Adjust proof tooling to support CBMC v6 (#170)

With CBMC v6, unwinding assertions are enabled by default, and object
bits no longer need to be set at compile time. Update various build
rules to use the latest template as provided with CBMC starter kit.

Co-authored-by: Aniruddha Kanhere <60444055+AniruddhaKanhere@users.noreply.github.com>

.github/workflows/ci.yml

@@ -162,9 +162,9 @@ jobs:
       - name: Set up CBMC runner
         uses: FreeRTOS/CI-CD-Github-Actions/set_up_cbmc_runner@main
         with:
-          cbmc_version: "5.95.1"
           cadical_tag: "latest"
           kissat_tag: "latest"
+          cbmc_version: "6.3.1"
       - name: Run CBMC
         uses: FreeRTOS/CI-CD-Github-Actions/run_cbmc@main
         with:

test/cbmc/proofs/Makefile.common

@@ -4,7 +4,7 @@
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: MIT-0
 
-CBMC_STARTER_KIT_VERSION = CBMC starter kit 2.10
+CBMC_STARTER_KIT_VERSION = CBMC starter kit 2.11
 
 ################################################################
 # The CBMC Starter Kit depends on the files Makefile.common and
@@ -211,10 +211,13 @@ CHECKFLAGS += $(USE_EXTERNAL_SAT_SOLVER)
 
 ifeq ($(strip $(ENABLE_POOLS)),)
   POOL =
+  INIT_POOLS =
 else ifeq ($(strip $(EXPENSIVE)),)
   POOL =
+  INIT_POOLS =
 else
   POOL = --pool expensive
+  INIT_POOLS = --pools expensive:1
 endif
 
 # Similar to the pool feature above. If Litani is new enough, enable
@@ -229,36 +232,43 @@ endif
 #
 # Each variable below controls a specific property checking flag
 # within CBMC. If desired, a property flag can be disabled within
-# a particular proof by nulling the corresponding variable. For
-# instance, the following line:
+# a particular proof by nulling the corresponding variable when CBMC's default
+# is not to perform such checks, or setting to --no-<CHECK>-check when CBMC's
+# default is to perform such checks. For instance, the following lines:
 #
-#     CHECK_FLAG_POINTER_CHECK =
+#     CBMC_FLAG_POINTER_CHECK = --no-pointer-check
+#     CBMC_FLAG_UNSIGNED_OVERFLOW_CHECK =
 #
-# would disable the --pointer-check CBMC flag within:
+# would disable pointer checks and unsigned overflow checks with CBMC flag
+# within:
 #   * an entire project when added to Makefile-project-defines
 #   * a specific proof when added to the harness Makefile
 
-CBMC_FLAG_MALLOC_MAY_FAIL ?= --malloc-may-fail
-CBMC_FLAG_MALLOC_FAIL_NULL ?= --malloc-fail-null
-CBMC_FLAG_BOUNDS_CHECK ?= --bounds-check
+CBMC_FLAG_MALLOC_MAY_FAIL ?= # set to --no-malloc-may-fail to disable
+CBMC_FLAG_BOUNDS_CHECK ?= # set to --no-bounds-check to disable
 CBMC_FLAG_CONVERSION_CHECK ?= --conversion-check
-CBMC_FLAG_DIV_BY_ZERO_CHECK ?= --div-by-zero-check
+CBMC_FLAG_DIV_BY_ZERO_CHECK ?= # set to --no-div-by-zero-check to disable
 CBMC_FLAG_FLOAT_OVERFLOW_CHECK ?= --float-overflow-check
 CBMC_FLAG_NAN_CHECK ?= --nan-check
-CBMC_FLAG_POINTER_CHECK ?= --pointer-check
+CBMC_FLAG_POINTER_CHECK ?= #set to --no-pointer-check to disable
 CBMC_FLAG_POINTER_OVERFLOW_CHECK ?= --pointer-overflow-check
-CBMC_FLAG_POINTER_PRIMITIVE_CHECK ?= --pointer-primitive-check
-CBMC_FLAG_SIGNED_OVERFLOW_CHECK ?= --signed-overflow-check
-CBMC_FLAG_UNDEFINED_SHIFT_CHECK ?= --undefined-shift-check
+CBMC_FLAG_POINTER_PRIMITIVE_CHECK ?= # set to --no-pointer-primitive-check to disable
+CBMC_FLAG_SIGNED_OVERFLOW_CHECK ?= # set to --no-signed-overflow-check to disable
+CBMC_FLAG_UNDEFINED_SHIFT_CHECK ?= # set to --no-undefined-shift-check to disable
 CBMC_FLAG_UNSIGNED_OVERFLOW_CHECK ?= --unsigned-overflow-check
-CBMC_FLAG_UNWINDING_ASSERTIONS ?= --unwinding-assertions
+CBMC_FLAG_UNWINDING_ASSERTIONS ?= # set to --no-unwinding-assertions to disable
 CBMC_DEFAULT_UNWIND ?= --unwind 1
 CBMC_FLAG_FLUSH ?= --flush
 
 # CBMC flags used for property checking and coverage checking
 
 CBMCFLAGS += $(CBMC_FLAG_FLUSH)
 
+# CBMC 6.0.0 enables all standard checks by default, which can make coverage analysis
+# very slow. See https://github.com/diffblue/cbmc/issues/8389
+# For now, we disable these checks when generating coverage info.
+COVERFLAGS ?= --no-standard-checks --malloc-may-fail --malloc-fail-null
+
 # CBMC flags used for property checking
 
 CHECKFLAGS += $(CBMC_FLAG_BOUNDS_CHECK)
@@ -299,8 +309,8 @@ CHECKFLAGS += $(CBMC_FLAG_UNSIGNED_OVERFLOW_CHECK)
 NONDET_STATIC ?=
 
 # Flags to pass to goto-cc for compilation and linking
-COMPILE_FLAGS ?= -Wall
-LINK_FLAGS ?= -Wall
+COMPILE_FLAGS ?= -Wall -Werror
+LINK_FLAGS ?= -Wall -Werror
 EXPORT_FILE_LOCAL_SYMBOLS ?= --export-file-local-symbols
 
 # During instrumentation, it adds models of C library functions
@@ -404,7 +414,7 @@ endif
 
 # Optional configuration library flags
 OPT_CONFIG_LIBRARY ?=
-CBMC_OPT_CONFIG_LIBRARY := $(CBMC_FLAG_MALLOC_MAY_FAIL) $(CBMC_FLAG_MALLOC_FAIL_NULL) $(CBMC_STRING_ABSTRACTION)
+CBMC_OPT_CONFIG_LIBRARY := $(CBMC_FLAG_MALLOC_MAY_FAIL) $(CBMC_STRING_ABSTRACTION)
 
 # Proof writers could add function contracts in their source code.
 # These contracts are ignored by default, but may be enabled in two distinct
@@ -453,7 +463,7 @@ endif
 # The default unwind should only be used in DFCC mode without loop contracts.
 # When loop contracts are applied, we only unwind specified loops.
 # If any loops remain after loop contracts have been applied, CBMC might try
-# to unwind the program indefinetly, because we do not pass default unwind
+# to unwind the program indefinitely, because we do not pass default unwind
 # (i.e., --unwind 1) to CBMC when in DFCC mode.
 # We must not use a default unwind command in DFCC mode, because contract instrumentation
 # introduces loops encoding write set inclusion checks that must be dynamically unwound during
@@ -510,7 +520,6 @@ COMMA :=,
 # Set C compiler defines
 
 CBMCFLAGS += --object-bits $(CBMC_OBJECT_BITS)
-COMPILE_FLAGS += --object-bits $(CBMC_OBJECT_BITS)
 
 DEFINES += -DCBMC=1
 DEFINES += -DCBMC_OBJECT_BITS=$(CBMC_OBJECT_BITS)
@@ -833,6 +842,23 @@ $(LOGDIR)/result.xml: $(HARNESS_GOTO).goto
 	  --stderr-file $(LOGDIR)/result-err-log.txt \
 	  --description "$(PROOF_UID): checking safety properties"
 
+$(LOGDIR)/result.txt: $(HARNESS_GOTO).goto
+	$(LITANI) add-job \
+	  $(POOL) \
+	  --command \
+	    '$(CBMC) $(CBMC_VERBOSITY) $(CBMCFLAGS) $(CBMC_FLAG_UNWINDING_ASSERTIONS) $(CHECKFLAGS) --trace $<' \
+	  --inputs $^ \
+	  --outputs $@ \
+	  --ci-stage test \
+	  --stdout-file $@ \
+	  $(MEMORY_PROFILING) \
+	  --ignore-returns 10 \
+	  --timeout $(CBMC_TIMEOUT) \
+	  --pipeline-name "$(PROOF_UID)" \
+	  --tags "stats-group:safety checks" \
+	  --stderr-file $(LOGDIR)/result-err-log.txt \
+	  --description "$(PROOF_UID): checking safety properties"
+
 $(LOGDIR)/property.xml: $(HARNESS_GOTO).goto
 	$(LITANI) add-job \
 	  --command \
@@ -898,7 +924,7 @@ litani-path:
 _goto: $(HARNESS_GOTO).goto
 goto:
 	@ echo Running 'litani init'
-	$(LITANI) init --project $(PROJECT_NAME)
+	$(LITANI) init $(INIT_POOLS) --project $(PROJECT_NAME)
 	@ echo Running 'litani add-job'
 	$(MAKE) -B _goto
 	@ echo Running 'litani build'
@@ -907,7 +933,7 @@ goto:
 _result: $(LOGDIR)/result.txt
 result:
 	@ echo Running 'litani init'
-	$(LITANI) init --project $(PROJECT_NAME)
+	$(LITANI) init $(INIT_POOLS) --project $(PROJECT_NAME)
 	@ echo Running 'litani add-job'
 	$(MAKE) -B _result
 	@ echo Running 'litani build'
@@ -916,7 +942,7 @@ result:
 _property: $(LOGDIR)/property.xml
 property:
 	@ echo Running 'litani init'
-	$(LITANI) init --project $(PROJECT_NAME)
+	$(LITANI) init $(INIT_POOLS) --project $(PROJECT_NAME)
 	@ echo Running 'litani add-job'
 	$(MAKE) -B _property
 	@ echo Running 'litani build'
@@ -925,7 +951,7 @@ property:
 _coverage: $(LOGDIR)/coverage.xml
 coverage:
 	@ echo Running 'litani init'
-	$(LITANI) init --project $(PROJECT_NAME)
+	$(LITANI) init $(INIT_POOLS) --project $(PROJECT_NAME)
 	@ echo Running 'litani add-job'
 	$(MAKE) -B _coverage
 	@ echo Running 'litani build'
@@ -934,7 +960,7 @@ coverage:
 _report: $(PROOFDIR)/report
 report:
 	@ echo Running 'litani init'
-	$(LITANI) init --project $(PROJECT_NAME)
+	$(LITANI) init $(INIT_POOLS) --project $(PROJECT_NAME)
 	@ echo Running 'litani add-job'
 	$(MAKE) -B _report
 	@ echo Running 'litani build'