From 4e147a4eafb2e5d5543b57352b23a49a815cc0d5 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <njn@valgrind.org>
Date: Tue, 30 Sep 2003 13:51:23 +0000
Subject: [PATCH] Added VG_(getcwd_alloc)(), which is much easier to use than
 VG_(getcwd)(). (getcwd() is really a pretty stupid syscall)

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@1867
---
 cachegrind/cg_main.c  | 12 ++++--------
 coregrind/vg_mylibc.c | 19 +++++++++++++++++++
 include/vg_skin.h     |  4 ++++
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/cachegrind/cg_main.c b/cachegrind/cg_main.c
index 87756e132..1e584c795 100644
--- a/cachegrind/cg_main.c
+++ b/cachegrind/cg_main.c
@@ -2022,7 +2022,6 @@ void SK_(print_debug_usage)(void)
 
 void SK_(pre_clo_init)(void)
 {
-   UInt  buf_size = 100;
    Char* base_dir = NULL;
    
    VG_(details_name)            ("Cachegrind");
@@ -2043,17 +2042,14 @@ void SK_(pre_clo_init)(void)
    VG_(register_compact_helper)((Addr) & log_0I_2D_cache_access);
    VG_(register_compact_helper)((Addr) & log_1I_2D_cache_access);
 
-   /* getcwd() fails if the buffer isn't big enough -- keep doubling size
-      until it succeeds. */
-   while (NULL == base_dir) {
-      base_dir = VG_(malloc)(buf_size);
-      if (NULL == VG_(getcwd)(base_dir, buf_size))
-         buf_size *= 2;
-   }
+   /* Get working directory */
+   sk_assert( VG_(getcwd_alloc)(&base_dir) );
+
    /* Block is big enough for dir name + cachegrind.out.<pid> */
    cachegrind_out_file = VG_(malloc)((VG_(strlen)(base_dir) + 32)*sizeof(Char));
    VG_(sprintf)(cachegrind_out_file, "%s/cachegrind.out.%d",
                 base_dir, VG_(getpid)());
+   VG_(free)(base_dir);
 }
 
 void SK_(post_clo_init)(void)
diff --git a/coregrind/vg_mylibc.c b/coregrind/vg_mylibc.c
index 7fbf9283c..60e3b84fe 100644
--- a/coregrind/vg_mylibc.c
+++ b/coregrind/vg_mylibc.c
@@ -1212,6 +1212,25 @@ Char* VG_(getcwd) ( Char* buf, Int size )
    return VG_(is_kerror)(res) ? ((Char*)NULL) : (Char*)res;
 }
 
+/* Alternative version that does allocate the memory.  Easier to use. */
+Bool VG_(getcwd_alloc) ( Char** out )
+{
+   UInt size = 4;
+
+   *out = NULL;
+   while (True) {
+      *out = VG_(malloc)(size);
+      if (NULL == VG_(getcwd)(*out, size)) {
+         VG_(free)(*out);
+         if (size > 65535)
+            return False;
+         size *= 2;
+      } else {
+         return True;
+      }
+   }
+}
+
 
 /* ---------------------------------------------------------------------
    Misc functions looking for a proper home.
diff --git a/include/vg_skin.h b/include/vg_skin.h
index 34370a9c0..d2cae54be 100644
--- a/include/vg_skin.h
+++ b/include/vg_skin.h
@@ -428,6 +428,10 @@ extern Int  VG_(stat)   ( Char* file_name, struct vki_stat* buf );
 
 extern Char* VG_(getcwd) ( Char* buf, Int size );
 
+/* Easier to use than VG_(getcwd)() -- does the buffer fiddling itself.
+   String put into 'cwd' is VG_(malloc)'d, and should be VG_(free)'d.
+   Returns False if it fails.  Will fail if the pathname is > 65535 bytes. */
+extern Bool VG_(getcwd_alloc) ( Char** cwd );
 
 /* ------------------------------------------------------------------ */
 /* assert.h */