71910784b3
When there is an error introduced by #include-ing a file we should be able to hit the disk (in cling's context) the next time. The user could fix it in the meanwhile. Newer clang supports a flag which can be used to mark the user files as volatile. This means that the file stat will be invalidated, causing clang to hit the disk and fetch the new content of the FileEntry. The complication comes from the fact that when the file size of the file entry is invalidated the cache in the SourceManager is not syncronized, thus clang issued an error. The patch in clang checks if the file size == 0 and the modification time == 0 this means that we are in cling's context and have to sync the cache and continue with no errors. This fixes an issue exposed by Jerome's implementation. Before we removed the entire FileEntry to achieve the same behavior, however the SourceManager kept the reference to it. This leads to seg faults when iterating over the included files (eg. .files or .storeState)
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1. I N S T A L L A T I O N I N S T R U C T I O N S
1.1 Dependencies
CLING source depends on the LLVM [1] and CLANG [2] headers and libraries.
You will also need CMake [3] >= 2.6.1 or GNU Make to build all of those
packages and subversion [4] to get the source code.
[1] http://llvm.org
[2] http://clang.llvm.org
[3] http://cmake.org
[4] http://subversion.tigris.org/
1.2 Building
To build LLVM and CLANG you must:
* Check out the sources:
mkdir src
cd src
svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm
cd llvm/tools
svn co http://llvm.org/svn/llvm-project/cfe/trunk clang
svn co http://root.cern.ch/svn/root/trunk/interpreter/cling cling
cd ..
* Apply some patches
cat tools/cling/patches/* | patch -p0
* Configure, build and install them, either using CMake:
cd ..
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=/some/install/dir \
-DLLVM_TARGETS_TO_BUILD=CBackend\;CppBackend\;X86 \
-DCMAKE_BUILD_TYPE=Debug \
-DCMAKE_CXX_COMPILER=`which c++` \
-DCMAKE_C_COMPILER=`which gcc` \
../llvm
make
make install
or GNU Make (see ../src/configure --help for all options):
cd ..
mkdir build
cd build
../llvm/configure --prefix=/some/install/dir
make
make install
2. U S A G E
To interpret a C file type: "./cling test.c". To invoke cling in the
interactive mode type "cling" without file name. Use ".L filename" to
load libraries or C++ files. Type C++ code at the prompt to interpret it.