Commit Larry Doolittle's buffers-on-stack/buffers-via-malloc patch.
-Erik
diff --git a/docs/style-guide.txt b/docs/style-guide.txt
index 9a3b102..1a04e44 100644
--- a/docs/style-guide.txt
+++ b/docs/style-guide.txt
@@ -402,7 +402,7 @@
memory penalty for this buffer, even if the applet that uses said buffer is
not run. This can be fixed, thusly:
- static char *buffer
+ static char *buffer;
...
other_func()
{
@@ -418,7 +418,7 @@
declared on the stack in the *_main() function and made available globally by
assigning them to a global pointer thusly:
- static char *pbuffer
+ static char *pbuffer;
...
other_func()
{
@@ -430,13 +430,13 @@
pbuffer = buffer; /* but available globally */
...
-Thus:
- - global static buffers are eliminated
- - we don't grow the text segment as much because no malloc() call is made;
- memory is automatically allocated on the stack when execution context
- enters the function. (We still grow text a little bit because of the
- assignment, but that's cheap compared to a function call.)
- - the buffer is still available globally via the pointer
+This last approach has some advantages (low code size, space not used until
+it's needed), but can be a problem in some low resource machines that have
+very limited stack space (e.g., uCLinux). busybox.h declares a macro that
+implements compile-time selection between xmalloc() and stack creation, so
+you can code the line in question as
+ RESERVE_BB_BUFFER(buffer, BUFSIZ);
+and the right thing will happen, based on the customer's configuration.
