* symtab.c (find_pc_sect_psymtab): Add comments. Handle psymtabs

	with no symbols.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 59eec00340bb8887ffe03e5743331336cfc41799..96816cbedd2d25c69c8eac2aa217e2bc8c55ede9 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2007-01-04  Daniel Jacobowitz  <dan@codesourcery.com>
+
+       * symtab.c (find_pc_sect_psymtab): Add comments.  Handle psymtabs
+       with no symbols.
+
 2007-01-04  Daniel Jacobowitz  <dan@codesourcery.com>
 
        * memory-map.c (struct_memory_map_parsing_data): Remove most

diff --git a/gdb/symtab.c b/gdb/symtab.c
index 62109358ffa376ee7b3824d7738a3d991a3355b4..8f79feeaf712e0a9bd2cf7cb1332841b093706bb 100644 (file)
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -795,7 +795,7 @@ find_pc_sect_psymtab (CORE_ADDR pc, asection *section)
       {
        struct partial_symtab *tpst;
        struct partial_symtab *best_pst = pst;
-       struct partial_symbol *best_psym = NULL;
+       CORE_ADDR best_addr = pst->textlow;
 
        /* An objfile that has its functions reordered might have
           many partial symbol tables containing the PC, but
@@ -820,36 +820,42 @@ find_pc_sect_psymtab (CORE_ADDR pc, asection *section)
            if (pc >= tpst->textlow && pc < tpst->texthigh)
              {
                struct partial_symbol *p;
+               CORE_ADDR this_addr;
 
+               /* NOTE: This assumes that every psymbol has a
+                  corresponding msymbol, which is not necessarily
+                  true; the debug info might be much richer than the
+                  object's symbol table.  */
                p = find_pc_sect_psymbol (tpst, pc, section);
                if (p != NULL
                    && SYMBOL_VALUE_ADDRESS (p)
                    == SYMBOL_VALUE_ADDRESS (msymbol))
                  return (tpst);
+
+               /* Also accept the textlow value of a psymtab as a
+                  "symbol", to provide some support for partial
+                  symbol tables with line information but no debug
+                  symbols (e.g. those produced by an assembler).  */
                if (p != NULL)
+                 this_addr = SYMBOL_VALUE_ADDRESS (p);
+               else
+                 this_addr = tpst->textlow;
+
+               /* Check whether it is closer than our current
+                  BEST_ADDR.  Since this symbol address is
+                  necessarily lower or equal to PC, the symbol closer
+                  to PC is the symbol which address is the highest.
+                  This way we return the psymtab which contains such
+                  best match symbol. This can help in cases where the
+                  symbol information/debuginfo is not complete, like
+                  for instance on IRIX6 with gcc, where no debug info
+                  is emitted for statics. (See also the nodebug.exp
+                  testcase.) */
+               if (this_addr > best_addr)
                  {
-                   /* We found a symbol in this partial symtab which
-                      matches (or is closest to) PC, check whether it
-                      is closer than our current BEST_PSYM.  Since
-                      this symbol address is necessarily lower or
-                      equal to PC, the symbol closer to PC is the
-                      symbol which address is the highest.  */
-                   /* This way we return the psymtab which contains
-                      such best match symbol. This can help in cases
-                      where the symbol information/debuginfo is not
-                      complete, like for instance on IRIX6 with gcc,
-                      where no debug info is emitted for
-                      statics. (See also the nodebug.exp
-                      testcase.)  */
-                   if (best_psym == NULL
-                       || SYMBOL_VALUE_ADDRESS (p)
-                       > SYMBOL_VALUE_ADDRESS (best_psym))
-                     {
-                       best_psym = p;
-                       best_pst = tpst;
-                     }
+                   best_addr = this_addr;
+                   best_pst = tpst;
                  }
-
              }
          }
        return (best_pst);