[clang] bbd0d12 - Implement -frecord-command-line for XCOFF
Jake Egan via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 10 09:47:16 PDT 2023
Author: Jake Egan
Date: 2023-07-10T12:47:07-04:00
New Revision: bbd0d123d3aaa67d8bed9d16d9001b33540fc04d
URL: https://github.com/llvm/llvm-project/commit/bbd0d123d3aaa67d8bed9d16d9001b33540fc04d
DIFF: https://github.com/llvm/llvm-project/commit/bbd0d123d3aaa67d8bed9d16d9001b33540fc04d.diff
LOG: Implement -frecord-command-line for XCOFF
This patch extends support of the option `-frecord-command-line` to XCOFF. XCOFF doesn’t have custom sections like ELF, so the command line data is emitted to a .info section instead. A C_INFO symbol is generated with the .info section to preserve the command line data past the link step. Multiple command lines are separated by newlines and null bytes. The command line data can be retrieved on AIX with command `what file_name`.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D153600
Added:
llvm/test/CodeGen/PowerPC/aix-command-line-metadata.ll
Modified:
clang/lib/Driver/ToolChains/Clang.cpp
llvm/include/llvm/CodeGen/AsmPrinter.h
llvm/include/llvm/MC/MCStreamer.h
llvm/include/llvm/MC/MCXCOFFStreamer.h
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/MC/MCAsmStreamer.cpp
llvm/lib/MC/MCStreamer.cpp
llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
Removed:
################################################################################
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index efdb7889bc838b..a9efab7ae07816 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -7153,7 +7153,8 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
auto FRecordSwitches =
Args.hasFlag(options::OPT_frecord_command_line,
options::OPT_fno_record_command_line, false);
- if (FRecordSwitches && !Triple.isOSBinFormatELF())
+ if (FRecordSwitches && !Triple.isOSBinFormatELF() &&
+ !Triple.isOSBinFormatXCOFF())
D.Diag(diag::err_drv_unsupported_opt_for_target)
<< Args.getLastArg(options::OPT_frecord_command_line)->getAsString(Args)
<< TripleStr;
diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
index 8d2684698233a4..0ac497c5f8efbd 100644
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -866,7 +866,7 @@ class AsmPrinter : public MachineFunctionPass {
/// Emit llvm.ident metadata in an '.ident' directive.
void emitModuleIdents(Module &M);
/// Emit bytes for llvm.commandline metadata.
- void emitModuleCommandLines(Module &M);
+ virtual void emitModuleCommandLines(Module &M);
GCMetadataPrinter *getOrCreateGCPrinter(GCStrategy &S);
void emitGlobalAlias(Module &M, const GlobalAlias &GA);
diff --git a/llvm/include/llvm/MC/MCStreamer.h b/llvm/include/llvm/MC/MCStreamer.h
index 5f12fcc1c840b7..dcd84a6efda0e8 100644
--- a/llvm/include/llvm/MC/MCStreamer.h
+++ b/llvm/include/llvm/MC/MCStreamer.h
@@ -647,6 +647,12 @@ class MCStreamer {
/// \param Sym - The symbol on the .ref directive.
virtual void emitXCOFFRefDirective(const MCSymbol *Symbol);
+ /// Emit a C_INFO symbol with XCOFF embedded metadata to the .info section.
+ ///
+ /// \param Name - The embedded metadata name
+ /// \param Metadata - The embedded metadata
+ virtual void emitXCOFFCInfoSym(StringRef Name, StringRef Metadata);
+
/// Emit an ELF .size directive.
///
/// This corresponds to an assembler statement such as:
diff --git a/llvm/include/llvm/MC/MCXCOFFStreamer.h b/llvm/include/llvm/MC/MCXCOFFStreamer.h
index aea2a3265d572c..a3db636e5b3a93 100644
--- a/llvm/include/llvm/MC/MCXCOFFStreamer.h
+++ b/llvm/include/llvm/MC/MCXCOFFStreamer.h
@@ -40,6 +40,10 @@ class MCXCOFFStreamer : public MCObjectStreamer {
void emitXCOFFExceptDirective(const MCSymbol *Symbol, const MCSymbol *Trap,
unsigned Lang, unsigned Reason,
unsigned FunctionSize, bool hasDebug) override;
+ void emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) override {
+ report_fatal_error("emitXCOFFCInfoSym is not implemented yet on "
+ "object generation path");
+ }
};
} // end namespace llvm
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index b1e41c573a87f9..79a4e168e7e795 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -486,6 +486,11 @@ bool AsmPrinter::doInitialization(Module &M) {
}
}
+ // On AIX, emit bytes for llvm.commandline metadata after .file so that the
+ // C_INFO symbol is preserved if any csect is kept by the linker.
+ if (TM.getTargetTriple().isOSBinFormatXCOFF())
+ emitModuleCommandLines(M);
+
GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
assert(MI && "AsmPrinter didn't require GCModuleInfo?");
for (const auto &I : *MI)
@@ -2330,7 +2335,9 @@ bool AsmPrinter::doFinalization(Module &M) {
emitModuleIdents(M);
// Emit bytes for llvm.commandline metadata.
- emitModuleCommandLines(M);
+ // The command line metadata is emitted earlier on XCOFF.
+ if (!TM.getTargetTriple().isOSBinFormatXCOFF())
+ emitModuleCommandLines(M);
// Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
// split-stack is used.
diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 78950ed0b095dc..06de70ad2f395a 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -36,6 +36,7 @@
#include "llvm/Support/LEB128.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
+#include <algorithm>
#include <optional>
using namespace llvm;
@@ -200,6 +201,7 @@ class MCAsmStreamer final : public MCStreamer {
const MCSymbol *Trap,
unsigned Lang, unsigned Reason,
unsigned FunctionSize, bool hasDebug) override;
+ void emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) override;
void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
@@ -966,6 +968,70 @@ void MCAsmStreamer::emitXCOFFExceptDirective(const MCSymbol *Symbol,
EmitEOL();
}
+void MCAsmStreamer::emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) {
+ const char InfoDirective[] = "\t.info ";
+ const char *Separator = ", ";
+ constexpr int WordSize = sizeof(uint32_t);
+
+ // Start by emitting the .info pseudo-op and C_INFO symbol name.
+ OS << InfoDirective;
+ PrintQuotedString(Name, OS);
+ OS << Separator;
+
+ size_t MetadataSize = Metadata.size();
+
+ // Emit the 4-byte length of the metadata.
+ OS << format_hex(MetadataSize, 10) << Separator;
+
+ // Nothing left to do if there's no metadata.
+ if (MetadataSize == 0) {
+ EmitEOL();
+ return;
+ }
+
+ // Metadata needs to be padded out to an even word size when generating
+ // assembly because the .info pseudo-op can only generate words of data. We
+ // apply the same restriction to the object case for consistency, however the
+ // linker doesn't require padding, so it will only save bytes specified by the
+ // length and discard any padding.
+ uint32_t PaddedSize = alignTo(MetadataSize, WordSize);
+ uint32_t PaddingSize = PaddedSize - MetadataSize;
+
+ // Write out the payload a word at a time.
+ //
+ // The assembler has a limit on the number of operands in an expression,
+ // so we need multiple .info pseudo-ops. We choose a small number of words
+ // per pseudo-op to keep the assembly readable.
+ constexpr int WordsPerDirective = 5;
+ // Force emitting a new directive to keep the first directive purely about the
+ // name and size of the note.
+ int WordsBeforeNextDirective = 0;
+ auto PrintWord = [&](const uint8_t *WordPtr) {
+ if (WordsBeforeNextDirective-- == 0) {
+ EmitEOL();
+ OS << InfoDirective;
+ WordsBeforeNextDirective = WordsPerDirective;
+ }
+ OS << Separator;
+ uint32_t Word = llvm::support::endian::read32be(WordPtr);
+ OS << format_hex(Word, 10);
+ };
+
+ size_t Index = 0;
+ for (; Index + WordSize <= MetadataSize; Index += WordSize)
+ PrintWord(reinterpret_cast<const uint8_t *>(Metadata.data()) + Index);
+
+ // If there is padding, then we have at least one byte of payload left
+ // to emit.
+ if (PaddingSize) {
+ assert(PaddedSize - Index == WordSize);
+ std::array<uint8_t, WordSize> LastWord = {0};
+ ::memcpy(LastWord.data(), Metadata.data() + Index, MetadataSize - Index);
+ PrintWord(LastWord.data());
+ }
+ EmitEOL();
+}
+
void MCAsmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
assert(MAI->hasDotTypeDotSizeDirective());
OS << "\t.size\t";
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index e1b0fd5f1009ef..7f9c0c3b0b8dff 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -1208,6 +1208,11 @@ void MCStreamer::emitXCOFFExceptDirective(const MCSymbol *Symbol,
"XCOFF targets");
}
+void MCStreamer::emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) {
+ llvm_unreachable("emitXCOFFCInfoSym is only supported on"
+ "XCOFF targets");
+}
+
void MCStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
void MCStreamer::emitELFSymverDirective(const MCSymbol *OriginalSym,
StringRef Name, bool KeepOriginalSym) {}
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index add1c5727a5d53..a089d61616e1a0 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -290,6 +290,8 @@ class PPCAIXAsmPrinter : public PPCAsmPrinter {
bool doFinalization(Module &M) override;
void emitTTypeReference(const GlobalValue *GV, unsigned Encoding) override;
+
+ void emitModuleCommandLines(Module &M) override;
};
} // end anonymous namespace
@@ -2954,6 +2956,26 @@ createPPCAsmPrinterPass(TargetMachine &tm,
return new PPCLinuxAsmPrinter(tm, std::move(Streamer));
}
+void PPCAIXAsmPrinter::emitModuleCommandLines(Module &M) {
+ const NamedMDNode *NMD = M.getNamedMetadata("llvm.commandline");
+ if (!NMD || !NMD->getNumOperands())
+ return;
+
+ std::string S;
+ raw_string_ostream RSOS(S);
+ for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
+ const MDNode *N = NMD->getOperand(i);
+ assert(N->getNumOperands() == 1 &&
+ "llvm.commandline metadata entry can have only one operand");
+ const MDString *MDS = cast<MDString>(N->getOperand(0));
+ // Add "@(#)" to support retrieving the command line information with the
+ // AIX "what" command
+ RSOS << "@(#)opt " << MDS->getString() << "\n";
+ RSOS.write('\0');
+ }
+ OutStreamer->emitXCOFFCInfoSym(".GCC.command.line", RSOS.str());
+}
+
// Force static initialization.
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializePowerPCAsmPrinter() {
TargetRegistry::RegisterAsmPrinter(getThePPC32Target(),
diff --git a/llvm/test/CodeGen/PowerPC/aix-command-line-metadata.ll b/llvm/test/CodeGen/PowerPC/aix-command-line-metadata.ll
new file mode 100644
index 00000000000000..2164fed525e18a
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/aix-command-line-metadata.ll
@@ -0,0 +1,23 @@
+; RUN: llc -mtriple powerpc-ibm-aix-xcoff < %s | \
+; RUN: FileCheck --check-prefix=ASM %s
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff < %s | \
+; RUN: FileCheck --check-prefix=ASM %s
+
+; RUN: not --crash llc -mtriple powerpc-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
+; RUN: FileCheck --check-prefix=OBJ %s
+; RUN: not --crash llc -mtriple powerpc64-ibm-aix-xcoff -filetype=obj < %s 2>&1 | \
+; RUN: FileCheck --check-prefix=OBJ %s
+
+; Verify that llvm.commandline metadata is emitted to .info sections and that the
+; metadata is padded if necessary.
+
+; OBJ: LLVM ERROR: emitXCOFFCInfoSym is not implemented yet on object generation path
+
+; ASM: .info ".GCC.command.line", 0x0000003a,
+; ASM: .info , 0x40282329, 0x6f707420, 0x636c616e, 0x67202d63, 0x6f6d6d61, 0x6e64202d
+; ASM: .info , 0x6c696e65, 0x0a004028, 0x23296f70, 0x7420736f, 0x6d657468, 0x696e6720
+; ASM: .info , 0x656c7365, 0x20313233, 0x0a000000
+
+!llvm.commandline = !{!0, !1}
+!0 = !{!"clang -command -line"}
+!1 = !{!"something else 123"}
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