[RISCV] Pass target-abi via module flag metadata

[khchen]

Summary

in D71387, and this we agree encoding target-abi in module would make sense.
This patch only emit target-abi for RISCV because the first user is probably only the RISC-V target.

[lenary]

Please can you also add code for ensuring that the target-abi module flag matches the -target-abi command line flag in llvm?

[khchen]

In D72755#1821540, @lenary wrote:

Please can you also add code for ensuring that the target-abi module flag matches the -target-abi command line flag in llvm?

please see D72768, thanks!

[lenary]

LGTM, Thank You!

clang/lib/CodeGen/CodeGenModule.cpp

if (   Arch == llvm::Triple::arm
       || Arch == llvm::Triple::armeb
       || Arch == llvm::Triple::thumb
       || Arch == llvm::Triple::thumbeb) {
     // The minimum width of an enum in bytes
     uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
     getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
   }
 
+  if (Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64) {
+    StringRef ABIStr = Target.getABI();
+    llvm::LLVMContext &Ctx = TheModule.getContext();
+    getModule().addModuleFlag(llvm::Module::Error, "target-abi",
+                              llvm::MDString::get(Ctx, ABIStr));
+  }
+
   if (CodeGenOpts.SanitizeCfiCrossDso) {
     // Indicate that we want cross-DSO control flow integrity checks.
     getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
   }
 
   if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
     getModule().addModuleFlag(llvm::Module::Override,
                               "CFI Canonical Jump Tables",

clang/test/CodeGen/riscv-metadata.c

+// RUN: %clang_cc1 -triple riscv32 -target-abi ilp32 -emit-llvm -o - %s | FileCheck -check-prefix=ILP32 %s
+// RUN: %clang_cc1 -triple riscv32 -target-feature +f -target-abi ilp32f -emit-llvm -o - %s | FileCheck -check-prefix=ILP32F %s
+// RUN: %clang_cc1 -triple riscv32 -target-feature +d -target-abi ilp32d -emit-llvm -o - %s | FileCheck -check-prefix=ILP32D %s
+// RUN: %clang_cc1 -triple riscv64 -target-abi lp64 -emit-llvm -o - %s | FileCheck -check-prefix=LP64 %s
+// RUN: %clang_cc1 -triple riscv64 -target-feature +f -target-abi lp64f -emit-llvm -o - %s | FileCheck -check-prefix=LP64F %s
+// RUN: %clang_cc1 -triple riscv64 -target-feature +d -target-abi lp64d -emit-llvm -o - %s | FileCheck -check-prefix=LP64D %s
+
+// ILP32: !{{[0-9]+}} = !{i32 1, !"target-abi", !"ilp32"}
+// ILP32F: !{{[0-9]+}} = !{i32 1, !"target-abi", !"ilp32f"}
+// ILP32D: !{{[0-9]+}} = !{i32 1, !"target-abi", !"ilp32d"}
+
+// LP64: !{{[0-9]+}} = !{i32 1, !"target-abi", !"lp64"}
+// LP64F: !{{[0-9]+}} = !{i32 1, !"target-abi", !"lp64f"}
+// LP64D: !{{[0-9]+}} = !{i32 1, !"target-abi", !"lp64d"}