[OE-core] [PATCH 1/1] sanity.bbclass: check TMPDIR is not too long

[Robert Yang]

When the length of TMPDIR is longer than a threshold, there would be an
"Argument list too long" error when building gcc-cross, this is the
error from the exec(), the maximum length of argument is defined in
/usr/include/linux/limits.h:

  #define ARG_MAX       131072    /* # bytes of args + environ for exec() */

It's hard to determine the threshold of the TMPDIR, here is the
experimental value:
len(TMPDIR) = 182	Success
len(TMPDIR) = 192	Failed

So set the maximum length of TMPDIR to 180 seems proper.

[YOCTO #2434]

Signed-off-by: Robert Yang <liezhi.yang at windriver.com>
---
 meta/classes/sanity.bbclass |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/meta/classes/sanity.bbclass b/meta/classes/sanity.bbclass
index 687ddeb..6aaac1e 100644
--- a/meta/classes/sanity.bbclass
+++ b/meta/classes/sanity.bbclass
@@ -30,6 +30,7 @@ def check_sanity_sstate_dir_change(sstate_dir, data):
     testmsg = ""
     if sstate_dir != "":
         testmsg = check_create_long_filename(sstate_dir, "SSTATE_DIR")
+
     return testmsg
 
 def check_sanity_tmpdir_change(tmpdir, data):
@@ -83,6 +84,12 @@ def check_create_long_filename(filepath, pathname):
             return "Failed to create a file in %s: %s" % (pathname, strerror)
     return ""
 
+def check_long_path(filepath, pathname):
+    # The 180 is just an empirical value
+    if len(filepath) > 180:
+	return "The path length of %s is too long, this would cause the \"Argument list too long\" error, please use a shorter path.\n" % pathname
+    return ""
+
 def check_connectivity(d):
     # URI's to check can be set in the CONNECTIVITY_CHECK_URIS variable
     # using the same syntax as for SRC_URI. If the variable is not set
@@ -353,6 +360,10 @@ def check_sanity(e):
     tmpdir = data.getVar('TMPDIR', e.data, True)
     sstate_dir = data.getVar('SSTATE_DIR', e.data, True)
 
+    # Check whether the length of TMPDIR is too long to cause the
+    # argument list too long error
+    messages = messages + check_long_path(tmpdir, "TMPDIR")
+
     # Check saved sanity info
     last_sanity_version = 0
     last_tmpdir = ""
-- 
1.7.1