phosek updated this revision to Diff 365635.
phosek retitled this revision from "[InstrProfiling] Generate runtime hook for
ELF platforms" to "[InstrProfiling] Generate runtime hook for Fuchsia".
phosek edited the summary of this revision.
phosek added a comment.
I have reworked the change and restricted it only to Fuchsia for now which is
where this change is still desirable.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D98061/new/
https://reviews.llvm.org/D98061
Files:
clang/docs/UsersManual.rst
clang/lib/Driver/ToolChains/Fuchsia.cpp
clang/lib/Driver/ToolChains/Fuchsia.h
clang/test/Driver/fuchsia.c
llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
llvm/test/Instrumentation/InstrProfiling/profiling.ll
Index: llvm/test/Instrumentation/InstrProfiling/profiling.ll
===================================================================
--- llvm/test/Instrumentation/InstrProfiling/profiling.ll
+++ llvm/test/Instrumentation/InstrProfiling/profiling.ll
@@ -54,11 +54,12 @@
declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
-; ELF: @llvm.compiler.used = appending global {{.*}} @__llvm_profile_runtime_user {{.*}} @__profd_foo {{.*}} @__profd_bar {{.*}} @__profd_baz
+; ELF: @llvm.compiler.used = appending global {{.*}} @__llvm_profile_runtime {{.*}} @__profd_foo {{.*}} @__profd_bar {{.*}} @__profd_baz
; MACHO: @llvm.used = appending global {{.*}} @__llvm_profile_runtime_user {{.*}} @__profd_foo {{.*}} @__profd_bar {{.*}} @__profd_baz
; WIN: @llvm.compiler.used = appending global {{.*}} @__llvm_profile_runtime_user {{.*}} @__profd_foo {{.*}} @__profd_bar {{.*}} @__profd_baz
; ELF_GENERIC: define internal void @__llvm_profile_register_functions() unnamed_addr {
+; ELF_GENERIC-NEXT: call void @__llvm_profile_register_function(i8* bitcast (i32* @__llvm_profile_runtime to i8*))
; ELF_GENERIC-NEXT: call void @__llvm_profile_register_function(i8* bitcast ({ i64, i64, i64, i8*, i8*, i32, [2 x i16] }* @__profd_foo to i8*))
; ELF_GENERIC-NEXT: call void @__llvm_profile_register_function(i8* bitcast ({ i64, i64, i64, i8*, i8*, i32, [2 x i16] }* @__profd_bar to i8*))
; ELF_GENERIC-NEXT: call void @__llvm_profile_register_function(i8* bitcast ({ i64, i64, i64, i8*, i8*, i32, [2 x i16] }* @__profd_baz to i8*))
Index: llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -548,8 +548,11 @@
UsedVars.clear();
TT = Triple(M.getTargetTriple());
+ bool MadeChange;
+
// Emit the runtime hook even if no counters are present.
- bool MadeChange = emitRuntimeHook();
+ if (!TT.isOSFuchsia())
+ MadeChange = emitRuntimeHook();
// Improve compile time by avoiding linear scans when there is no work.
GlobalVariable *CoverageNamesVar =
@@ -589,6 +592,8 @@
emitVNodes();
emitNameData();
emitRegistration();
+ if (!TT.isOSFuchsia())
+ emitRuntimeHook();
emitUses();
emitInitialization();
return true;
@@ -1110,9 +1115,9 @@
}
bool InstrProfiling::emitRuntimeHook() {
- // We expect the linker to be invoked with -u<hook_var> flag for Linux or
- // Fuchsia, in which case there is no need to emit the user function.
- if (TT.isOSLinux() || TT.isOSFuchsia())
+ // We expect the linker to be invoked with -u<hook_var> flag for Linux
+ // in which case there is no need to emit the external variable.
+ if (TT.isOSLinux())
return false;
// If the module's provided its own runtime, we don't need to do anything.
@@ -1125,23 +1130,28 @@
new GlobalVariable(*M, Int32Ty, false, GlobalValue::ExternalLinkage,
nullptr, getInstrProfRuntimeHookVarName());
- // Make a function that uses it.
- auto *User = Function::Create(FunctionType::get(Int32Ty, false),
- GlobalValue::LinkOnceODRLinkage,
- getInstrProfRuntimeHookVarUseFuncName(), M);
- User->addFnAttr(Attribute::NoInline);
- if (Options.NoRedZone)
- User->addFnAttr(Attribute::NoRedZone);
- User->setVisibility(GlobalValue::HiddenVisibility);
- if (TT.supportsCOMDAT())
- User->setComdat(M->getOrInsertComdat(User->getName()));
-
- IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", User));
- auto *Load = IRB.CreateLoad(Int32Ty, Var);
- IRB.CreateRet(Load);
-
- // Mark the user variable as used so that it isn't stripped out.
- CompilerUsedVars.push_back(User);
+ if (TT.isOSBinFormatELF()) {
+ // Mark the user variable as used so that it isn't stripped out.
+ CompilerUsedVars.push_back(Var);
+ } else {
+ // Make a function that uses it.
+ auto *User = Function::Create(FunctionType::get(Int32Ty, false),
+ GlobalValue::LinkOnceODRLinkage,
+ getInstrProfRuntimeHookVarUseFuncName(), M);
+ User->addFnAttr(Attribute::NoInline);
+ if (Options.NoRedZone)
+ User->addFnAttr(Attribute::NoRedZone);
+ User->setVisibility(GlobalValue::HiddenVisibility);
+ if (TT.supportsCOMDAT())
+ User->setComdat(M->getOrInsertComdat(User->getName()));
+
+ IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", User));
+ auto *Load = IRB.CreateLoad(Int32Ty, Var);
+ IRB.CreateRet(Load);
+
+ // Mark the function as used so that it isn't stripped out.
+ CompilerUsedVars.push_back(User);
+ }
return true;
}
Index: clang/test/Driver/fuchsia.c
===================================================================
--- clang/test/Driver/fuchsia.c
+++ clang/test/Driver/fuchsia.c
@@ -249,7 +249,6 @@
// RUN: -fuse-ld=lld 2>&1 \
// RUN: | FileCheck %s -check-prefix=CHECK-PROFRT-AARCH64
// CHECK-PROFRT-AARCH64: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
-// CHECK-PROFRT-AARCH64: "-u__llvm_profile_runtime"
// CHECK-PROFRT-AARCH64: "[[RESOURCE_DIR]]{{/|\\\\}}lib{{/|\\\\}}aarch64-unknown-fuchsia{{/|\\\\}}libclang_rt.profile.a"
// RUN: %clang %s -### --target=x86_64-unknown-fuchsia \
@@ -258,5 +257,4 @@
// RUN: -fuse-ld=lld 2>&1 \
// RUN: | FileCheck %s -check-prefix=CHECK-PROFRT-X86_64
// CHECK-PROFRT-X86_64: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
-// CHECK-PROFRT-X86_64: "-u__llvm_profile_runtime"
// CHECK-PROFRT-X86_64: "[[RESOURCE_DIR]]{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}libclang_rt.profile.a"
Index: clang/lib/Driver/ToolChains/Fuchsia.h
===================================================================
--- clang/lib/Driver/ToolChains/Fuchsia.h
+++ clang/lib/Driver/ToolChains/Fuchsia.h
@@ -71,9 +71,6 @@
SanitizerMask getSupportedSanitizers() const override;
SanitizerMask getDefaultSanitizers() const override;
- void addProfileRTLibs(const llvm::opt::ArgList &Args,
- llvm::opt::ArgStringList &CmdArgs) const override;
-
RuntimeLibType
GetRuntimeLibType(const llvm::opt::ArgList &Args) const override;
CXXStdlibType
Index: clang/lib/Driver/ToolChains/Fuchsia.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Fuchsia.cpp
+++ clang/lib/Driver/ToolChains/Fuchsia.cpp
@@ -437,13 +437,3 @@
}
return Res;
}
-
-void Fuchsia::addProfileRTLibs(const llvm::opt::ArgList &Args,
- llvm::opt::ArgStringList &CmdArgs) const {
- // Add linker option -u__llvm_profile_runtime to cause runtime
- // initialization module to be linked in.
- if (needsProfileRT(Args))
- CmdArgs.push_back(Args.MakeArgString(
- Twine("-u", llvm::getInstrProfRuntimeHookVarName())));
- ToolChain::addProfileRTLibs(Args, CmdArgs);
-}
Index: clang/docs/UsersManual.rst
===================================================================
--- clang/docs/UsersManual.rst
+++ clang/docs/UsersManual.rst
@@ -2345,6 +2345,14 @@
Note that these flags should appear after the corresponding profile
flags to have an effect.
+.. note::
+
+ When none of the translation units inside a binary is instrumented, in the
+ case of Fuchsia the profile runtime will not be linked into the binary and
+ no profile will be produced, while on other platforms the profile runtime
+ will be linked and profile will be produced but there will not be any
+ counters.
+
Instrumenting only selected files or functions
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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