Read corrrect auxiliary entry in AIX

Fix handling of XCOFF function auxiliary entries, in particular when
the xlc -qfuncsect or gcc -ffunction-sections compiler option is used
in AIX.  Also handle C_WEAKEXT storage class.

gdb/
2016-10-21  Sangamesh Mallayya  <sangamesh.swamy@in.ibm.com>
	    Ulrich Weigand  <uweigand@de.ibm.com>

	* xcoffread.c (read_xcoff_symtab): Read correct function auxiliary
	entry if xlc -qfuncsect or gcc -ffunction-sections compiler option
	is used in AIX.
	(read_xcoff_symtab): Handle C_WEAKEXT storage class.
	(process_xcoff_symbol): Likewise.
	(scan_xcoff_symtab): Likewise.

Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8ce7845b0057b0cd560128326fa1263cd3e66a49..8381b8e842f9363814bfd1e11a778d2cae4dbda8 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2017-04-27  Sangamesh Mallayya  <sangamesh.swamy@in.ibm.com>
+           Ulrich Weigand  <uweigand@de.ibm.com>
+
+       * xcoffread.c (read_xcoff_symtab): Read correct function auxiliary
+       entry if xlc -qfuncsect or gcc -ffunction-sections compiler option
+       is used in AIX.
+       (read_xcoff_symtab): Handle C_WEAKEXT storage class.
+       (process_xcoff_symbol): Likewise.
+       (scan_xcoff_symtab): Likewise.
+
 2017-04-26  Alan Hayward  <alan.hayward@arm.com>
 
        * ia64-tdep.c (examine_prologue): Use get_frame_register_unsigned.

diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index 4f22cecec9de9574b25b8858ae973d90758b0dd1..138f941cabadacd73d0db5db94315ef5dbb966ba 100644 (file)
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -1143,8 +1143,8 @@ read_xcoff_symtab (struct objfile *objfile, struct partial_symtab *pst)
          /* Done with all files, everything from here on is globals.  */
        }
 
-      if ((cs->c_sclass == C_EXT || cs->c_sclass == C_HIDEXT)
-         && cs->c_naux == 1)
+      if (cs->c_sclass == C_EXT || cs->c_sclass == C_HIDEXT ||
+         cs->c_sclass == C_WEAKEXT)
        {
          /* Dealing with a symbol with a csect entry.  */
 
@@ -1154,9 +1154,41 @@ read_xcoff_symtab (struct objfile *objfile, struct partial_symtab *pst)
 #define        CSECT_SMTYP(PP) (SMTYP_SMTYP(CSECT(PP).x_smtyp))
 #define        CSECT_SCLAS(PP) (CSECT(PP).x_smclas)
 
-         /* Convert the auxent to something we can access.  */
-         bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
-                               0, cs->c_naux, &main_aux);
+         /* Convert the auxent to something we can access.
+            XCOFF can have more than one auxiliary entries.
+
+            Actual functions will have two auxiliary entries, one to have the
+            function size and other to have the smtype/smclass (LD/PR).
+
+            c_type value of main symbol table will be set only in case of
+            C_EXT/C_HIDEEXT/C_WEAKEXT storage class symbols.
+            Bit 10 of type is set if symbol is a function, ie the value is set
+            to 32(0x20). So we need to read the first function auxiliay entry
+            which contains the size. */
+         if (cs->c_naux > 1 && ISFCN (cs->c_type))
+         {
+           /* a function entry point.  */
+
+           fcn_start_addr = cs->c_value;
+
+           /* save the function header info, which will be used
+              when `.bf' is seen.  */
+           fcn_cs_saved = *cs;
+
+           /* Convert the auxent to something we can access.  */
+           bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
+                                 0, cs->c_naux, &fcn_aux_saved);
+           continue;
+         }
+         /* Read the csect auxiliary header, which is always the last by
+            onvention. */
+         bfd_coff_swap_aux_in (abfd,
+                              raw_auxptr
+                              + ((coff_data (abfd)->local_symesz)
+                              * (cs->c_naux - 1)),
+                              cs->c_type, cs->c_sclass,
+                              cs->c_naux - 1, cs->c_naux,
+                              &main_aux);
 
          switch (CSECT_SMTYP (&main_aux))
            {
@@ -1241,16 +1273,11 @@ read_xcoff_symtab (struct objfile *objfile, struct partial_symtab *pst)
 
              switch (CSECT_SCLAS (&main_aux))
                {
+               /* We never really come to this part as this case has been
+                  handled in ISFCN check above.
+                  This and other cases of XTY_LD are kept just for
+                  reference. */
                case XMC_PR:
-                 /* a function entry point.  */
-               function_entry_point:
-
-                 fcn_start_addr = cs->c_value;
-
-                 /* save the function header info, which will be used
-                    when `.bf' is seen.  */
-                 fcn_cs_saved = *cs;
-                 fcn_aux_saved = main_aux;
                  continue;
 
                case XMC_GL:
@@ -1283,16 +1310,6 @@ read_xcoff_symtab (struct objfile *objfile, struct partial_symtab *pst)
            }
        }
 
-      /* If explicitly specified as a function, treat is as one.  This check
-        evaluates to true for @FIX* bigtoc CSECT symbols, so it must occur
-        after the above CSECT check.  */
-      if (ISFCN (cs->c_type) && cs->c_sclass != C_TPDEF)
-       {
-         bfd_coff_swap_aux_in (abfd, raw_auxptr, cs->c_type, cs->c_sclass,
-                               0, cs->c_naux, &main_aux);
-         goto function_entry_point;
-       }
-
       switch (cs->c_sclass)
        {
        case C_FILE:
@@ -1574,7 +1591,7 @@ process_xcoff_symbol (struct coff_symbol *cs, struct objfile *objfile)
       SYMBOL_ACLASS_INDEX (sym) = LOC_BLOCK;
       SYMBOL_DUP (sym, sym2);
 
-      if (cs->c_sclass == C_EXT)
+      if (cs->c_sclass == C_EXT || C_WEAKEXT)
        add_symbol_to_list (sym2, &global_symbols);
       else if (cs->c_sclass == C_HIDEXT || cs->c_sclass == C_STAT)
        add_symbol_to_list (sym2, &file_symbols);
@@ -2250,6 +2267,7 @@ scan_xcoff_symtab (minimal_symbol_reader &reader,
        {
        case C_EXT:
        case C_HIDEXT:
+       case C_WEAKEXT:
          {
            /* The CSECT auxent--always the last auxent.  */
            union internal_auxent csect_aux;