Fix minor issues in ABI conversions.

include/vast/Conversion/ABI/Common.hpp

@@ -0,0 +1,8 @@
+// Copyright (c) 2024-present, Trail of Bits, Inc.
+
+#pragma once
+
+namespace vast::conv::abi
+{
+    static inline const std::string abi_func_name_prefix = "vast.abi.";
+} // namespace vast::conv::abi

lib/vast/Conversion/ABI/EmitABI.cpp

@@ -1,4 +1,4 @@
 // Copyright (c) 2021-present, Trail of Bits, Inc.
 
 #include "vast/Conversion/Passes.hpp"
 
@@ -18,6 +18,8 @@
 
 #include "../PassesDetails.hpp"
 
+#include "vast/Conversion/ABI/Common.hpp"
+
 #include "vast/Conversion/Common/Patterns.hpp"
 #include "vast/Conversion/TypeConverters/TypeConverter.hpp"
 
@@ -227,7 +229,7 @@
                         op.getLoc(),
                         // Temporal, to avoid verification issues, will be changed once
                         // original func is removed.
-                        "vast.abi" + op.getName().str(),
+                        conv::abi::abi_func_name_prefix + op.getName().str(),
                         this->abified_type(),
                         core::GlobalLinkageKind::InternalLinkage,
                         other_attrs,
@@ -237,7 +239,8 @@
                 // Copying visibility from the original function results in error?
                 wrapper.setVisibility(mlir::SymbolTable::Visibility::Private);
 
-                mk_prologue(wrapper);
+                if (!op.getBody().empty())
+                    mk_prologue(wrapper);
 
                 return wrapper;
             }
@@ -757,7 +760,7 @@
                     return mlir::failure();
 
                 auto name = func.getName();
-                if (!name.consume_front("vast.abi"))
+                if (!name.consume_front(conv::abi::abi_func_name_prefix))
                     return mlir::failure();
 
                 auto abi_map_it = abi_info_map.find(name.str());
@@ -805,9 +808,8 @@
 
             auto should_transform = [&](hl::FuncOp op)
             {
-                // TODO(abi): Due to some issues with location info of arguments
-                //            declaration are not yet supported.
-                return op.getName() == "main" && !op.isDeclaration();
+                // TODO(conv:abi): We should always emit main with a fixed type.
+                return op.getName() == "main";
             };
 
             target.addDynamicallyLegalOp< hl::FuncOp >(should_transform);
@@ -830,7 +832,7 @@
             auto is_return_legal = [&](hl::ReturnOp op)
             {
                 auto func = op->getParentOfType< abi::FuncOp >();
-                if (!func || func.getName() == "main")
+                if (!func)
                     return true;
 
                 for (auto val : op.getResult())

lib/vast/Conversion/ABI/LowerABI.cpp

@@ -1,4 +1,4 @@
 // Copyright (c) 2021-present, Trail of Bits, Inc.
 
 #include "vast/Conversion/Passes.hpp"
 
@@ -18,6 +18,7 @@
 #include "../PassesDetails.hpp"
 
 #include "vast/Conversion/Common/Patterns.hpp"
+#include "vast/Conversion/ABI/Common.hpp"
 
 #include "vast/Dialect/HighLevel/HighLevelAttributes.hpp"
 #include "vast/Dialect/HighLevel/HighLevelTypes.hpp"
@@ -604,7 +605,7 @@
                 op.getAllArgAttrs(arg_attrs);
 
                 auto name = op.getName();
-                if (!name.consume_front("vast.abi"))
+                if (!name.consume_front(conv::abi::abi_func_name_prefix))
                     return mlir::failure();
 
                 auto fn = rewriter.create< hl::FuncOp >(

lib/vast/Conversion/FromHL/ToLLCF.cpp

@@ -1,4 +1,4 @@
 // Copyright (c) 2021-present, Trail of Bits, Inc.
 
 #include "vast/Conversion/Passes.hpp"
 
@@ -25,6 +25,7 @@
 
 
 #include "vast/Dialect/Core/CoreTraits.hpp"
+#include "vast/Dialect/Core/CoreOps.hpp"
 #include "vast/Dialect/HighLevel/HighLevelDialect.hpp"
 #include "vast/Dialect/LowLevel/LowLevelOps.hpp"
 
@@ -457,6 +458,7 @@
             , while_op
             , for_op
             , replace< hl::ReturnOp, ll::ReturnOp >
+            , replace< core::ImplicitReturnOp, ll::ReturnOp >
         >;
 
     } // namespace pattern
@@ -474,7 +476,9 @@
 
             trg.addIllegalOp< hl::ContinueOp >();
             trg.addIllegalOp< hl::BreakOp >();
+
             trg.addIllegalOp< hl::ReturnOp >();
+            trg.addIllegalOp< core::ImplicitReturnOp >();
 
             trg.addLegalOp< mlir::cf::BranchOp >();
             trg.markUnknownOpDynamicallyLegal([](auto){ return true; });

test/vast/Compile/SingleSource/putchar-a.c

@@ -1,5 +1,4 @@
 // RUN: %vast-front -o %t %s && %t | %file-check %s
-// REQUIRES: abi
 
 int putchar(int);
 

test/vast/Compile/SingleSource/puts-a.c

@@ -1,5 +1,4 @@
 // RUN: %vast-front -o %t %s && %t hello | %file-check %s
-// REQUIRES: abi
 
 int puts(const char *);