev_register cookie)
+{
+ return nullptr;
+}
+
+static inline void *dwarf2_frame_allocate_fn_data
+ (const frame_info_ptr &this_frame, void **this_cache,
+ fn_prev_register cookie, unsigned long size)
+{
+ return nullptr;
+}
+
+static inline int dwarf2_fetch_cfa_info (struct gdbarch *gdbarch, CORE_ADDR pc,
+ struct dwarf2_per_cu_data *data,
+ int *regnum_out, LONGEST *offset_out,
+ CORE_ADDR *text_offset_out,
+ const gdb_byte **cfa_start_out,
+ const gdb_byte **cfa_end_out)
+{
+ return 0;
+}
+
+static inline void
+ dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch,
+ int (*adjust_regnum) (struct gdbarch *,
+ int, int))
+{}
+
+#endif /* DWARF_FORMAT_AVAILABLE */
+
#endif /* GDB_DWARF2_FRAME_H */
diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h
index ee88fd4..c672320 100644
--- a/gdb/dwarf2/loc.h
+++ b/gdb/dwarf2/loc.h
@@ -103,28 +103,6 @@ struct property_addr_info
const property_addr_info *next;
};
-/* Converts a dynamic property into a static one. FRAME is the frame in which
- the property is evaluated; if NULL, the selected frame (if any) is used
- instead.
-
- ADDR_STACK is the stack of addresses that might be needed to evaluate the
- property. When evaluating a property that is not related to a type, it can
- be NULL.
-
- Returns true if PROP could be converted and the static value is passed
- back into VALUE, otherwise returns false.
-
- Any values in PUSH_VALUES will be pushed before evaluating the location
- expression, PUSH_VALUES[0] will be pushed first, then PUSH_VALUES[1],
- etc. This means the during evaluation PUSH_VALUES[0] will be at the
- bottom of the stack. */
-
-bool dwarf2_evaluate_property (const struct dynamic_prop *prop,
- const frame_info_ptr &frame,
- const property_addr_info *addr_stack,
- CORE_ADDR *value,
- gdb::array_view<CORE_ADDR> push_values = {});
-
/* A helper for the compiler interface that compiles a single dynamic
property to C code.
@@ -311,8 +289,53 @@ extern struct value *indirect_synthetic_pointer
Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if
it cannot resolve the parameter for any reason. */
+#if defined(DWARF_FORMAT_AVAILABLE)
+
+/* Converts a dynamic property into a static one. FRAME is the frame in which
+ the property is evaluated; if NULL, the selected frame (if any) is used
+ instead.
+
+ ADDR_STACK is the stack of addresses that might be needed to evaluate the
+ property. When evaluating a property that is not related to a type, it can
+ be NULL.
+
+ Returns true if PROP could be converted and the static value is passed
+ back into VALUE, otherwise returns false.
+
+ Any values in PUSH_VALUES will be pushed before evaluating the location
+ expression, PUSH_VALUES[0] will be pushed first, then PUSH_VALUES[1],
+ etc. This means the during evaluation PUSH_VALUES[0] will be at the
+ bottom of the stack. */
+
+bool dwarf2_evaluate_property (const struct dynamic_prop *prop,
+ const frame_info_ptr &frame,
+ const property_addr_info *addr_stack,
+ CORE_ADDR *value,
+ gdb::array_view<CORE_ADDR> push_values = {});
+
extern struct value *value_of_dwarf_reg_entry (struct type *type,
const frame_info_ptr &frame,
enum call_site_parameter_kind kind,
union call_site_parameter_u kind_u);
+
+#else /* DWARF_FORMAT_AVAILABLE */
+
+static inline bool
+dwarf2_evaluate_property (const struct dynamic_prop *, const frame_info_ptr &,
+ const property_addr_info *, CORE_ADDR *,
+ gdb::array_view<CORE_ADDR> = {})
+{
+ return false;
+}
+
+static inline struct value *
+value_of_dwarf_reg_entry (struct type *type, const frame_info_ptr &frame,
+ enum call_site_parameter_kind kind,
+ union call_site_parameter_u kind_u)
+{
+ error (_("No dwarf support available."));
+}
+
+#endif /* DWARF_FORMAT_AVAILABLE */
+
#endif /* GDB_DWARF2_LOC_H */
diff --git a/gdb/dwarf2/public.h b/gdb/dwarf2/public.h
index ed504c6..f9e7488 100644
--- a/gdb/dwarf2/public.h
+++ b/gdb/dwarf2/public.h
@@ -30,6 +30,8 @@ enum class dw_index_kind
DEBUG_NAMES,
};
+#if defined(DWARF_FORMAT_AVAILABLE)
+
/* Try to locate the sections we need for DWARF 2 debugging
information. If these are found, begin reading the DWARF and
return true. Otherwise, return false. NAMES points to the dwarf2
@@ -44,4 +46,27 @@ extern bool dwarf2_initialize_objfile
extern void dwarf2_build_frame_info (struct objfile *);
+/* Append the DWARF-2 frame unwinders to GDBARCH's list. */
+
+void dwarf2_append_unwinders (struct gdbarch *gdbarch);
+
+#else /* DWARF_FORMAT_AVAILABLE */
+
+static inline bool
+dwarf2_initialize_objfile (struct objfile *,
+ const struct dwarf2_debug_sections * = nullptr,
+ bool = false)
+{
+ warning (_("No dwarf support available."));
+ return false;
+}
+
+static inline void
+dwarf2_build_frame_info (struct objfile *)
+{
+ warning (_("No dwarf support available."));
+}
+
+#endif /* DWARF_FORMAT_AVAILABLE */
+
#endif /* GDB_DWARF2_PUBLIC_H */
diff --git a/gdb/frame-unwind.c b/gdb/frame-unwind.c
index 9ed2dee..c60a349 100644
--- a/gdb/frame-unwind.c
+++ b/gdb/frame-unwind.c
@@ -49,6 +49,7 @@ static constexpr std::initializer_list<const frame_unwind *>
standard_unwinders =
{
&dummy_frame_unwind,
+#if defined(DWARF_FORMAT_AVAILABLE)
/* The DWARF tailcall sniffer must come before the inline sniffer.
Otherwise, we can end up in a situation where a DWARF frame finds
tailcall information, but then the inline sniffer claims a frame
@@ -57,6 +58,7 @@ static constexpr std::initializer_list<const frame_unwind *>
activated if the newer frame was created using the DWARF
unwinder, and it also found tailcall information. */
&dwarf2_tailcall_frame_unwind,
+#endif
&inline_frame_unwind,
};
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 624c9b1..9c57f30 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -6184,12 +6184,22 @@ builtin_type (struct objfile *objfile)
return builtin_type (objfile->arch ());
}
-/* See gdbtypes.h. */
+/* See dwarf2/call-site.h. */
CORE_ADDR
call_site::pc () const
{
+ /* dwarf2_per_objfile is defined in dwarf/read.c, so if that is disabled
+ at configure time, we won't be able to use this relocate function.
+ This is dwarf-specific, and would ideally be in call-site.h, but
+ including dwarf2/read.h in dwarf2/call-site.h will lead to things being
+ included in the wrong order and many compilation errors will happen.
+ This is the next best thing. */
+#if defined(DWARF_FORMAT_AVAILABLE)
return per_objfile->relocate (m_unrelocated_pc);
+#else
+ gdb_assert_not_reached ("unexpected call_site object found");
+#endif
}
void _initialize_gdbtypes ();
