simple-object-xcoff.c (simple_object_xcoff_find_sections): Search symbol table for...

2017-06-07  Tony Reix  <tony.reix@atos.net>
            Matthieu Sarter  <matthieu.sarter.external@atos.net>
            David Edelsohn  <dje.gcc@gmail.com>

        * simple-object-xcoff.c (simple_object_xcoff_find_sections):
        Search symbol table for .go_export symbol and apply pfn if found.

Co-Authored-By: David Edelsohn <dje.gcc@gmail.com>
Co-Authored-By: Matthieu Sarter <matthieu.sarter.external@atos.net>
From-SVN: r248999

diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index 0bc64a5..6e9ff71 100644 (file)
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,10 @@
+2017-06-07  Tony Reix  <tony.reix@atos.net>
+           Matthieu Sarter  <matthieu.sarter.external@atos.net>
+           David Edelsohn  <dje.gcc@gmail.com>
+
+       * simple-object-xcoff.c (simple_object_xcoff_find_sections):
+       Search symbol table for .go_export symbol and apply pfn if found.
+
 2017-05-31  DJ Delorie  <dj@redhat.com>
 
        * configure.ac (strnlen): Add to AC_CHECK_DECLS.

diff --git a/libiberty/simple-object-xcoff.c b/libiberty/simple-object-xcoff.c
index 8a15939..7be1bf3 100644 (file)
--- a/libiberty/simple-object-xcoff.c
+++ b/libiberty/simple-object-xcoff.c
@@ -138,15 +138,15 @@ struct external_syment
   union {
     struct {
       union {
-        /* The name of the symbol.  There is an implicit null character
-           after the end of the array.  */
-        char n_name[N_SYMNMLEN];
-        struct {
-          /* If n_zeroes is zero, n_offset is the offset the name from
-             the start of the string table.  */
-          unsigned char n_zeroes[4];
-          unsigned char n_offset[4];
-        } n;
+/* The name of the symbol.  There is an implicit null character
+   after the end of the array.  */
+       char n_name[N_SYMNMLEN];
+       struct {
+         /* If n_zeroes is zero, n_offset is the offset the name from
+            the start of the string table.  */
+         unsigned char n_zeroes[4];
+         unsigned char n_offset[4];
+       } n;
       } n;
 
       /* The symbol's value.  */
@@ -258,6 +258,8 @@ union external_auxent
 #define C_STAT         (3)
 #define C_FILE         (103)
 
+#define DBXMASK                0x80
+
 /* Private data for an simple_object_read.  */
 
 struct simple_object_xcoff_read
@@ -403,7 +405,9 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
   unsigned int nscns;
   char *strtab;
   size_t strtab_size;
+  struct external_syment *symtab = NULL;
   unsigned int i;
+  off_t textptr = 0;
 
   scnhdr_size = u64 ? SCNHSZ64 : SCNHSZ32;
   scnbuf = XNEWVEC (unsigned char, scnhdr_size * ocr->nscns);
@@ -485,10 +489,118 @@ simple_object_xcoff_find_sections (simple_object_read *sobj,
                                              u.xcoff32.s_size));
        }
 
+      if (strcmp (name, ".text") == 0)
+       textptr = scnptr;
       if (!(*pfn) (data, name, scnptr, size))
        break;
     }
 
+  /* Special handling for .go_export CSECT. */
+  if (textptr != 0 && ocr->nsyms > 0)
+    {
+      unsigned char *sym, *aux;
+      const char *n_name;
+      unsigned long n_value, n_offset, n_zeroes, x_scnlen;
+
+      /* Read symbol table. */
+      symtab = XNEWVEC (struct external_syment, ocr->nsyms * SYMESZ);
+      if (!simple_object_internal_read (sobj->descriptor,
+                                       sobj->offset + ocr->symptr,
+                                       (unsigned char *)symtab,
+                                       ocr->nsyms * SYMESZ,
+                                       &errmsg, err))
+       {
+         XDELETEVEC (symtab);
+         XDELETEVEC (scnbuf);
+         return NULL;
+       }
+
+      /* Search in symbol table if we have a ".go_export" symbol. */
+      for (i = 0; i < ocr->nsyms; ++i)
+       {
+         sym = (unsigned char *)&symtab[i];
+
+         if (symtab[i].n_sclass[0] & DBXMASK)
+           {
+             /* Skip debug symbols whose names are in stabs. */
+             i += symtab[i].n_numaux[0];
+             continue;
+           }
+         if (u64)
+           {
+             n_value = fetch_64 (sym + offsetof (struct external_syment,
+                                                 u.xcoff64.n_value));
+             n_offset = fetch_32 (sym + offsetof (struct external_syment,
+                                                  u.xcoff64.n_offset));
+           }
+         else
+           {
+             /* ".go_export" is longer than N_SYMNMLEN */
+             n_zeroes = fetch_32 (sym + offsetof (struct external_syment,
+                                                  u.xcoff32.n.n.n_zeroes));
+             if (n_zeroes != 0)
+               {
+                 /* Skip auxiliary entries. */
+                 i += symtab[i].n_numaux[0];
+                 continue;
+               }
+             n_value = fetch_32 (sym + offsetof (struct external_syment,
+                                                 u.xcoff32.n_value));
+             n_offset = fetch_32 (sym + offsetof (struct external_syment,
+                                                  u.xcoff32.n.n.n_offset));
+           }
+
+         /* The real section name is found in the string table.  */
+         if (strtab == NULL)
+           {
+             strtab = simple_object_xcoff_read_strtab (sobj,
+                                                       &strtab_size,
+                                                       &errmsg, err);
+             if (strtab == NULL)
+               {
+                  XDELETEVEC (symtab);
+                 XDELETEVEC (scnbuf);
+                 return errmsg;
+               }
+           }
+
+         if (n_offset >= strtab_size)
+            {
+             XDELETEVEC (strtab);
+             XDELETEVEC (symtab);
+             XDELETEVEC (scnbuf);
+             *err = 0;
+             return "section string index out of range";
+            }
+          n_name = strtab + n_offset;
+
+         if (!strcmp(n_name, ".go_export"))
+           {
+             /* Found .go_export symbol, read auxiliary entry. */
+             if (i + 1 >= ocr->nsyms)
+               break;
+
+             aux = (unsigned char *)&symtab[i + 1];
+             if (u64)
+               {
+                 x_scnlen = fetch_32 (aux + offsetof (union external_auxent,
+                                                      u.xcoff64.x_csect.x_scnlen_lo));
+               }
+             else
+               {
+                 x_scnlen = fetch_32 (aux + offsetof (union external_auxent,
+                                                      u.xcoff32.x_csect.x_scnlen));
+               }
+             (*pfn) (data, ".go_export", textptr + n_value, x_scnlen);
+             break;
+           }
+         /* Skip auxiliary entries. */
+         i += symtab[i].n_numaux[0];
+       }
+    }
+
+  if (symtab != NULL)
+    XDELETEVEC (symtab);
   if (strtab != NULL)
     XDELETEVEC (strtab);
   XDELETEVEC (scnbuf);