[cfe-dev] prepare for calling ParseAST. Fatal error

[Manuel Klimek via cfe-dev]

What's your overall goal? If you want to write a clang AST based too, I'd
propose to look at libtooling (http://clang.llvm.org/docs/LibTooling.html)
which handles all this setup for you.

On Tue, Nov 1, 2016 at 3:19 PM Ivan Kush via cfe-dev <cfe-dev at lists.llvm.org>
wrote:

> I'm reading the book `Getting Started with LLVM Core Libraries` and trying
> to implement an example from page 100 `Chapter 4: Frontend`. But got an
> error on the last line of code `clang::ParseAST(CI.getSema());`:
>
>     [bash at bash book]$ ./book_clang test.c
>     fatal error: error opening file '<invalid loc>':
>
>
> What should I add to prepare for `ParseAST`?
>
> code:
>
>     #include "llvm/ADT/IntrusiveRefCntPtr.h"
>     #include "llvm/Support/CommandLine.h"
>
>     #include "clang/Basic/Diagnostic.h"
>
>     #include "clang/Frontend/CompilerInstance.h"
>
>     #include "clang/Basic/TargetInfo.h"
>     #include "clang/Basic/TargetOptions.h"
>
>     #include "llvm/Support/Host.h"
>     #include <memory>
>     #include <string>
>
>     #include "clang/Basic/FileManager.h"
>     #include "clang/Basic/SourceManager.h"
>     #include "clang/Lex/PreprocessorOptions.h"
>     #include "clang/Lex/Preprocessor.h"
>
>     #include "clang/AST/ASTConsumer.h"
>     #include "clang/Frontend/ASTConsumers.h"
>
>     #include "llvm/Support/raw_ostream.h"
>
>     #include "clang/Parse/ParseAST.h"
>
>     #include "clang/AST/ASTContext.h"
>
>
>     static llvm::cl::opt<std::string> fileName(llvm::cl::Positional,
> llvm::cl::desc("Input file"), llvm::cl::Required);
>
>     int main(int argc, char **argv)
>     {
>         llvm::cl::ParseCommandLineOptions(argc, argv, "My simple front
> end\n");
>         clang::CompilerInstance CI;
>         clang::DiagnosticOptions diagnosticOptions;
>         CI.createDiagnostics();
>
>         std::shared_ptr<clang::TargetOptions> PTO =
> std::make_shared<clang::TargetOptions>();
>         PTO->Triple = llvm::sys::getDefaultTargetTriple();
>         clang::TargetInfo *PTI =
> clang::TargetInfo::CreateTargetInfo(CI.getDiagnostics(), PTO);
>         CI.setTarget(PTI);
>
>         CI.createFileManager();//References getFileSystemOpts(),
> clang::vfs::getRealFileSystem(), hasVirtualFileSystem(), and
> setVirtualFileSystem().
>         CI.createSourceManager( CI.getFileManager());//References
> getDiagnostics().
>         CI.createPreprocessor(clang::TU_Complete);
>         CI.getPreprocessorOpts().UsePredefines = false;
>
>         std::unique_ptr< clang::ASTConsumer > astConsumer =
> clang::CreateASTPrinter(NULL, "");
>         CI.setASTConsumer(std::move(astConsumer));
>
>         CI.createASTContext();
>         CI.createSema(clang::TU_Complete, NULL);//after getASTConsumer(),
> getASTContext(), and getPreprocessor().
>         const clang::FileEntry *file =
> CI.getFileManager().getFile(fileName);
>         if (!file) {
>             llvm::errs() << "File not found: " << fileName;
>             return 1;
>         }
>         CI.getSourceManager().createFileID(file, clang::SourceLocation(),
> clang::SrcMgr::C_User);
>
>
>         CI.getDiagnosticClient().BeginSourceFile(CI.getLangOpts(), 0);
>         clang::ParseAST(CI.getSema());
>         // Print AST statistics
>     //   CI.getASTContext().PrintStats();
>     //  CI.getASTContext().Idents.PrintStats();
>
>         return 0;
>     }
>
> for executable need to pass c-file, for example:
> **test.c**
>
>     int main() {
>     char *msg = "Hello, world!\n";
>     write(1, msg, 14);
>     return 0;
>     }
>
>
>
>
> --
> Best wishes,
> Ivan Kush
> _______________________________________________
> cfe-dev mailing list
> cfe-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>
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