[hackers] [scc] [cc2] Remove statements in apply() || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Wed, 27 Apr 2016 20:46:33 +0200 (CEST)

commit 950cfce031fb38e6337e087c398dc4e7c5efc467
Author: Roberto E. Vargas Caballero <Roberto E. Vargas Caballero>
AuthorDate: Mon Apr 25 21:53:57 2016 +0200
Commit: Roberto E. Vargas Caballero <Roberto E. Vargas Caballero>
CommitDate: Tue Apr 26 20:02:08 2016 +0200

    [cc2] Remove statements in apply()
    
    A usage case of apply() may be optimization, and we need some way
    of removing unwanted statments, and we can use the return value
    of the parameter function to mark what statements must be deleted.

diff --git a/cc2/node.c b/cc2/node.c
index 8fe75c0..96c3e90 100644
--- a/cc2/node.c
+++ b/cc2/node.c
_AT_@ -9,6 +9,7 @@
 
 #define NNODES 32
 
+Node *curstmt;
 Symbol *curfun;
 Type rtype;
 
_AT_@ -18,7 +19,7 @@ struct arena {
 };
 
 static struct arena *arena;
-static Node *freep, *stmtp;
+static Node *freep;
 static int inhome;
 
 Node *
_AT_@ -50,14 +51,38 @@ addstmt(Node *np)
         if (!curfun->u.stmt)
                 curfun->u.stmt = np;
         else
- stmtp->next = np;
+ curstmt->next = np;
         np->next = NULL;
- np->prev = stmtp;
- stmtp = np;
+ np->prev = curstmt;
+ curstmt = np;
 
         return np;
 }
 
+Node *
+delstmt(void)
+{
+ Node *next, *prev;
+
+ next = curstmt->next;
+ prev = curstmt->prev;
+ if (next)
+ next->prev = prev;
+ if (prev)
+ prev->next = next;
+ else
+ curfun->u.stmt = next;
+ deltree(curstmt);
+
+ return curstmt = next;
+}
+
+Node *
+nextstmt(void)
+{
+ return curstmt = curstmt->next;
+}
+
 void
 delnode(Node *np)
 {
_AT_@ -87,17 +112,15 @@ cleannodes(void)
         }
         arena = NULL;
         freep = NULL;
- stmtp = NULL;
+ curstmt = NULL;
 }
 
 void
 apply(Node *(*fun)(Node *))
 {
- Node *np;
-
         if (!curfun)
                 return;
-
- for (np = curfun->u.stmt; np; np = np->next)
- (*fun)(np);
+ curstmt = curfun->u.stmt;
+ while (curstmt)
+ (*fun)(curstmt) ? nextstmt() : delstmt();
 }
Received on Wed Apr 27 2016 - 20:46:33 CEST