Re: PATCH: PR gold/14675: No eh_frame info registered in exception_static_test

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Mon, Dec 22, 2014 at 09:37:38AM -0800, Cary Coutant wrote:
> > Here is an idea.  Does it look OK?
> 
> I don't like the idea of making a file named "crtbegin" magic, and
> with this patch, any link *without* such a file will no longer
> optimize eh data.
> 

Here is a different approach.  We always optimize eh data unless we
see crti followed by crtbeginT.  If it is true, we start to optimize eh
data only when we see crtbeginT.  It only leaves any eh data before
crtbeginT unoptimized.  This patch changes the output eh data only when
there is crti followed by crtbeginT.  OK for trunk and 2.25 branch?

Thanks.


H.J.
---
>From 355d5e8db8f93fd2e5e73fc972bf3c3c818a4d66 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sat, 20 Dec 2014 05:45:51 -0800
Subject: [PATCH] Treat .eh_frame section before crtbeginT as normal input

Force the exception frame section from input files before the crtbeginT
file to be handled as an ordinary input section if we aren't creating
the exception frame header.  If we don't do this, we won't correctly
handle the special marker symbol in the exception frame section in the
crtbeginT file.

	PR gold/14675
	* ehframe.cc (Eh_frame::add_ehframe_input_section): Force the
	exception frame section from input files if it can't be
	optimized.
	(Eh_frame::add_ehframe_input_section<32, false>): Updated.
	(Eh_frame::add_ehframe_input_section<32, true>): Likewise.
	(Eh_frame::add_ehframe_input_section<64, false>): Likewise.
	(Eh_frame::add_ehframe_input_section<64, true>): Likewise.
	* ehframe.h (Eh_frame::add_ehframe_input_section): Add a
	bool parameter to indicate if the exception frame section
	can be optimized.
	* layout.cc (Layout::Layout): Initialize optimize_ehframe_ to
	!has_crtbeginT.
	(Layout::layout_eh_frame): Pass this->optimize_ehframe_ to
	Eh_frame::add_ehframe_input_section.
	(Layout::make_eh_frame_section): Set this->optimize_ehframe_
	to true when processing the crtbeginT file if it is on command
	line.
	(Layout::match_file_name (const char*, const char*)): New.
	(Layout::match_file_name(const Relobj*, const char*): Use it.
	* layout.h (Layout::Layout): Add has_crtbeginT.
	(Layout::match_file_name (const char*, const char*)): New.
	(Layout): Add an optimize_ehframe_ member.
	* main.cc (main): Pass command_line.has_crtbeginT() to layout.
	* options.cc: Include "layout.h".
	(Input_arguments::add_file): Set this->has_crtbeginT_ to true
	if there is a crtbeginT file and the last one is a crti file.
	* options.h (Input_arguments::Input_arguments): Initialize
	has_crtbeginT_ and last_is_crti_ to false.
	(Input_arguments::has_crtbeginT): New function.
	(Input_arguments::has_crtbeginT_): New bool member.
	(Input_arguments::last_is_crti_): Likewise.
	(Command_line::has_crtbeginT): New function.
---
 gold/ChangeLog  | 36 ++++++++++++++++++++++++++++++++++++
 gold/ehframe.cc | 31 +++++++++++++++++++++----------
 gold/ehframe.h  |  6 ++++--
 gold/layout.cc  | 37 +++++++++++++++++++++++++++++--------
 gold/layout.h   | 10 +++++++++-
 gold/main.cc    |  3 ++-
 gold/options.cc | 12 ++++++++++++
 gold/options.h  | 17 ++++++++++++++++-
 8 files changed, 129 insertions(+), 23 deletions(-)

diff --git a/gold/ChangeLog b/gold/ChangeLog
index 93529fe..d2ad829 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,39 @@
+2015-01-07  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gold/14675
+	* ehframe.cc (Eh_frame::add_ehframe_input_section): Force the
+	exception frame section from input files if it can't be
+	optimized.
+	(Eh_frame::add_ehframe_input_section<32, false>): Updated.
+	(Eh_frame::add_ehframe_input_section<32, true>): Likewise.
+	(Eh_frame::add_ehframe_input_section<64, false>): Likewise.
+	(Eh_frame::add_ehframe_input_section<64, true>): Likewise.
+	* ehframe.h (Eh_frame::add_ehframe_input_section): Add a
+	bool parameter to indicate if the exception frame section
+	can be optimized.
+	* layout.cc (Layout::Layout): Initialize optimize_ehframe_ to
+	!has_crtbeginT.
+	(Layout::layout_eh_frame): Pass this->optimize_ehframe_ to
+	Eh_frame::add_ehframe_input_section.
+	(Layout::make_eh_frame_section): Set this->optimize_ehframe_
+	to true when processing the crtbeginT file if it is on command
+	line.
+	(Layout::match_file_name (const char*, const char*)): New.
+	(Layout::match_file_name(const Relobj*, const char*): Use it.
+	* layout.h (Layout::Layout): Add has_crtbeginT.
+	(Layout::match_file_name (const char*, const char*)): New.
+	(Layout): Add an optimize_ehframe_ member.
+	* main.cc (main): Pass command_line.has_crtbeginT() to layout.
+	* options.cc: Include "layout.h".
+	(Input_arguments::add_file): Set this->has_crtbeginT_ to true
+	if there is a crtbeginT file and the last one is a crti file.
+	* options.h (Input_arguments::Input_arguments): Initialize
+	has_crtbeginT_ and last_is_crti_ to false.
+	(Input_arguments::has_crtbeginT): New function.
+	(Input_arguments::has_crtbeginT_): New bool member.
+	(Input_arguments::last_is_crti_): Likewise.
+	(Command_line::has_crtbeginT): New function.
+
 2015-01-06  H.J. Lu  <hongjiu.lu@intel.com>
 	    Cary Coutant  <ccoutant@google.com>
 
diff --git a/gold/ehframe.cc b/gold/ehframe.cc
index faea1a8..2fee0ff 100644
--- a/gold/ehframe.cc
+++ b/gold/ehframe.cc
@@ -576,7 +576,8 @@ Eh_frame::add_ehframe_input_section(
     section_size_type symbol_names_size,
     unsigned int shndx,
     unsigned int reloc_shndx,
-    unsigned int reloc_type)
+    unsigned int reloc_type,
+    bool optimize_ehframe)
 {
   // Get the section contents.
   section_size_type contents_len;
@@ -595,15 +596,21 @@ Eh_frame::add_ehframe_input_section(
     return false;
 
   New_cies new_cies;
-  if (!this->do_add_ehframe_input_section(object, symbols, symbols_size,
+  bool recognized_eh_frame_section
+    = this->do_add_ehframe_input_section(object, symbols, symbols_size,
 					  symbol_names, symbol_names_size,
 					  shndx, reloc_shndx,
 					  reloc_type, pcontents,
-					  contents_len, &new_cies))
+					  contents_len, &new_cies);
+  if (!recognized_eh_frame_section && this->eh_frame_hdr_ != NULL)
+    this->eh_frame_hdr_->found_unrecognized_eh_frame_section();
+
+  // If we don't unrecognize the exception frame section or it can't
+  // be optimized, then return false to force it to be handled as an
+  // ordinary input section.
+  if (!recognized_eh_frame_section
+      || (this->eh_frame_hdr_ == NULL && !optimize_ehframe))
     {
-      if (this->eh_frame_hdr_ != NULL)
-	this->eh_frame_hdr_->found_unrecognized_eh_frame_section();
-
       for (New_cies::iterator p = new_cies.begin();
 	   p != new_cies.end();
 	   ++p)
@@ -1224,7 +1231,8 @@ Eh_frame::add_ehframe_input_section<32, false>(
     section_size_type symbol_names_size,
     unsigned int shndx,
     unsigned int reloc_shndx,
-    unsigned int reloc_type);
+    unsigned int reloc_type,
+    bool optimize_ehframe);
 #endif
 
 #ifdef HAVE_TARGET_32_BIG
@@ -1238,7 +1246,8 @@ Eh_frame::add_ehframe_input_section<32, true>(
     section_size_type symbol_names_size,
     unsigned int shndx,
     unsigned int reloc_shndx,
-    unsigned int reloc_type);
+    unsigned int reloc_type,
+    bool optimize_ehframe);
 #endif
 
 #ifdef HAVE_TARGET_64_LITTLE
@@ -1252,7 +1261,8 @@ Eh_frame::add_ehframe_input_section<64, false>(
     section_size_type symbol_names_size,
     unsigned int shndx,
     unsigned int reloc_shndx,
-    unsigned int reloc_type);
+    unsigned int reloc_type,
+    bool optimize_ehframe);
 #endif
 
 #ifdef HAVE_TARGET_64_BIG
@@ -1266,7 +1276,8 @@ Eh_frame::add_ehframe_input_section<64, true>(
     section_size_type symbol_names_size,
     unsigned int shndx,
     unsigned int reloc_shndx,
-    unsigned int reloc_type);
+    unsigned int reloc_type,
+    bool optimize_ehframe);
 #endif
 
 } // End namespace gold.
diff --git a/gold/ehframe.h b/gold/ehframe.h
index aa2bd31..73e0fd4 100644
--- a/gold/ehframe.h
+++ b/gold/ehframe.h
@@ -371,7 +371,8 @@ class Eh_frame : public Output_section_data
   // is the relocation section if any (0 for none, -1U for multiple).
   // RELOC_TYPE is the type of the relocation section if any.  This
   // returns whether the section was incorporated into the .eh_frame
-  // data.
+  // data.  OPTIMIZE_EHFRAME is true if the exception frame section
+  // can be optimized.
   template<int size, bool big_endian>
   bool
   add_ehframe_input_section(Sized_relobj_file<size, big_endian>* object,
@@ -380,7 +381,8 @@ class Eh_frame : public Output_section_data
 			    const unsigned char* symbol_names,
 			    section_size_type symbol_names_size,
 			    unsigned int shndx, unsigned int reloc_shndx,
-			    unsigned int reloc_type);
+			    unsigned int reloc_type,
+			    bool optimize_ehframe);
 
   // Add a CIE and an FDE for a PLT section, to permit unwinding
   // through a PLT.  The FDE data should start with 8 bytes of zero,
diff --git a/gold/layout.cc b/gold/layout.cc
index acc03b2..1ef4d18 100644
--- a/gold/layout.cc
+++ b/gold/layout.cc
@@ -418,7 +418,8 @@ Layout_task_runner::run(Workqueue* workqueue, const Task* task)
 
 // Layout methods.
 
-Layout::Layout(int number_of_input_files, Script_options* script_options)
+Layout::Layout(int number_of_input_files, Script_options* script_options,
+	       bool has_crtbeginT)
   : number_of_input_files_(number_of_input_files),
     script_options_(script_options),
     namepool_(),
@@ -469,6 +470,7 @@ Layout::Layout(int number_of_input_files, Script_options* script_options)
     unique_segment_for_sections_specified_(false),
     incremental_inputs_(NULL),
     record_output_section_data_from_script_(false),
+    optimize_ehframe_(!has_crtbeginT),
     script_output_section_data_list_(),
     segment_states_(NULL),
     relaxation_debug_check_(NULL),
@@ -1428,7 +1430,8 @@ Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
 							 symbol_names_size,
 							 shndx,
 							 reloc_shndx,
-							 reloc_type))
+							 reloc_type,
+							 this->optimize_ehframe_))
     {
       os->update_flags_for_input_section(shdr.get_sh_flags());
 
@@ -1485,6 +1488,14 @@ Layout::make_eh_frame_section(const Relobj* object)
   if (os == NULL)
     return NULL;
 
+  // optimize_ehframe_ is false only if there is a crtbeginT file on
+  // command line.  We can't optimize the exception frame section
+  // until we have seen the crtbeginT file.
+  if (!this->optimize_ehframe_
+      && object != NULL
+      && Layout::match_file_name(object, "crtbeginT"))
+    this->optimize_ehframe_ = true;
+
   if (this->eh_frame_section_ == NULL)
     {
       this->eh_frame_section_ = os;
@@ -5092,19 +5103,18 @@ Layout::output_section_name(const Relobj* relobj, const char* name,
   return name;
 }
 
-// Return true if RELOBJ is an input file whose base name matches
-// FILE_NAME.  The base name must have an extension of ".o", and must
-// be exactly FILE_NAME.o or FILE_NAME, one character, ".o".  This is
+// Return true if FILE is an input file whose base name matches
+// MATCH.  The base name must have an extension of ".o", and must
+// be exactly MATCH.o or MATCH, one character, ".o".  This is
 // to match crtbegin.o as well as crtbeginS.o without getting confused
 // by other possibilities.  Overall matching the file name this way is
 // a dreadful hack, but the GNU linker does it in order to better
 // support gcc, and we need to be compatible.
 
 bool
-Layout::match_file_name(const Relobj* relobj, const char* match)
+Layout::match_file_name(const char* file, const char* match)
 {
-  const std::string& file_name(relobj->name());
-  const char* base_name = lbasename(file_name.c_str());
+  const char* base_name = lbasename(file);
   size_t match_len = strlen(match);
   if (strncmp(base_name, match, match_len) != 0)
     return false;
@@ -5114,6 +5124,17 @@ Layout::match_file_name(const Relobj* relobj, const char* match)
   return memcmp(base_name + base_len - 2, ".o", 2) == 0;
 }
 
+// Return true if FILE is an input file whose base name matches
+// MATCH.  The base name must have an extension of ".o", and must
+// be exactly MATCH.o or MATCH, one character, ".o".
+
+bool
+Layout::match_file_name(const Relobj* relobj, const char* match)
+{
+  const std::string& file_name(relobj->name());
+  return Layout::match_file_name(file_name.c_str(), match);
+}
+
 // Check if a comdat group or .gnu.linkonce section with the given
 // NAME is selected for the link.  If there is already a section,
 // *KEPT_SECTION is set to point to the existing section and the
diff --git a/gold/layout.h b/gold/layout.h
index aec0c53..bf4a44a 100644
--- a/gold/layout.h
+++ b/gold/layout.h
@@ -488,7 +488,7 @@ enum Output_section_order
 class Layout
 {
  public:
-  Layout(int number_of_input_files, Script_options*);
+  Layout(int number_of_input_files, Script_options*, bool has_crtbeginT);
 
   ~Layout()
   {
@@ -757,6 +757,12 @@ class Layout
 	    || strncmp(name, ".stab", sizeof(".stab") - 1) == 0);
   }
 
+  // Return true if FILE is an input file whose base name matches
+  // FILE_NAME.  The base name must have an extension of ".o", and
+  // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
+  static bool
+  match_file_name(const char* file, const char* file_name);
+
   // Return true if RELOBJ is an input file whose base name matches
   // FILE_NAME.  The base name must have an extension of ".o", and
   // must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
@@ -1420,6 +1426,8 @@ class Layout
   Incremental_inputs* incremental_inputs_;
   // Whether we record output section data created in script
   bool record_output_section_data_from_script_;
+  // Whether to optimize the exception frame section.
+  bool optimize_ehframe_;
   // List of output data that needs to be removed at relaxation clean up.
   Output_section_data_list script_output_section_data_list_;
   // Structure to save segment states before entering the relaxation loop.
diff --git a/gold/main.cc b/gold/main.cc
index c5e50d6..a3aea4b 100644
--- a/gold/main.cc
+++ b/gold/main.cc
@@ -227,7 +227,8 @@ main(int argc, char** argv)
 
   // The layout object.
   Layout layout(command_line.number_of_input_files(),
-		&command_line.script_options());
+		&command_line.script_options(),
+		command_line.has_crtbeginT());
 
   if (layout.incremental_inputs() != NULL)
     layout.incremental_inputs()->report_command_line(argc, argv);
diff --git a/gold/options.cc b/gold/options.cc
index 7eb8f27..8db9a13 100644
--- a/gold/options.cc
+++ b/gold/options.cc
@@ -38,6 +38,7 @@
 #include "script.h"
 #include "target-select.h"
 #include "options.h"
+#include "layout.h"
 #include "plugin.h"
 
 namespace gold
@@ -1346,6 +1347,17 @@ Input_arguments::add_file(Input_file_argument& file)
       return this->input_argument_list_.back().lib()->add_file(file);
     }
   this->input_argument_list_.push_back(Input_argument(file));
+  if (Layout::match_file_name(file.name(), "crti"))
+    this->last_is_crti_ = true;
+  else
+    {
+      // Set has_crtbeginT_ to true only if the last one is a crti file.
+      if (!this->has_crtbeginT_
+	  && this->last_is_crti_
+	  && Layout::match_file_name(file.name(), "crtbeginT"))
+	this->has_crtbeginT_ = true;
+      this->last_is_crti_ = false;
+    }
   return this->input_argument_list_.back();
 }
 
diff --git a/gold/options.h b/gold/options.h
index 956a7f4..83bdd20 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -1970,7 +1970,8 @@ class Input_arguments
   typedef Input_argument_list::const_iterator const_iterator;
 
   Input_arguments()
-    : input_argument_list_(), in_group_(false), in_lib_(false), file_count_(0)
+    : input_argument_list_(), in_group_(false), in_lib_(false),
+      file_count_(0), has_crtbeginT_(false), last_is_crti_(false)
   { }
 
   // Add a file.
@@ -2030,11 +2031,20 @@ class Input_arguments
   number_of_input_files() const
   { return this->file_count_; }
 
+  // Return whether there is a crtbeginT file.
+  bool
+  has_crtbeginT() const
+  { return this->has_crtbeginT_; }
+
  private:
   Input_argument_list input_argument_list_;
   bool in_group_;
   bool in_lib_;
   unsigned int file_count_;
+  // Whether there is a crtbeginT file.
+  bool has_crtbeginT_;
+  // Whether the last one is a crti file.
+  bool last_is_crti_;
 };
 
 
@@ -2103,6 +2113,11 @@ class Command_line
   end() const
   { return this->inputs_.end(); }
 
+  // Whether there is a crtbeginT file.
+  bool
+  has_crtbeginT() const
+  { return this->inputs_.has_crtbeginT(); }
+
  private:
   Command_line(const Command_line&);
   Command_line& operator=(const Command_line&);
-- 
1.9.3