Hello,
I get a crash in my program that uses exceptions and the LLVM JIT,
even though the exceptions are controlled and thrown/catched in a part
that doesn't deal with LLVM. I noticed that llvm-config --cxxflags
includes the -fno-exceptions flag. Do I need to throw no exceptions
whatsoever in my application to use LLVM JIT?
As a minimal example, I modified the code in
https://github.com/llvm-mirror/llvm/tree/master/examples/Kaleidoscope/BuildingAJIT/Chapter2.
In toy.cpp, I update LogError to throw an exception:
std::unique_ptr<ExprAST> LogError(const char *Str) {
fprintf(stderr, "Error: %s\n", Str);
throw std::runtime_error("");
}
and I catch that exception in MainLoop:
static void MainLoop() {
while (true) {
fprintf(stderr, "ready> ");
try {
switch (CurTok) {
...
}
} catch (std::runtime_error &e) {
fprintf(stderr, "%s\n", e.what());
}
}
}
I compile with:
clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs
--libs core orcjit native` -O3 -fexceptions -o toy
./toy
ready> var 3 = 2
ready> Error: expected identifier after var
ready> 1
terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc
zsh: abort ./toy
Technical details:
- LLVM latest master (commit 2c4ca6832fa6b306ee6a7010bfb80a3f2596f824)
on https://github.com/llvm-mirror/llvm.git
- clang version 8.0.0-3
Thank you,
--
Julien Lopez
Hi Julien, You can turn on exceptions for your example by adding '-frtti -fexceptions' to your clang invocation: clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core orcjit native` -frtti -fexceptions -O3 -fexceptions -o toy You can also enable exception support and RTTI in your LLVM builds by adding -DLLVM_ENABLE_RTTI=On -DLLVM_ENABLE_EH=On to your CMake invocation. Cheers, Lang. On Mon, Nov 18, 2019 at 5:44 AM Julien Lopez via llvm-dev < llvm-dev at lists.llvm.org> wrote:> Hello, > > I get a crash in my program that uses exceptions and the LLVM JIT, > even though the exceptions are controlled and thrown/catched in a part > that doesn't deal with LLVM. I noticed that llvm-config --cxxflags > includes the -fno-exceptions flag. Do I need to throw no exceptions > whatsoever in my application to use LLVM JIT? > > As a minimal example, I modified the code in > > https://github.com/llvm-mirror/llvm/tree/master/examples/Kaleidoscope/BuildingAJIT/Chapter2 > . > In toy.cpp, I update LogError to throw an exception: > > std::unique_ptr<ExprAST> LogError(const char *Str) { > fprintf(stderr, "Error: %s\n", Str); > throw std::runtime_error(""); > } > > and I catch that exception in MainLoop: > > static void MainLoop() { > while (true) { > fprintf(stderr, "ready> "); > try { > switch (CurTok) { > ... > } > } catch (std::runtime_error &e) { > fprintf(stderr, "%s\n", e.what()); > } > } > } > > I compile with: > > clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs > --libs core orcjit native` -O3 -fexceptions -o toy > ./toy > ready> var 3 = 2 > ready> Error: expected identifier after var > > ready> 1 > terminate called after throwing an instance of 'std::bad_alloc' > what(): std::bad_alloc > zsh: abort ./toy > > Technical details: > - LLVM latest master (commit 2c4ca6832fa6b306ee6a7010bfb80a3f2596f824) > on https://github.com/llvm-mirror/llvm.git > - clang version 8.0.0-3 > > Thank you, > > -- > Julien Lopez > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20191121/00b59c4b/attachment.html>
Hi Lang, Thank you for your reply. I didn't know about LLVM_ENABLE_RTTI and LLVM_ENABLE_EH, I'll give it a try. I realized yesterday that my minimal example doesn't actually capture the error I get in my real application, my mistake. I'll investigate all of this and come back with a better minimal example if I can't figure it out on my own. Thanks again! -- Julien On Thu, 21 Nov 2019 at 21:01, Lang Hames <lhames at gmail.com> wrote:> > Hi Julien, > > You can turn on exceptions for your example by adding '-frtti -fexceptions' to your clang invocation: > > clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core orcjit native` -frtti -fexceptions -O3 -fexceptions -o toy > > You can also enable exception support and RTTI in your LLVM builds by adding -DLLVM_ENABLE_RTTI=On -DLLVM_ENABLE_EH=On to your CMake invocation. > > Cheers, > Lang. > > > > On Mon, Nov 18, 2019 at 5:44 AM Julien Lopez via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> >> Hello, >> >> I get a crash in my program that uses exceptions and the LLVM JIT, >> even though the exceptions are controlled and thrown/catched in a part >> that doesn't deal with LLVM. I noticed that llvm-config --cxxflags >> includes the -fno-exceptions flag. Do I need to throw no exceptions >> whatsoever in my application to use LLVM JIT? >> >> As a minimal example, I modified the code in >> https://github.com/llvm-mirror/llvm/tree/master/examples/Kaleidoscope/BuildingAJIT/Chapter2. >> In toy.cpp, I update LogError to throw an exception: >> >> std::unique_ptr<ExprAST> LogError(const char *Str) { >> fprintf(stderr, "Error: %s\n", Str); >> throw std::runtime_error(""); >> } >> >> and I catch that exception in MainLoop: >> >> static void MainLoop() { >> while (true) { >> fprintf(stderr, "ready> "); >> try { >> switch (CurTok) { >> ... >> } >> } catch (std::runtime_error &e) { >> fprintf(stderr, "%s\n", e.what()); >> } >> } >> } >> >> I compile with: >> >> clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs >> --libs core orcjit native` -O3 -fexceptions -o toy >> ./toy >> ready> var 3 = 2 >> ready> Error: expected identifier after var >> >> ready> 1 >> terminate called after throwing an instance of 'std::bad_alloc' >> what(): std::bad_alloc >> zsh: abort ./toy >> >> Technical details: >> - LLVM latest master (commit 2c4ca6832fa6b306ee6a7010bfb80a3f2596f824) >> on https://github.com/llvm-mirror/llvm.git >> - clang version 8.0.0-3 >> >> Thank you, >> >> -- >> Julien Lopez >> _______________________________________________ >> LLVM Developers mailing list >> llvm-dev at lists.llvm.org >> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev