Introduce a new builtin, __builtin_dump_struct, that is useful for dumping structure contents at runtime in circumstances where debuggers may not be easily available (such as in kernel work).
Patch by Paul Semel.
llvm-svn: 329762
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 2be9b78..73b95d9 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -14,6 +14,7 @@
#include "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "CGOpenCLRuntime.h"
+#include "CGRecordLayout.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "ConstantEmitter.h"
@@ -930,6 +931,93 @@
return RValue::get(Overflow);
}
+static llvm::Value *dumpRecord(CodeGenFunction &CGF, QualType RType,
+ Value *&RecordPtr, CharUnits Align, Value *Func,
+ int Lvl) {
+ const auto *RT = RType->getAs<RecordType>();
+ ASTContext &Context = CGF.getContext();
+ RecordDecl *RD = RT->getDecl()->getDefinition();
+ ASTContext &Ctx = RD->getASTContext();
+ const ASTRecordLayout &RL = Ctx.getASTRecordLayout(RD);
+ std::string Pad = std::string(Lvl * 4, ' ');
+
+ Value *GString =
+ CGF.Builder.CreateGlobalStringPtr(RType.getAsString() + " {\n");
+ Value *Res = CGF.Builder.CreateCall(Func, {GString});
+
+ static llvm::DenseMap<QualType, const char *> Types;
+ if (Types.empty()) {
+ Types[Context.CharTy] = "%c";
+ Types[Context.BoolTy] = "%d";
+ Types[Context.IntTy] = "%d";
+ Types[Context.UnsignedIntTy] = "%u";
+ Types[Context.LongTy] = "%ld";
+ Types[Context.UnsignedLongTy] = "%lu";
+ Types[Context.LongLongTy] = "%lld";
+ Types[Context.UnsignedLongLongTy] = "%llu";
+ Types[Context.ShortTy] = "%hd";
+ Types[Context.UnsignedShortTy] = "%hu";
+ Types[Context.VoidPtrTy] = "%p";
+ Types[Context.FloatTy] = "%f";
+ Types[Context.DoubleTy] = "%f";
+ Types[Context.LongDoubleTy] = "%Lf";
+ Types[Context.getPointerType(Context.CharTy)] = "%s";
+ }
+
+ for (const auto *FD : RD->fields()) {
+ uint64_t Off = RL.getFieldOffset(FD->getFieldIndex());
+ Off = Ctx.toCharUnitsFromBits(Off).getQuantity();
+
+ Value *FieldPtr = RecordPtr;
+ if (RD->isUnion())
+ FieldPtr = CGF.Builder.CreatePointerCast(
+ FieldPtr, CGF.ConvertType(Context.getPointerType(FD->getType())));
+ else
+ FieldPtr = CGF.Builder.CreateStructGEP(CGF.ConvertType(RType), FieldPtr,
+ FD->getFieldIndex());
+
+ GString = CGF.Builder.CreateGlobalStringPtr(
+ llvm::Twine(Pad)
+ .concat(FD->getType().getAsString())
+ .concat(llvm::Twine(' '))
+ .concat(FD->getNameAsString())
+ .concat(" : ")
+ .str());
+ Value *TmpRes = CGF.Builder.CreateCall(Func, {GString});
+ Res = CGF.Builder.CreateAdd(Res, TmpRes);
+
+ QualType CanonicalType =
+ FD->getType().getUnqualifiedType().getCanonicalType();
+
+ // We check whether we are in a recursive type
+ if (CanonicalType->isRecordType()) {
+ Value *TmpRes =
+ dumpRecord(CGF, CanonicalType, FieldPtr, Align, Func, Lvl + 1);
+ Res = CGF.Builder.CreateAdd(TmpRes, Res);
+ continue;
+ }
+
+ // We try to determine the best format to print the current field
+ llvm::Twine Format = Types.find(CanonicalType) == Types.end()
+ ? Types[Context.VoidPtrTy]
+ : Types[CanonicalType];
+
+ Address FieldAddress = Address(FieldPtr, Align);
+ FieldPtr = CGF.Builder.CreateLoad(FieldAddress);
+
+ // FIXME Need to handle bitfield here
+ GString = CGF.Builder.CreateGlobalStringPtr(
+ Format.concat(llvm::Twine('\n')).str());
+ TmpRes = CGF.Builder.CreateCall(Func, {GString, FieldPtr});
+ Res = CGF.Builder.CreateAdd(Res, TmpRes);
+ }
+
+ GString = CGF.Builder.CreateGlobalStringPtr(Pad + "}\n");
+ Value *TmpRes = CGF.Builder.CreateCall(Func, {GString});
+ Res = CGF.Builder.CreateAdd(Res, TmpRes);
+ return Res;
+}
+
RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
unsigned BuiltinID, const CallExpr *E,
ReturnValueSlot ReturnValue) {
@@ -1196,6 +1284,18 @@
return RValue::get(ComplexVal.first);
}
+ case Builtin::BI__builtin_dump_struct: {
+ Value *Func = EmitScalarExpr(E->getArg(1)->IgnoreImpCasts());
+ CharUnits Arg0Align = EmitPointerWithAlignment(E->getArg(0)).getAlignment();
+
+ const Expr *Arg0 = E->getArg(0)->IgnoreImpCasts();
+ QualType Arg0Type = Arg0->getType()->getPointeeType();
+
+ Value *RecordPtr = EmitScalarExpr(Arg0);
+ Value *Res = dumpRecord(*this, Arg0Type, RecordPtr, Arg0Align, Func, 0);
+ return RValue::get(Res);
+ }
+
case Builtin::BI__builtin_cimag:
case Builtin::BI__builtin_cimagf:
case Builtin::BI__builtin_cimagl: