[NFC][MC][CodeEmitterGen] Extract error reporting into a helper function #159778

jurahul · 2025-09-19T13:38:24Z

Extract error reporting code emitted by CodeEmitterGen into MCCodeEmitter static members functions.
Additionally, remove unused ErrorHandling.h header from several files.

llvmbot · 2025-09-19T14:44:50Z

@llvm/pr-subscribers-backend-hexagon
@llvm/pr-subscribers-llvm-mc
@llvm/pr-subscribers-backend-arm
@llvm/pr-subscribers-backend-mips

@llvm/pr-subscribers-backend-powerpc

Author: Rahul Joshi (jurahul)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/159778.diff

12 Files Affected:

(modified) llvm/include/llvm/MC/MCCodeEmitter.h (+7-1)
(modified) llvm/lib/MC/MCCodeEmitter.cpp (+14)
(modified) llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/Sparc/MCTargetDesc/SparcMCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCCodeEmitter.cpp (-1)
(modified) llvm/lib/Target/VE/MCTargetDesc/VEMCCodeEmitter.cpp (-1)
(modified) llvm/utils/TableGen/CodeEmitterGen.cpp (+4-15)
(modified) llvm/utils/TableGen/Common/VarLenCodeEmitterGen.cpp (+1-4)

diff --git a/llvm/include/llvm/MC/MCCodeEmitter.h b/llvm/include/llvm/MC/MCCodeEmitter.h
index 1c454c3795c2c..5369bd2d330f6 100644
--- a/llvm/include/llvm/MC/MCCodeEmitter.h
+++ b/llvm/include/llvm/MC/MCCodeEmitter.h
@@ -10,13 +10,13 @@
 #define LLVM_MC_MCCODEEMITTER_H
 
 #include "llvm/Support/Compiler.h"
+#include <optional>
 
 namespace llvm {
 
 class MCFixup;
 class MCInst;
 class MCSubtargetInfo;
-class raw_ostream;
 template<typename T> class SmallVectorImpl;
 
 /// MCCodeEmitter - Generic instruction encoding interface.
@@ -36,6 +36,12 @@ class LLVM_ABI MCCodeEmitter {
   virtual void encodeInstruction(const MCInst &Inst, SmallVectorImpl<char> &CB,
                                  SmallVectorImpl<MCFixup> &Fixups,
                                  const MCSubtargetInfo &STI) const = 0;
+
+protected:
+  // Helper function used by CodeEmitterGen for error reporting.
+  [[noreturn]] static void
+  ReportFatalError(const MCInst &Inst,
+                   std::optional<unsigned> OpNum = std::nullopt);
 };
 
 } // end namespace llvm
diff --git a/llvm/lib/MC/MCCodeEmitter.cpp b/llvm/lib/MC/MCCodeEmitter.cpp
index 0d114f12d58c5..fad7cab6bed72 100644
--- a/llvm/lib/MC/MCCodeEmitter.cpp
+++ b/llvm/lib/MC/MCCodeEmitter.cpp
@@ -7,9 +7,23 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
 
 using namespace llvm;
 
 MCCodeEmitter::MCCodeEmitter() = default;
 
 MCCodeEmitter::~MCCodeEmitter() = default;
+
+void MCCodeEmitter::ReportFatalError(const MCInst &Inst,
+                                     std::optional<unsigned> OpNum) {
+  std::string msg;
+  raw_string_ostream Msg(msg);
+  Msg << "Unsupported instruction " << Inst;
+  if (OpNum)
+    Msg << ", OpNum = " << *OpNum;
+  report_fatal_error(msg.c_str());
+}
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp
index 6e5a69030dbc6..21ff55e9d9a7f 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp
@@ -25,7 +25,6 @@
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <cstdint>
 
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
index c56b589519533..4a87c638f5fc3 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp
@@ -30,7 +30,6 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/TargetParser/Triple.h"
 #include <cassert>
diff --git a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp
index dfe0fa973c9b3..021dceb0e0789 100644
--- a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCCodeEmitter.cpp
@@ -25,7 +25,6 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <cstddef>
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
index a8369f2b28fb7..bbfd0872cc4cd 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
@@ -28,7 +28,6 @@
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <cstdint>
diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
index 8ed7c68f54e7f..48c31c91e9338 100644
--- a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
+++ b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
@@ -22,7 +22,6 @@
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/TargetParser/Triple.h"
 #include <cassert>
diff --git a/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCCodeEmitter.cpp b/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCCodeEmitter.cpp
index cfa3511436b97..cb02e33b8e5dd 100644
--- a/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCCodeEmitter.cpp
@@ -28,7 +28,6 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <cstdint>
 
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCCodeEmitter.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCCodeEmitter.cpp
index 59d1db784c688..383c96e8cca73 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCCodeEmitter.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCCodeEmitter.cpp
@@ -21,7 +21,6 @@
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
-#include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <cstdint>
 
diff --git a/llvm/lib/Target/VE/MCTargetDesc/VEMCCodeEmitter.cpp b/llvm/lib/Target/VE/MCTargetDesc/VEMCCodeEmitter.cpp
index 711937c488275..ab719390e3245 100644
--- a/llvm/lib/Target/VE/MCTargetDesc/VEMCCodeEmitter.cpp
+++ b/llvm/lib/Target/VE/MCTargetDesc/VEMCCodeEmitter.cpp
@@ -25,7 +25,6 @@
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/EndianStream.h"
-#include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <cstdint>
 
diff --git a/llvm/utils/TableGen/CodeEmitterGen.cpp b/llvm/utils/TableGen/CodeEmitterGen.cpp
index a61ba54d3ffd2..3877f4070c8b1 100644
--- a/llvm/utils/TableGen/CodeEmitterGen.cpp
+++ b/llvm/utils/TableGen/CodeEmitterGen.cpp
@@ -471,12 +471,8 @@ void CodeEmitterGen::run(raw_ostream &O) {
     << ";\n";
   O << R"(
   const unsigned opcode = MI.getOpcode();
-  if (opcode < FirstSupportedOpcode) {
-    std::string msg;
-    raw_string_ostream Msg(msg);
-    Msg << "Unsupported instruction: " << MI;
-    report_fatal_error(Msg.str().c_str());
-  }
+  if (opcode < FirstSupportedOpcode)
+    ReportFatalError(MI);
   unsigned TableIndex = opcode - FirstSupportedOpcode;
 )";
 
@@ -502,10 +498,7 @@ void CodeEmitterGen::run(raw_ostream &O) {
 
   // Default case: unhandled opcode.
   O << "  default:\n"
-    << "    std::string msg;\n"
-    << "    raw_string_ostream Msg(msg);\n"
-    << "    Msg << \"Not supported instr: \" << MI;\n"
-    << "    report_fatal_error(Msg.str().c_str());\n"
+    << "    ReportFatalError(MI);\n"
     << "  }\n";
   if (UseAPInt)
     O << "  Inst = Value;\n";
@@ -522,11 +515,7 @@ void CodeEmitterGen::run(raw_ostream &O) {
     << "  switch (MI.getOpcode()) {\n";
   emitCaseMap(O, BitOffsetCaseMap);
   O << "  }\n"
-    << "  std::string msg;\n"
-    << "  raw_string_ostream Msg(msg);\n"
-    << "  Msg << \"Not supported instr[opcode]: \" << MI << \"[\" << OpNum "
-       "<< \"]\";\n"
-    << "  report_fatal_error(Msg.str().c_str());\n"
+    << "  ReportFatalError(MI, OpNum);\n"
     << "}\n\n"
     << "#endif // GET_OPERAND_BIT_OFFSET\n\n";
 }
diff --git a/llvm/utils/TableGen/Common/VarLenCodeEmitterGen.cpp b/llvm/utils/TableGen/Common/VarLenCodeEmitterGen.cpp
index b617a3dbca586..c069316a58497 100644
--- a/llvm/utils/TableGen/Common/VarLenCodeEmitterGen.cpp
+++ b/llvm/utils/TableGen/Common/VarLenCodeEmitterGen.cpp
@@ -320,10 +320,7 @@ void VarLenCodeEmitterGen::run(raw_ostream &OS) {
   }
   // Default case: unhandled opcode
   OS << "  default:\n"
-     << "    std::string msg;\n"
-     << "    raw_string_ostream Msg(msg);\n"
-     << "    Msg << \"Not supported instr: \" << MI;\n"
-     << "    report_fatal_error(Msg.str().c_str());\n"
+     << "    ReportFatalError(MI);\n"
      << "  }\n";
   OS << "}\n\n";
 }

llvm/lib/MC/MCCodeEmitter.cpp

llvm/utils/TableGen/CodeEmitterGen.cpp

llvm/lib/MC/MCCodeEmitter.cpp

s-barannikov

LGTM

llvm/utils/TableGen/CodeEmitterGen.cpp

[NFC][MC][CodeEmitterGen] Extract error eporting into a helper function

7c1feb9

jurahul marked this pull request as ready for review September 19, 2025 14:44

llvmbot added backend:ARM backend:AArch64 backend:Hexagon backend:MIPS backend:PowerPC backend:Sparc backend:SystemZ tablegen llvm:mc Machine (object) code labels Sep 19, 2025

jurahul requested review from lenary and s-barannikov September 19, 2025 14:46

s-barannikov reviewed Sep 19, 2025

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s-barannikov reviewed Sep 19, 2025

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jurahul requested a review from s-barannikov September 19, 2025 17:52

s-barannikov reviewed Sep 19, 2025

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jurahul added 2 commits September 19, 2025 10:54

Remove unused header

36a5b10

Use reportFatalInternalError

fcb1b70

s-barannikov approved these changes Sep 19, 2025

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s-barannikov reviewed Sep 19, 2025

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0fb6c9c

lenary approved these changes Sep 19, 2025

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jurahul added 2 commits September 20, 2025 05:01

Merge branch 'main' into cgmc_extract_report_error

999867a

Merge branch 'main' into cgmc_extract_report_error

779a757

jurahul merged commit b7908e3 into llvm:main Sep 23, 2025
9 checks passed

jurahul deleted the cgmc_extract_report_error branch September 23, 2025 16:05

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[NFC][MC][CodeEmitterGen] Extract error reporting into a helper function #159778

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[NFC][MC][CodeEmitterGen] Extract error reporting into a helper function #159778

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jurahul commented Sep 19, 2025 •

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