commit 00733b2cefbdd4763554f4f40b53265a60428fdb
author Nathan Chancellor <nathan@kernel.org> Tue Mar 23 15:16:50 2021 -0700
committer Copybara-Service <copybara-worker@google.com> Thu Mar 25 13:19:47 2021 -0700
tree 26d05cf5105544beaa903dbd17f9fa8b80999769
parent dd8d537de46b54909c527de66157547af48310b4

[RISCV] Fix mcount name

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.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D98881

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
GitOrigin-RevId: ef58ae86ba778ed7d01cd3f6bd6d08f943abab44

lib/Basic/Targets/OSTargets.h

diff --git a/lib/Basic/Targets/OSTargets.h b/lib/Basic/Targets/OSTargets.h
index 539466c..4de1b8d 100644
--- a/lib/Basic/Targets/OSTargets.h
+++ b/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;
     }
   }
 };

lib/Basic/Targets/RISCV.h

diff --git a/lib/Basic/Targets/RISCV.h b/lib/Basic/Targets/RISCV.h
index abae51e..8df6e05 100644
--- a/lib/Basic/Targets/RISCV.h
+++ b/lib/Basic/Targets/RISCV.h
@@ -59,6 +59,7 @@
     WCharType = SignedInt;
     WIntType = UnsignedInt;
     HasRISCVVTypes = true;
+    MCountName = "_mcount";
   }
 
   bool setCPU(const std::string &Name) override {

test/CodeGen/mcount.c

diff --git a/test/CodeGen/mcount.c b/test/CodeGen/mcount.c
index 649f0b5..8f994ab 100644
--- a/test/CodeGen/mcount.c
+++ b/test/CodeGen/mcount.c
@@ -12,6 +12,13 @@
 // 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-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