X-Git-Url: https://pd.if.org/git/?p=pccts;a=blobdiff_plain;f=h%2Fast.c;fp=h%2Fast.c;h=da6b8de08ac2a9e3855eb003385f35b379b02237;hp=0000000000000000000000000000000000000000;hb=c4e55222e892b8762e11f2425a64611e898ef20e;hpb=ce574debecd6000fadcd6e193d253e4761a311d6

diff --git a/h/ast.c b/h/ast.c
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+/* Abstract syntax tree manipulation functions
+ *
+ * SOFTWARE RIGHTS
+ *
+ * We reserve no LEGAL rights to the Purdue Compiler Construction Tool
+ * Set (PCCTS) -- PCCTS is in the public domain.  An individual or
+ * company may do whatever they wish with source code distributed with
+ * PCCTS or the code generated by PCCTS, including the incorporation of
+ * PCCTS, or its output, into commerical software.
+ * 
+ * We encourage users to develop software with PCCTS.  However, we do ask
+ * that credit is given to us for developing PCCTS.  By "credit",
+ * we mean that if you incorporate our source code into one of your
+ * programs (commercial product, research project, or otherwise) that you
+ * acknowledge this fact somewhere in the documentation, research report,
+ * etc...  If you like PCCTS and have developed a nice tool with the
+ * output, please mention that you developed it using PCCTS.  In
+ * addition, we ask that this header remain intact in our source code.
+ * As long as these guidelines are kept, we expect to continue enhancing
+ * this system and expect to make other tools available as they are
+ * completed.
+ *
+ * ANTLR 1.33
+ * Terence Parr
+ * Parr Research Corporation
+ * with Purdue University and AHPCRC, University of Minnesota
+ * 1989-1995
+ */
+#ifdef __STDC__
+#include <stdarg.h>
+#else
+#include <varargs.h>
+#endif
+
+/* ensure that tree manipulation variables are current after a rule
+ * reference
+ */
+void
+#ifdef __STDC__
+zzlink(AST **_root, AST **_sibling, AST **_tail)
+#else
+zzlink(_root, _sibling, _tail)
+AST **_root, **_sibling, **_tail;
+#endif
+{
+	if ( *_sibling == NULL ) return;
+	if ( *_root == NULL ) *_root = *_sibling;
+	else if ( *_root != *_sibling ) (*_root)->down = *_sibling;
+	if ( *_tail==NULL ) *_tail = *_sibling;
+	while ( (*_tail)->right != NULL ) *_tail = (*_tail)->right;
+}
+
+AST *
+#ifdef __STDC__
+zzastnew(void)
+#else
+zzastnew()
+#endif
+{
+	AST *p = (AST *) calloc(1, sizeof(AST));
+	if ( p == NULL ) fprintf(stderr,"%s(%d): cannot allocate AST node\n",__FILE__,__LINE__);
+	return p;
+}
+
+/* add a child node to the current sibling list */
+void
+#ifdef __STDC__
+zzsubchild(AST **_root, AST **_sibling, AST **_tail)
+#else
+zzsubchild(_root, _sibling, _tail)
+AST **_root, **_sibling, **_tail;
+#endif
+{
+	AST *n;
+	zzNON_GUESS_MODE {
+	n = zzastnew();
+#ifdef DEMAND_LOOK
+	zzcr_ast(n, &(zzaCur), LA(0), LATEXT(0));
+#else
+	zzcr_ast(n, &(zzaCur), LA(1), LATEXT(1));
+#endif
+	zzastPush( n );
+	if ( *_tail != NULL ) (*_tail)->right = n;
+	else {
+		*_sibling = n;
+		if ( *_root != NULL ) (*_root)->down = *_sibling;
+	}
+	*_tail = n;
+	if ( *_root == NULL ) *_root = *_sibling;
+	}
+}
+
+/* make a new AST node.  Make the newly-created
+ * node the root for the current sibling list.  If a root node already
+ * exists, make the newly-created node the root of the current root.
+ */
+void
+#ifdef __STDC__
+zzsubroot(AST **_root, AST **_sibling, AST **_tail)
+#else
+zzsubroot(_root, _sibling, _tail)
+AST **_root, **_sibling, **_tail;
+#endif
+{
+	AST *n;
+	zzNON_GUESS_MODE {
+	n = zzastnew();
+#ifdef DEMAND_LOOK
+	zzcr_ast(n, &(zzaCur), LA(0), LATEXT(0));
+#else
+	zzcr_ast(n, &(zzaCur), LA(1), LATEXT(1));
+#endif
+	zzastPush( n );
+	if ( *_root != NULL )
+		if ( (*_root)->down == *_sibling ) *_sibling = *_tail = *_root;
+	*_root = n;
+	(*_root)->down = *_sibling;
+	}
+}
+
+/* Apply function to root then each sibling
+ * example: print tree in child-sibling LISP-format (AST has token field)
+ *
+ *	void show(tree)
+ *	AST *tree;
+ *	{
+ *		if ( tree == NULL ) return;
+ *		printf(" %s", zztokens[tree->token]);
+ *	}
+ *
+ *	void before() { printf(" ("); }
+ *	void after()  { printf(" )"); }
+ *
+ *	LISPdump() { zzpre_ast(tree, show, before, after); }
+ *
+ */
+void
+#ifdef __STDC__
+zzpre_ast(
+	  AST *tree,
+	  void (*func)(AST *),   /* apply this to each tree node */
+	  void (*before)(AST *), /* apply this to root of subtree before preordering it */
+	  void (*after)(AST *))  /* apply this to root of subtree after preordering it */
+#else
+zzpre_ast(tree, func, before, after)
+AST *tree;
+void (*func)(),   /* apply this to each tree node */
+	 (*before)(), /* apply this to root of subtree before preordering it */
+	 (*after)();  /* apply this to root of subtree after preordering it */
+#endif
+{
+	while ( tree!= NULL )
+	{
+		if ( tree->down != NULL ) (*before)(tree);
+		(*func)(tree);
+		zzpre_ast(tree->down, func, before, after);
+		if ( tree->down != NULL ) (*after)(tree);
+		tree = tree->right;
+	}
+}
+
+/* free all AST nodes in tree; apply func to each before freeing */
+void
+#ifdef __STDC__
+zzfree_ast(AST *tree)
+#else
+zzfree_ast(tree)
+AST *tree;
+#endif
+{
+	if ( tree == NULL ) return;
+	zzfree_ast( tree->down );
+	zzfree_ast( tree->right );
+	zztfree( tree );
+}
+
+/* build a tree (root child1 child2 ... NULL)
+ * If root is NULL, simply make the children siblings and return ptr
+ * to 1st sibling (child1).  If root is not single node, return NULL.
+ *
+ * Siblings that are actually siblins lists themselves are handled
+ * correctly.  For example #( NULL, #( NULL, A, B, C), D) results
+ * in the tree ( NULL A B C D ).
+ *
+ * Requires at least two parameters with the last one being NULL.  If
+ * both are NULL, return NULL.
+ */
+#ifdef __STDC__
+AST *zztmake(AST *rt, ...)
+#else
+AST *zztmake(va_alist)
+va_dcl
+#endif
+{
+	va_list ap;
+	register AST *child, *sibling=NULL, *tail, *w;
+	AST *root;
+
+#ifdef __STDC__
+	va_start(ap, rt);
+	root = rt;
+#else
+	va_start(ap);
+	root = va_arg(ap, AST *);
+#endif
+
+	if ( root != NULL )
+		if ( root->down != NULL ) return NULL;
+	child = va_arg(ap, AST *);
+	while ( child != NULL )
+	{
+		for (w=child; w->right!=NULL; w=w->right) {;} /* find end of child */
+		if ( sibling == NULL ) {sibling = child; tail = w;}
+		else {tail->right = child; tail = w;}
+		child = va_arg(ap, AST *);
+	}
+	if ( root==NULL ) root = sibling;
+	else root->down = sibling;
+	va_end(ap);
+	return root;
+}
+
+/* tree duplicate */
+AST *
+#ifdef __STDC__
+zzdup_ast(AST *t)
+#else
+zzdup_ast(t)
+AST *t;
+#endif
+{
+	AST *u;
+	
+	if ( t == NULL ) return NULL;
+	u = zzastnew();
+	*u = *t;
+#ifdef zzAST_DOUBLE
+	u->up = NULL;		/* set by calling invocation */
+	u->left = NULL;
+#endif
+	u->right = zzdup_ast(t->right);
+	u->down = zzdup_ast(t->down);
+#ifdef zzAST_DOUBLE
+	if ( u->right!=NULL ) u->right->left = u;
+	if ( u->down!=NULL ) u->down->up = u;
+#endif
+	return u;
+}
+
+void
+#ifdef __STDC__
+zztfree(AST *t)
+#else
+zztfree(t)
+AST *t;
+#endif
+{
+#ifdef zzd_ast
+	zzd_ast( t );
+#endif
+	free( t );
+}
+
+#ifdef zzAST_DOUBLE
+/*
+ * Set the 'up', and 'left' pointers of all nodes in 't'.
+ * Initial call is double_link(your_tree, NULL, NULL).
+ */
+void
+#ifdef __STDC__
+zzdouble_link(AST *t, AST *left, AST *up)
+#else
+zzdouble_link(t, left, up)
+AST *t, *left, *up;
+#endif
+{
+	if ( t==NULL ) return;
+	t->left = left;
+	t->up = up;
+	zzdouble_link(t->down, NULL, t);
+	zzdouble_link(t->right, t, up);
+}
+#endif