TApplencourt · Oct 1, 2026 · Jul 29, 2026 · Sep 21, 2026 · Sep 21, 2026 · Sep 21, 2026
diff --git a/.github/actions/setup-thapi/action.yml b/.github/actions/setup-thapi/action.yml
@@ -42,11 +42,17 @@ runs:
       packages: gcc g++ ruby ruby-dev elfutils libelf-dev libpopt-dev libdw-dev libprotobuf-dev protobuf-compiler valgrind libc6-dbg libglib2.0-dev libnuma-dev llvm-dev
   - name: Install Ruby Dependencies
     shell: bash
-    # metababel 2.0.0 is a breaking release: it replaced the MIP-0
-    # `length_field_path` this branch emits with a MIP-1 field location. Pin to
-    # the series matching configure.ac's `metababel >= 1.1.3` until THAPI moves
-    # to MIP 1.
-    run: sudo gem install nokogiri babeltrace2 opencl_ruby_ffi 'metababel:~> 1.1' cast-to-yaml
+    run: sudo gem install nokogiri opencl_ruby_ffi metababel cast-to-yaml
+  - name: Install babeltrace2-ruby
+    shell: bash
+    # The published gem (0.1.5) predates BLOB support, so it cannot read the
+    # traces THAPI now writes. Build it from the branch until a release
+    # carries those commits.
+    run: |
+      git clone --depth 1 https://github.com/argonne-lcf/babeltrace2-ruby.git
+      cd babeltrace2-ruby
+      gem build babeltrace2.gemspec
+      sudo gem install --local ./babeltrace2-*.gem
   - name: Set PKG_CONFIG
     shell: bash
     run: |
@@ -70,10 +76,8 @@ runs:
     shell: bash
     if: steps.efficios_dep.outputs.cache-hit != 'true'
     run: |
-      git clone https://github.com/lttng/lttng-ust -b v2.14.0
+      git clone https://github.com/lttng/lttng-ust -b v2.16.0
       cd lttng-ust
-      wget https://raw.githubusercontent.com/argonne-lcf/THAPI-spack/a57eb4fa1b2b8621bb0e83a6ec25e48e3a761d15/packages/lttng-ust/55cca69.diff
-      patch -p1 < 55cca69.diff
       ./bootstrap
       ./configure --disable-man-pages --prefix=$HOME/efficios_dep/
       make -j$(nproc)
@@ -82,7 +86,7 @@ runs:
     shell: bash
     if: steps.efficios_dep.outputs.cache-hit != 'true'
     run: |
-      git clone https://github.com/argonne-lcf/lttng-tools.git -b anl-v2.14.0
+      git clone https://github.com/argonne-lcf/lttng-tools.git -b anl-v2.16.0
       cd lttng-tools
       ./bootstrap
       ./configure --disable-man-pages --disable-bin-lttng-crash --prefix=$HOME/efficios_dep
@@ -92,15 +96,8 @@ runs:
     shell: bash
     if: steps.efficios_dep.outputs.cache-hit != 'true'
     run: |
-      git clone https://github.com/argonne-lcf/babeltrace.git -b anl-ms3
-      # TODO use anl-ms3-v2.1.2 when ctf.archive.reader doesn't segfault anymore
+      git clone https://github.com/argonne-lcf/babeltrace.git -b anl-ms3-v2.1.2
       cd babeltrace
-      # Fix include path
-      wget https://raw.githubusercontent.com/argonne-lcf/THAPI/4418916620496fd66cde0b3d5e241bed0a4c18a3/.github/workflows/bt_makefile.patch
-      patch -p1 < bt_makefile.patch
-      # Null char
-      wget https://raw.githubusercontent.com/argonne-lcf/THAPI-spack/ddc9a12a498331a7c312941df0d4e7078d03ae93/packages/babeltrace2/0001-Prevent-null-character-from-stopping-string-decoding.patch
-      patch -p1 < 0001-Prevent-null-character-from-stopping-string-decoding.patch
       ./bootstrap
       ./configure --disable-man-pages --prefix=$HOME/efficios_dep
       make -j$(nproc)

diff --git a/backends/cuda/cuda_events.yaml b/backends/cuda/cuda_events.yaml
@@ -1,68 +1,67 @@
----
 lttng_ust_cuda_args:
   events:
   - name: arg_count
     args:
-    - [ CUfunction, f ]
-    - [ size_t, argCount ]
+    - [CUfunction, f]
+    - [size_t, argCount]
     fields:
-    - [ ctf_integer_hex, uintptr_t, f, "(uintptr_t)f" ]
-    - [ ctf_integer, size_t, argCount, argCount ]
+    - [ctf_integer_hex, uintptr_t, f, "(uintptr_t)f"]
+    - [ctf_integer, size_t, argCount, argCount]
   - name: arg_value
     args:
-    - [ CUfunction, f ]
-    - [ size_t, argIndex ]
-    - [ "void *", kernelParam ]
-    - [ size_t, argSize ]
+    - [CUfunction, f]
+    - [size_t, argIndex]
+    - ["void *", kernelParam]
+    - [size_t, argSize]
     fields:
-    - [ ctf_integer_hex, uintptr_t, f, "(uintptr_t)f" ]
-    - [ ctf_integer, size_t, argIndex, argIndex ]
-    - [ ctf_integer_hex, uintptr_t, kernelParam, "(uintptr_t)kernelParam" ]
-    - [ ctf_sequence_text, uint8_t, kernelParam_val, "(uint8_t *)kernelParam", size_t, "kernelParam ? argSize : 0" ]
+    - [ctf_integer_hex, uintptr_t, f, "(uintptr_t)f"]
+    - [ctf_integer, size_t, argIndex, argIndex]
+    - [ctf_integer_hex, uintptr_t, kernelParam, "(uintptr_t)kernelParam"]
+    - [lttng_ust_field_variable_length_blob, kernelParam_val, "(uint8_t *)kernelParam", size_t, "kernelParam ? argSize : 0"]
 lttng_ust_cuda_profiling:
   events:
   - name: event_profiling
     args:
-    - [ CUevent, hStart ]
-    - [ CUevent, hStop ]
+    - [CUevent, hStart]
+    - [CUevent, hStop]
     fields:
-    - [ ctf_integer_hex, uintptr_t, hStart, "(uintptr_t)hStart" ]
-    - [ ctf_integer_hex, uintptr_t, hStop, "(uintptr_t)hStop" ]
+    - [ctf_integer_hex, uintptr_t, hStart, "(uintptr_t)hStart"]
+    - [ctf_integer_hex, uintptr_t, hStop, "(uintptr_t)hStop"]
   - name: event_profiling_results
     args:
-    - [ CUevent, hStart ]
-    - [ CUevent, hStop ]
-    - [ CUresult, startStatus ]
-    - [ CUresult, stopStatus ]
-    - [ CUresult, status ]
-    - [ float, milliseconds ]
+    - [CUevent, hStart]
+    - [CUevent, hStop]
+    - [CUresult, startStatus]
+    - [CUresult, stopStatus]
+    - [CUresult, status]
+    - [float, milliseconds]
     fields:
-    - [ ctf_integer_hex, uintptr_t, hStart, "(uintptr_t)hStart" ]
-    - [ ctf_integer_hex, uintptr_t, hStop, "(uintptr_t)hStop" ]
-    - [ ctf_integer, CUresult, startStatus, startStatus ]
-    - [ ctf_integer, CUresult, stopStatus, stopStatus ]
-    - [ ctf_integer, CUresult, status, status ]
-    - [ ctf_float, float, milliseconds, milliseconds ]
+    - [ctf_integer_hex, uintptr_t, hStart, "(uintptr_t)hStart"]
+    - [ctf_integer_hex, uintptr_t, hStop, "(uintptr_t)hStop"]
+    - [ctf_integer, CUresult, startStatus, startStatus]
+    - [ctf_integer, CUresult, stopStatus, stopStatus]
+    - [ctf_integer, CUresult, status, status]
+    - [ctf_float, float, milliseconds, milliseconds]
 lttng_ust_cuda_exports:
   events:
   - name: export_called
     args:
-    - [ CUuuid *, pExportTableId ]
-    - [ size_t, exportOffset ]
+    - [CUuuid *, pExportTableId]
+    - [size_t, exportOffset]
     fields:
-    - [ ctf_integer_hex, uintptr_t, pExportTableId, "(uintptr_t)pExportTableId" ]
-    - [ ctf_integer_hex, size_t, exportOffset, exportOffset ]
-    - [ ctf_sequence_text, uint8_t, pExportTableId_val, pExportTableId, size_t, "sizeof(CUuuid)" ]
+    - [ctf_integer_hex, uintptr_t, pExportTableId, "(uintptr_t)pExportTableId"]
+    - [ctf_integer_hex, size_t, exportOffset, exportOffset]
+    - [lttng_ust_field_variable_length_blob, pExportTableId_val, pExportTableId, size_t, "sizeof(CUuuid)"]
 lttng_ust_cuda_properties:
   events:
   - name: device
     args:
-    - [ int,  ordinal ]
-    - [ CUdevice , device ]
-    - [ char *, name ]
-    - [ CUuuid *, uuid ]
+    - [int, ordinal]
+    - [CUdevice, device]
+    - [char *, name]
+    - [CUuuid *, uuid]
     fields:
-    - [ ctf_integer, int, ordinal, ordinal ]
-    - [ ctf_integer_hex, int, device, device ]
-    - [ ctf_string, name, name ]
-    - [ ctf_sequence_text, uint8_t, uuid, uuid, size_t, "sizeof(CUuuid)" ]
+    - [ctf_integer, int, ordinal, ordinal]
+    - [ctf_integer_hex, int, device, device]
+    - [ctf_string, name, name]
+    - [lttng_ust_field_variable_length_blob, uuid, uuid, size_t, "sizeof(CUuuid)"]
diff --git a/backends/cuda/cuda_meta_parameters.yaml b/backends/cuda/cuda_meta_parameters.yaml
@@ -295,7 +295,7 @@ meta_parameters:
   cuMipmappedArrayGetLevel:
     - [OutScalar, pLevelArray]
   cuMemGetHandleForAddressRange:
-    - [OutLTTng, handle, ctf_sequence_text, uint8_t, handle_val, handle, size_t, "handleType == CU_MEM_RANGE_HANDLE_TYPE_DMA_BUF_FD ? sizeof(int) : 0"]
+    - [OutLTTng, handle, lttng_ust_field_variable_length_blob, handle_val, handle, size_t, "handleType == CU_MEM_RANGE_HANDLE_TYPE_DMA_BUF_FD ? sizeof(int) : 0"]
   cuMemAddressReserve:
     - [OutScalar, ptr]
   cuMemCreate:
@@ -311,10 +311,10 @@ meta_parameters:
     - [InScalar, location]
     - [OutScalar, flags]
   cuMemExportToShareableHandle:
-    - [OutLTTng, shareableHandle, ctf_sequence_text, uint8_t, shareableHandle_val, shareableHandle, size_t, "handleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
+    - [OutLTTng, shareableHandle, lttng_ust_field_variable_length_blob, shareableHandle_val, shareableHandle, size_t, "handleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
   cuMemImportFromShareableHandle:
     - [OutScalar, handle]
-    - [InLTTng, osHandle, ctf_sequence_text, uint8_t, osHandle_val, osHandle, size_t, "shHandleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
+    - [InLTTng, osHandle, lttng_ust_field_variable_length_blob, osHandle_val, osHandle, size_t, "shHandleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
   cuMemGetAllocationGranularity:
     - [InScalar, prop]
     - [OutScalar, granularity]
@@ -327,15 +327,15 @@ meta_parameters:
   cuMemAllocAsync_ptsz:
     - [OutScalar, dptr]
   cuMemPoolSetAttribute:
-    - [InLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [InLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == CU_MEMPOOL_ATTR_REUSE_FOLLOW_EVENT_DEPENDENCIES ? sizeof(int) : \
       attr == CU_MEMPOOL_ATTR_REUSE_ALLOW_OPPORTUNISTIC ? sizeof(int) : \
       attr == CU_MEMPOOL_ATTR_REUSE_ALLOW_INTERNAL_DEPENDENCIES ? sizeof(int) : \
       attr == CU_MEMPOOL_ATTR_RELEASE_THRESHOLD ? sizeof(cuuint64_t) : \
       attr == CU_MEMPOOL_ATTR_RESERVED_MEM_HIGH ? sizeof(cuuint64_t) : \
       attr == CU_MEMPOOL_ATTR_USED_MEM_HIGH ? sizeof(cuuint64_t) : 0"]
   cuMemPoolGetAttribute:
-    - [OutLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [OutLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == CU_MEMPOOL_ATTR_REUSE_FOLLOW_EVENT_DEPENDENCIES ? sizeof(int) : \
       attr == CU_MEMPOOL_ATTR_REUSE_ALLOW_OPPORTUNISTIC ? sizeof(int) : \
       attr == CU_MEMPOOL_ATTR_REUSE_ALLOW_INTERNAL_DEPENDENCIES ? sizeof(int) : \
@@ -357,9 +357,9 @@ meta_parameters:
   cuMemAllocFromPoolAsync_ptsz:
     - [OutScalar, dptr]
   cuMemPoolExportToShareableHandle:
-    - [OutLTTng, handle_out, ctf_sequence_text, uint8_t, handle_out_val, handle_out, size_t, "handleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
+    - [OutLTTng, handle_out, lttng_ust_field_variable_length_blob, handle_out_val, handle_out, size_t, "handleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
   cuMemPoolImportFromShareableHandle:
-    - [InLTTng, handle, ctf_sequence_text, uint8_t, handle_val, handle, size_t, "handleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
+    - [InLTTng, handle, lttng_ust_field_variable_length_blob, handle_val, handle, size_t, "handleType == CU_MEM_HANDLE_TYPE_POSIX_FILE_DESCRIPTOR ? sizeof(int) : 0"]
     - [OutScalar, pool_out]
   cuMemPoolExportPointer:
     - [OutScalar, shareData_out]
@@ -373,7 +373,7 @@ meta_parameters:
     - [InScalar, prop]
     - [OutScalar, granularity]
   cuPointerGetAttribute:
-    - [OutLTTng, data, ctf_sequence_text, uint8_t, data_val, data, size_t, "\
+    - [OutLTTng, data, lttng_ust_field_variable_length_blob, data_val, data, size_t, "\
       attribute == CU_POINTER_ATTRIBUTE_CONTEXT ? sizeof(CUcontext) : \
       attribute == CU_POINTER_ATTRIBUTE_MEMORY_TYPE ? sizeof(unsigned int) : \
       attribute == CU_POINTER_ATTRIBUTE_DEVICE_POINTER ? sizeof(CUdeviceptr) : \
@@ -400,7 +400,7 @@ meta_parameters:
     - [InArray, attributes, numAttributes]
     - [InArray, dataSizes, numAttributes]
   cuPointerSetAttribute:
-    - [InLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "attribute == CU_POINTER_ATTRIBUTE_SYNC_MEMOPS ? sizeof(uint8_t) : 0"]
+    - [InLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "attribute == CU_POINTER_ATTRIBUTE_SYNC_MEMOPS ? sizeof(uint8_t) : 0"]
   cuPointerGetAttributes:
     - [InArray, attributes, numAttributes]
     - [OutArray, data, numAttributes]
@@ -626,13 +626,13 @@ meta_parameters:
   cuGraphMemFreeNodeGetParams:
     - [OutScalar, dptr_out]
   cuDeviceGetGraphMemAttribute:
-    - [OutLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [OutLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == CU_GRAPH_MEM_ATTR_USED_MEM_CURRENT ? sizeof(cuuint64_t) : \
       attr == CU_GRAPH_MEM_ATTR_USED_MEM_HIGH ? sizeof(cuuint64_t) : \
       attr == CU_GRAPH_MEM_ATTR_RESERVED_MEM_CURRENT ? sizeof(cuuint64_t) : \
       attr == CU_GRAPH_MEM_ATTR_RESERVED_MEM_HIGH ? sizeof(cuuint64_t) : 0"]
   cuDeviceSetGraphMemAttribute:
-    - [InLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [InLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == CU_GRAPH_MEM_ATTR_USED_MEM_HIGH ? sizeof(cuuint64_t) : \
       attr == CU_GRAPH_MEM_ATTR_RESERVED_MEM_HIGH ? sizeof(cuuint64_t) : 0"]
   cuGraphClone:

diff --git a/backends/hip/hip_meta_parameters.yaml b/backends/hip/hip_meta_parameters.yaml
@@ -93,7 +93,7 @@ meta_parameters:
   hipPointerGetAttributes:
     - [OutScalar, attributes]
   hipPointerGetAttribute:
-    - [OutLTTng, data, ctf_sequence_text, uint8_t, data_val, data, size_t, "\
+    - [OutLTTng, data, lttng_ust_field_variable_length_blob, data_val, data, size_t, "\
       attribute == HIP_POINTER_ATTRIBUTE_CONTEXT ? 0 : \
       attribute == HIP_POINTER_ATTRIBUTE_MEMORY_TYPE ? sizeof(unsigned int) : \
       attribute == HIP_POINTER_ATTRIBUTE_DEVICE_POINTER ? sizeof(hipDeviceptr_t) : \
@@ -146,7 +146,7 @@ meta_parameters:
   hipMallocAsync:
     - [OutScalar, dev_ptr]
   hipMemPoolSetAttribute:
-    - [InLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [InLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == hipMemPoolReuseFollowEventDependencies ? sizeof(int) : \
       attr == hipMemPoolReuseAllowOpportunistic ? sizeof(int) : \
       attr == hipMemPoolReuseAllowInternalDependencies ? sizeof(int) : \
@@ -156,7 +156,7 @@ meta_parameters:
       attr == hipMemPoolAttrUsedMemCurrent ? 0 : \
       attr == hipMemPoolAttrUsedMemHigh ? 0 : 0"]
   hipMemPoolGetAttribute:
-    - [OutLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [OutLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == hipMemPoolReuseFollowEventDependencies ? sizeof(int) : \
       attr == hipMemPoolReuseAllowOpportunistic ? sizeof(int) : \
       attr == hipMemPoolReuseAllowInternalDependencies ? sizeof(int) : \
@@ -176,10 +176,10 @@ meta_parameters:
   hipMallocFromPoolAsync:
     - [OutScalar, dev_ptr]
   hipMemPoolExportToShareableHandle:
-    - [OutLTTng, shared_handle, ctf_sequence_text, uint8_t, shared_handle_val, shared_handle, size_t, "\
+    - [OutLTTng, shared_handle, lttng_ust_field_variable_length_blob, shared_handle_val, shared_handle, size_t, "\
       handle_type == hipMemHandleTypePosixFileDescriptor ? sizeof(int) : 0"]
   hipMemPoolImportFromShareableHandle:
-    - [InLTTng, shared_handle, ctf_sequence_text, uint8_t, shared_handle_val, shared_handle, size_t, "\
+    - [InLTTng, shared_handle, lttng_ust_field_variable_length_blob, shared_handle_val, shared_handle, size_t, "\
       handle_type == hipMemHandleTypePosixFileDescriptor ? sizeof(int) : 0"]
     - [OutScalar, mem_pool]
   hipMemPoolExportPointer:
@@ -516,13 +516,13 @@ meta_parameters:
   hipGraphEventWaitNodeGetEvent:
     - [OutScalar, event_out]
   hipDeviceGetGraphMemAttribute:
-    - [OutLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [OutLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == hipGraphMemAttrUsedMemCurrent ? sizeof(uint64_t) : \
       attr == hipGraphMemAttrUsedMemHigh ? sizeof(uint64_t) : \
       attr == hipGraphMemAttrReservedMemCurrent ? sizeof(uint64_t) : \
       attr == hipGraphMemAttrReservedMemHigh ? sizeof(uint64_t) : 0"]
   hipDeviceSetGraphMemAttribute:
-    - [InLTTng, value, ctf_sequence_text, uint8_t, value_val, value, size_t, "\
+    - [InLTTng, value, lttng_ust_field_variable_length_blob, value_val, value, size_t, "\
       attr == hipGraphMemAttrUsedMemHigh ? sizeof(uint64_t) : \
       attr == hipGraphMemAttrReservedMemHigh ? sizeof(uint64_t) : 0"]
   hipUserObjectCreate:
@@ -533,7 +533,7 @@ meta_parameters:
     - [InScalar, prop]
     - [OutScalar, handle]
   hipMemExportToShareableHandle:
-    - [OutLTTng, shareableHandle, ctf_sequence_text, uint8_t, shareableHandle_val, shareableHandle, size_t, "\
+    - [OutLTTng, shareableHandle, lttng_ust_field_variable_length_blob, shareableHandle_val, shareableHandle, size_t, "\
       handleType == hipMemHandleTypePosixFileDescriptor ? sizeof(int) : 0"]
   hipMemGetAccess:
     - [InScalar, location]
@@ -544,7 +544,7 @@ meta_parameters:
   hipMemGetAllocationPropertiesFromHandle:
     - [OutScalar, prop]
   hipMemImportFromShareableHandle:
-    - [InLTTng, osHandle, ctf_sequence_text, uint8_t, osHandle_val, osHandle, size_t, "\
+    - [InLTTng, osHandle, lttng_ust_field_variable_length_blob, osHandle_val, osHandle, size_t, "\
       shHandleType == hipMemHandleTypePosixFileDescriptor ? sizeof(int) : 0"]
     - [OutScalar, handle]
   hipMemMapArrayAsync:

diff --git a/backends/opencl/gen_babeltrace_cl_model.rb b/backends/opencl/gen_babeltrace_cl_model.rb
@@ -53,9 +53,14 @@ def parse_field(field)
     d[:field_class][:type] = unsigned?(field['type']) ? 'integer_unsigned' : 'integer_signed'
     d[:field_class][:field_value_range] = integer_size(field['type'], field['pointer'])
     d[:field_class][:preferred_display_base] = 16 if field['lttng'] == 'ctf_integer_hex'
-  when 'ctf_string', 'ctf_sequence_text'
+  when 'ctf_string'
     d[:field_class][:type] = 'string'
     d[:metadata] = { be_class: cl_to_class(field['type']) } if field['structure']
+  when 'lttng_ust_field_variable_length_blob'
+    d[:field_class][:type] = 'blob_dynamic'
+    d[:field_class][:length_field_location] = payload_length_field_location(field['name'])
+    d[:field_class][:media_type] = LTTng::TracepointField.media_type(field['type'])
+    d[:metadata] = { be_class: cl_to_class(field['type']) } if field['structure']
   when 'ctf_array'
     d[:field_class][:type] = 'array_static'
     d_field = parse_field({ 'lttng' => 'ctf_integer', 'type' => field['type'], 'pointer' => field['pointer'] })
@@ -65,13 +70,13 @@ def parse_field(field)
     d[:field_class][:type] = 'array_dynamic'
     d_field = parse_field({ 'lttng' => 'ctf_integer', 'type' => field['type'], 'pointer' => field['pointer'] })
     d[:field_class][:element_field_class] = d_field[:field_class]
-    d[:field_class][:length_field_path] = "EVENT_PAYLOAD[\"_#{field['name']}_length\"]"
+    d[:field_class][:length_field_location] = payload_length_field_location(field['name'])
 
   when 'ctf_sequence_hex'
     d[:field_class][:type] = 'array_dynamic'
     d_field = parse_field({ 'lttng' => 'ctf_integer_hex', 'type' => field['type'], 'pointer' => field['pointer'] })
     d[:field_class][:element_field_class] = d_field[:field_class]
-    d[:field_class][:length_field_path] = "EVENT_PAYLOAD[\"_#{field['name']}_length\"]"
+    d[:field_class][:length_field_location] = payload_length_field_location(field['name'])
   when 'ctf_enum'
     d[:field_class][:type] = unsigned?(field['type']) ? 'enumeration_unsigned' : 'enumeration_signed'
     enum_type = field['enum_type']
@@ -99,7 +104,7 @@ def parse_field(field)
       parsed_field[:field_class][:element_field_class][:cast_type] = match[1]
     end
 
-    if (field['array'] || field['structure']) && field['lttng'].match('ctf_sequence')
+    if (field['array'] || field['structure']) && implicit_length_field?(field['lttng'])
 
       additional_parsed_field = parse_field({ 'name' => length_field_name(sub_name),
                                               'lttng' => 'ctf_integer', 'type' => 'size_t' })