MaskRay created this revision.
MaskRay added reviewers: dberris, kristof.beyls, nickdesaulniers, rnk, rsmith,
void.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
MaskRay added a parent revision: D72221: Support function attribute
patchable_function_entry.
MaskRay added subscribers: uweigand, jonpa.
In the backend, this feature is implemented with the function attribute
"patchable-function-entry". Both the attribute and XRay use
TargetOpcode::PATCHABLE_FUNCTION_ENTER, so the two features are
incompatible.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D72222
Files:
clang/include/clang/Basic/CodeGenOptions.def
clang/include/clang/Basic/DiagnosticDriverKinds.td
clang/include/clang/Driver/Options.td
clang/lib/CodeGen/CodeGenFunction.cpp
clang/lib/Driver/ToolChains/Clang.cpp
clang/lib/Driver/XRayArgs.cpp
clang/lib/Frontend/CompilerInvocation.cpp
clang/test/CodeGen/patchable-function-entry.c
clang/test/Sema/patchable-function-entry-attr.cpp
Index: clang/test/Sema/patchable-function-entry-attr.cpp
===================================================================
--- clang/test/Sema/patchable-function-entry-attr.cpp
+++ clang/test/Sema/patchable-function-entry-attr.cpp
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 -triple aarch64 -fsyntax-only -verify=silence %s
+// RUN: %clang_cc1 -triple i386 -fsyntax-only -verify=silence %s
// RUN: %clang_cc1 -triple x86_64 -fsyntax-only -verify=silence %s
// RUN: %clang_cc1 -triple ppc64le -fsyntax-only -verify %s
Index: clang/test/CodeGen/patchable-function-entry.c
===================================================================
--- clang/test/CodeGen/patchable-function-entry.c
+++ clang/test/CodeGen/patchable-function-entry.c
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 -triple aarch64 -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64 -emit-llvm %s -fpatchable-function-entry=1 -o - | FileCheck --check-prefixes=CHECK,OPT %s
// CHECK: define void @f0() #0
__attribute__((patchable_function_entry(0))) void f0() {}
@@ -16,5 +17,9 @@
__attribute__((patchable_function_entry(2,0))) void f20decl();
__attribute__((noinline)) void f20decl() {}
+// OPT: define void @f() #2
+void f() {}
+
// CHECK: attributes #0 = { {{.*}} "patchable-function-entry"="0,0"
// CHECK: attributes #1 = { {{.*}} "patchable-function-entry"="2,0"
+// OPT: attributes #2 = { {{.*}} "patchable-function-entry"="1,0"
Index: clang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- clang/lib/Frontend/CompilerInvocation.cpp
+++ clang/lib/Frontend/CompilerInvocation.cpp
@@ -1101,6 +1101,8 @@
parseXRayInstrumentationBundle("-fxray-instrumentation-bundle=", A, Args,
Diags, Opts.XRayInstrumentationBundle);
+ Opts.PatchableFunctionEntrySize =
+ getLastArgIntValue(Args, OPT_fpatchable_function_entry, 0, Diags);
Opts.InstrumentForProfiling = Args.hasArg(OPT_pg);
Opts.CallFEntry = Args.hasArg(OPT_mfentry);
Opts.MNopMCount = Args.hasArg(OPT_mnop_mcount);
Index: clang/lib/Driver/XRayArgs.cpp
===================================================================
--- clang/lib/Driver/XRayArgs.cpp
+++ clang/lib/Driver/XRayArgs.cpp
@@ -70,6 +70,13 @@
D.Diag(diag::err_drv_clang_unsupported)
<< (std::string(XRayInstrumentOption) + " on " + Triple.str());
}
+
+ // Both XRay and -fpatchable-function-entry use
+ // TargetOpcode::PATCHABLE_FUNCTION_ENTER.
+ if (Arg *A = Args.getLastArg(options::OPT_fpatchable_function_entry))
+ D.Diag(diag::err_drv_incompatible_options)
+ << "-fxray-instrument" << A->getSpelling();
+
XRayInstrument = true;
if (const Arg *A =
Args.getLastArg(options::OPT_fxray_instruction_threshold_,
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -4998,6 +4998,24 @@
const XRayArgs &XRay = TC.getXRayArgs();
XRay.addArgs(TC, Args, CmdArgs, InputType);
+ if (Arg *A = Args.getLastArg(options::OPT_fpatchable_function_entry)) {
+ StringRef S0 = A->getValue(), S = S0;
+ unsigned Size, Start = 0;
+ if (!Triple.isAArch64() && Triple.getArch() != llvm::Triple::x86 &&
+ Triple.getArch() != llvm::Triple::x86_64)
+ D.Diag(diag::err_drv_unsupported_opt_for_target)
+ << A->getAsString(Args) << TripleStr;
+ else if (S.consumeInteger(10, Size) ||
+ (!S.empty() && (!S.consume_front(",") ||
+ S.consumeInteger(10, Start) || !S.empty())))
+ D.Diag(diag::err_drv_invalid_argument_to_option)
+ << S0 << A->getOption().getName();
+ else if (Start)
+ D.Diag(diag::err_drv_clang_unsupported) << Start;
+ else
+ CmdArgs.push_back(Args.MakeArgString(A->getSpelling() + Twine(Size)));
+ }
+
if (TC.SupportsProfiling()) {
Args.AddLastArg(CmdArgs, options::OPT_pg);
Index: clang/lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.cpp
+++ clang/lib/CodeGen/CodeGenFunction.cpp
@@ -824,6 +824,8 @@
Fn->addFnAttr(
"patchable-function-entry",
(Twine(Attr->getSize()) + "," + Twine(Attr->getStart())).str());
+ else if (unsigned Size = CGM.getCodeGenOpts().PatchableFunctionEntrySize)
+ Fn->addFnAttr("patchable-function-entry", (Twine(Size) + ",0").str());
}
// Add no-jump-tables value.
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -1700,6 +1700,8 @@
def fno_max_type_align : Flag<["-"], "fno-max-type-align">, Group<f_Group>;
def fpascal_strings : Flag<["-"], "fpascal-strings">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Recognize and construct Pascal-style string literals">;
+def fpatchable_function_entry : Joined<["-"], "fpatchable-function-entry=">, Group<f_Group>, Flags<[CC1Option]>,
+ HelpText<"Generate N NOPs at function entry">;
def fpcc_struct_return : Flag<["-"], "fpcc-struct-return">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Override the default ABI to return all structs on the stack">;
def fpch_preprocess : Flag<["-"], "fpch-preprocess">, Group<f_Group>;
Index: clang/include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticDriverKinds.td
+++ clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -74,6 +74,7 @@
"unsupported runtime library '%0' for platform '%1'">;
def err_drv_invalid_unwindlib_name : Error<
"invalid unwind library name in argument '%0'">;
+def err_drv_incompatible_options : Error<"'%0' and '%1' cannot be used together">;
def err_drv_incompatible_unwindlib : Error<
"--rtlib=libgcc requires --unwindlib=libgcc">;
def err_drv_invalid_stdlib_name : Error<
Index: clang/include/clang/Basic/CodeGenOptions.def
===================================================================
--- clang/include/clang/Basic/CodeGenOptions.def
+++ clang/include/clang/Basic/CodeGenOptions.def
@@ -110,6 +110,8 @@
///< XRay instrumentation.
VALUE_CODEGENOPT(XRayInstructionThreshold , 32, 200)
+VALUE_CODEGENOPT(PatchableFunctionEntrySize , 32, 0) ///< Number of NOPs at function entry
+
CODEGENOPT(InstrumentForProfiling , 1, 0) ///< Set when -pg is enabled.
CODEGENOPT(CallFEntry , 1, 0) ///< Set when -mfentry is enabled.
CODEGENOPT(MNopMCount , 1, 0) ///< Set when -mnop-mcount is enabled.
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