Problem with stock llvmc configuration for C

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1

Hi,

Apparently there are two bugs in tools/llvmc/c:

/.../llvm/tools/llvmc/c:12: Error: Invalid top level configuration item
/.../llvm/tools/llvmc/c:28: Error: Expecting a program name
/.../llvm/tools/llvmc/c had 2 errors. Terminating.

The first error relates to the following line(s):

   lang.libs=%llvmgccdir%/lib %llvmgccdir%/lib \
     %llvmgccdir%/lib/gcc/%llvmgccarch%

... the other one to:

   translator.command=%llvmcc1% -quiet %in% -o %out% \
   ...

Apparently, %llvmgccdir% and %llvmcc1% are not recognized as a useful variable by the llvmc configuration parser. I found out in tools/llvmc/Configuration.cpp that two other library-related variables exist, notably %libdir% and %libs%, but it's not clear what they do.

Currently, I tried to solve the problems like this:

lang.libs=%libdir%
#this does not work: lang.libs=%libdir% %libs%

... and:

   translator.command=llvm-gcc -quiet %in% -o %out% \
   ...

Only the solution to the second problem really seems to work, the other one is accepted by llvmc, but I also get:

/usr/bin/ld: Undefined symbols:
_main
collect2: ld returned 1 exit status
llvmc: Action failed

How can this library problem be solved?

Kind regards,

Bram Adams
GH-SEL, INTEC, Ghent University (Belgium)

2

Hi,

Apparently there are two bugs in tools/llvmc/c:

This tool is, as yet, unfinished.

/.../llvm/tools/llvmc/c:12: Error: Invalid top level configuration item
/.../llvm/tools/llvmc/c:28: Error: Expecting a program name
/.../llvm/tools/llvmc/c had 2 errors. Terminating.

The first error relates to the following line(s):

   lang.libs=%llvmgccdir%/lib %llvmgccdir%/lib \
     %llvmgccdir%/lib/gcc/%llvmgccarch%

... the other one to:

   translator.command=%llvmcc1% -quiet %in% -o %out% \
   ...

Okay.

Apparently, %llvmgccdir% and %llvmcc1% are not recognized as a useful
variable by the llvmc configuration parser.

Actually, they are. See tools/llvmc/ConfigurationDriver.cpp around line
304. Also, they are recognized by the lexer. Its more likely that when
you configured LLVM you didn't provide the --with-llvmgccdir= option.

I found out in tools/
llvmc/Configuration.cpp that two other library-related variables
exist, notably %libdir% and %libs%, but it's not clear what they do.

%libdir% expands to LLVM_LIBDIR which is the installation location of
LLVM libraries.
%libs% expands to the list of system (non-LLVM) libraries needed to link
with LLVM.

Currently, I tried to solve the problems like this:

lang.libs=%libdir%
#this does not work: lang.libs=%libdir% %libs%

Did you install LLVM yet? If not, the directories are empty.

... and:

   translator.command=llvm-gcc -quiet %in% -o %out% \
   ...

Only the solution to the second problem really seems to work, the
other one is accepted by llvmc, but I also get:

/usr/bin/ld: Undefined symbols:
_main
collect2: ld returned 1 exit status
llvmc: Action failed

How can this library problem be solved?

Probably with "make install" from LLVM build directory and by
configuring LLVM with --with-llvmgccdir=.

Please note that llvmc is (still!) a work in progress. The configuration
code, in particular, is due for some improvement. Please see PR686
(http://llvm.org/bugs/show_bug.cgi?id=686) for further details.

Kind regards,

Bram Adams
GH-SEL, INTEC, Ghent University (Belgium)

Hope it helps,

Reid

3

Hi,

Apparently, %llvmgccdir% and %llvmcc1% are not recognized as a useful
variable by the llvmc configuration parser.

Actually, they are. See tools/llvmc/ConfigurationDriver.cpp around line
304. Also, they are recognized by the lexer. Its more likely that when
you configured LLVM you didn't provide the --with-llvmgccdir= option.

They're indeed mentioned, but somehow they were not added to the switch-statements in the corresponding parsing functions for the various configuration options. I attached a patch in which this is resolved, as well as two other bugs:
  * an off-by-one error in a loop copying a command's arguments into an array (first argument was dismissed; garbage added at the end);
  * %...%'s in a command name were not substituted, whereas they were in the command's arguments.

The patch solved things for me, but it's not perfect yet.

I found out in tools/
llvmc/Configuration.cpp that two other library-related variables
exist, notably %libdir% and %libs%, but it's not clear what they do.

%libdir% expands to LLVM_LIBDIR which is the installation location of
LLVM libraries.
%libs% expands to the list of system (non-LLVM) libraries needed to link
with LLVM.

OK.

Kind regards,

Bram Adams
GH-SEL, INTEC, Ghent University (Belgium)

PS: I recently saw an email passing by in which someone else was talking about a patch for llvmc. Has that one been committed yet?

patch.llvmc-1.8 (4.38 KB)

4

Hi Bram,

Patches all looked good. I've committed them unchanged. Thanks for the
contribution!

Patches here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20060814/036798.html

Reid.

5

Bram Adams wrote:

Hi,

Apparently, %llvmgccdir% and %llvmcc1% are not recognized as a useful
variable by the llvmc configuration parser.

Actually, they are. See tools/llvmc/ConfigurationDriver.cpp around line
304. Also, they are recognized by the lexer. Its more likely that when
you configured LLVM you didn't provide the --with-llvmgccdir= option.

They're indeed mentioned, but somehow they were not added to the
switch-statements in the corresponding parsing functions for the
various configuration options. I attached a patch in which this is
resolved, as well as two other bugs:
* an off-by-one error in a loop copying a command's arguments into an
array (first argument was dismissed; garbage added at the end);
* %...%'s in a command name were not substituted, whereas they were in
the command's arguments.

The patch solved things for me, but it's not perfect yet.

Damn. And I was testing my version of the same patch... So for, IWFM
with one small problem: with the gcc 4.0 frontend, "-emit-llvm" needs to
be added to all of the translator.command lines. Not entirely sure how
to conditionalize that in the configuration files.

-scooter

6

Hi Scott,

What is needed is a complete overhaul of the configuration mechanism. We
have plans to generalize it and make it possible have several of the
standard configurations "built in" to llvmc while still allowing others
to be loaded from shared objects or read from files. For further
details, please see:

http://llvm.org/bugs/show_bug.cgi?id=686

Reid.

7

Reid Spencer wrote:

8

llvmc is useful for other people working on their own front-ends. llvm does support the GCC front-end well, but we would like to support custom ones even better :slight_smile:

-Chris