Incorrect dependences in generated Makefile for dislin

[bernecky]

With commit # b6efaff, I did:
mkdir build
cd build
cmake ..
make -j32

and got this failure:

[ 81%] Building dislin/DislinCanvas.sac module for target `mt_pth'
abort: Error loading external header information for module `DislinSystem'
abort: (/home/sac/sac/BASE/dislin/build/lib/tree/host/libDislinSystemTree.so): Failed getting library function:
abort: /usr/local/libexec/sac2c/1.3.3-MijasCosta-572-g9eca/libsac2c_p.so: undefined symbol: __DislinSystem_HEADERS
compilation failed while Loading SAC program.
make[2]: *** [src-mt_pth/CMakeFiles/mt_pth-module-DislinQuick.dir/build.make:75: lib/host/mt-pth/libDislinCanvasMod.so] Error 1
make[2]: Leaving directory '/home/sac/sac/BASE/dislin/build'
make[1]: *** [CMakeFiles/Makefile2:463: src-mt_pth/CMakeFiles/mt_pth-module-DislinQuick.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....

The make completed successfully when I did "make -j" again.

[ashinkarov]

Weird... This means that somehow we are missing DislinCanvas -> DislinSystem dependency. But we use a generic mechanism here:

Dislin/src/CMakeLists.txt

Line 69 in b6efaff

RESOLVE_SAC_DEPENDENCIES ("${name}" "${SAC_SRC}" moddep_list)

and then add a dependency here:

Dislin/src/CMakeLists.txt

Line 79 in b6efaff

DEPENDS ${moddep_list}

Something is not being propagated correctly.

[ashinkarov]

So I printed the generated list of dependencies for that module, and it says:
Module /tmp/Dislin/build/lib/host/mt-pth/libDislinCanvasMod.so/ & /tmp/Dislin/build/lib/tree/host/libDislinCanvasTree.so depends on:

• /tmp/Dislin/build/lib/host/mt-pth/libDislinPageMod.so
• /tmp/Dislin/build/lib/tree/host/libDislinPageTree.so
• /tmp/Dislin/build/lib/host/mt-pth/libDislinSystemMod.so
• /tmp/Dislin/build/lib/tree/host/libDislinSystemTree.so

which looks about right to me. Hm...

[ashinkarov]

If I look at the generated file for the DislinCanvas module in src-mt_pth/CMakeFiles/mt_pth-module-DislinCanvas.dir/build.make, it looks rather sane to me. However, one thing I am wondering now. When we run sac2c, it produces both Mod and Tree files. And each sac-module target specifies two outputs, the Mod file and the Tree file. The problem is that these Tree files point to the same location. This is not a problem for Cmake, but it may be a problem for a highly parallel build. E.g we build System for mt-pth, it creates a Tree file, we start building Canvas, and at that very time we build System for seq target, which actually phisically rewrites the Tree file. Bad things could happen...

@bernecky , can you try to leave only one target in the CmakeLists:
SET (TARGETS mt_pth CACHE STRING "Build stdlib-jpeg for these targets")
and see whether you can reproduce a similar effect.

@hv15 didn't we discuss that this problem could bite our ass at a certain point?

P.S. I might be totally wrong, as it is a very trivial build that "should" just work.

[bernecky]

I am running the single-target mt_pth build now, for the second time. First time ran OK; second time failed.
Let's try it again with seq. That failed first time.