[PATCH] D74698: [CodeGen] -pg shouldn't add "frame-pointer"="all" fn attr w/ -mfentry

[Nick Desaulniers via Phabricator via cfe-commits]

nickdesaulniers created this revision.
nickdesaulniers added reviewers: void, manojgupta, dberris.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

$ clang -O2 -pg -mfentry foo.c

was adding frame pointers to all functions. This was exposed via
compiling the Linux kernel for x86_64 with CONFIG_FUNCTION_TRACER
enabled.

Fixes: pr/44934


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D74698

Files:
  clang/lib/Driver/ToolChains/Clang.cpp
  clang/test/CodeGen/fentry.c


Index: clang/test/CodeGen/fentry.c
===================================================================
--- clang/test/CodeGen/fentry.c
+++ clang/test/CodeGen/fentry.c
@@ -2,6 +2,7 @@
 // RUN: %clang_cc1 -pg -mfentry -triple x86_64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s
 // RUN: %clang_cc1 -mfentry -triple i386-unknown-unknown -emit-llvm -o - %s | FileCheck -check-prefix=NOPG %s
 // RUN: %clang_cc1 -mfentry -triple x86_64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck -check-prefix=NOPG %s
+// RUN: %clang_cc1 -pg -mfentry -emit-llvm -o - %s | FileCheck -check-prefix=NOFP  %s
 
 int foo(void) {
   return 0;
@@ -16,3 +17,4 @@
 //CHECK-NOT: attributes #1 = { {{.*}}"fentry-call"="true"{{.*}} }
 //NOPG-NOT: attributes #0 = { {{.*}}"fentry-call"{{.*}} }
 //NOPG-NOT: attributes #1 = { {{.*}}"fentry-call"{{.*}} }
+//NOFP-NOT: "frame-pointer"="all"
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -526,7 +526,7 @@
 
 static bool useFramePointerForTargetByDefault(const ArgList &Args,
                                               const llvm::Triple &Triple) {
-  if (Args.hasArg(options::OPT_pg))
+  if (Args.hasArg(options::OPT_pg) && !Args.hasArg(options::OPT_mfentry))
     return true;
 
   switch (Triple.getArch()) {
@@ -6150,7 +6150,8 @@
   }
 
   if (Arg *A = Args.getLastArg(options::OPT_pg))
-    if (FPKeepKind == CodeGenOptions::FramePointerKind::None)
+    if (FPKeepKind == CodeGenOptions::FramePointerKind::None &&
+        !Args.hasArg(options::OPT_mfentry))
       D.Diag(diag::err_drv_argument_not_allowed_with) << "-fomit-frame-pointer"
                                                       << A->getAsString(Args);
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D74698.244915.patch
Type: text/x-patch
Size: 1808 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200217/88aba1f5/attachment.bin>