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From: Lawrence D'Oliveiro <ldo@nz.invalid>
Newsgroups: comp.lang.c
Subject: Re: Fixing a sample from K&R book using cake static analyser
Date: Mon, 24 Jun 2024 00:34:22 -0000 (UTC)
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On Mon, 24 Jun 2024 00:25:56 +0100, Ben Bacarisse wrote:

> struct nlist *install(const char *name, const char *defn)
> {
>      struct nlist *node = lookup(name);
>      if (node) {
>           char *new_defn = strdup(defn);
>           if (new_defn) {
>                free(node->defn);
>                node->defn = new_defn;
>                return node;
>           }
>           else return NULL;
>      }
>      else {
>           struct nlist *new_node = malloc(sizeof *new_node);
>           char *new_name = strdup(name), *new_defn = strdup(defn);
>           if (new_node && new_name && new_defn) {
>                unsigned hashval = hash(name);
>                new_node->name = new_name;
>                new_node->defn = new_defn;
>                new_node->next = hashtab[hashval];
>                return hashtab[hashval] = new_node;
>           }
>           else {
>                free(new_defn);
>                free(new_name);
>                free(new_node);
>                return NULL;
>           }
>      }
> }
> 
> We have four cases:
> 
>   node with the name found
>      new definition allocated new definition not allocated
>   node with the name not found
>      new node, name and definition all allocated not all of new node,
>      name and definition allocated.
> 
> We can very simply reason about all of these situations.

Too many different paths in the control flow, though. I think it’s a good 
idea to minimize that.