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-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp44
-rw-r--r--llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h37
2 files changed, 71 insertions, 10 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 45875667027..4621ecbb510 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -76,6 +76,17 @@ static cl::opt<bool> GenerateARangeSection("generate-arange-section",
cl::desc("Generate dwarf aranges"),
cl::init(false));
+static cl::opt<DebuggerKind>
+DebuggerTuningOpt("debugger-tune",
+ cl::desc("Tune debug info for a particular debugger"),
+ cl::init(DebuggerKind::Default),
+ cl::values(
+ clEnumValN(DebuggerKind::GDB, "gdb", "gdb"),
+ clEnumValN(DebuggerKind::LLDB, "lldb", "lldb"),
+ clEnumValN(DebuggerKind::SCE, "sce",
+ "SCE targets (e.g. PS4)"),
+ clEnumValEnd));
+
namespace {
enum DefaultOnOff { Default, Enable, Disable };
}
@@ -197,32 +208,44 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
UsedNonDefaultText(false),
SkeletonHolder(A, "skel_string", DIEValueAllocator),
IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
- IsPS4(Triple(A->getTargetTriple()).isPS4()),
AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
dwarf::DW_FORM_data4)),
AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
dwarf::DW_FORM_data4)),
AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
dwarf::DW_FORM_data4)),
- AccelTypes(TypeAtoms) {
+ AccelTypes(TypeAtoms), DebuggerTuning(DebuggerKind::Default) {
CurFn = nullptr;
CurMI = nullptr;
+ Triple TT(Asm->getTargetTriple());
+
+ // Make sure we know our "debugger tuning." The command-line option takes
+ // precedence; fall back to triple-based defaults.
+ if (DebuggerTuningOpt != DebuggerKind::Default)
+ DebuggerTuning = DebuggerTuningOpt;
+ else if (IsDarwin || TT.isOSFreeBSD())
+ DebuggerTuning = DebuggerKind::LLDB;
+ else if (TT.isPS4CPU())
+ DebuggerTuning = DebuggerKind::SCE;
+ else
+ DebuggerTuning = DebuggerKind::GDB;
- // Turn on accelerator tables for Darwin by default, pubnames by
- // default for non-Darwin/PS4, and handle split dwarf.
+ // Turn on accelerator tables for LLDB by default.
if (DwarfAccelTables == Default)
- HasDwarfAccelTables = IsDarwin;
+ HasDwarfAccelTables = tuneForLLDB();
else
HasDwarfAccelTables = DwarfAccelTables == Enable;
+ // Handle split DWARF. Off by default for now.
if (SplitDwarf == Default)
HasSplitDwarf = false;
else
HasSplitDwarf = SplitDwarf == Enable;
+ // Pubnames/pubtypes on by default for GDB.
if (DwarfPubSections == Default)
- HasDwarfPubSections = !IsDarwin && !IsPS4;
+ HasDwarfPubSections = tuneForGDB();
else
HasDwarfPubSections = DwarfPubSections == Enable;
@@ -230,9 +253,12 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
: MMI->getModule()->getDwarfVersion();
- // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
- // Everybody else uses GNU's.
- UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
+ // Work around a GDB bug. GDB doesn't support the standard opcode;
+ // SCE doesn't support GNU's; LLDB prefers the standard opcode, which
+ // is defined as of DWARF 3.
+ // See GDB bug 11616 - DW_OP_form_tls_address is unimplemented
+ // https://sourceware.org/bugzilla/show_bug.cgi?id=11616
+ UseGNUTLSOpcode = tuneForGDB() || DwarfVersion < 3;
Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 36502225c29..57bb8d0229d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -203,6 +203,30 @@ struct SymbolCU {
DwarfCompileUnit *CU;
};
+/// Identify a debugger for "tuning" the debug info.
+///
+/// The "debugger tuning" concept allows us to present a more intuitive
+/// interface that unpacks into different sets of defaults for the various
+/// individual feature-flag settings, that suit the preferences of the
+/// various debuggers. However, it's worth remembering that debuggers are
+/// not the only consumers of debug info, and some variations in DWARF might
+/// better be treated as target/platform issues. Fundamentally,
+/// o if the feature is useful (or not) to a particular debugger, regardless
+/// of the target, that's a tuning decision;
+/// o if the feature is useful (or not) on a particular platform, regardless
+/// of the debugger, that's a target decision.
+/// It's not impossible to see both factors in some specific case.
+///
+/// The "tuning" should be used to set defaults for individual feature flags
+/// in DwarfDebug; if a given feature has a more specific command-line option,
+/// that option should take precedence over the tuning.
+enum class DebuggerKind {
+ Default, // No specific tuning requested.
+ GDB, // Tune debug info for gdb.
+ LLDB, // Tune debug info for lldb.
+ SCE // Tune debug info for SCE targets (e.g. PS4).
+};
+
/// Collects and handles dwarf debug information.
class DwarfDebug : public AsmPrinterHandler {
/// Target of Dwarf emission.
@@ -338,7 +362,6 @@ class DwarfDebug : public AsmPrinterHandler {
/// True iff there are multiple CUs in this module.
bool SingleCU;
bool IsDarwin;
- bool IsPS4;
AddressPool AddrPool;
@@ -349,6 +372,9 @@ class DwarfDebug : public AsmPrinterHandler {
DenseMap<const Function *, DISubprogram *> FunctionDIs;
+ // Identify a debugger for "tuning" the debug info.
+ DebuggerKind DebuggerTuning;
+
MCDwarfDwoLineTable *getDwoLineTable(const DwarfCompileUnit &);
const SmallVectorImpl<std::unique_ptr<DwarfUnit>> &getUnits() {
@@ -565,6 +591,15 @@ public:
/// standard DW_OP_form_tls_address opcode
bool useGNUTLSOpcode() const { return UseGNUTLSOpcode; }
+ /// \defgroup DebuggerTuning Predicates to tune DWARF for a given debugger.
+ ///
+ /// Returns whether we are "tuning" for a given debugger.
+ /// @{
+ bool tuneForGDB() const { return DebuggerTuning == DebuggerKind::GDB; }
+ bool tuneForLLDB() const { return DebuggerTuning == DebuggerKind::LLDB; }
+ bool tuneForSCE() const { return DebuggerTuning == DebuggerKind::SCE; }
+ /// @}
+
// Experimental DWARF5 features.
/// Returns whether or not to emit tables that dwarf consumers can
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