abidw: add option to omit the compilation directory

The compilation directory contains machine specific information
therefore breaks reproducibility of abidw's output across different
build paths. Hence introduce --no-comp-dir-path (as in the xml
attribute). Internally I decided to not carry on the duplication of
'dir' and 'path' and used 'comp_dir'.

Thanks to earlier changes, adding an option boils down to adding it to
set_common_options and to the write_context along with some auxiliary
functions for setting and getting.

write_translation_unit uses the flag in the write_context and omits the
comp-dir-path if asked for.

	* include/abg-writer.h (set_write_comp_dir): Declare new function.
	(set_common_options): Use it.
	* src/abg-writer.cc (write_context::m_write_comp_dir): Define new
	data member.
	(write_context::write_context): Initialize it.
	(write_context::{g,s}et_write_comp_dir): Define new member
	accessors.
	(set_write_comp_dir): Define new free-form getter.
	(write_translation_unit): Teach to respect write_comp_dir flag of
	write_context.
	* tools/abidw.cc (options::write_corpus_path): Define new data
	member.
	(options::options): Initialize it.
	(display_usage): Add doc string for a new command line option: --no-comp-dir-path.
	(parse_command_line): Parse the new command line option --no-comp-dir-path.

Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>

include/abg-writer.h

@@ -59,6 +59,9 @@ set_write_architecture(write_context& ctxt, bool flag);
 void
 set_write_corpus_path(write_context& ctxt, bool flag);
 
+void
+set_write_comp_dir(write_context& ctxt, bool flag);
+
 /// A convenience generic function to set common options (usually used
 /// by Libabigail tools) from a generic options carrying-object, into
 /// a given @ref write_context.
@@ -76,6 +79,7 @@ set_common_options(write_context& ctxt, const OPTS& opts)
   set_show_locs(ctxt, opts.show_locs);
   set_write_architecture(ctxt, opts.write_architecture);
   set_write_corpus_path(ctxt, opts.write_corpus_path);
+  set_write_comp_dir(ctxt, opts.write_comp_dir);
 }
 
 void

src/abg-writer.cc

@@ -167,6 +167,7 @@ class write_context
   bool					m_show_locs;
   bool					m_write_architecture;
   bool					m_write_corpus_path;
+  bool					m_write_comp_dir;
   mutable type_ptr_map			m_type_id_map;
   mutable type_ptr_set_type		m_emitted_type_set;
   type_ptr_set_type			m_emitted_decl_only_set;
@@ -197,7 +198,8 @@ public:
       m_annotate(false),
       m_show_locs(true),
       m_write_architecture(true),
-      m_write_corpus_path(true)
+      m_write_corpus_path(true),
+      m_write_comp_dir(true)
   {}
 
   /// Getter of the environment we are operating from.
@@ -267,6 +269,21 @@ public:
   set_write_corpus_path(bool f)
   {m_write_corpus_path = f;}
 
+  /// Getter of the comp-dir-path option.
+  ///
+  /// @return true iff compilation dir information shall be emitted
+  bool
+  get_write_comp_dir()
+  {return m_write_comp_dir;}
+
+  /// Setter of the comp-dir-path option
+  ///
+  /// @param f the new value of the flag.
+  void
+  set_write_comp_dir(bool f)
+  {m_write_comp_dir = f;}
+
+
   /// Getter of the "show-locs" option.
   ///
   /// When this option is true then the XML writer emits location
@@ -1819,6 +1836,18 @@ void
 set_write_corpus_path(write_context& ctxt, bool flag)
 {ctxt.set_write_corpus_path(flag);}
 
+/// Set the 'write-comp-dir' flag.
+///
+/// When this flag is set then the XML writer will emit compilation dir
+/// information
+///
+/// @param ctxt the context to set this flag on to.
+///
+/// @param flag the new value of the 'write-comp-dir' flag.
+void
+set_write_comp_dir(write_context& ctxt, bool flag)
+{ctxt.set_write_comp_dir(flag);}
+
 /// Serialize a translation unit to an output stream.
 ///
 /// @param ctxt the context of the serialization.  It contains e.g,
@@ -1851,7 +1880,7 @@ write_translation_unit(write_context&	       ctxt,
   if (!tu.get_path().empty())
     o << " path='" << xml::escape_xml_string(tu.get_path()) << "'";
 
-  if (!tu.get_compilation_dir_path().empty())
+  if (!tu.get_compilation_dir_path().empty() && ctxt.get_write_comp_dir())
     o << " comp-dir-path='"
       << xml::escape_xml_string(tu.get_compilation_dir_path()) << "'";
 

tools/abidw.cc

@@ -96,6 +96,7 @@ struct options
   bool			show_base_name_alt_debug_info_path;
   bool			write_architecture;
   bool			write_corpus_path;
+  bool			write_comp_dir;
   bool			load_all_types;
   bool			linux_kernel_mode;
   bool			corpus_group_for_linux;
@@ -112,6 +113,7 @@ struct options
       show_base_name_alt_debug_info_path(),
       write_architecture(true),
       write_corpus_path(true),
+      write_comp_dir(true),
       load_all_types(),
       linux_kernel_mode(true),
       corpus_group_for_linux(false),
@@ -150,6 +152,7 @@ display_usage(const string& prog_name, ostream& out)
     << "  --no-architecture  do not emit architecture info in the output\n"
     << "  --no-corpus-path  do not take the path to the corpora into account\n"
     << "  --no-show-locs  do not show location information\n"
+    << "  --no-comp-dir-path  do not show compilation path information\n"
     << "  --check-alternate-debug-info <elf-path>  check alternate debug info "
     "of <elf-path>\n"
     << "  --check-alternate-debug-info-base-name <elf-path>  check alternate "
@@ -257,6 +260,8 @@ parse_command_line(int argc, char* argv[], options& opts)
 	opts.write_corpus_path = false;
       else if (!strcmp(argv[i], "--no-show-locs"))
 	opts.show_locs = false;
+      else if (!strcmp(argv[i], "--no-comp-dir-path"))
+	opts.write_comp_dir = false;
       else if (!strcmp(argv[i], "--check-alternate-debug-info")
 	       || !strcmp(argv[i], "--check-alternate-debug-info-base-name"))
 	{