[PATCH] D99220: [RISCV] Fix mcount name

[Nathan Chancellor via Phabricator via cfe-commits]

nathanchance created this revision.
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GCC's name for this symbol is _mcount, which the Linux kernel expects in
a few different place:

  $ echo 'int main(void) { return 0; }' | riscv32-linux-gcc -c -pg -o tmp.o -x c -
  
  $ llvm-objdump -dr tmp.o | grep mcount
                          0000000c:  R_RISCV_CALL _mcount
  
  $ echo 'int main(void) { return 0; }' | riscv64-linux-gcc -c -pg -o tmp.o -x c -
  
  $ llvm-objdump -dr tmp.o | grep mcount
                  000000000000000c:  R_RISCV_CALL _mcount
  
  $ echo 'int main(void) { return 0; }' | clang -c -pg -o tmp.o --target=riscv32-linux-gnu -x c -
  
  $ llvm-objdump -dr tmp.o | grep mcount
                          0000000a:  R_RISCV_CALL_PLT     mcount
  
  $ echo 'int main(void) { return 0; }' | clang -c -pg -o tmp.o --target=riscv64-linux-gnu -x c -
  
  $ llvm-objdump -dr tmp.o | grep mcount
                  000000000000000a:  R_RISCV_CALL_PLT     mcount

Set MCountName to "_mcount" in RISCVTargetInfo then prevent it from
getting overridden in certain OSTargetInfo constructors.

Signed-off-by: Nathan Chancellor <nathan at kernel.org>


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D99220

Files:
  clang/lib/Basic/Targets/OSTargets.h
  clang/lib/Basic/Targets/RISCV.h
  clang/test/CodeGen/mcount.c


Index: clang/test/CodeGen/mcount.c
===================================================================
--- clang/test/CodeGen/mcount.c
+++ clang/test/CodeGen/mcount.c
@@ -12,6 +12,15 @@
 // RUN: %clang_cc1 -pg -triple mipsel-unknown-gnu-linux -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
 // RUN: %clang_cc1 -pg -triple mips64-unknown-gnu-linux -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
 // RUN: %clang_cc1 -pg -triple mips64el-unknown-gnu-linux -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv32 -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv64 -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv32-elf -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv64-elf -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv32-linux -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv64-linux -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv64-freebsd -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv64-freebsd -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
+// RUN: %clang_cc1 -pg -triple riscv64-openbsd -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-PREFIXED,NO-MCOUNT1 %s
 // RUN: %clang_cc1 -pg -triple powerpc-netbsd -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-DOUBLE-PREFIXED,NO-MCOUNT1 %s
 // RUN: %clang_cc1 -pg -triple powerpc64-netbsd -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-DOUBLE-PREFIXED,NO-MCOUNT1 %s
 // RUN: %clang_cc1 -pg -triple powerpc64le-netbsd -emit-llvm -o - %s | FileCheck -check-prefixes=CHECK-DOUBLE-PREFIXED,NO-MCOUNT1 %s
Index: clang/lib/Basic/Targets/RISCV.h
===================================================================
--- clang/lib/Basic/Targets/RISCV.h
+++ clang/lib/Basic/Targets/RISCV.h
@@ -59,6 +59,7 @@
     WCharType = SignedInt;
     WIntType = UnsignedInt;
     HasRISCVVTypes = true;
+    MCountName = "_mcount";
   }
 
   bool setCPU(const std::string &Name) override {
Index: clang/lib/Basic/Targets/OSTargets.h
===================================================================
--- clang/lib/Basic/Targets/OSTargets.h
+++ clang/lib/Basic/Targets/OSTargets.h
@@ -261,6 +261,9 @@
     case llvm::Triple::arm:
       this->MCountName = "__mcount";
       break;
+    case llvm::Triple::riscv32:
+    case llvm::Triple::riscv64:
+      break;
     }
   }
 };
@@ -491,6 +494,9 @@
     case llvm::Triple::sparcv9:
       this->MCountName = "_mcount";
       break;
+    case llvm::Triple::riscv32:
+    case llvm::Triple::riscv64:
+      break;
     }
   }
 };


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