Initial revision

1 files changed, 614 insertions, 0 deletions

diff --git a/gas/symbols.c b/gas/symbols.c
new file mode 100644
index 0000000..445160a
--- /dev/null
+++ b/gas/symbols.c
@@ -0,0 +1,614 @@
+/* symbols.c -symbol table-
+   Copyright (C) 1987, 1990, 1991 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.  */
+
+/* static const char rcsid[] = "$Id$"; */
+
+#include "as.h"
+
+#include "obstack.h"		/* For "symbols.h" */
+#include "subsegs.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;
+
+symbolS*		dot_text_symbol;
+symbolS*		dot_data_symbol;
+symbolS*		dot_bss_symbol;
+
+struct obstack	notes;
+
+/*
+ * 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 LOCAL_LABELS_DOLLAR
+int local_label_defined[10];
+#endif
+
+
+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));
+  S_SET_SEGMENT(&abs_symbol, SEG_ABSOLUTE);	/* Can't initialise a union. Sigh. */
+  bzero ((char *)(local_label_counter), sizeof(local_label_counter) );
+  local_bss_counter = 0;
+}
+
+/*
+ *			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 ) != '\0') ;;
+
+  /* The label, as a '\0' ended string, starts at symbol_name_build. */
+  return(symbol_name_build);
+} /* local_label_name() */
+
+
+void local_colon (n)
+int n;	/* just saw "n:" */
+{
+  local_label_counter [n] ++;
+#ifdef LOCAL_LABELS_DOLLAR
+  local_label_defined[n]=1;
+#endif
+  colon (local_label_name (n, 0));
+}
+
+/*
+ *			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.
+ * 2nd argument is now a SEG rather than a TYPE.  The mapping between
+ * segments and types is mostly encapsulated herein (actually, we inherit it
+ * from macros in struc-symbol.h).
+ */
+
+symbolS *symbol_new(name, segment, value, frag)
+char *name;			/* It is copied, the caller can destroy/modify */
+segT segment;			/* Segment identifier (SEG_<something>) */
+long value;			/* Symbol value */
+fragS *frag;			/* Associated fragment */
+{
+	unsigned int name_length;
+	char *preserved_copy_of_name;
+	symbolS *symbolP;
+	
+	name_length = strlen(name) + 1; /* +1 for \0 */
+	obstack_grow(&notes, name, name_length);
+	preserved_copy_of_name = obstack_finish(&notes);
+	symbolP = (symbolS *)obstack_alloc(&notes, sizeof(symbolS));
+	
+#if STRIP_UNDERSCORE
+	S_SET_NAME(symbolP, (*preserved_copy_of_name == '_'
+					    ? preserved_copy_of_name + 1
+					    : preserved_copy_of_name));
+#else /* STRIP_UNDERSCORE */
+	S_SET_NAME(symbolP, preserved_copy_of_name);
+#endif /* STRIP_UNDERSCORE */
+
+	S_SET_SEGMENT(symbolP, segment);
+	S_SET_VALUE(symbolP, value);
+	symbol_clear_list_pointers(symbolP);
+
+	symbolP->sy_frag = frag;
+	symbolP->sy_forward = NULL; /* JF */
+	symbolP->sy_number = ~0;
+	symbolP->sy_name_offset = ~0;
+
+	/*
+	 * Link to end of symbol chain.
+	 */
+	symbol_append(symbolP, symbol_lastP, &symbol_rootP, &symbol_lastP);
+
+	obj_symbol_new_hook(symbolP);
+	
+#ifdef DEBUG
+	verify_symbol_chain(symbol_rootP, symbol_lastP);
+#endif /* DEBUG */
+
+	return(symbolP);
+} /* symbol_new() */
+
+
+/*
+ *			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 symbolS * symbolP; /* symbol we are working with */
+
+#ifdef LOCAL_LABELS_DOLLAR
+  /* Sun local labels 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,
+			 0L,
+			 NULL);
+
+    /* 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_find(sym_name)) != 0) {
+#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 ((SEGMENT_TO_SYMBOL_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))
+	      && (S_GET_VALUE(symbolP) == 0)) {
+		  symbolP->sy_frag  = frag_now;
+		  symbolP->sy_other = const_flag;
+		  S_SET_VALUE(symbolP, obstack_next_free(& frags) - frag_now->fr_literal);
+		  symbolP->sy_type |= SEGMENT_TO_SYMBOL_TYPE((int) now_seg); /* keep N_EXT bit */
+		  return;
+	  }
+#endif	/* VMS */
+	  /*
+	   *	Now check for undefined symbols
+	   */
+	  if (!S_IS_DEFINED(symbolP)) {
+		  if (S_GET_VALUE(symbolP) == 0) {
+			  symbolP->sy_frag  = frag_now;
+#ifdef VMS
+			  symbolP->sy_other = const_flag;
+#endif
+			  S_SET_VALUE(symbolP, obstack_next_free(&frags) - frag_now->fr_literal);
+			  S_SET_SEGMENT(symbolP, now_seg);
+#ifdef N_UNDF
+			  know(N_UNDF == 0);
+#endif /* if we have one, it better be zero. */
+			  
+		  } else {
+			  /*
+			   *	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
+			   *
+			   * This only used to be allowed on VMS gas, but Sun cc
+			   * on the sparc also depends on it.
+			   */
+			  char New_Type = SEGMENT_TO_SYMBOL_TYPE((int) now_seg);
+			  
+			  if (((!S_IS_DEBUG(symbolP) && !S_IS_DEFINED(symbolP) && S_IS_EXTERNAL(symbolP))
+			       || (S_GET_SEGMENT(symbolP) == SEG_BSS))
+			      && ((now_seg == SEG_DATA)
+				  || (now_seg == S_GET_SEGMENT(symbolP)))) {
+				  /*
+				   *	Select which of the 2 cases this is
+				   */
+				  if (now_seg != SEG_DATA) {
+					  /*
+					   *   New .comm for prev .comm symbol.
+					   *	If the new size is larger we just
+					   *	change its value.  If the new size
+					   *	is smaller, we ignore this symbol
+					   */
+					  if (S_GET_VALUE(symbolP)
+					      < ((unsigned) (obstack_next_free(& frags) - frag_now->fr_literal))) {
+						  S_SET_VALUE(symbolP, 
+							      obstack_next_free(& frags) -
+							      frag_now->fr_literal);
+					  }
+				  } else {
+					  /*
+					   *	It is a .comm/.lcomm being converted
+					   *	to initialized data.
+					   */
+					  symbolP->sy_frag  = frag_now;
+#ifdef VMS
+					  symbolP->sy_other = const_flag;
+#endif /* VMS */
+					  S_SET_VALUE(symbolP, obstack_next_free(& frags) - frag_now->fr_literal);
+					  S_SET_SEGMENT(symbolP, now_seg); /* keep N_EXT bit */
+				  }
+			  } else {
+#ifdef OBJ_COFF
+				  as_fatal("Symbol \"%s\" is already defined as \"%s\"/%d.",
+					   sym_name,
+					   segment_name(S_GET_SEGMENT(symbolP)),
+					   S_GET_VALUE(symbolP));
+#else /* OBJ_COFF */
+				  as_fatal("Symbol \"%s\" is already defined as \"%s\"/%d.%d.%d.",
+					   sym_name,
+					   segment_name(S_GET_SEGMENT(symbolP)),
+					   S_GET_OTHER(symbolP), S_GET_DESC(symbolP),
+					   S_GET_VALUE(symbolP));
+#endif /* OBJ_COFF */
+			  }
+		  } /* if the undefined symbol has no value */
+	  } else {
+		  as_fatal("Symbol %s already defined.", sym_name);
+	  } /* if this symbol is not yet defined */
+
+  } else {
+	  symbolP = symbol_new(sym_name,
+				now_seg, 
+				(valueT)(obstack_next_free(&frags)-frag_now->fr_literal),
+				frag_now);
+#ifdef VMS
+	  S_SET_OTHER(symbolP, const_flag);
+#endif /* VMS */
+	  
+	  symbol_table_insert(symbolP);
+  } /* if we have seen this symbol before */
+
+  return;
+} /* colon() */
+
+
+/*
+ *			symbol_table_insert()
+ *
+ * Die if we can't insert the symbol.
+ *
+ */
+
+void symbol_table_insert(symbolP)
+symbolS *symbolP;
+{
+	register char *error_string;
+	
+	know(symbolP);
+	know(S_GET_NAME(symbolP));
+	
+	if (*(error_string = hash_jam(sy_hash, S_GET_NAME(symbolP), (char *)symbolP))) {
+		as_fatal("Inserting \"%s\" into symbol table failed: %s",
+			 S_GET_NAME(symbolP), error_string);
+	} /* on error */
+} /* symbol_table_insert() */
+
+/*
+ *			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_find(name);
+	
+	if (symbolP == NULL) {
+		symbolP = symbol_make(name);
+
+		symbol_table_insert(symbolP);
+	} /* if symbol wasn't found */
+
+	return(symbolP);
+} /* symbol_find_or_make() */
+
+symbolS *symbol_make(name)
+char *name;
+{
+	symbolS *symbolP;
+
+	/* Let the machine description default it, e.g. for register names. */
+	symbolP = md_undefined_symbol(name);
+	
+	if (!symbolP) {
+		symbolP = symbol_new(name,
+				     SEG_UNKNOWN,
+				     0,
+				     &zero_address_frag);
+	} /* if md didn't build us a symbol */
+
+	return(symbolP);
+} /* symbol_make() */
+
+/*
+ *			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;
+{
+#ifndef STRIP_UNDERSCORE
+#define STRIP_UNDERSCORE 0
+#endif /* STRIP_UNDERSCORE */
+    return symbol_find_base(name, STRIP_UNDERSCORE);
+}
+
+symbolS *symbol_find_base(name, strip_underscore)
+char *name;
+int strip_underscore;
+{
+    if(strip_underscore && *name == '_') name++;
+    return ( (symbolS *) hash_find( sy_hash, name ));
+}
+
+/*
+ * Once upon a time, symbols were kept in a singly linked list.  At
+ * least coff needs to be able to rearrange them from time to time, for
+ * which a doubly linked list is much more convenient.  Loic did these
+ * as macros which seemed dangerous to me so they're now functions.
+ * xoxorich.
+ */
+
+/* Link symbol ADDME after symbol TARGET in the chain. */
+void symbol_append(addme, target, rootPP, lastPP)
+symbolS *addme;
+symbolS *target;
+symbolS **rootPP;
+symbolS **lastPP;
+{
+	if (target == NULL) {
+		know(*rootPP == NULL);
+		know(*lastPP == NULL);
+		*rootPP = addme;
+		*lastPP = addme;
+		return;
+	} /* if the list is empty */
+
+	if (target->sy_next != NULL) {
+#ifdef SYMBOLS_NEED_BACKPOINTERS
+		target->sy_next->sy_previous = addme;
+#endif /* SYMBOLS_NEED_BACKPOINTERS */
+	} else {
+		know(*lastPP == target);
+		*lastPP = addme;
+	} /* if we have a next */
+	
+	addme->sy_next = target->sy_next;
+	target->sy_next = addme;
+
+#ifdef SYMBOLS_NEED_BACKPOINTERS
+	addme->sy_previous = target;
+#endif /* SYMBOLS_NEED_BACKPOINTERS */
+
+#ifdef DEBUG
+	verify_symbol_chain(*rootPP, *lastPP);
+#endif /* DEBUG */
+
+	return;
+} /* symbol_append() */
+
+#ifdef SYMBOLS_NEED_BACKPOINTERS
+/* Remove SYMBOLP from the list. */
+void symbol_remove(symbolP, rootPP, lastPP)
+symbolS *symbolP;
+symbolS **rootPP;
+symbolS **lastPP;
+{
+	if (symbolP == *rootPP) {
+		*rootPP = symbolP->sy_next;
+	} /* if it was the root */
+
+	if (symbolP == *lastPP) {
+		*lastPP = symbolP->sy_previous;
+	} /* if it was the tail */
+
+	if (symbolP->sy_next != NULL) {
+		symbolP->sy_next->sy_previous = symbolP->sy_previous;
+	} /* if not last */
+	
+	if (symbolP->sy_previous != NULL) {
+		symbolP->sy_previous->sy_next = symbolP->sy_next;
+	} /* if not first */
+	
+#ifdef DEBUG
+	verify_symbol_chain(*rootPP, *lastPP);
+#endif /* DEBUG */
+
+	return;
+} /* symbol_remove() */
+
+/* Set the chain pointers of SYMBOL to null. */
+void symbol_clear_list_pointers(symbolP)
+symbolS *symbolP;
+{
+    symbolP->sy_next = NULL;
+    symbolP->sy_previous = NULL;
+} /* symbol_clear_list_pointers() */
+
+/* Link symbol ADDME before symbol TARGET in the chain. */
+void symbol_insert(addme, target, rootPP, lastPP)
+symbolS *addme;
+symbolS *target;
+symbolS **rootPP;
+symbolS **lastPP;
+{
+    if (target->sy_previous != NULL) {
+	    target->sy_previous->sy_next = addme;
+    } else {
+	    know(*rootPP == target);
+	    *rootPP = addme;
+    } /* if not first */
+
+    addme->sy_previous = target->sy_previous;
+    target->sy_previous = addme;
+    addme->sy_next = target;
+
+#ifdef DEBUG
+    verify_symbol_chain(*rootPP, *lastPP);
+#endif /* DEBUG */
+
+    return;
+} /* symbol_insert() */
+#endif /* SYMBOLS_NEED_BACKPOINTERS */
+
+void verify_symbol_chain(rootP, lastP)
+symbolS *rootP;
+symbolS *lastP;
+{
+	symbolS *symbolP = rootP;
+
+	if (symbolP == NULL) {
+		return;
+	} /* empty chain */
+
+	for ( ; symbol_next(symbolP) != NULL; symbolP = symbol_next(symbolP)) {
+#ifdef SYMBOLS_NEED_BACKPOINTERS
+		/*$if (symbolP->sy_previous) {
+			know(symbolP->sy_previous->sy_next == symbolP);
+		} else {
+			know(symbolP == rootP);
+		}$*/ /* both directions */
+		know(symbolP->sy_next->sy_previous == symbolP);
+#else /* SYMBOLS_NEED_BACKPOINTERS */
+		;
+#endif /* SYMBOLS_NEED_BACKPOINTERS */
+	} /* verify pointers */
+
+	know(lastP == symbolP);
+
+	return;
+} /* verify_symbol_chain() */
+
+
+/*
+ * Local Variables:
+ * comment-column: 0
+ * fill-column: 131
+ * End:
+ */
+
+/* end: symbols.c */