From 845b48b293f388d93686ecaddf3bfa02a91760dd Mon Sep 17 00:00:00 2001
From: youben11 <ayoub.benaissa@zama.ai>
Date: Wed, 2 Mar 2022 15:07:58 +0100
Subject: [PATCH] refactor: remove variable length array usages

---
 compiler/CMakeLists.txt                 | 10 ----------
 compiler/lib/ClientLib/ClientLambda.cpp |  6 +++---
 compiler/lib/ClientLib/Serializers.cpp  |  3 ++-
 compiler/lib/ServerLib/ServerLambda.cpp |  5 +++--
 4 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/compiler/CMakeLists.txt b/compiler/CMakeLists.txt
index 2577786bb..a4d794b96 100644
--- a/compiler/CMakeLists.txt
+++ b/compiler/CMakeLists.txt
@@ -12,16 +12,6 @@ if (APPLE)
   add_definitions("-Wno-narrowing")
 endif()
 
-add_compile_options(-Wfatal-errors) # stop at first error
- # variable length array = vla
-if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-  # using Clang
-  add_compile_options(-Wno-vla-extension)
-elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-  # using GCC
-  add_compile_options(-Wno-vla)
-endif()
-
 # If we are trying to build the compiler with LLVM/MLIR as libraries
 if( NOT DEFINED LLVM_EXTERNAL_CONCRETELANG_SOURCE_DIR )
   message(FATAL_ERROR "Concrete compiler requires a unified build with LLVM/MLIR")
diff --git a/compiler/lib/ClientLib/ClientLambda.cpp b/compiler/lib/ClientLib/ClientLambda.cpp
index 2be553a2f..203ce6798 100644
--- a/compiler/lib/ClientLib/ClientLambda.cpp
+++ b/compiler/lib/ClientLib/ClientLambda.cpp
@@ -138,11 +138,11 @@ decryptReturnedTensor(std::istream &istream, ClientLambda &lambda,
            << expectedRank << " which cannot be decrypted to rank " << rank;
   }
   OUTCOME_TRY(auto values, lambda.decryptReturnedValues(keySet, istream));
-  size_t sizes[rank];
+  llvm::SmallVector<size_t, 6> sizes;
   for (size_t dim = 0; dim < rank; dim++) {
-    sizes[dim] = shape.dimensions[dim];
+    sizes.push_back(shape.dimensions[dim]);
   }
-  return flatToTensor<DecryptedTensor>(values, sizes);
+  return flatToTensor<DecryptedTensor>(values, sizes.data());
 }
 
 outcome::checked<decrypted_tensor_1_t, StringError>
diff --git a/compiler/lib/ClientLib/Serializers.cpp b/compiler/lib/ClientLib/Serializers.cpp
index 6ea8e8413..9a5e20a81 100644
--- a/compiler/lib/ClientLib/Serializers.cpp
+++ b/compiler/lib/ClientLib/Serializers.cpp
@@ -82,10 +82,11 @@ std::ostream &operator<<(std::ostream &ostream, const ClientParameters &cp) {
 std::istream &operator>>(std::istream &istream, ClientParameters &params) {
   size_t size;
   readSize(istream, size);
-  char buffer[size + 1];
+  char *buffer = new char[size + 1];
   buffer[size] = '\0'; // llvm::json::parse requires \0 ended buffer.
   istream.read(buffer, size);
   auto paramsOrErr = llvm::json::parse<ClientParameters>(buffer);
+  delete[] buffer;
   if (auto err = paramsOrErr.takeError()) {
     llvm::errs() << "Parsing client parameters error: " << std::move(err)
                  << "\n";
diff --git a/compiler/lib/ServerLib/ServerLambda.cpp b/compiler/lib/ServerLib/ServerLambda.cpp
index cc424453d..94f2c7834 100644
--- a/compiler/lib/ServerLib/ServerLambda.cpp
+++ b/compiler/lib/ServerLib/ServerLambda.cpp
@@ -61,8 +61,8 @@ encrypted_scalars_and_sizes_t encrypted_scalars_and_sizes_t_from_MemRef(
   for (size_t r = 0; r < memref_rank; r++) {
     result.sizes[r] = sizes[r];
   }
-  size_t
-      index[memref_rank]; // ephemeral multi dim index to compute global strides
+  size_t *index = new size_t[memref_rank]; // ephemeral multi dim index to
+                                           // compute global strides
   for (size_t r = 0; r < memref_rank; r++) {
     index[r] = 0;
   }
@@ -74,6 +74,7 @@ encrypted_scalars_and_sizes_t encrypted_scalars_and_sizes_t_from_MemRef(
     result.values[i] = aligned[offset + g_index];
     next_coord_index(index, sizes, memref_rank);
   }
+  delete[] index;
   return result;
 }