386BSD 0.1 development

Work on file usr/src/usr.bin/gas/symbols.c

Co-Authored-By: Lynne Greer Jolitz <ljolitz@cardio.ucsf.edu>
Synthesized-from: 386BSD-0.1

diff --git a/usr/src/usr.bin/gas/symbols.c b/usr/src/usr.bin/gas/symbols.c
new file mode 100644 (file)
index 0000000..ce7197a
--- /dev/null
+++ b/usr/src/usr.bin/gas/symbols.c
@@ -0,0 +1,438 @@
+/* symbols.c -symbol table-
+   Copyright (C) 1987 Free Software Foundation, Inc.
+
+This file is part of GAS, the GNU Assembler.
+
+GAS 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 1, or (at your option)
+any later version.
+
+GAS 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 GAS; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+
+#include "as.h"
+#include "hash.h"
+#include "obstack.h"           /* For "symbols.h" */
+#include "struc-symbol.h"
+#include "symbols.h"
+#include "frags.h"
+
+#ifndef WORKING_DOT_WORD
+extern int new_broken_words;
+#endif
+#ifdef VMS
+extern char const_flag;
+#endif
+
+static
+struct hash_control *
+sy_hash;                       /* symbol-name => struct symbol pointer */
+
+                               /* Below are commented in "symbols.h". */
+unsigned int local_bss_counter;
+symbolS * symbol_rootP;
+symbolS * symbol_lastP;
+symbolS        abs_symbol;
+struct obstack notes;
+
+
+
+symbolS * symbol_find();       /* Keep C compiler happy. */
+
+/*
+ * Un*x idea of local labels. They are made by "n:" where n
+ * is any decimal digit. Refer to them with
+ *  "nb" for previous (backward) n:
+ *  or "nf" for next (forward) n:.
+ *
+ * Like Un*x AS, we have one set of local label counters for entire assembly,
+ * not one set per (sub)segment like in most assemblers. This implies that
+ * one can refer to a label in another segment, and indeed some crufty
+ * compilers have done just that.
+ *
+ * I document the symbol names here to save duplicating words elsewhere.
+ * The mth occurence of label n: is turned into the symbol "Ln^Am" where
+ * n is a digit and m is a decimal number. "L" makes it a label discarded
+ * unless debugging and "^A"('\1') ensures no ordinary symbol SHOULD get the
+ * same name as a local label symbol. The first "4:" is "L4^A1" - the m
+ * numbers begin at 1.
+ */
+
+typedef short unsigned int
+local_label_countT;
+
+static local_label_countT
+local_label_counter[10];
+
+static                         /* Returned to caller, then copied. */
+  char symbol_name_build[12];  /* used for created names ("4f") */
+
+#ifdef SUN_ASM_SYNTAX
+int local_label_defined[10];
+#endif
+
+\f
+void
+symbol_begin()
+{
+  symbol_lastP = NULL;
+  symbol_rootP = NULL;         /* In case we have 0 symbols (!!) */
+  sy_hash = hash_new();
+  bzero ((char *)(& abs_symbol), sizeof(abs_symbol));
+  abs_symbol . sy_type = N_ABS;        /* Can't initialise a union. Sigh. */
+  bzero ((char *)(local_label_counter), sizeof(local_label_counter) );
+  local_bss_counter = 0;
+}
+\f
+/*
+ *                     local_label_name()
+ *
+ * Caller must copy returned name: we re-use the area for the next name.
+ */
+
+char *                         /* Return local label name. */
+local_label_name(n, augend)
+     register int n;   /* we just saw "n:", "nf" or "nb" : n a digit */
+     register int augend; /* 0 for nb, 1 for n:, nf */
+{
+  register char *      p;
+  register char *      q;
+  char symbol_name_temporary[10]; /* build up a number, BACKWARDS */
+
+  know( n >= 0 );
+  know( augend == 0 || augend == 1 );
+  p = symbol_name_build;
+  * p ++ = 'L';
+  * p ++ = n + '0';            /* Make into ASCII */
+  * p ++ = 1;                  /* ^A */
+  n = local_label_counter [ n ] + augend;
+                               /* version number of this local label */
+  /*
+   * Next code just does sprintf( {}, "%d", n);
+   * It is more elegant to do the next part recursively, but a procedure
+   * call for each digit emitted is considered too costly.
+   */
+  q = symbol_name_temporary;
+  for (*q++=0; n; q++)         /* emits NOTHING if n starts as 0 */
+    {
+      know(n>0);               /* We expect n > 0 always */
+      *q = n % 10 + '0';
+      n /= 10;
+    }
+  while ( * p ++ = * -- q )
+    {
+    }
+  /* The label, as a '\0' ended string, starts at symbol_name_build. */
+  return (symbol_name_build);
+}
+
+
+void
+local_colon (n)
+     int               n;      /* just saw "n:" */
+{
+  local_label_counter [n] ++;
+#ifdef SUN_ASM_SYNTAX
+  local_label_defined[n]=1;
+#endif
+  colon (local_label_name (n, 0));
+}
+\f
+/*
+ *                     symbol_new()
+ *
+ * Return a pointer to a new symbol.
+ * Die if we can't make a new symbol.
+ * Fill in the symbol's values.
+ * Add symbol to end of symbol chain.
+ *
+ *
+ * Please always call this to create a new symbol.
+ *
+ * Changes since 1985: Symbol names may not contain '\0'. Sigh.
+ */
+
+symbolS *
+symbol_new (name, type, other, desc, value, frag)
+     char *            name;   /* We copy this: OK to alter your copy. */
+     unsigned char     type;   /* As in <a.out.h>. */
+     char              other;  /* As in <a.out.h>. */
+     short int         desc;   /* As in <a.out.h>. */
+     valueT            value;  /* As in <a.out.h>, often an address. */
+                               /* Often used as offset from frag address. */
+     struct frag *     frag;   /* For sy_frag. */
+{
+  register symbolS *           symbolP;
+  register char *              preserved_copy_of_name;
+  register unsigned int                name_length;
+           char *              p;
+
+  name_length = strlen(name) + 1;
+  obstack_grow(&notes,name,name_length);
+  p=obstack_finish(&notes);
+  /* obstack_1done( &notes, name, name_length, &p ); */
+  preserved_copy_of_name = p;
+  p=obstack_alloc(&notes,sizeof(struct symbol));
+  /* obstack_1blank( &notes, sizeof(struct symbol), &p ); */
+  symbolP                      = (symbolS *) p;
+  symbolP -> sy_name           = preserved_copy_of_name;
+  symbolP -> sy_type           = type;
+  symbolP -> sy_other          = other;
+  symbolP -> sy_desc           = desc;
+  symbolP -> sy_value          = value;
+  symbolP -> sy_frag           = frag;
+  symbolP -> sy_next           = NULL; /* End of chain. */
+  symbolP -> sy_forward                = NULL; /* JF */
+#ifdef SUSPECT
+  symbolP -> sy_name_offset    = ~ 0; /* Impossible offset catches errors. */
+  symbolP -> sy_number         = ~ 0; /* Ditto. */
+#endif
+  /*
+   * Link to end of symbol chain.
+   */
+  if (symbol_lastP)
+    {
+      symbol_lastP -> sy_next = symbolP;
+    }
+  else
+    {
+      symbol_rootP = symbolP;
+    }
+  symbol_lastP = symbolP;
+
+  return (symbolP);
+}
+\f
+/*
+ *                     colon()
+ *
+ * We have just seen "<name>:".
+ * Creates a struct symbol unless it already exists.
+ *
+ * Gripes if we are redefining a symbol incompatibly (and ignores it).
+ *
+ */
+void
+colon (sym_name)               /* just seen "x:" - rattle symbols & frags */
+     register char *  sym_name; /* symbol name, as a cannonical string */
+                               /* We copy this string: OK to alter later. */
+{
+  register struct symbol * symbolP; /* symbol we are working with */
+
+#ifdef SUN_ASM_SYNTAX
+  /* Sun local labes go out of scope whenever a non-local symbol is
+     defined.  */
+
+  if(*sym_name !='L')
+    bzero((void *)local_label_defined,sizeof(local_label_defined));
+#endif
+
+#ifndef WORKING_DOT_WORD
+  if(new_broken_words) {
+    struct broken_word *a;
+    int possible_bytes;
+    fragS *frag_tmp;
+    char *frag_opcode;
+    extern md_short_jump_size;
+    extern md_long_jump_size;
+
+    possible_bytes=md_short_jump_size+new_broken_words*md_long_jump_size;
+    frag_tmp=frag_now;
+    frag_opcode=frag_var(rs_broken_word,possible_bytes,possible_bytes,(relax_substateT)0,(symbolS *)broken_words,(long int)0,(char *)0);
+
+    /* We want to store the pointer to where to insert the jump table in the
+       fr_opcode of the rs_broken_word frag.  This requires a little hackery */
+    while(frag_tmp && (frag_tmp->fr_type!=rs_broken_word || frag_tmp->fr_opcode))
+      frag_tmp=frag_tmp->fr_next;
+    know(frag_tmp);
+    frag_tmp->fr_opcode=frag_opcode;
+    new_broken_words = 0;
+
+    for(a=broken_words;a && a->dispfrag==0;a=a->next_broken_word)
+      a->dispfrag=frag_tmp;
+  }
+#endif
+  if (symbolP = symbol_table_lookup( sym_name ))
+    {
+#ifdef VMS
+      /*
+       *       If the new symbol is .comm AND it has a size of zero,
+       *       we ignore it (i.e. the old symbol overrides it)
+       */
+      if ((seg_N_TYPE [(int) now_seg] == (N_UNDF | N_EXT)) &&
+         ((obstack_next_free(& frags) - frag_now -> fr_literal) == 0))
+               return;
+      /*
+       *       If the old symbol is .comm and it has a size of zero,
+       *       we override it with the new symbol value.
+       */
+      if ((symbolP -> sy_type == (N_UNDF | N_EXT)) &&
+         (symbolP->sy_value == 0)) {
+             symbolP -> sy_frag  = frag_now;
+             symbolP -> sy_other = const_flag;
+             symbolP -> sy_value = obstack_next_free(& frags) - frag_now -> fr_literal;
+             symbolP -> sy_type |= seg_N_TYPE [(int) now_seg]; /* keep N_EXT bit */
+             return;
+      }
+#endif /* VMS */
+      /*
+       *       Now check for undefined symbols
+       */
+      if ((symbolP -> sy_type & N_TYPE) == N_UNDF)
+       {
+         if(   symbolP -> sy_other == 0
+            && symbolP -> sy_desc  == 0
+            && symbolP -> sy_value == 0)
+           {
+             symbolP -> sy_frag  = frag_now;
+#ifdef VMS
+               symbolP -> sy_other = const_flag;
+#endif
+             symbolP -> sy_value = obstack_next_free(& frags) - frag_now -> fr_literal;
+             know( N_UNDF == 0 );
+             symbolP -> sy_type |= seg_N_TYPE [(int) now_seg]; /* keep N_EXT bit */
+           }
+         else
+           {
+#ifdef VMS
+             /*
+              *        There are still several cases to check:
+              *                A .comm/.lcomm symbol being redefined as
+              *                        initialized data is OK
+              *                A .comm/.lcomm symbol being redefined with
+              *                        a larger size is also OK
+              */
+             char New_Type = seg_N_TYPE [(int) now_seg];
+             if (((symbolP->sy_type == (N_UNDF | N_EXT)) ||
+                  (symbolP->sy_type == N_BSS)) &&
+                 (((New_Type & ~N_EXT) == N_DATA) ||
+                  (New_Type == symbolP->sy_type))) {
+                       /*
+                        *      Select which of the 2 cases this is
+                        */
+                       if (New_Type == symbolP->sy_type) {
+                               /*
+                                *      If the new size is larger we just
+                                *      change its value.  If the new size
+                                *      is smaller, we ignore this symbol
+                                */
+                               if (symbolP->sy_value <
+                                       (obstack_next_free(& frags) -
+                                               frag_now -> fr_literal)) {
+                                     symbolP -> sy_value = 
+                                       obstack_next_free(& frags) -
+                                               frag_now -> fr_literal;
+                               }
+                       } else {
+                               /*
+                                *      It is a .comm/.lcomm being converted
+                                *      to initialized data.
+                                */
+                               symbolP -> sy_frag  = frag_now;
+                               symbolP -> sy_other = const_flag;
+                               symbolP -> sy_value = obstack_next_free(& frags) - frag_now -> fr_literal;
+                               symbolP -> sy_type |= seg_N_TYPE [(int) now_seg]; /* keep N_EXT bit */
+                       }
+             } else {
+#endif /* VMS */
+             as_fatal( "Symbol \"%s\" is already defined as \"%s\"/%d.%d.%d.",
+                     sym_name,
+                     seg_name [(int) N_TYPE_seg [symbolP -> sy_type & N_TYPE]],
+                     symbolP -> sy_other, symbolP -> sy_desc,
+                     symbolP -> sy_value);
+#ifdef VMS
+               }
+#endif /* VMS */
+           }
+       }
+      else
+       {
+         as_fatal("Symbol %s already defined.",sym_name);
+       }
+    }
+  else
+    {
+      symbolP = symbol_new (sym_name,
+                           (unsigned char)(seg_N_TYPE [(int) now_seg]),
+#ifdef VMS
+                           const_flag,
+#else
+                           0,
+#endif
+                           0,
+                           (valueT)(obstack_next_free(&frags)-frag_now->fr_literal),
+                           frag_now);
+      symbol_table_insert (symbolP);
+    }
+}
+
+\f
+/*
+ *                     symbol_table_insert()
+ *
+ * Die if we can't insert the symbol.
+ *
+ */
+
+void
+symbol_table_insert (symbolP)
+     struct symbol *   symbolP;
+{
+  register char *      error_string;
+
+  know( symbolP );
+  know( symbolP -> sy_name );
+  if ( * (error_string = hash_jam (sy_hash, symbolP -> sy_name, (char *)symbolP)))
+    {
+      as_fatal( "Inserting \"%s\" into symbol table failed: %s",
+             symbolP -> sy_name, error_string);
+    }
+}
+\f
+/*
+ *                     symbol_find_or_make()
+ *
+ * If a symbol name does not exist, create it as undefined, and insert
+ * it into the symbol table. Return a pointer to it.
+ */
+symbolS *
+symbol_find_or_make (name)
+     char *    name;
+{
+  register symbolS *   symbolP;
+
+  symbolP = symbol_table_lookup (name);
+  if (symbolP == NULL)
+    {
+      symbolP = symbol_new (name, N_UNDF, 0, 0, 0, & zero_address_frag);
+      symbol_table_insert (symbolP);
+    }
+  return (symbolP);
+}
+
+/*
+ *                     symbol_find()
+ * 
+ * Implement symbol table lookup.
+ * In: A symbol's name as a string: '\0' can't be part of a symbol name.
+ * Out:        NULL if the name was not in the symbol table, else the address
+ *     of a struct symbol associated with that name.
+ */
+
+symbolS *
+symbol_find (name)
+     char *    name;
+{
+  return ( (symbolS *) hash_find( sy_hash, name ));
+}
+
+
+/* end: symbols.c */