* blockframe.c (find_pc_partial_function): Use the minimal symbol

	size to control the cache entry, if available.
	* minsyms.c (lookup_minimal_symbol_by_pc_section): Handle minimal
	symbols with zero and non-zero sizes differently.

	* gdb.arch/i386-size.c, gdb.arch/i386-size.exp: New files.

6 files changed, 258 insertions, 42 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5fd306f..ef7d2b9 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2006-07-18  Daniel Jacobowitz  <dan@codesourcery.com>
 
+	* blockframe.c (find_pc_partial_function): Use the minimal symbol
+	size to control the cache entry, if available.
+	* minsyms.c (lookup_minimal_symbol_by_pc_section): Handle minimal
+	symbols with zero and non-zero sizes differently.
+
+2006-07-18  Daniel Jacobowitz  <dan@codesourcery.com>
+
 	* linux-thread-db.c (td_thr_getfpregs_p, td_thr_getgregs_p)
 	(td_thr_setfpregs_p, td_thr_setgregs_p, thread_db_get_info)
 	(thread_db_fetch_registers, thread_db_store_registers)
diff --git a/gdb/blockframe.c b/gdb/blockframe.c
index dbb1b43..ba298c3 100644
--- a/gdb/blockframe.c
+++ b/gdb/blockframe.c
@@ -280,27 +280,34 @@ find_pc_partial_function (CORE_ADDR pc, char **name, CORE_ADDR *address,
   cache_pc_function_name = DEPRECATED_SYMBOL_NAME (msymbol);
   cache_pc_function_section = section;
 
-  /* Use the lesser of the next minimal symbol in the same section, or
-     the end of the section, as the end of the function.  */
+  /* If the minimal symbol has a size, use it for the cache.
+     Otherwise use the lesser of the next minimal symbol in the same
+     section, or the end of the section, as the end of the
+     function.  */
 
-  /* Step over other symbols at this same address, and symbols in
-     other sections, to find the next symbol in this section with
-     a different address.  */
-
-  for (i = 1; DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL; i++)
+  if (MSYMBOL_SIZE (msymbol) != 0)
+    cache_pc_function_high = cache_pc_function_low + MSYMBOL_SIZE (msymbol);
+  else
     {
-      if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
-	  && SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
-	break;
-    }
+      /* Step over other symbols at this same address, and symbols in
+	 other sections, to find the next symbol in this section with
+	 a different address.  */
 
-  if (DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL
-      && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
-    cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
-  else
-    /* We got the start address from the last msymbol in the objfile.
-       So the end address is the end of the section.  */
-    cache_pc_function_high = osect->endaddr;
+      for (i = 1; DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL; i++)
+	{
+	  if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
+	      && SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
+	    break;
+	}
+
+      if (DEPRECATED_SYMBOL_NAME (msymbol + i) != NULL
+	  && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
+	cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
+      else
+	/* We got the start address from the last msymbol in the objfile.
+	   So the end address is the end of the section.  */
+	cache_pc_function_high = osect->endaddr;
+    }
 
  return_cached_value:
 
diff --git a/gdb/minsyms.c b/gdb/minsyms.c
index e8ef95e..ae4c23a 100644
--- a/gdb/minsyms.c
+++ b/gdb/minsyms.c
@@ -412,6 +412,8 @@ lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, asection *section)
 
       if (objfile->minimal_symbol_count > 0)
 	{
+	  int best_zero_sized = -1;
+
           msymbol = objfile->msymbols;
 	  lo = 0;
 	  hi = objfile->minimal_symbol_count - 1;
@@ -461,34 +463,91 @@ lookup_minimal_symbol_by_pc_section (CORE_ADDR pc, asection *section)
 			 == SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1])))
 		hi++;
 
+	      /* Skip various undesirable symbols.  */
+	      while (hi >= 0)
+		{
+		  /* Skip any absolute symbols.  This is apparently
+		     what adb and dbx do, and is needed for the CM-5.
+		     There are two known possible problems: (1) on
+		     ELF, apparently end, edata, etc. are absolute.
+		     Not sure ignoring them here is a big deal, but if
+		     we want to use them, the fix would go in
+		     elfread.c.  (2) I think shared library entry
+		     points on the NeXT are absolute.  If we want
+		     special handling for this it probably should be
+		     triggered by a special mst_abs_or_lib or some
+		     such.  */
+
+		  if (msymbol[hi].type == mst_abs)
+		    {
+		      hi--;
+		      continue;
+		    }
+
+		  /* If SECTION was specified, skip any symbol from
+		     wrong section.  */
+		  if (section
+		      /* Some types of debug info, such as COFF,
+			 don't fill the bfd_section member, so don't
+			 throw away symbols on those platforms.  */
+		      && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
+		      && SYMBOL_BFD_SECTION (&msymbol[hi]) != section)
+		    {
+		      hi--;
+		      continue;
+		    }
+
+		  /* If the minimal symbol has a zero size, save it
+		     but keep scanning backwards looking for one with
+		     a non-zero size.  A zero size may mean that the
+		     symbol isn't an object or function (e.g. a
+		     label), or it may just mean that the size was not
+		     specified.  */
+		  if (MSYMBOL_SIZE (&msymbol[hi]) == 0
+		      && best_zero_sized == -1)
+		    {
+		      best_zero_sized = hi;
+		      hi--;
+		      continue;
+		    }
+
+		  /* Otherwise, this symbol must be as good as we're going
+		     to get.  */
+		  break;
+		}
+
+	      /* If HI has a zero size, and best_zero_sized is set,
+		 then we had two or more zero-sized symbols; prefer
+		 the first one we found (which may have a higher
+		 address).  Also, if we ran off the end, be sure
+		 to back up.  */
+	      if (best_zero_sized != -1
+		  && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
+		hi = best_zero_sized;
+
+	      /* If the minimal symbol has a non-zero size, and this
+		 PC appears to be outside the symbol's contents, then
+		 refuse to use this symbol.  If we found a zero-sized
+		 symbol with an address greater than this symbol's,
+		 use that instead.  We assume that if symbols have
+		 specified sizes, they do not overlap.  */
+
+	      if (hi >= 0
+		  && MSYMBOL_SIZE (&msymbol[hi]) != 0
+		  && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
+			    + MSYMBOL_SIZE (&msymbol[hi])))
+		{
+		  if (best_zero_sized != -1)
+		    hi = best_zero_sized;
+		  else
+		    /* Go on to the next object file.  */
+		    continue;
+		}
+
 	      /* The minimal symbol indexed by hi now is the best one in this
 	         objfile's minimal symbol table.  See if it is the best one
 	         overall. */
 
-	      /* Skip any absolute symbols.  This is apparently what adb
-	         and dbx do, and is needed for the CM-5.  There are two
-	         known possible problems: (1) on ELF, apparently end, edata,
-	         etc. are absolute.  Not sure ignoring them here is a big
-	         deal, but if we want to use them, the fix would go in
-	         elfread.c.  (2) I think shared library entry points on the
-	         NeXT are absolute.  If we want special handling for this
-	         it probably should be triggered by a special
-	         mst_abs_or_lib or some such.  */
-	      while (hi >= 0
-		     && msymbol[hi].type == mst_abs)
-		--hi;
-
-	      /* If "section" specified, skip any symbol from wrong section */
-	      /* This is the new code that distinguishes it from the old function */
-	      if (section)
-		while (hi >= 0
-		       /* Some types of debug info, such as COFF,
-			  don't fill the bfd_section member, so don't
-			  throw away symbols on those platforms.  */
-		       && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
-		       && SYMBOL_BFD_SECTION (&msymbol[hi]) != section)
-		  --hi;
-
 	      if (hi >= 0
 		  && ((best_symbol == NULL) ||
 		      (SYMBOL_VALUE_ADDRESS (best_symbol) <
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 7f49b3d..0a50407 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,9 @@
 2006-07-18  Daniel Jacobowitz  <dan@codesourcery.com>
 
+	* gdb.arch/i386-size.c, gdb.arch/i386-size.exp: New files.
+
+2006-07-18  Daniel Jacobowitz  <dan@codesourcery.com>
+
 	* gdb.threads/print-threads.exp: Use gdb_breakpoint.
 
 2006-07-17  Mark Kettenis  <kettenis@gnu.org>
diff --git a/gdb/testsuite/gdb.arch/i386-size.c b/gdb/testsuite/gdb.arch/i386-size.c
new file mode 100644
index 0000000..80357dd
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/i386-size.c
@@ -0,0 +1,50 @@
+/* Symbol size test program.
+
+   Copyright 2006 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifdef SYMBOL_PREFIX
+#define SYMBOL(str)	SYMBOL_PREFIX #str
+#else
+#define SYMBOL(str)	#str
+#endif
+
+void
+trap (void)
+{
+  asm ("int $0x03");
+}
+
+/* Jump from a function with its symbol size set, to a function
+   named by a local label.  If GDB does not look at the sizes of
+   symbols, we will still appear to be in the first function.  */
+
+asm(".text\n"
+    "    .align 8\n"
+    "    .globl " SYMBOL (main) "\n"
+    SYMBOL (main) ":\n"
+    "    pushl %ebp\n"
+    "    mov   %esp, %ebp\n"
+    "    call  .Lfunc\n"
+    "    ret\n"
+    "    .size " SYMBOL (main) ", .-" SYMBOL (main) "\n"
+    ".Lfunc:\n"
+    "    pushl %ebp\n"
+    "    mov   %esp, %ebp\n"
+    "    call  " SYMBOL (trap) "\n");
diff --git a/gdb/testsuite/gdb.arch/i386-size.exp b/gdb/testsuite/gdb.arch/i386-size.exp
new file mode 100644
index 0000000..dcf67e9
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/i386-size.exp
@@ -0,0 +1,89 @@
+# Copyright 2006 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  
+
+# Please email any bugs, comments, and/or additions to this file to:
+# bug-gdb@gnu.org
+
+# This file is part of the gdb testsuite.
+
+if $tracelevel {
+    strace $tracelevel
+}
+
+# Test that GDB can see the sizes of symbols.
+
+if ![istarget "i?86-*-*"] then {
+    verbose "Skipping i386 unwinder tests."
+    return
+}
+
+set testfile "i386-size"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+# some targets have leading underscores on assembly symbols.
+# TODO: detect this automatically
+set additional_flags ""
+if [istarget "i?86-*-cygwin*"] then {
+  set additional_flags "additional_flags=-DSYMBOL_PREFIX=\"_\""
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
+	  executable [list debug $additional_flags]] != "" } {
+    untested "i386-size"
+    return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+# We use gdb_run_cmd so this stands a chance to work for remote
+# targets too.
+gdb_run_cmd
+
+gdb_expect {
+    -re "Program received signal SIGTRAP.*$gdb_prompt $" {
+	pass "run past main"
+    }
+    -re ".*$gdb_prompt $" {
+	fail "run past main"
+    }
+    timeout {
+	fail "run past main (timeout)"
+    }
+}
+
+set message "backtrace shows no function"
+gdb_test_multiple "backtrace 10" $message {
+    -re "#1\[ \t]*$hex in main.*$gdb_prompt $" {
+	fail $message
+    }
+    -re "#1\[ \t]*$hex in \\?\\? \\(\\).*$gdb_prompt $" {
+	pass $message
+    }
+}
+
+set message "disassemble stops at end of main"
+gdb_test_multiple "disassemble main" $message {
+    -re "call.*<trap>.*$gdb_prompt $" {
+	fail $message
+    }
+    -re "<main\\+8>:\[ \t\]+ret\[ \t\r\n\]+End of.*$gdb_prompt $" {
+	pass $message
+    }
+}