[PATCH 2/2, RFC] Allow restricting analyzed decls to exported symbols

[Dodji Seketeli <dodji@seketeli.org>]

Hello,

Profiling showed that the DWARF reader scans too much data.

Basically, in build_translation_unit_and_add_to_ir,
build_ir_node_from_die is called on every single DIE that is seen, for
a given translation unit.

There are interfaces (function and variable decls) that are not
associated with exported ELF symbols and that are analyzed by
build_ir_node_from_die nonetheless.  For instance, interfaces that are
visible outside of their translation units are analyzed and the types
that are reachable from those interfaces are analyzed as well.

Once that is done, an ABI corpus is built with the subset of
interfaces that have exported ELF symbol (strictly those that are part
of the ABI), but types that are not necessarily reachable from those
ABI interfaces can also be put into the ABI corpus.

Some tools make use of this "lose" behaviour of libabigail.  For
instance, abicompat precisely wants to analyze interfaces with
undefined symbols.  For an application, those interfaces represents
the interfaces that the application expects to be provided by some
shared library.

When analyzing the exported interface of the Linux Kernel (or any
other huge application) however, analyzing more types than necessary
appears to incur a huge time penalty.

So, this patch introduces an optional behaviour whereby
build_translation_unit_and_add_to_ir is restricted to analyzing
interfaces that have exported ELF symbols only.  So only the types
reachable from those interfaces are analyzed.  This more than halves
the time spent by "abidw --noout vmlinux".

Strictly speaking, this new behaviour is triggered by a new option named
--exported-interfaces-only, supported by the tools abidw, abidiff,
abipkgdiff and kmidiff.

When looking at the Linux Kernel however, this option is enabled by
default.

Note that an option --allow-non-exported-interfaces is also introduce
to function under the previous model of operations.  This option is
enabled by default on all the tools when they are not looking at the
Linux Kernel.

With this enabled, analyzing the Linux Kernel is back to taking less
than a minute on a reasonable machine.

	* doc/manuals/tools-use-libabigail.txt: New doc text.
	* doc/manuals/Makefile.am: Add the new tools-use-libabigail.rst
	tool to the source distribution.
	* doc/manuals/abidiff.rst: Include the new
	tools-use-libabigail.rst.  Document the --exported-interfaces-only
	and --allow-non-exported-interfaces.
	* doc/manuals/abidw.rst: Likewise.
	* doc/manuals/abipkgdiff.rst: Likewise.
	* doc/manuals/kmidiff.rst: Likewise.
	* include/abg-ir.h
	(environment::{user_set_analyze_exported_interfaces_only,
	analyze_exported_interfaces_only}): Declare new accessors.
	* src/abg-ir.cc
	(environment::{user_set_analyze_exported_interfaces_only,
	analyze_exported_interfaces_only}): Define new accessors.
	* src/abg-dwarf-reader.cc (die_is_variable_decl)
	(die_is_function_decl): Define new static functions.
	(read_context::is_decl_die_with_exported_symbol): Define new
	member function.
	(read_context::get_{function,variable}_address): Const-ify the
	Dwarf_Die* parameter.
	(build_translation_unit_and_add_to_ir): If the user asks to
	analyze exported interfaces only,  the analyze only interfaces
	that have exported ELF symbols.
	(read_debug_info_into_corpus): If we are looking at the Linux
	Kernel, then only analyze exported interfaces unless the user asks
	otherwise.
	* src/abg-ir-priv.h
	(environment::priv::analyze_exported_interfaces_only_): Define new
	data member.
	* tools/abidiff.cc (options::exported_interfaces_only): Define new
	data member.
	(display_usage): Add new help strings for
	--exported-interfaces-only and --allow-non-exported-interfaces.
	(parse_command_line): Parse the new options
	--exported-interfaces-only and --allow-non-exported-interfaces.
	(main): Pass the value of opts.exported_interfaces_only to the
	environment.
	* tools/abidw.cc (options::exported_interfaces_only): Define new
	data member.
	(display_usage): Add new help strings for
	--exported-interfaces-only and --allow-non-exported-interfaces.
	(parse_command_line): Parse the new options
	(load_corpus_and_write_abixml)
	(load_kernel_corpus_group_and_write_abixml): Pass the value of
	opts.exported_interfaces_only onto the environment.
	* tools/abipkgdiff.cc (options::exported_interfaces_only): Define new
	data member.
	(display_usage): Add new help strings for
	--exported-interfaces-only and --allow-non-exported-interfaces.
	(parse_command_line): Parse the new options
	(compare_task::perform, self_compare_task::perform): Pass the
	value of opts.exported_interfaces_only onto the environment.
	(compare_prepared_linux_kernel_packages): Likewise.
	* tools/kmidiff.cc(options::exported_interfaces_only): Define new
	data member.
	(display_usage): Add new help strings for
	--exported-interfaces-only and --allow-non-exported-interfaces.
	(parse_command_line): Parse the new options
	(main): Pass the value of opts.exported_interfaces_only onto the
	environment.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
---
 doc/manuals/Makefile.am              |   3 +-
 doc/manuals/abidiff.rst              |  52 ++++++++++++
 doc/manuals/abidw.rst                |  82 ++++++++++++++++---
 doc/manuals/abipkgdiff.rst           |  51 ++++++++++++
 doc/manuals/kmidiff.rst              |  52 +++++++++++-
 doc/manuals/tools-use-libabigail.txt |  16 ++++
 include/abg-ir.h                     |   9 +++
 src/abg-dwarf-reader.cc              | 113 ++++++++++++++++++++++++---
 src/abg-ir-priv.h                    |   2 +
 src/abg-ir.cc                        |  36 +++++++++
 tools/abidiff.cc                     |  12 +++
 tools/abidw.cc                       |  15 ++++
 tools/abipkgdiff.cc                  |  21 +++++
 tools/kmidiff.cc                     |  12 +++
 14 files changed, 449 insertions(+), 27 deletions(-)
 create mode 100644 doc/manuals/tools-use-libabigail.txt

diff --git a/doc/manuals/Makefile.am b/doc/manuals/Makefile.am
index 894b38f1..e2813785 100644
--- a/doc/manuals/Makefile.am
+++ b/doc/manuals/Makefile.am
@@ -14,7 +14,8 @@ libabigail-concepts.rst \
 libabigail-overview.rst \
 libabigail-tools.rst \
 fedabipkgdiff.rst \
-kmidiff.rst
+kmidiff.rst \
+tools-use-libabigail.txt
 
 # You can set these variables from the command line.
 SPHINXOPTS    =
diff --git a/doc/manuals/abidiff.rst b/doc/manuals/abidiff.rst
index a15515be..0c711d9e 100644
--- a/doc/manuals/abidiff.rst
+++ b/doc/manuals/abidiff.rst
@@ -18,6 +18,8 @@ be accompanied with their debug information in `DWARF`_ format.
 Otherwise, only `ELF`_ symbols that were added or removed are
 reported.
 
+.. include:: tools-use-libabigail.txt
+
 .. _abidiff_invocation_label:
 
 Invocation
@@ -197,6 +199,56 @@ Options
     consumption of the tool on binaries with a lot of publicly defined
     and exported types.
 
+  * ``--exported-interfaces-only``
+
+    By default, when looking at the debug information accompanying a
+    binary, this tool analyzes the descriptions of the types reachable
+    by the interfaces (functions and variables) that are visible
+    outside of their translation unit.  Once that analysis is done, an
+    ABI corpus is constructed by only considering the subset of types
+    reachable from interfaces associated to `ELF`_ symbols that are
+    defined and exported by the binary.  It's those final ABI Corpora
+    that are compared by this tool.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, especially when those binaries are
+    applications, as opposed to shared libraries.  One example of such
+    applications is the `Linux Kernel`_.  Analyzing massive ABI
+    corpora like these can be extremely slow.
+
+    To mitigate that performance issue, this option allows libabigail
+    to only analyze types that are reachable from interfaces
+    associated with defined and exported `ELF`_ symbols.
+
+    Note that this option is turned on by default when analyzing the
+    `Linux Kernel`_.  Otherwise, it's turned off by default.
+
+  * ``--allow-non-exported-interfaces``
+
+    When looking at the debug information accompanying a binary, this
+    tool analyzes the descriptions of the types reachable by the
+    interfaces (functions and variables) that are visible outside of
+    their translation unit.  Once that analysis is done, an ABI corpus
+    is constructed by only considering the subset of types reachable
+    from interfaces associated to `ELF`_ symbols that are defined and
+    exported by the binary.  It's those final ABI Corpora that are
+    compared by this tool.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, especially when those binaries are
+    applications, as opposed to shared libraries.  One example of such
+    applications is the `Linux Kernel`_.  Analyzing massive ABI
+    Corpora like these can be extremely slow.
+
+    In the presence of an "average sized" binary however one can
+    afford having libabigail analyze all interfaces that are visible
+    outside of their translation unit, using this option.
+
+    Note that this option is turned on by default, unless we are in
+    the presence of the `Linux Kernel`_.
+
   * ``--stat``
 
     Rather than displaying the detailed ABI differences between
diff --git a/doc/manuals/abidw.rst b/doc/manuals/abidw.rst
index bdd6204d..a3055c7e 100644
--- a/doc/manuals/abidw.rst
+++ b/doc/manuals/abidw.rst
@@ -12,14 +12,19 @@ defined ELF symbols of the file.  The input shared library must
 contain associated debug information in `DWARF`_ format.
 
 When given the ``--linux-tree`` option, this program can also handle a
-Linux kernel tree.  That is, a directory tree that contains both the
-vmlinux binary and Linux kernel modules.  It analyses those Linux
-kernel binaries and emits an XML representation of the interface
-between the kernel and its module, to standard output.  In this case,
-we don't call it an ABI, but a KMI (Kernel Module Interface).  The
-emitted KMI includes all the globally defined functions and variables,
-along with a complete representation of their types.  The input
-binaries must contain associated debug information in `DWARF`_ format.
+`Linux kernel`_ tree.  That is, a directory tree that contains both
+the vmlinux binary and `Linux Kernel`_ modules.  It analyses those
+`Linux Kernel`_ binaries and emits an XML representation of the
+interface between the kernel and its module, to standard output.  In
+this case, we don't call it an ABI, but a KMI (Kernel Module
+Interface).  The emitted KMI includes all the globally defined
+functions and variables, along with a complete representation of their
+types.  The input binaries must contain associated debug information
+in `DWARF`_ format.
+
+.. include:: tools-use-libabigail.txt
+
+.. _abidiff_invocation_label:
 
 Invocation
 ==========
@@ -92,7 +97,7 @@ Options
 
   * ``--kmi-whitelist | -kaw`` <*path-to-whitelist*>
 
-    When analyzing a Linux kernel binary, this option points to the
+    When analyzing a `Linux Kernel`_ binary, this option points to the
     white list of names of ELF symbols of functions and variables
     which ABI must be written out.  That white list is called a "
     Kernel Module Interface white list".  This is because for the
@@ -105,7 +110,7 @@ Options
 
     If this option is not provided -- thus if no white list is
     provided -- then the entire KMI, that is, all publicly defined and
-    exported functions and global variables by the Linux Kernel
+    exported functions and global variables by the `Linux Kernel`_
     binaries is emitted.
     
   * ``--linux-tree | --lt``
@@ -115,9 +120,10 @@ Options
     In that case, this program emits the representation of the Kernel
     Module Interface (KMI) on the standard output.
 
-    Below is an example of usage of ``abidw`` on a Linux Kernel tree.
+    Below is an example of usage of ``abidw`` on a `Linux Kernel`_
+    tree.
 
-    First, checkout a Linux kernel source tree and build it.  Then
+    First, checkout a `Linux Kernel`_ source tree and build it.  Then
     install the kernel modules in a directory somewhere.  Copy the
     vmlinux binary into that directory too.  And then serialize the
     KMI of that kernel to disk, using ``abidw``: ::
@@ -171,6 +177,56 @@ Options
     representation build by Libabigail to represent the ABI and will
     not end up in the abi XML file.
 
+  * ``--exported-interfaces-only``
+
+    By default, when looking at the debug information accompanying a
+    binary, this tool analyzes the descriptions of the types reachable
+    by the interfaces (functions and variables) that are visible
+    outside of their translation unit.  Once that analysis is done, an
+    ABI corpus is constructed by only considering the subset of types
+    reachable from interfaces associated to `ELF`_ symbols that are
+    defined and exported by the binary.  It's that final ABI corpus
+    which textual representation is saved as ``ABIXML``.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, especially when those binaries are
+    applications, as opposed to shared libraries.  One example of such
+    applications is the `Linux Kernel`_.  Analyzing massive ABI
+    corpora like these can be extremely slow.
+
+    To mitigate that performance issue, this option allows libabigail
+    to only analyze types that are reachable from interfaces
+    associated with defined and exported `ELF`_ symbols.
+
+    Note that this option is turned on by default when analyzing the
+    `Linux Kernel`_.  Otherwise, it's turned off by default.
+
+  * ``--allow-non-exported-interfaces``
+
+    When looking at the debug information accompanying a binary, this
+    tool analyzes the descriptions of the types reachable by the
+    interfaces (functions and variables) that are visible outside of
+    their translation unit.  Once that analysis is done, an ABI corpus
+    is constructed by only considering the subset of types reachable
+    from interfaces associated to `ELF`_ symbols that are defined and
+    exported by the binary.  It's that final ABI corpus which textual
+    representation is saved as ``ABIXML``.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, especially when those binaries are
+    applications, as opposed to shared libraries.  One example of such
+    applications is the `Linux Kernel`_.  Analyzing massive ABI
+    corpora like these can be extremely slow.
+
+    In the presence of an "average sized" binary however one can
+    afford having libabigail analyze all interfaces that are visible
+    outside of their translation unit, using this option.
+
+    Note that this option is turned on by default, unless we are in
+    the presence of the `Linux Kernel`_.
+
   * ``--no-linux-kernel-mode``
 
     Without this option, if abipkgiff detects that the binaries it is
@@ -308,4 +364,4 @@ standard `here
 .. _ELF: http://en.wikipedia.org/wiki/Executable_and_Linkable_Format
 .. _DWARF: http://www.dwarfstd.org
 .. _GNU: http://www.gnu.org
-
+.. _Linux Kernel: https://kernel.org/
diff --git a/doc/manuals/abipkgdiff.rst b/doc/manuals/abipkgdiff.rst
index 15ea9072..9114775a 100644
--- a/doc/manuals/abipkgdiff.rst
+++ b/doc/manuals/abipkgdiff.rst
@@ -19,6 +19,7 @@ information directly in a section of said binaries.  In those cases,
 obviously, no separate debug information package is needed as the tool
 will find the debug information inside the binaries.
 
+.. include:: tools-use-libabigail.txt
 
 .. _abipkgdiff_invocation_label:
 
@@ -277,6 +278,56 @@ Options
     global functions and variables are analyzed, so the tool detects
     and reports changes on these reachable types only.
 
+  * ``--exported-interfaces-only``
+
+    By default, when looking at the debug information accompanying a
+    binary, this tool analyzes the descriptions of the types reachable
+    by the interfaces (functions and variables) that are visible
+    outside of their translation unit.  Once that analysis is done, an
+    ABI corpus is constructed by only considering the subset of types
+    reachable from interfaces associated to `ELF`_ symbols that are
+    defined and exported by the binary.  It's those final ABI Corpora
+    that are compared by this tool.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, especially when those binaries are
+    applications, as opposed to shared libraries.  One example of such
+    applications is the `Linux Kernel`_.  Analyzing massive ABI
+    corpora like these can be extremely slow.
+
+    To mitigate that performance issue, this option allows libabigail
+    to only analyze types that are reachable from interfaces
+    associated with defined and exported `ELF`_ symbols.
+
+    Note that this option is turned on by default when analyzing the
+    `Linux Kernel`_.  Otherwise, it's turned off by default.
+
+  * ``--allow-non-exported-interfaces``
+
+    When looking at the debug information accompanying a binary, this
+    tool analyzes the descriptions of the types reachable by the
+    interfaces (functions and variables) that are visible outside of
+    their translation unit.  Once that analysis is done, an ABI corpus
+    is constructed by only considering the subset of types reachable
+    from interfaces associated to `ELF`_ symbols that are defined and
+    exported by the binary.  It's those final ABI Corpora that are
+    compared by this tool.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, especially when those binaries are
+    applications, as opposed to shared libraries.  One example of such
+    applications is the `Linux Kernel`_.  Analyzing massive ABI
+    Corpora like these can be extremely slow.
+
+    In the presence of an "average sized" binary however one can
+    afford having libabigail analyze all interfaces that are visible
+    outside of their translation unit, using this option.
+
+    Note that this option is turned on by default, unless we are in
+    the presence of the `Linux Kernel`_.
+
   *  ``--redundant``
 
     In the diff reports, do display redundant changes.  A redundant
diff --git a/doc/manuals/kmidiff.rst b/doc/manuals/kmidiff.rst
index ce8168ae..53010189 100644
--- a/doc/manuals/kmidiff.rst
+++ b/doc/manuals/kmidiff.rst
@@ -55,6 +55,10 @@ command line looks like: ::
 		       linux/v4.5/build/modules \
 		       linux/v4.6/build/modules
 
+
+.. include:: tools-use-libabigail.txt
+
+
 Invocation
 ==========
 
@@ -67,8 +71,8 @@ Environment
 
 By default, ``kmidiff`` compares all the interfaces (exported
 functions and variables) between the Kernel and its modules.  In
-practice, though, users want to compare a subset of the those
-interfaces.
+practice, though, some users might want to compare a subset of the
+those interfaces.
 
 Users can then define a "white list" of the interfaces to compare.
 Such a white list is a just a file in the "INI" format that looks
@@ -91,8 +95,11 @@ function or variable.  Only those interfaces along with the types
 reachable from their signatures are going to be compared by
 ``kmidiff`` recursively.
 
-Note that kmidiff compares the interfaces exported by the ``vmlinux``
-binary and by the all of the compiled modules.
+Note that by default kmidiff analyzes the types reachable from the
+interfaces associated with `ELF`_ symbols that are defined and
+exported by the `Linux Kernel`_ as being the union of the ``vmlinux``
+binary and all its compiled modules.  It then compares those
+interfaces (along with their types).
 
 Options
 =======
@@ -180,6 +187,38 @@ Options
     exported interfaces.  This is the default kind of report emitted
     by tools like ``abidiff`` or ``abipkgdiff``.
 
+  * ``--exported-interfaces-only``
+
+    When using this option, this tool analyzes the descriptions of the
+    types reachable by the interfaces (functions and variables)
+    associated with `ELF`_ symbols that are defined and exported by
+    the `Linux Kernel`_.
+
+    Otherwise, the tool also has the ability to analyze the
+    descriptions of the types reachable by the interfaces associated
+    with `ELF`_ symbols that are visible outside their translation
+    unit.  This later possibility is however much more resource
+    intensive and results in much slower operations.
+
+    That is why this option is enabled by default.
+
+
+  * ``--allow-non-exported-interfaces``
+
+    When using this option, this tool analyzes the descriptions of the
+    types reachable by the interfaces (functions and variables) that
+    are visible outside of their translation unit.  Once that analysis
+    is done, an ABI Corpus is constructed by only considering the
+    subset of types reachable from interfaces associated to `ELF`_
+    symbols that are defined and exported by the binary.  It's that
+    final ABI corpus which is compared against another one.
+
+    The problem with that approach however is that analyzing all the
+    interfaces that are visible from outside their translation unit
+    can amount to a lot of data, leading to very slow operations.
+
+    Note that this option is turned off by default.
+
   * ``--show-bytes``
 
     Show sizes and offsets in bytes, not bits.  This option is
@@ -198,3 +237,8 @@ Options
   * ``--show-dec``
 
     Show sizes and offsets in decimal base.
+
+
+.. _ELF: http://en.wikipedia.org/wiki/Executable_and_Linkable_Format
+.. _ksymtab: http://en.wikipedia.org/wiki/Executable_and_Linkable_Format
+.. _Linux Kernel: https://kernel.org
diff --git a/doc/manuals/tools-use-libabigail.txt b/doc/manuals/tools-use-libabigail.txt
new file mode 100644
index 00000000..43edf296
--- /dev/null
+++ b/doc/manuals/tools-use-libabigail.txt
@@ -0,0 +1,16 @@
+This tool uses the libabigail library to analyze the binary as well as its
+associated debug information.  Here is its general mode of operation.
+
+When instructed to do so, a binary and its associated debug
+information is read and analyzed.  To that effect, libabigail analyzes
+by default the descriptions of the types reachable by the interfaces
+(functions and variables) that are visible outside of their
+translation unit.  Once that analysis is done, an Application Binary
+Interface Corpus is constructed by only considering the subset of
+types reachable from interfaces associated to `ELF`_ symbols that are
+defined and exported by the binary.  It's that final ABI corpus which
+libabigail considers as representing the ABI of the analyzed binary.
+
+Libabigail then has capabilities to generate textual representations
+of ABI Corpora, compare them, analyze their changes and report about
+them.
diff --git a/include/abg-ir.h b/include/abg-ir.h
index a857d041..61338edb 100644
--- a/include/abg-ir.h
+++ b/include/abg-ir.h
@@ -197,6 +197,15 @@ public:
   const config&
   get_config() const;
 
+  bool
+  user_set_analyze_exported_interfaces_only() const;
+
+  void
+  analyze_exported_interfaces_only(bool f);
+
+  bool
+  analyze_exported_interfaces_only() const;
+
 #ifdef WITH_DEBUG_SELF_COMPARISON
   void
   set_self_comparison_debug_input(const corpus_sptr& corpus);
diff --git a/src/abg-dwarf-reader.cc b/src/abg-dwarf-reader.cc
index e41172c1..cba89664 100644
--- a/src/abg-dwarf-reader.cc
+++ b/src/abg-dwarf-reader.cc
@@ -402,6 +402,12 @@ die_is_decl(const Dwarf_Die* die);
 static bool
 die_is_declaration_only(Dwarf_Die* die);
 
+static bool
+die_is_variable_decl(const Dwarf_Die *die);
+
+static bool
+die_is_function_decl(const Dwarf_Die *die);
+
 static bool
 die_has_size_attribute(const Dwarf_Die *die);
 
@@ -5303,6 +5309,44 @@ public:
     return symbol;
   }
 
+  /// Test if a DIE represents a decl (function or variable) that has
+  /// a symbol that is exported, whatever that means.  This is
+  /// supposed to work for Linux Kernel binaries as well.
+  ///
+  /// This is useful to limit the amount of DIEs taken into account to
+  /// the strict limit of what an ABI actually means.  Limiting the
+  /// volume of DIEs analyzed this way is an important optimization to
+  /// keep big binaries "manageable" by libabigail.
+  ///
+  /// @param DIE the die to consider.
+  bool
+  is_decl_die_with_exported_symbol(const Dwarf_Die *die)
+  {
+    if (!die || !die_is_decl(die))
+      return false;
+
+    bool result = false, address_found = false, symbol_is_exported = false;;
+    Dwarf_Addr decl_symbol_address = 0;
+
+    if (die_is_variable_decl(die))
+      {
+	if ((address_found = get_variable_address(die, decl_symbol_address)))
+	  symbol_is_exported =
+	    !!variable_symbol_is_exported(decl_symbol_address);
+      }
+    else if (die_is_function_decl(die))
+      {
+	if ((address_found = get_function_address(die, decl_symbol_address)))
+	  symbol_is_exported =
+	    !!function_symbol_is_exported(decl_symbol_address);
+      }
+
+    if (address_found)
+      result = symbol_is_exported;
+
+    return result;
+  }
+
   /// Getter for the symtab reader. Will load the symtab from the elf handle if
   /// not yet set.
   ///
@@ -5580,16 +5624,18 @@ public:
   ///
   /// @return true if the function address was found.
   bool
-  get_function_address(Dwarf_Die* function_die, Dwarf_Addr& address) const
+  get_function_address(const Dwarf_Die* function_die, Dwarf_Addr& address) const
   {
-    if (!die_address_attribute(function_die, DW_AT_low_pc, address))
+    if (!die_address_attribute(const_cast<Dwarf_Die*>(function_die),
+			       DW_AT_low_pc, address))
       // So no DW_AT_low_pc was found.  Let's see if the function DIE
       // has got a DW_AT_ranges attribute instead.  If it does, the
       // first address of the set of addresses represented by the
       // value of that DW_AT_ranges represents the function (symbol)
       // address we are looking for.
-      if (!get_first_exported_fn_address_from_DW_AT_ranges(function_die,
-							   address))
+      if (!get_first_exported_fn_address_from_DW_AT_ranges
+	  (const_cast<Dwarf_Die*>(function_die),
+	   address))
 	return false;
 
     address = maybe_adjust_fn_sym_address(address);
@@ -5611,11 +5657,12 @@ public:
   ///
   /// @return true if the variable address was found.
   bool
-  get_variable_address(Dwarf_Die*	variable_die,
+  get_variable_address(const Dwarf_Die* variable_die,
 		       Dwarf_Addr&	address) const
   {
     bool is_tls_address = false;
-    if (!die_location_address(variable_die, address, is_tls_address))
+    if (!die_location_address(const_cast<Dwarf_Die*>(variable_die),
+			      address, is_tls_address))
       return false;
     if (!is_tls_address)
       address = maybe_adjust_var_sym_address(address);
@@ -7155,6 +7202,40 @@ die_is_declaration_only(Dwarf_Die* die)
   return false;
 }
 
+/// Test if a DIE is for a function decl.
+///
+/// @param die the DIE to consider.
+///
+/// @return true iff @p die represents a function decl.
+static bool
+die_is_function_decl(const Dwarf_Die *die)
+{
+  if (!die)
+    return false;
+
+  int tag = dwarf_tag(const_cast<Dwarf_Die*>(die));
+  if (tag == DW_TAG_subprogram)
+    return true;
+  return false;
+}
+
+/// Test if a DIE is for a variable decl.
+///
+/// @param die the DIE to consider.
+///
+/// @return true iff @p die represents a variable decl.
+static bool
+die_is_variable_decl(const Dwarf_Die *die)
+{
+    if (!die)
+    return false;
+
+  int tag = dwarf_tag(const_cast<Dwarf_Die*>(die));
+  if (tag == DW_TAG_variable)
+    return true;
+  return false;
+}
+
 /// Test if a DIE has size attribute.
 ///
 /// @param die the DIE to consider.
@@ -12690,9 +12771,13 @@ build_translation_unit_and_add_to_ir(read_context&	ctxt,
   result->set_is_constructed(false);
 
   do
-    build_ir_node_from_die(ctxt, &child,
-			   die_is_public_decl(&child),
-			   dwarf_dieoffset(&child));
+    // Analyze all the DIEs we encounter unless we are asked to only
+    // analyze exported interfaces and the types reachables from them.
+    if (!ctxt.env()->analyze_exported_interfaces_only()
+	|| ctxt.is_decl_die_with_exported_symbol(&child))
+      build_ir_node_from_die(ctxt, &child,
+			     die_is_public_decl(&child),
+			     dwarf_dieoffset(&child));
   while (dwarf_siblingof(&child, &child) == 0);
 
   if (!ctxt.var_decls_to_re_add_to_tree().empty())
@@ -15699,6 +15784,16 @@ read_debug_info_into_corpus(read_context& ctxt)
     origin |= corpus::LINUX_KERNEL_BINARY_ORIGIN;
   ctxt.current_corpus()->set_origin(origin);
 
+  if (origin & corpus::LINUX_KERNEL_BINARY_ORIGIN
+      && !ctxt.env()->user_set_analyze_exported_interfaces_only())
+    // So we are looking at the Linux Kernel and the user has not set
+    // any particular option regarding the amount of types to analyse.
+    // In that case, we need to only analyze types that are reachable
+    // from exported interfaces otherwise we get such a massive amount
+    // of type DIEs to look at that things are just too slow down the
+    // road.
+    ctxt.env()->analyze_exported_interfaces_only(true);
+
   ctxt.current_corpus()->set_soname(ctxt.dt_soname());
   ctxt.current_corpus()->set_needed(ctxt.dt_needed());
   ctxt.current_corpus()->set_architecture_name(ctxt.elf_architecture());
diff --git a/src/abg-ir-priv.h b/src/abg-ir-priv.h
index 45b711b7..21734b25 100644
--- a/src/abg-ir-priv.h
+++ b/src/abg-ir-priv.h
@@ -26,6 +26,7 @@ namespace ir
 {
 
 using std::string;
+using abg_compat::optional;
 
 /// The result of structural comparison of type ABI artifacts.
 enum comparison_result
@@ -443,6 +444,7 @@ struct environment::priv
   bool					decl_only_class_equals_definition_;
   bool					use_enum_binary_only_equality_;
   bool					allow_type_comparison_results_caching_;
+  optional<bool>			analyze_exported_interfaces_only_;
 #ifdef WITH_DEBUG_SELF_COMPARISON
   bool					self_comparison_debug_on_;
 #endif
diff --git a/src/abg-ir.cc b/src/abg-ir.cc
index 91c8e99b..02d68e63 100644
--- a/src/abg-ir.cc
+++ b/src/abg-ir.cc
@@ -3674,6 +3674,42 @@ const config&
 environment::get_config() const
 {return priv_->config_;}
 
+/// Getter for a property that says if the user actually did set the
+/// analyze_exported_interfaces_only() property.  If not, it means
+/// the default behaviour prevails.
+///
+/// @return tru iff the user did set the
+/// analyze_exported_interfaces_only() property.
+bool
+environment::user_set_analyze_exported_interfaces_only() const
+{return priv_->analyze_exported_interfaces_only_.has_value();}
+
+/// Setter for the property that controls if we are to restrict the
+/// analysis to the types that are only reachable from the exported
+/// interfaces only, or if the set of types should be more broad than
+/// that.  Typically, we'd restrict the analysis to types reachable
+/// from exported interfaces only (stricto sensu, that would really be
+/// only the types that are part of the ABI of well designed
+/// libraries) for performance reasons.
+///
+/// @param f the value of the flag.
+void
+environment::analyze_exported_interfaces_only(bool f)
+{priv_->analyze_exported_interfaces_only_ = f;}
+
+/// Getter for the property that controls if we are to restrict the
+/// analysis to the types that are only reachable from the exported
+/// interfaces only, or if the set of types should be more broad than
+/// that.  Typically, we'd restrict the analysis to types reachable
+/// from exported interfaces only (stricto sensu, that would really be
+/// only the types that are part of the ABI of well designed
+/// libraries) for performance reasons.
+///
+/// @param f the value of the flag.
+bool
+environment::analyze_exported_interfaces_only() const
+{return priv_->analyze_exported_interfaces_only_.value_or(false);}
+
 #ifdef WITH_DEBUG_SELF_COMPARISON
 /// Setter of the corpus of the input corpus of the self comparison
 /// that takes place when doing "abidw --debug-abidiff <binary>".
diff --git a/tools/abidiff.cc b/tools/abidiff.cc
index 97b036cb..e0bb35ac 100644
--- a/tools/abidiff.cc
+++ b/tools/abidiff.cc
@@ -29,6 +29,7 @@ using std::ostream;
 using std::cout;
 using std::cerr;
 using std::shared_ptr;
+using abg_compat::optional;
 using abigail::ir::environment;
 using abigail::ir::environment_sptr;
 using abigail::translation_unit;
@@ -74,6 +75,7 @@ struct options
   vector<string>	headers_dirs2;
   vector<string>        header_files2;
   bool			drop_private_types;
+  optional<bool>	exported_interfaces_only;
   bool			linux_kernel_mode;
   bool			no_default_supprs;
   bool			no_arch;
@@ -197,6 +199,9 @@ display_usage(const string& prog_name, ostream& out)
     << " --header-file2|--hf2 <path>  the path to one header of file2\n"
     << " --drop-private-types  drop private types from "
     "internal representation\n"
+    << "  --exported-interfaces-only  analyze exported interfaces only\n"
+    << "  --allow-non-exported-interfaces  analyze interfaces that "
+    "might not be exported\n"
     << " --no-linux-kernel-mode  don't consider the input binaries as "
        "linux kernel binaries\n"
     << " --kmi-whitelist|-w  path to a "
@@ -403,6 +408,10 @@ parse_command_line(int argc, char* argv[], options& opts)
 	}
       else if (!strcmp(argv[i], "--drop-private-types"))
 	opts.drop_private_types = true;
+      else if (!strcmp(argv[i], "--exported-interfaces-only"))
+	opts.exported_interfaces_only = true;
+      else if (!strcmp(argv[i], "--allow-non-exported-interfaces"))
+	opts.exported_interfaces_only = false;
       else if (!strcmp(argv[i], "--no-default-suppression"))
 	opts.no_default_supprs = true;
       else if (!strcmp(argv[i], "--no-architecture"))
@@ -1130,6 +1139,9 @@ main(int argc, char* argv[])
       t2_type = guess_file_type(opts.file2);
 
       environment_sptr env(new environment);
+      if (opts.exported_interfaces_only.has_value())
+	env->analyze_exported_interfaces_only(*opts.exported_interfaces_only);
+
 #ifdef WITH_DEBUG_SELF_COMPARISON
 	    if (opts.do_debug)
 	      env->self_comparison_debug_is_on(true);
diff --git a/tools/abidw.cc b/tools/abidw.cc
index 9a27a029..f38d6048 100644
--- a/tools/abidw.cc
+++ b/tools/abidw.cc
@@ -40,6 +40,7 @@ using std::ostream;
 using std::ofstream;
 using std::vector;
 using std::shared_ptr;
+using abg_compat::optional;
 using abigail::tools_utils::emit_prefix;
 using abigail::tools_utils::temp_file;
 using abigail::tools_utils::temp_file_sptr;
@@ -114,6 +115,7 @@ struct options
   bool			do_log;
   bool			drop_private_types;
   bool			drop_undefined_syms;
+  optional<bool>	exported_interfaces_only;
   type_id_style_kind	type_id_style;
 #ifdef WITH_DEBUG_SELF_COMPARISON
   string		type_id_file_path;
@@ -187,6 +189,9 @@ display_usage(const string& prog_name, ostream& out)
     << "  --short-locs  only print filenames rather than paths\n"
     << "  --drop-private-types  drop private types from representation\n"
     << "  --drop-undefined-syms  drop undefined symbols from representation\n"
+    << "  --exported-interfaces-only  analyze exported interfaces only\n"
+    << "  --allow-non-exported-interfaces  analyze interfaces that "
+    "might not be exported\n"
     << "  --no-comp-dir-path  do not show compilation path information\n"
     << "  --no-elf-needed  do not show the DT_NEEDED information\n"
     << "  --no-write-default-sizes  do not emit pointer size when it equals"
@@ -368,6 +373,10 @@ parse_command_line(int argc, char* argv[], options& opts)
 	opts.drop_private_types = true;
       else if (!strcmp(argv[i], "--drop-undefined-syms"))
 	opts.drop_undefined_syms = true;
+      else if (!strcmp(argv[i], "--exported-interfaces-only"))
+	opts.exported_interfaces_only = true;
+      else if (!strcmp(argv[i], "--allow-non-exported-interfaces"))
+	opts.exported_interfaces_only = false;
       else if (!strcmp(argv[i], "--no-linux-kernel-mode"))
 	opts.linux_kernel_mode = false;
       else if (!strcmp(argv[i], "--abidiff"))
@@ -606,6 +615,9 @@ load_corpus_and_write_abixml(char* argv[],
             }
         }
 
+      if (opts.exported_interfaces_only.has_value())
+	env->analyze_exported_interfaces_only(*opts.exported_interfaces_only);
+
       t.start();
       corp = dwarf_reader::read_corpus_from_elf(ctxt, s);
       t.stop();
@@ -813,6 +825,9 @@ load_kernel_corpus_group_and_write_abixml(char* argv[],
   timer t, global_timer;
   suppressions_type supprs;
 
+  if (opts.exported_interfaces_only.has_value())
+    env->analyze_exported_interfaces_only(*opts.exported_interfaces_only);
+
   if (opts.do_log)
     emit_prefix(argv[0], cerr)
       << "going to build ABI representation of the Linux Kernel ...\n";
diff --git a/tools/abipkgdiff.cc b/tools/abipkgdiff.cc
index 551080b9..656d5882 100644
--- a/tools/abipkgdiff.cc
+++ b/tools/abipkgdiff.cc
@@ -106,6 +106,7 @@ using std::set;
 using std::ostringstream;
 using std::shared_ptr;
 using std::dynamic_pointer_cast;
+using abg_compat::optional;
 using abigail::workers::task;
 using abigail::workers::task_sptr;
 using abigail::workers::queue;
@@ -205,6 +206,7 @@ public:
   bool		fail_if_no_debug_info;
   bool		show_identical_binaries;
   bool		self_check;
+  optional<bool> exported_interfaces_only;
 #ifdef WITH_CTF
   bool		use_ctf;
 #endif
@@ -868,6 +870,9 @@ display_usage(const string& prog_name, ostream& out)
     "full impact analysis report rather than the default leaf changes reports\n"
     << " --non-reachable-types|-t  consider types non reachable"
     " from public interfaces\n"
+    << "  --exported-interfaces-only  analyze exported interfaces only\n"
+    << "  --allow-non-exported-interfaces  analyze interfaces that "
+    "might not be exported\n"
     << " --no-linkage-name		do not display linkage names of "
     "added/removed/changed\n"
     << " --redundant                    display redundant changes\n"
@@ -2076,6 +2081,10 @@ public:
     abigail::elf_reader::status detailed_status =
       abigail::elf_reader::STATUS_UNKNOWN;
 
+    if (args->opts.exported_interfaces_only.has_value())
+      env->analyze_exported_interfaces_only
+	(*args->opts.exported_interfaces_only);
+
     status |= compare(args->elf1, args->debug_dir1, args->private_types_suppr1,
 		      args->elf2, args->debug_dir2, args->private_types_suppr2,
 		      args->opts, env, diff, ctxt, &detailed_status);
@@ -2142,6 +2151,10 @@ public:
     diff_context_sptr ctxt;
     corpus_diff_sptr diff;
 
+    if (args->opts.exported_interfaces_only.has_value())
+      env->analyze_exported_interfaces_only
+	(*args->opts.exported_interfaces_only);
+
     abigail::elf_reader::status detailed_status =
       abigail::elf_reader::STATUS_UNKNOWN;
 
@@ -3024,6 +3037,10 @@ compare_prepared_linux_kernel_packages(package& first_package,
   string dist_root2 = second_package.extracted_dir_path();
 
   abigail::ir::environment_sptr env(new abigail::ir::environment);
+  if (opts.exported_interfaces_only.has_value())
+    env->analyze_exported_interfaces_only
+      (*opts.exported_interfaces_only);
+
   suppressions_type supprs;
   corpus_group_sptr corpus1, corpus2;
   corpus1 = build_corpus_group_from_kernel_dist_under(dist_root1,
@@ -3326,6 +3343,10 @@ parse_command_line(int argc, char* argv[], options& opts)
       else if (!strcmp(argv[i], "--full-impact")
 	       ||!strcmp(argv[i], "-f"))
 	opts.show_full_impact_report = true;
+      else if (!strcmp(argv[i], "--exported-interfaces-only"))
+	opts.exported_interfaces_only = true;
+      else if (!strcmp(argv[i], "--allow-non-exported-interfaces"))
+	opts.exported_interfaces_only = false;
       else if (!strcmp(argv[i], "--no-linkage-name"))
 	opts.show_linkage_names = false;
       else if (!strcmp(argv[i], "--redundant"))
diff --git a/tools/kmidiff.cc b/tools/kmidiff.cc
index 8fd3fed9..f3332765 100644
--- a/tools/kmidiff.cc
+++ b/tools/kmidiff.cc
@@ -29,6 +29,7 @@ using std::vector;
 using std::ostream;
 using std::cout;
 using std::cerr;
+using abg_compat::optional;
 
 using namespace abigail::tools_utils;
 using namespace abigail::dwarf_reader;
@@ -60,6 +61,7 @@ struct options
   bool			show_hexadecimal_values;
   bool			show_offsets_sizes_in_bits;
   bool			show_impacted_interfaces;
+  optional<bool>	exported_interfaces_only;
 #ifdef WITH_CTF
   bool			use_ctf;
 #endif
@@ -120,6 +122,9 @@ display_usage(const string& prog_name, ostream& out)
     << " --impacted-interfaces|-i  show interfaces impacted by ABI changes\n"
     << " --full-impact|-f  show the full impact of changes on top-most "
 	 "interfaces\n"
+    << "  --exported-interfaces-only  analyze exported interfaces only\n"
+    << "  --allow-non-exported-interfaces  analyze interfaces that "
+    "might not be exported\n"
     << " --show-bytes  show size and offsets in bytes\n"
     << " --show-bits  show size and offsets in bits\n"
     << " --show-hex  show size and offset in hexadecimal\n"
@@ -262,6 +267,10 @@ parse_command_line(int argc, char* argv[], options& opts)
       else if (!strcmp(argv[i], "--full-impact")
 	       || !strcmp(argv[i], "-f"))
 	opts.leaf_changes_only = false;
+      else if (!strcmp(argv[i], "--exported-interfaces-only"))
+	opts.exported_interfaces_only = true;
+      else if (!strcmp(argv[i], "--allow-non-exported-interfaces"))
+	opts.exported_interfaces_only = false;
       else if (!strcmp(argv[i], "--show-bytes"))
 	opts.show_offsets_sizes_in_bits = false;
       else if (!strcmp(argv[i], "--show-bits"))
@@ -408,6 +417,9 @@ main(int argc, char* argv[])
 
   environment_sptr env(new environment);
 
+  if (opts.exported_interfaces_only.has_value())
+    env->analyze_exported_interfaces_only(*opts.exported_interfaces_only);
+
   corpus_group_sptr group1, group2;
   string debug_info_root_dir;
   corpus::origin origin =
-- 
2.37.2



-- 
		Dodji