[llvm] 121a49d - [LiveDebugValues] Add switches for using instr-ref variable locations
Jeremy Morse via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 25 06:59:29 PDT 2020
Author: Jeremy Morse
Date: 2020-08-25T14:58:48+01:00
New Revision: 121a49d839d79f5a72be3e22a9d156c9e4b219dc
URL: https://github.com/llvm/llvm-project/commit/121a49d839d79f5a72be3e22a9d156c9e4b219dc
DIFF: https://github.com/llvm/llvm-project/commit/121a49d839d79f5a72be3e22a9d156c9e4b219dc.diff
LOG: [LiveDebugValues] Add switches for using instr-ref variable locations
This patch adds the -Xclang option
"-fexperimental-debug-variable-locations" and same LLVM CodeGen option,
to pick which variable location tracking solution to use.
Right now all the switch does is pick which LiveDebugValues
implementation to use, the normal VarLoc one or the instruction
referencing one in rGae6f78824031. Over time, the aim is to add fragments
of support in aid of the value-tracking RFC:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139440.html
also controlled by this command line switch. That will slowly move
variable locations to be defined by an instruction calculating a value,
and a DBG_INSTR_REF instruction referring to that value. Thus, this is
going to grow into a "use the new kind of variable locations" switch,
rather than just "use the new LiveDebugValues implementation".
Differential Revision: https://reviews.llvm.org/D83048
Added:
clang/test/Driver/debug-var-experimental-switch.c
Modified:
clang/include/clang/Basic/CodeGenOptions.def
clang/include/clang/Driver/Options.td
clang/lib/CodeGen/BackendUtil.cpp
clang/lib/Frontend/CompilerInvocation.cpp
llvm/include/llvm/CodeGen/CommandFlags.h
llvm/include/llvm/Target/TargetOptions.h
llvm/lib/CodeGen/CommandFlags.cpp
llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def
index cbd9df998e78..0f03373c4e25 100644
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -325,6 +325,9 @@ ENUM_CODEGENOPT(DebuggerTuning, llvm::DebuggerKind, 2,
/// emitted.
VALUE_CODEGENOPT(DwarfVersion, 3, 0)
+/// Whether to use experimental new variable location tracking.
+CODEGENOPT(ValueTrackingVariableLocations, 1, 0)
+
/// Whether we should emit CodeView debug information. It's possible to emit
/// CodeView and DWARF into the same object.
CODEGENOPT(EmitCodeView, 1, 0)
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 05aa79d06464..5da072ee4cc2 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -3870,6 +3870,9 @@ def fdebug_pass_manager : Flag<["-"], "fdebug-pass-manager">,
HelpText<"Prints debug information for the new pass manager">;
def fno_debug_pass_manager : Flag<["-"], "fno-debug-pass-manager">,
HelpText<"Disables debug printing for the new pass manager">;
+def fexperimental_debug_variable_locations : Flag<["-"],
+ "fexperimental-debug-variable-locations">,
+ HelpText<"Use experimental new value-tracking variable locations">;
// The driver option takes the key as a parameter to the -msign-return-address=
// and -mbranch-protection= options, but CC1 has a separate option so we
// don't have to parse the parameter twice.
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 566affa91b76..093650ac0066 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -520,6 +520,8 @@ static void initTargetOptions(DiagnosticsEngine &Diags,
Options.EmitAddrsig = CodeGenOpts.Addrsig;
Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
+ Options.ValueTrackingVariableLocations =
+ CodeGenOpts.ValueTrackingVariableLocations;
Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 175985bd950a..0313ff4c363b 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -835,6 +835,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
llvm::is_contained(DebugEntryValueArchs, T.getArch()))
Opts.EmitCallSiteInfo = true;
+ Opts.ValueTrackingVariableLocations =
+ Args.hasArg(OPT_fexperimental_debug_variable_locations);
+
Opts.DisableO0ImplyOptNone = Args.hasArg(OPT_disable_O0_optnone);
Opts.DisableRedZone = Args.hasArg(OPT_disable_red_zone);
Opts.IndirectTlsSegRefs = Args.hasArg(OPT_mno_tls_direct_seg_refs);
diff --git a/clang/test/Driver/debug-var-experimental-switch.c b/clang/test/Driver/debug-var-experimental-switch.c
new file mode 100644
index 000000000000..9c7a782e9e2b
--- /dev/null
+++ b/clang/test/Driver/debug-var-experimental-switch.c
@@ -0,0 +1,2 @@
+// RUN: %clang -Xclang -fexperimental-debug-variable-locations -fsyntax-only -disable-llvm-passes %s
+int main() {}
diff --git a/llvm/include/llvm/CodeGen/CommandFlags.h b/llvm/include/llvm/CodeGen/CommandFlags.h
index 1b77556dcbb1..39df106b97ef 100644
--- a/llvm/include/llvm/CodeGen/CommandFlags.h
+++ b/llvm/include/llvm/CodeGen/CommandFlags.h
@@ -116,6 +116,8 @@ bool getEmitCallSiteInfo();
bool getEnableDebugEntryValues();
+bool getValueTrackingVariableLocations();
+
bool getForceDwarfFrameSection();
bool getXRayOmitFunctionIndex();
diff --git a/llvm/include/llvm/Target/TargetOptions.h b/llvm/include/llvm/Target/TargetOptions.h
index c3f0963f5997..063fa9375114 100644
--- a/llvm/include/llvm/Target/TargetOptions.h
+++ b/llvm/include/llvm/Target/TargetOptions.h
@@ -126,8 +126,8 @@ namespace llvm {
EmitStackSizeSection(false), EnableMachineOutliner(false),
SupportsDefaultOutlining(false), EmitAddrsig(false),
EmitCallSiteInfo(false), SupportsDebugEntryValues(false),
- EnableDebugEntryValues(false), ForceDwarfFrameSection(false),
- XRayOmitFunctionIndex(false),
+ EnableDebugEntryValues(false), ValueTrackingVariableLocations(false),
+ ForceDwarfFrameSection(false), XRayOmitFunctionIndex(false),
FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {}
/// DisableFramePointerElim - This returns true if frame pointer elimination
@@ -285,6 +285,11 @@ namespace llvm {
/// production.
bool ShouldEmitDebugEntryValues() const;
+ // When set to true, use experimental new debug variable location tracking,
+ // which seeks to follow the values of variables rather than their location,
+ // post isel.
+ unsigned ValueTrackingVariableLocations : 1;
+
/// Emit DWARF debug frame section.
unsigned ForceDwarfFrameSection : 1;
diff --git a/llvm/lib/CodeGen/CommandFlags.cpp b/llvm/lib/CodeGen/CommandFlags.cpp
index 0ada09f469b7..a47608cf6dd9 100644
--- a/llvm/lib/CodeGen/CommandFlags.cpp
+++ b/llvm/lib/CodeGen/CommandFlags.cpp
@@ -85,6 +85,7 @@ CGOPT(bool, EnableStackSizeSection)
CGOPT(bool, EnableAddrsig)
CGOPT(bool, EmitCallSiteInfo)
CGOPT(bool, EnableDebugEntryValues)
+CGOPT(bool, ValueTrackingVariableLocations)
CGOPT(bool, ForceDwarfFrameSection)
CGOPT(bool, XRayOmitFunctionIndex)
@@ -400,6 +401,12 @@ codegen::RegisterCodeGenFlags::RegisterCodeGenFlags() {
cl::init(false));
CGBINDOPT(EnableDebugEntryValues);
+ static cl::opt<bool> ValueTrackingVariableLocations(
+ "experimental-debug-variable-locations",
+ cl::desc("Use experimental new value-tracking variable locations"),
+ cl::init(false));
+ CGBINDOPT(ValueTrackingVariableLocations);
+
static cl::opt<bool> ForceDwarfFrameSection(
"force-dwarf-frame-section",
cl::desc("Always emit a debug frame section."), cl::init(false));
@@ -475,6 +482,7 @@ TargetOptions codegen::InitTargetOptionsFromCodeGenFlags() {
Options.EmitAddrsig = getEnableAddrsig();
Options.EmitCallSiteInfo = getEmitCallSiteInfo();
Options.EnableDebugEntryValues = getEnableDebugEntryValues();
+ Options.ValueTrackingVariableLocations = getValueTrackingVariableLocations();
Options.ForceDwarfFrameSection = getForceDwarfFrameSection();
Options.XRayOmitFunctionIndex = getXRayOmitFunctionIndex();
diff --git a/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp b/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp
index b8584e8386cb..770c46ec8436 100644
--- a/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues/LiveDebugValues.cpp
@@ -14,6 +14,7 @@
#include "llvm/CodeGen/Passes.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
+#include "llvm/Target/TargetMachine.h"
/// \file LiveDebugValues.cpp
///
@@ -40,7 +41,10 @@ class LiveDebugValues : public MachineFunctionPass {
static char ID;
LiveDebugValues();
- ~LiveDebugValues() { delete TheImpl; }
+ ~LiveDebugValues() {
+ if (TheImpl)
+ delete TheImpl;
+ }
/// Calculate the liveness information for the given machine function.
bool runOnMachineFunction(MachineFunction &MF) override;
@@ -57,6 +61,7 @@ class LiveDebugValues : public MachineFunctionPass {
private:
LDVImpl *TheImpl;
+ TargetPassConfig *TPC;
};
char LiveDebugValues::ID = 0;
@@ -69,10 +74,24 @@ INITIALIZE_PASS(LiveDebugValues, DEBUG_TYPE, "Live DEBUG_VALUE analysis", false,
/// Default construct and initialize the pass.
LiveDebugValues::LiveDebugValues() : MachineFunctionPass(ID) {
initializeLiveDebugValuesPass(*PassRegistry::getPassRegistry());
- TheImpl = llvm::makeVarLocBasedLiveDebugValues();
+ TheImpl = nullptr;
}
bool LiveDebugValues::runOnMachineFunction(MachineFunction &MF) {
- auto *TPC = getAnalysisIfAvailable<TargetPassConfig>();
+ if (!TheImpl) {
+ TPC = getAnalysisIfAvailable<TargetPassConfig>();
+
+ bool InstrRefBased = false;
+ if (TPC) {
+ auto &TM = TPC->getTM<TargetMachine>();
+ InstrRefBased = TM.Options.ValueTrackingVariableLocations;
+ }
+
+ if (InstrRefBased)
+ TheImpl = llvm::makeInstrRefBasedLiveDebugValues();
+ else
+ TheImpl = llvm::makeVarLocBasedLiveDebugValues();
+ }
+
return TheImpl->ExtendRanges(MF, TPC);
}
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