Re: [ccache] ccache - .d files with absolute system header paths
Hello, Actually, the google aosp code has the schema I mentioned. I just don't want to change it in our makefiles(nor can I influence the upstream) (they use clang) As far as my patch, I used objdump to see that there are no absolute paths. Thanks, Venkat. On Sat, Sep 16, 2017 at 1:16 PM, Anders Björklund via ccache < ccache@lists.samba.org> wrote: > Karanam Suryanarayana Rao Venkata Krishna wrote: > > Hello, > > I think I discovered a scenario that results in cache misses in spite of > > using CCACHE_BASEDIR. > > Consider the following command: > > > > CCACHE_BASEDIR=$PWD /bin/bash -c "ccache clang++ > > -fdebug-prefix-map=/proc/self/cwd= -g -c -MD -MF hello.d -o hello.o > > hello.cpp" > > > > It seems to me that is is perfectly alright to ask for debug prefix > mapping > > like: "-fdebug-prefix-map=/proc/self/cwd=" > > Unfortunately, ccache is ending up hashing gnu_getcwd(); thus, even > though > > we use CCACHE_BASEDIR setting, such a cache cannot be shared by other > > users' from different workspaces resulting in cache misses. > ... > > > > If the string after "=" in the mapping is null string, then, I hash "./". > > Can't you just use "$PWD" and ".", instead of this elaborate scheme ? > > Especially since using /proc/self/cwd doesn't even work, not with GCC... > i.e. when you give that prefix, it will just look for that path string > > In the actual debug info, you will _still_ have a reference the cwd. > > /Anders > ___ > ccache mailing list > ccache@lists.samba.org > https://lists.samba.org/mailman/listinfo/ccache > ___ ccache mailing list ccache@lists.samba.org https://lists.samba.org/mailman/listinfo/ccache
Re: [ccache] ccache - .d files with absolute system header paths
Karanam Suryanarayana Rao Venkata Krishna wrote: > Hello, > I think I discovered a scenario that results in cache misses in spite of > using CCACHE_BASEDIR. > Consider the following command: > > CCACHE_BASEDIR=$PWD /bin/bash -c "ccache clang++ > -fdebug-prefix-map=/proc/self/cwd= -g -c -MD -MF hello.d -o hello.o > hello.cpp" > > It seems to me that is is perfectly alright to ask for debug prefix mapping > like: "-fdebug-prefix-map=/proc/self/cwd=" > Unfortunately, ccache is ending up hashing gnu_getcwd(); thus, even though > we use CCACHE_BASEDIR setting, such a cache cannot be shared by other > users' from different workspaces resulting in cache misses. ... > > If the string after "=" in the mapping is null string, then, I hash "./". Can't you just use "$PWD" and ".", instead of this elaborate scheme ? Especially since using /proc/self/cwd doesn't even work, not with GCC... i.e. when you give that prefix, it will just look for that path string In the actual debug info, you will _still_ have a reference the cwd. /Anders ___ ccache mailing list ccache@lists.samba.org https://lists.samba.org/mailman/listinfo/ccache
Re: [ccache] ccache - .d files with absolute system header paths
Hello,
I think I discovered a scenario that results in cache misses in spite of
using CCACHE_BASEDIR.
Consider the following command:
CCACHE_BASEDIR=$PWD /bin/bash -c "ccache clang++
-fdebug-prefix-map=/proc/self/cwd= -g -c -MD -MF hello.d -o hello.o
hello.cpp"
It seems to me that is is perfectly alright to ask for debug prefix mapping
like: "-fdebug-prefix-map=/proc/self/cwd="
Unfortunately, ccache is ending up hashing gnu_getcwd(); thus, even though
we use CCACHE_BASEDIR setting, such a cache cannot be shared by other
users' from different workspaces resulting in cache misses.
I tested the following code to fix this problem(there by making such a
cache sharable) I'm looking forward to your feedback on this.
--- ccache-3.3_orig/ccache-3.3/ccache.c2016-08-27 16:57:18.0
+0200
+++ ccache-3.3/ccache.c2017-09-06 11:21:06.065818333 +0200
@@ -1525,6 +1525,11 @@
free(cwd);
cwd = dir;
}
+if (strcmp(new, "") == 0) {
+ cc_log("forReview: empty string on the
right size of debug_prefix_map: %s", debug_prefix_map);
+ cwd = format("%s/", ".");
+ cc_log("forReview: Hence, hashing '%s'
as CWD", cwd);
+}
free(old);
free(new);
If the string after "=" in the mapping is null string, then, I hash "./".
regards,
Venkat.
On Mon, Sep 4, 2017 at 4:24 PM, Joel Rosdahl wrote:
> Hi Karanam,
>
> > From just ccache's point of view, is there a way to force relative
> paths into the
> > .d files at all?
>
> Yes, ccache version 3.3 and newer knows how to do this. See the release
> notes for ccache 3.3: http://ccache.samba.org/
> releasenotes.html#_ccache_3_3
>
> -- Joel
>
___
ccache mailing list
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https://lists.samba.org/mailman/listinfo/ccache
Re: [ccache] ccache - .d files with absolute system header paths
Hi Karanam, > From just ccache's point of view, is there a way to force relative paths into the > .d files at all? Yes, ccache version 3.3 and newer knows how to do this. See the release notes for ccache 3.3: http://ccache.samba.org/releasenotes.html#_ccache_3_3 -- Joel ___ ccache mailing list ccache@lists.samba.org https://lists.samba.org/mailman/listinfo/ccache
