I am trying to use libclang for source code analysis in an IDE for embedded software.
When targeting an ARM processor, I use -target arm-none-eabi to make sure that the appropriate preprocessor macros are defined, and this works well. I am also using -isystem to point libclang to the include files for my arm cross-compiler.
When I try to do the same for a RISC-V target using -target riscv-none-embed, clang_indexSourceFile returns error code 1 (CXError_Failure), which is a “generic error code, no further details are available” according to the comments in clang-c/CxErrorCode.h.
Does this mean that the RISC-V target is not supported yet, or is something else missing? Am I using the wrong target? In general, when clang_indexSourceFile returns an error code, is there a way to figure out the cause?
The C++ program below reproduces the problem. After installing either llvm-9.0.1 or the latest version on the master branch, compile with
g++ -o myclang myclang.cpp
and run with
./myclang -target riscv-none-embed empty.c
where empty.c is an empty file. The output is “Clang error 1: internal error”, and the return code is 1. Adding a source file and/or -isystem options does not change that. With -target arm-none-eabi, it succeeds (no output, return code 0).
Contents of myclang.cpp:
#include <clang-c/Index.h>
#include <iostream>
int main(int argc, char **argv)
{
CXIndex index = clang_createIndex(1, /*report diagnostics on stderr = */1);
CXIndexAction index_action = clang_IndexAction_create(index);
CXTranslationUnit clang_unit = 0;
unsigned clang_error = clang_indexSourceFile(
index_action,
0, // client data
0, 0, // callbacks
CXIndexOpt_IndexFunctionLocalSymbols | CXIndexOpt_IndexImplicitTemplateInstantiations,
0, // source file, or null if included in args
argv, argc,
0, 0, // unsaved files
&clang_unit, //&translation unit pointer or null
CXTranslationUnit_KeepGoing | CXTranslationUnit_DetailedPreprocessingRecord
);
if (clang_error) {
const char *clang_message[] = {
"no error",
"internal error", // Also returned when main source file cannot be opened
"crashed",
"invalid arguments",
"deserialization error"
};
const char *message = clang_message[
clang_error >= sizeof(clang_message)/sizeof(*clang_message)
? 1 : clang_error
];
std::cerr << "Clang error " << clang_error << ": " << message << std::endl;
}
return clang_error;
}