[Lldb-commits] [lldb] [llvm] [lldb][RISCV] function calls support in lldb expressions (PR #99336)

[via lldb-commits]

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@@ -471,6 +498,18 @@ static void SetupTargetOpts(CompilerInstance &compiler,
   // Set the target ABI
   if (std::string abi = GetClangTargetABI(target_arch); !abi.empty())
     compiler.getTargetOpts().ABI = std::move(abi);
+
+  if ((target_machine == llvm::Triple::riscv64 &&
+       compiler.getTargetOpts().ABI == "lp64f") ||
+      (target_machine == llvm::Triple::riscv32 &&
+       compiler.getTargetOpts().ABI == "ilp32f"))
+    compiler->getTargetOpts().FeaturesAsWritten.emplace_back("+f");
+
+  if ((target_machine == llvm::Triple::riscv64 &&
+       compiler.getTargetOpts().ABI == "lp64d") ||
+      (target_machine == llvm::Triple::riscv32 &&
+       compiler.getTargetOpts().ABI == "ilp32d"))
+    compiler->getTargetOpts().FeaturesAsWritten.emplace_back("+d");
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dlav-sc wrote:

> What happens if we just unconditionally add +d and +f? My thinking is that we could maybe just enable these features for all RISCV targets (like we do with x86 sse?) 

To be honest I don't know exactly, but I think it is a bad idea, because some RISCV targets may not support float/double instructions (F/D extension), while MCJIT will create hard-float instructions.

> I'm not super familiar with RISCV but are ilp32d/ilp32f/ilp64f/ilp32f all the supported ABI strings?

Nope, there is ilp32/lp64 for example, that don't support doubles instructions, so the first problem was that MCJIT used ilp32/lp64 ABIs by default, so there weren't any float or double instructions in the resulting assembly. Now I set ABI according to the one in the debuggee binary.

https://github.com/llvm/llvm-project/pull/99336