Solved Clang plugin, CMake and _types.h error

F

fbcan

Good afternoon folks!

I am trying to compile this c source file while performing some CLANG frontend action with a CLANG plugin.

My source code (test.c) includes a header file (section_insertion.h). This header file includes stdio.h because I use some size_t variables inside some structs

test.c

C: 
// Filename: test.c

#include "section_insertion.h"
void PAYLOAD();

int main(int argc, char *argv[]) {
    return 0;
}

section_insertion.h

C: 
//Filename: section_insertion.h

#include <stdio.h>

typedef struct {
    int num_a;
    int num_b;
    char caracter;
    size_t int_size;
} Payload_A;

Part 1: Building with base CLANG/LLVM.

My base CLANG/LLVM version is the following:
Bash: 
$ clang -v
FreeBSD clang version 11.0.1 (git@github.com:llvm/llvm-project.git llvmorg-11.0.1-0-g43ff75f2c3fe)
Target: x86_64-unknown-freebsd13.0
Thread model: posix
InstalledDir: /usr/bin

Then, I define the env variables:

Bash: 
$ export Clang_DIR=/usr/local/llvm11
$ export Clang_DIR=/usr/bin/clang

needed for the CMake script

Bash: 
$ cat CMakeLists.txt
cmake_minimum_required(VERSION 3.4.3)
project(clang-tutor-rename-plugin)

#===============================================================================
# 1. LOAD LLVM CONFIGURATION
#===============================================================================
# Set this to a valid LLVM installation dir
set(CT_Clang_INSTALL_DIR "" CACHE PATH "LLVM installation directory")

# Add the location of ClangConfig.cmake to CMake search paths (so that
# find_package can locate it)
list(APPEND CMAKE_PREFIX_PATH "${CT_Clang_INSTALL_DIR}/lib/cmake/clang/")

find_package(Clang REQUIRED CONFIG)

# HelloWorld includes headers from LLVM and Clang - update the include paths
# accordingly
include_directories(SYSTEM "${LLVM_INCLUDE_DIRS};${CLANG_INCLUDE_DIRS}")

#===============================================================================
# 2. LLVM-TUTOR BUILD CONFIGURATION
#===============================================================================
# Use the same C++ standard as LLVM does
set(CMAKE_CXX_STANDARD 14 CACHE STRING "")

# LLVM is normally built without RTTI. Be consistent with that.
if(NOT LLVM_ENABLE_RTTI)
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rttic -shared")
endif()

#===============================================================================
# 3. ADD THE TARGET
#===============================================================================
add_library(RenameMacro SHARED RenameMacro.cpp)

# Allow undefined symbols in shared objects on Darwin (this is the default
# behaviour on Linux)
target_link_libraries(RenameMacro
  "$<$<PLATFORM_ID:Darwin>:-undefined dynamic_lookup>")

set(CMAKE_VERBOSE_MAKEFILE on)

Then, building it using the base compiler warns me about not finding the ClangConfig.cmake file

Bash: 
$ cmake -DCT_Clang_INSTALL_DIR=$Clang_DIR $CLANG_TUTOR_DIR
-- The C compiler identification is Clang 11.0.1
-- The CXX compiler identification is Clang 11.0.1
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at CMakeLists.txt:14 (find_package):
  Could not find a package configuration file provided by "Clang" with any of
  the following names:
    ClangConfig.cmake
    clang-config.cmake
  Add the installation prefix of "Clang" to CMAKE_PREFIX_PATH or set
  "Clang_DIR" to a directory containing one of the above files.  If "Clang"
  provides a separate development package or SDK, be sure it has been
  installed.

-- Configuring incomplete, errors occurred!

Using the find command doesn't retrieve any file

Bash: 
find -name  ClangConfig.cmake

Part 2: Building with pkg llvm11 version

Installing llvm11 via pkg and checking the installed version
Bash: 
$ pkg install llvm11

$ clang11 -v
clang version 11.0.1
Target: x86_64-portbld-freebsd13.0
Thread model: posix
InstalledDir: /usr/local/llvm11/bin

Now, I can find the .cmake file, So, I set the path to it and build.

Bash: 
$ find -name  ClangConfig.cmake
/usr/local/llvm11/lib/cmake/clang/ClangConfig.cmake

$ export Clang_DIR=/usr/local/llvm11

$ cmake -DCT_Clang_INSTALL_DIR=$Clang_DIR $CLANG_TUTOR_DIR
-- Configuring done
-- Generating done
-- Build files have been written to: /home/freebsd/pluginClang/build

Part 3: Compile the clang plugin

Bash: 
$ make
make
/usr/local/bin/cmake -S/home/freebsd/pluginClang -B/home/freebsd/pluginClang/build --check-build-system CMakeFiles/Makefile.cmake 0
/usr/local/bin/cmake -E cmake_progress_start /home/freebsd/pluginClang/build/CMakeFiles /home/freebsd/pluginClang/build//CMakeFiles/progress.marks
make  -f CMakeFiles/Makefile2 all
make  -f CMakeFiles/RenameMacro.dir/build.make CMakeFiles/RenameMacro.dir/depend
cd /home/freebsd/pluginClang/build && /usr/local/bin/cmake -E cmake_depends "Unix Makefiles" /home/freebsd/pluginClang /home/freebsd/pluginClang /home/freebsd/pluginClang/build /home/freebsd/pluginClang/build /home/freebsd/pluginClang/build/CMakeFiles/RenameMacro.dir/DependInfo.cmake --color=
make  -f CMakeFiles/RenameMacro.dir/build.make CMakeFiles/RenameMacro.dir/build
[ 50%] Building CXX object CMakeFiles/RenameMacro.dir/RenameMacro.cpp.o
/usr/bin/c++ -DRenameMacro_EXPORTS -isystem /usr/local/llvm11/include -fPIC -MD -MT CMakeFiles/RenameMacro.dir/RenameMacro.cpp.o -MF CMakeFiles/RenameMacro.dir/RenameMacro.cpp.o.d -o CMakeFiles/RenameMacro.dir/RenameMacro.cpp.o -c /home/freebsd/pluginClang/RenameMacro.cpp
[100%] Linking CXX shared library libRenameMacro.so
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/RenameMacro.dir/link.txt --verbose=1
/usr/bin/c++ -fPIC -shared -Wl,-soname,libRenameMacro.so -o libRenameMacro.so CMakeFiles/RenameMacro.dir/RenameMacro.cpp.o
[100%] Built target RenameMacro
/usr/local/bin/cmake -E cmake_progress_start /home/freebsd/pluginClang/build/CMakeFiles 0

Part 4: Compile the source code using the clang plugin

Bash: 
$ ~/pluginClang/build $ ls
CMakeCache.txt          Makefile                libRenameMacro.so       test.c
CMakeFiles              cmake_install.cmake     section_insertion.h
Compiling the source code using Clang/LLVM with the plugin, throws me four errors. HOWEVER, it generates the output file into /tmp/test.c

Bash: 
$ clang11 cc1 -load ./libRenameMacro.so -plugin -rename-plugin test.c -v
clang -cc1 version 11.0.1 based upon LLVM 11.0.1 default target x86_64-portbld-freebsd13.0
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/llvm11/lib/clang/11.0.1/include
 /usr/include
End of search list.
In file included from test.c:1:
In file included from ./section_insertion.h:4:
In file included from /usr/include/stdio.h:43:
/usr/include/sys/_types.h:107:24: error: expected ';' at end of declaration list
        long long __max_align1 __aligned(_Alignof(long long));
                              ^
/usr/include/sys/_types.h:109:26: error: expected ';' at end of declaration list
        long double __max_align2 __aligned(_Alignof(long double));
                                ^
/usr/include/sys/_types.h:135:2: error: "No support for your compiler for stdargs"
#error "No support for your compiler for stdargs"
 ^
In file included from test.c:1:
In file included from ./section_insertion.h:4:
/usr/include/stdio.h:77:9: error: unknown type name '__va_list'
typedef __va_list       va_list;
        ^
encontro func
Output file created - /tmp/test.c
4 errors generated.

Using the -D __GNUCLIKE_BUILTIN_VARARGS flag, allows me to supress two errors but there are two left.

Bash: 
$ clang11 -cc1 -load ./libRenameMacro.so -plugin -rename-plugin test.c -D __GNUCLIKE_BUILTIN_VARARGS -v
clang -cc1 version 11.0.1 based upon LLVM 11.0.1 default target x86_64-portbld-freebsd13.0
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/llvm11/lib/clang/11.0.1/include
 /usr/include
End of search list.
In file included from test.c:1:
In file included from ./section_insertion.h:4:
In file included from /usr/include/stdio.h:43:
/usr/include/sys/_types.h:107:24: error: expected ';' at end of declaration list
        long long __max_align1 __aligned(_Alignof(long long));
                              ^
/usr/include/sys/_types.h:109:26: error: expected ';' at end of declaration list
        long double __max_align2 __aligned(_Alignof(long double));
                                ^
encontro func
Output file created - /tmp/test.c
2 errors generated.

The error is in /usr/include/sys/_types.h. The relevant lines on that header are:

C: 
$ cat /usr/include/sys/_types.h

typedef struct {
        long long __max_align1 __aligned(_Alignof(long long));
#ifndef _STANDALONE
        long double __max_align2 __aligned(_Alignof(long double));
#endif
} __max_align_t;

Although the output file is generated at /tmp/test.c, I am looking to solve those errors.
Does anybody know what I am doing wrong?

I also built the same plugin and test in Ubuntu and no errors were generated.
Thanks for reading and for the help in advance.


EDIT 1: Added test.c code
EDIT 2: Added section_insertion.h code
 
For starters you made a very detailed question and then given a brief, heavily edited test.c from which I can make no possible conclusion.
One can only guess. But you have issues in your cmake (code around -fno_rtti which is more for embedded use) but it's not activated anyway.
I think you need to show the code generating the error?
 
mark_j said:
For starters you made a very detailed question and then given a brief, heavily edited test.c from which I can make no possible conclusion.
One can only guess. But you have issues in your cmake (code around -fno_rtti which is more for embedded use) but it's not activated anyway.
I think you need to show the code generating the error?
Click to expand...

mark_j Hey! Sorry! I forgot to add test.c code

Here it goes my test.c code

C: 
// test.c
#include "section_insertion.h"
void PAYLOAD();

int main(int argc, char *argv[]) {
    return 0;
}

I just added it to the first message too.

Thanks Mark!
 
Your error stems from "In file included from ./section_insertion.h:4:" but you don't show section_insertion.h or is your code commented with "//section_header.h" actually section_insertion.h?

Anyway, perhaps your issue is utilising -cc1? The documentation is explicit here:
Directly call the parsing process by using the -cc1 option; this has the downside of not configuring the default header search paths, so you’ll need to specify the full system path configuration on the command line.
Click to expand...

Perhaps you could try --nostdlibinc?

Disclaimer: I've not done plugins since, oh, Clang 6?
Personal View: Their API was unstable then, I see no evidence that's changed but this is irrelevant to your question.
 
mark_j said:
Your error stems from "In file included from ./section_insertion.h:4:" but you don't show section_insertion.h or is your code commented with "//section_header.h" actually section_insertion.h?

Anyway, perhaps your issue is utilising -cc1? The documentation is explicit here:


Perhaps you could try --nostdlibinc?

Disclaimer: I've not done plugins since, oh, Clang 6?
Personal View: Their API was unstable then, I see no evidence that's changed but this is irrelevant to your question.
Click to expand...
mark_j Again, sorry for not including the full source and header files. I updated them on top.

As you guided and correctly mentioned, I switched from using -cc1 to -Xclang as you cited from the Docs: Running the plugin - Using the cc1 command line
Then, I added -c flag as it explains in Docs: I run clang -cc1 ... and get weird errors about missing headers to only run the preprocess, compile, and assemble steps.

The correct compilation command is:

Code: 
$ clang11 -Xclang -load  -Xclang ./libRenameMacro.so -Xclang -plugin -Xclang PPSplugin -c ../src/test.c -v

st.o -x c ../src/test.c

clang -cc1 version 11.0.1 based upon LLVM 11.0.1 default target x86_64-portbld-freebsd13.0
#include "..." search starts here:
#include <...> search starts here:
     /usr/local/llvm11/lib/clang/11.0.1/include
     /usr/include

End of search list.
encontro func
Output file created - /tmp/test.c

No errors generated. I could get rid of the 4 errors now so I didn't need to add the D __GNUCLIKE_BUILTIN_VARARGS flag.

Thank you very much Mark! I appreciate your help! Have a great week!
 
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