Don't #include utils/palloc.h in common/fe_memutils.h.

tglsfdc · tglsfdc · commit e4c1a496f232 · 2014-04-26T14:14:30.000-04:00
This breaks the principle that common/ ought not depend on anything in the
server, not only code-wise but in the headers.  The only arguable advantage
is avoidance of duplication of half a dozen extern declarations, and even
that is rather dubious, considering that the previous coding was wrong
about which declarations to duplicate: it exposed pnstrdup() to frontend
code even though no such function is provided in fe_memutils.c.

On the same principle, don't #include utils/memutils.h in the frontend
build of psprintf.c.  This requires duplicating the definition of
MaxAllocSize, but that seems fine to me: there's no a-priori reason why
frontend code should use the same size limit as the backend anyway.

In passing, clean up some rather odd layout and ordering choices that
were imposed on palloc.h to reduce the number of #ifdefs required by
the previous approach.

Per gripe from Christoph Berg.  There's still more work to do to make
include/common/ clean, but this part seems reasonably noncontroversial.
diff --git a/src/include/common/fe_memutils.h b/src/include/common/fe_memutils.h
@@ -9,12 +9,18 @@
 #ifndef FE_MEMUTILS_H
 #define FE_MEMUTILS_H
 
+/* "Safe" memory allocation functions --- these exit(1) on failure */
 extern char *pg_strdup(const char *in);
 extern void *pg_malloc(size_t size);
 extern void *pg_malloc0(size_t size);
 extern void *pg_realloc(void *pointer, size_t size);
 extern void pg_free(void *pointer);
 
-#include "utils/palloc.h"
+/* Equivalent functions, deliberately named the same as backend functions */
+extern char *pstrdup(const char *in);
+extern void *palloc(Size size);
+extern void *palloc0(Size size);
+extern void *repalloc(void *pointer, Size size);
+extern void pfree(void *pointer);
 
 #endif   /* FE_MEMUTILS_H */
diff --git a/src/include/utils/palloc.h b/src/include/utils/palloc.h
@@ -35,12 +35,10 @@
  */
 typedef struct MemoryContextData *MemoryContext;
 
-#ifndef FRONTEND
-
 /*
  * CurrentMemoryContext is the default allocation context for palloc().
- * We declare it here so that palloc() can be a macro.	Avoid accessing it
- * directly!  Instead, use MemoryContextSwitchTo() to change the setting.
+ * Avoid accessing it directly!  Instead, use MemoryContextSwitchTo()
+ * to change the setting.
  */
 extern PGDLLIMPORT MemoryContext CurrentMemoryContext;
 
@@ -51,6 +49,11 @@ extern void *MemoryContextAlloc(MemoryContext context, Size size);
 extern void *MemoryContextAllocZero(MemoryContext context, Size size);
 extern void *MemoryContextAllocZeroAligned(MemoryContext context, Size size);
 
+extern void *palloc(Size size);
+extern void *palloc0(Size size);
+extern void *repalloc(void *pointer, Size size);
+extern void pfree(void *pointer);
+
 /*
  * The result of palloc() is always word-aligned, so we can skip testing
  * alignment of the pointer when deciding which MemSet variant to use.
@@ -89,13 +92,8 @@ MemoryContextSwitchTo(MemoryContext context)
  * allocated in a context, not with malloc().
  */
 extern char *MemoryContextStrdup(MemoryContext context, const char *string);
-#endif   /* !FRONTEND */
 
 extern char *pstrdup(const char *in);
 extern char *pnstrdup(const char *in, Size len);
-extern void *palloc(Size size);
-extern void *palloc0(Size size);
-extern void pfree(void *pointer);
-extern void *repalloc(void *pointer, Size size);
 
 #endif   /* PALLOC_H */
