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Diffstat (limited to 'Source/Pccts/h/ast.c')
-rw-r--r-- | Source/Pccts/h/ast.c | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/Source/Pccts/h/ast.c b/Source/Pccts/h/ast.c new file mode 100644 index 0000000..9326ae1 --- /dev/null +++ b/Source/Pccts/h/ast.c @@ -0,0 +1,345 @@ +/* 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
+ * 1989-2000
+ */
+
+#include "pcctscfg.h"
+
+#ifdef PCCTS_USE_STDARG
+#include "pccts_stdarg.h"
+#else
+#include <varargs.h>
+#endif
+
+/* ensure that tree manipulation variables are current after a rule
+ * reference
+ */
+
+void
+#ifdef __USE_PROTOS
+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 __USE_PROTOS
+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 __USE_PROTOS
+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 __USE_PROTOS
+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 __USE_PROTOS
+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 */
+
+#if 0
+////void
+////#ifdef __USE_PROTOS
+////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 );
+////}
+#endif
+
+/*
+ MR19 Optimize freeing of the following structure to limit recursion
+ SAKAI Kiyotaka (ksakai@isr.co.jp)
+*/
+
+/*
+ NULL o
+ / \
+ NULL o
+ / \
+ NULL NULL
+*/
+
+/*
+ MR21 Another refinement to replace recursion with iteration
+ NAKAJIMA Mutsuki (muc@isr.co.jp).
+*/
+
+void
+#ifdef __USE_PROTOS
+zzfree_ast(AST *tree)
+#else
+zzfree_ast(tree)
+AST *tree;
+#endif
+{
+
+ AST *otree;
+
+ if (tree == NULL) return;
+
+ while (tree->down == NULL || tree->right == NULL) {
+
+ if (tree->down == NULL && tree->right == NULL) {
+ zztfree(tree);
+ return;
+ }
+
+ otree = tree;
+ if (tree->down == NULL) {
+ tree = tree->right;
+ } else {
+ tree = tree->down;
+ }
+ zztfree( otree );
+ }
+
+ while (tree != NULL) {
+ zzfree_ast(tree->down);
+ otree = tree;
+ tree = otree->right;
+ zztfree(otree);
+ }
+}
+
+/* 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 PCCTS_USE_STDARG
+AST *zztmake(AST *rt, ...)
+#else
+AST *zztmake(va_alist)
+va_dcl
+#endif
+{
+ va_list ap;
+ register AST *child, *sibling=NULL, *tail=NULL /* MR20 */, *w;
+ AST *root;
+
+#ifdef PCCTS_USE_STDARG
+ 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 __USE_PROTOS
+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 __USE_PROTOS
+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 __USE_PROTOS
+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
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