Giters

ARM-software / LLVM-embedded-toolchain-for-Arm

A project dedicated to building LLVM toolchain for 32-bit Arm embedded targets.

Geek Repo:Geek Repo

Github PK Tool:Github PK Tool

Cannot compile simple c++ program

erectcrested opened this issue · comments

commented

Hi.
I am trying to compile simple c++ program with semihosting without success. My cmdline is:

clang++ -o hello hello.cpp --config aarch64_semihost.cfg -T picolibcpp.ld -fuse-ld=lld

The program is:

#include <iostream>
using namespace std;

int main(int argc, char *argv[])
{
    cout << "Hello world!" << endl;
    return 0;
}

Since few commits ago it localization was not enabled so iostream was not usable at all. After localization was enabled I got some errors regarding wide characters support in iostream.

After changing -DLIBCXX_ENABLE_WIDE_CHARACTERS=OFF to -DLIBCXX_ENABLE_WIDE_CHARACTERS=ON in CMakeLists.txt I am getting the following errors:

clang++ -o hello hello.cpp --config aarch64_semihost.cfg -T picolibcpp.ld -fuse-ld=lld
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 948 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 1756 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 1764 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 1824 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 1956 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 2124 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 2304 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 2472 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 2648 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 2816 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 2912 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4048 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4144 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4236 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4332 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4424 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4520 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4612 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 4808 bytes
ld.lld: error: section '.text' will not fit in region 'flash': overflowed by 5032 bytes
ld.lld: error: too many errors emitted, stopping now (use --error-limit=0 to see all errors)
clang-16: error: ld.lld command failed with exit code 1 (use -v to see invocation)

commented

After localization was enabled I got some errors regarding wide characters support in iostream

It's possible your llvm-project checkout isn't up to date.

LIBCXX_ENABLE_WIDE_CHARACTERS=ON is not supported. However the errors you pasted don't look related to that. You might to change your linker script. See Using picolibc.ld.

See this test for an example of how to build a Hello World.

commented

Is there a reason why LIBCXX_ENABLE_WIDE_CHARACTERS=ON don't work?
I have juts now used the link you sent me and I saw you use microbit.ld script which is a wrapper around picolibc.ld script, just that it adds all the nesseccary sections location and sizes for: _flash and _ram.
So by using -T microbit.ld which I copied from here instead of -T picolibcpp.ld, the compilation finished successfully.

My toolchain is compiled with LIBCXX_ENABLE_WIDE_CHARACTERS=ON. Would it cause any problems?

commented

With LIBCXX_ENABLE_WIDE_CHARACTERS=ON I get error: undefined symbol: swprintf while linking the samples.

Glad you got it working.