Fix large literals (#323)

* Fix large literals * Restore previous logic * Clang16 supports literals for wide integers
lifting-bits · Apr 29, 2024 · a2d5ea7 · a2d5ea7
1 parent 0de1db1
commit a2d5ea7
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Showing 7 changed files with 12 additions and 78 deletions.
diff --git a/include/rellic/AST/ASTBuilder.h b/include/rellic/AST/ASTBuilder.h
@@ -49,12 +49,6 @@ class ASTBuilder {
   clang::CharacterLiteral *CreateCharLit(unsigned val);
   clang::StringLiteral *CreateStrLit(std::string val);
   clang::Expr *CreateFPLit(llvm::APFloat val);
-  // Casted literals
-  clang::Expr *CreateAdjustedIntLit(llvm::APSInt val);
-
-  clang::Expr *CreateAdjustedIntLit(llvm::APInt val) {
-    return CreateAdjustedIntLit(llvm::APSInt(val, /*isUnsigned=*/true));
-  };
   // Special values
   clang::Expr *CreateNull();
   clang::Expr *CreateUndefPointer(clang::QualType type);

diff --git a/include/rellic/AST/Util.h b/include/rellic/AST/Util.h
@@ -52,6 +52,7 @@ clang::Expr *Clone(clang::ASTUnit &unit, clang::Expr *stmt,
                    DecompilationContext::ExprToUseMap &provenance);
 
 std::string ClangThingToString(const clang::Stmt *stmt);
+std::string ClangThingToString(clang::QualType ty);
 
 z3::goal ApplyTactic(const z3::tactic &tactic, z3::expr expr);
 

diff --git a/lib/AST/ASTBuilder.cpp b/lib/AST/ASTBuilder.cpp
@@ -141,8 +141,6 @@ clang::IntegerLiteral *ASTBuilder::CreateIntLit(llvm::APSInt val) {
   clang::QualType type;
   if (value_size <= ctx.getIntWidth(ctx.IntTy)) {
     type = sign ? ctx.IntTy : ctx.UnsignedIntTy;
-  } else if (value_size > ctx.getIntWidth(ctx.LongLongTy)) {
-    type = sign ? ctx.LongLongTy : ctx.UnsignedLongLongTy;
   } else {
     type = GetLeastIntTypeForBitWidth(value_size, sign);
   }
@@ -159,20 +157,6 @@ clang::IntegerLiteral *ASTBuilder::CreateIntLit(llvm::APSInt val) {
   return clang::IntegerLiteral::Create(ctx, val, type, clang::SourceLocation());
 }
 
-clang::Expr *ASTBuilder::CreateAdjustedIntLit(llvm::APSInt val) {
-  auto lit{CreateIntLit(val)};
-  auto value_size{val.getBitWidth()};
-  // Cast the integer literal to a type of the smallest bit width
-  // that can contain `val`. Either `short` or `char`.
-  if (value_size <= ctx.getIntWidth(ctx.ShortTy) ||
-      value_size > ctx.getIntWidth(ctx.LongLongTy)) {
-    return CreateCStyleCast(
-        GetLeastIntTypeForBitWidth(value_size, val.isSigned()), lit);
-  } else {
-    return lit;
-  }
-}
-
 clang::CharacterLiteral *ASTBuilder::CreateCharLit(llvm::APInt val) {
   CHECK(val.getBitWidth() == 8U);
   return new (ctx) clang::CharacterLiteral(

diff --git a/lib/AST/ExprCombine.cpp b/lib/AST/ExprCombine.cpp
@@ -496,7 +496,7 @@ bool ExprCombine::VisitCStyleCastExpr(clang::CStyleCastExpr *cast) {
 
     switch (result.Val.getKind()) {
       case clang::APValue::ValueKind::Int: {
-        auto sub{dec_ctx.ast.CreateAdjustedIntLit(result.Val.getInt())};
+        auto sub{dec_ctx.ast.CreateIntLit(result.Val.getInt())};
         if (GetHash(dec_ctx.ast_ctx, cast) != GetHash(dec_ctx.ast_ctx, sub)) {
           substitutions[cast] = sub;
         }

diff --git a/lib/AST/IRToASTVisitor.cpp b/lib/AST/IRToASTVisitor.cpp
@@ -275,23 +275,7 @@ clang::Expr *ExprGen::CreateLiteralExpr(llvm::Constant *constant) {
     case llvm::Type::IntegerTyID: {
       if (llvm::isa<llvm::ConstantInt>(constant)) {
         auto val{llvm::cast<llvm::ConstantInt>(constant)->getValue()};
-        auto val_bitwidth{val.getBitWidth()};
-        auto ull_bitwidth{ast_ctx.getIntWidth(ast_ctx.LongLongTy)};
-        if (val_bitwidth == 1U) {
-          // Booleans
-          result = ast.CreateIntLit(val);
-        } else if (val.getActiveBits() <= ull_bitwidth) {
-          result = ast.CreateAdjustedIntLit(val);
-        } else {
-          // Values wider than `long long` will be represented as:
-          // (uint128_t)hi_64 << 64U | lo_64
-          auto lo{ast.CreateIntLit(val.extractBits(64U, 0U))};
-          auto hi{ast.CreateIntLit(val.extractBits(val_bitwidth - 64U, 64U))};
-          auto shl_val{ast.CreateIntLit(llvm::APInt(32U, 64U))};
-          result = ast.CreateCStyleCast(ast_ctx.UnsignedInt128Ty, hi);
-          result = ast.CreateShl(result, shl_val);
-          result = ast.CreateOr(result, lo);
-        }
+        result = ast.CreateIntLit(val);
       } else if (llvm::isa<llvm::UndefValue>(constant)) {
         result = ast.CreateUndefInteger(c_type);
       } else {

diff --git a/lib/AST/Util.cpp b/lib/AST/Util.cpp
@@ -329,6 +329,13 @@ std::string ClangThingToString(const clang::Stmt *stmt) {
   return s;
 }
 
+std::string ClangThingToString(clang::QualType ty) {
+  std::string s;
+  llvm::raw_string_ostream os(s);
+  ty.print(os, clang::PrintingPolicy(clang::LangOptions()));
+  return s;
+}
+
 z3::goal ApplyTactic(const z3::tactic &tactic, z3::expr expr) {
   z3::goal goal(tactic.ctx());
   goal.add(expr.simplify());

diff --git a/unittests/AST/ASTBuilder.cpp b/unittests/AST/ASTBuilder.cpp
@@ -70,18 +70,6 @@ TEST_SUITE("ASTBuilder::CreateIntLit") {
           CHECK(clang::isa<clang::IntegerLiteral>(lit));
           CHECK(lit->getType() == ctx.UnsignedIntTy);
         }
-
-        THEN(
-            "return a unsigned int typed integer literal casted to unsigned "
-            "char") {
-          auto cast{ast.CreateAdjustedIntLit(api)};
-          REQUIRE(cast != nullptr);
-          CHECK(clang::isa<clang::CStyleCastExpr>(cast));
-          CHECK(cast->getType() == ctx.UnsignedCharTy);
-          auto lit{cast->IgnoreCasts()};
-          CHECK(clang::isa<clang::IntegerLiteral>(lit));
-          CHECK(lit->getType() == ctx.UnsignedIntTy);
-        }
       }
     }
   }
@@ -99,18 +87,6 @@ TEST_SUITE("ASTBuilder::CreateIntLit") {
           CHECK(clang::isa<clang::IntegerLiteral>(lit));
           CHECK(lit->getType() == ctx.UnsignedIntTy);
         }
-
-        THEN(
-            "return a unsigned int typed integer literal casted to unsigned "
-            "short") {
-          auto cast{ast.CreateAdjustedIntLit(api)};
-          REQUIRE(cast != nullptr);
-          CHECK(clang::isa<clang::CStyleCastExpr>(cast));
-          CHECK(cast->getType() == ctx.UnsignedShortTy);
-          auto lit{cast->IgnoreCasts()};
-          CHECK(clang::isa<clang::IntegerLiteral>(lit));
-          CHECK(lit->getType() == ctx.UnsignedIntTy);
-        }
       }
     }
   }
@@ -156,23 +132,11 @@ TEST_SUITE("ASTBuilder::CreateIntLit") {
       rellic::ASTBuilder ast(*unit);
       GIVEN("128 bits wide llvm::APInt") {
         llvm::APInt api(128U, UINT64_C(42), /*isSigned=*/false);
-        THEN("return a unsigned long long typed integer literal") {
+        THEN("return a _uint128_t typed integer literal") {
           auto lit{ast.CreateIntLit(api)};
           REQUIRE(lit != nullptr);
           CHECK(clang::isa<clang::IntegerLiteral>(lit));
-          CHECK(lit->getType() == ctx.UnsignedLongLongTy);
-        }
-
-        THEN(
-            "return a unsigned long long typed integer literal casted to "
-            "_uint128_t") {
-          auto cast{ast.CreateAdjustedIntLit(api)};
-          REQUIRE(cast != nullptr);
-          CHECK(clang::isa<clang::CStyleCastExpr>(cast));
-          CHECK(cast->getType() == ctx.UnsignedInt128Ty);
-          auto lit{cast->IgnoreCasts()};
-          CHECK(clang::isa<clang::IntegerLiteral>(lit));
-          CHECK(lit->getType() == ctx.UnsignedLongLongTy);
+          CHECK(lit->getType() == ctx.UnsignedInt128Ty);
         }
       }
     }