Adjust proof tooling to support CBMC v6

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.
FreeRTOS · Aug 23, 2024 · e374e95 · e374e95
1 parent 29d86b4
commit e374e95
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diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -178,8 +178,7 @@ jobs:
       - name: Set up CBMC runner
         uses: FreeRTOS/CI-CD-Github-Actions/set_up_cbmc_runner@main
         with:
-          kissat_tag: latest
-          cbmc_version: "5.95.1"
+          cbmc_version: "6.1.1"
       - run: |
           git submodule update --init --recursive --checkout
           sudo apt-get update

diff --git a/test/cbmc/proofs/Makefile.common b/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 2.8
+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
@@ -450,6 +460,24 @@ ifdef APPLY_LOOP_CONTRACTS
   endif
 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 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
+# symex.
+ifneq ($(strip $(USE_DYNAMIC_FRAMES)),)
+ifneq ($(strip $(APPLY_LOOP_CONTRACTS)),)
+  UNWIND_0500_FLAGS=$(CBMC_UNWINDSET) $(CBMC_CPROVER_LIBRARY_UNWINDSET) $(CBMC_FLAG_UNWINDING_ASSERTIONS)
+  UNWIND_0500_DESC="$(PROOF_UID): unwinding specified subset of loops"
+else
+  UNWIND_0500_FLAGS=$(CBMC_UNWINDSET) $(CBMC_CPROVER_LIBRARY_UNWINDSET) $(CBMC_DEFAULT_UNWIND) $(CBMC_FLAG_UNWINDING_ASSERTIONS)
+  UNWIND_0500_DESC="$(PROOF_UID): unwinding all loops"
+endif
+endif
+
 # Silence makefile output (eg, long litani commands) unless VERBOSE is set.
 ifndef VERBOSE
     MAKEFLAGS := $(MAKEFLAGS) -s
@@ -492,7 +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)
@@ -604,7 +631,7 @@ $(REWRITTEN_SOURCES):
 # Build targets that make the relevant .goto files
 
 # Compile project sources
-$(PROJECT_GOTO)1.goto: $(PROJECT_SOURCES) $(REWRITTEN_SOURCES)
+$(PROJECT_GOTO)0100.goto: $(PROJECT_SOURCES) $(REWRITTEN_SOURCES)
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_CC) $(CBMC_VERBOSITY) $(COMPILE_FLAGS) $(EXPORT_FILE_LOCAL_SYMBOLS) $(INCLUDES) $(DEFINES) $^ -o $@' \
@@ -616,7 +643,7 @@ $(PROJECT_GOTO)1.goto: $(PROJECT_SOURCES) $(REWRITTEN_SOURCES)
 	  --description "$(PROOF_UID): building project binary"
 
 # Compile proof sources
-$(PROOF_GOTO)1.goto: $(PROOF_SOURCES)
+$(PROOF_GOTO)0100.goto: $(PROOF_SOURCES)
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_CC) $(CBMC_VERBOSITY) $(COMPILE_FLAGS) $(EXPORT_FILE_LOCAL_SYMBOLS) $(INCLUDES) $(DEFINES) $^ -o $@' \
@@ -628,7 +655,7 @@ $(PROOF_GOTO)1.goto: $(PROOF_SOURCES)
 	  --description "$(PROOF_UID): building proof binary"
 
 # Remove function bodies from project sources
-$(PROJECT_GOTO)2.goto: $(PROJECT_GOTO)1.goto
+$(PROJECT_GOTO)0200.goto: $(PROJECT_GOTO)0100.goto
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_INSTRUMENT) $(CBMC_VERBOSITY) $(CBMC_REMOVE_FUNCTION_BODY) $^ $@' \
@@ -640,7 +667,7 @@ $(PROJECT_GOTO)2.goto: $(PROJECT_GOTO)1.goto
 	  --description "$(PROOF_UID): removing function bodies from project sources"
 
 # Link project and proof sources into the proof harness
-$(HARNESS_GOTO)1.goto: $(PROOF_GOTO)1.goto $(PROJECT_GOTO)2.goto
+$(HARNESS_GOTO)0100.goto: $(PROOF_GOTO)0100.goto $(PROJECT_GOTO)0200.goto
 	$(LITANI) add-job \
 	  --command '$(GOTO_CC) $(CBMC_VERBOSITY) --function $(HARNESS_ENTRY) $^ $(LINK_FLAGS) -o $@' \
 	  --inputs $^ \
@@ -651,7 +678,7 @@ $(HARNESS_GOTO)1.goto: $(PROOF_GOTO)1.goto $(PROJECT_GOTO)2.goto
 	  --description "$(PROOF_UID): linking project to proof"
 
 # Restrict function pointers
-$(HARNESS_GOTO)2.goto: $(HARNESS_GOTO)1.goto
+$(HARNESS_GOTO)0200.goto: $(HARNESS_GOTO)0100.goto
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_INSTRUMENT) $(CBMC_VERBOSITY) $(CBMC_RESTRICT_FUNCTION_POINTER) --remove-function-pointers $^ $@' \
@@ -663,7 +690,7 @@ $(HARNESS_GOTO)2.goto: $(HARNESS_GOTO)1.goto
 	  --description "$(PROOF_UID): restricting function pointers in project sources"
 
 # Fill static variable with unconstrained values
-$(HARNESS_GOTO)3.goto: $(HARNESS_GOTO)2.goto
+$(HARNESS_GOTO)0300.goto: $(HARNESS_GOTO)0200.goto
 ifneq ($(strip $(CODE_CONTRACTS)),)
 	$(LITANI) add-job \
 	  --command 'cp $^ $@' \
@@ -686,7 +713,7 @@ else
 endif
 
 # Link CPROVER library if DFCC mode is on
-$(HARNESS_GOTO)4.goto: $(HARNESS_GOTO)3.goto
+$(HARNESS_GOTO)0400.goto: $(HARNESS_GOTO)0300.goto
 ifneq ($(strip $(USE_DYNAMIC_FRAMES)),)
 	$(LITANI) add-job \
 	  --command \
@@ -709,17 +736,17 @@ else
 endif
 
 # Early unwind all loops on DFCC mode; otherwise, only unwind loops in proof and project code
-$(HARNESS_GOTO)5.goto: $(HARNESS_GOTO)4.goto
+$(HARNESS_GOTO)0500.goto: $(HARNESS_GOTO)0400.goto
 ifneq ($(strip $(USE_DYNAMIC_FRAMES)),)
 	$(LITANI) add-job \
 	  --command \
-	    '$(GOTO_INSTRUMENT) $(CBMC_VERBOSITY) $(CBMC_UNWINDSET) $(CBMC_CPROVER_LIBRARY_UNWINDSET) $(CBMC_DEFAULT_UNWIND) $(CBMC_FLAG_UNWINDING_ASSERTIONS) $^ $@' \
+	    '$(GOTO_INSTRUMENT) $(CBMC_VERBOSITY) $(UNWIND_0500_FLAGS) $^ $@' \
 	  --inputs $^ \
 	  --outputs $@ \
 	  --stdout-file $(LOGDIR)/unwind_loops-log.txt \
 	  --pipeline-name "$(PROOF_UID)" \
 	  --ci-stage build \
-	  --description "$(PROOF_UID): unwinding all loops"
+	  --description $(UNWIND_0500_DESC)
 else ifneq ($(strip $(CODE_CONTRACTS)),)
 	$(LITANI) add-job \
 	  --command \
@@ -735,14 +762,14 @@ else
 	  --command 'cp $^ $@' \
 	  --inputs $^ \
 	  --outputs $@ \
-	  --stdout-file $(LOGDIR)/linking-library-models-log.txt \
+	  --stdout-file $(LOGDIR)/unwind_loops-log.txt \
 	  --pipeline-name "$(PROOF_UID)" \
 	  --ci-stage build \
 	  --description "$(PROOF_UID): not unwinding loops"
 endif
 
 # Replace function contracts, check function contracts, instrument for loop contracts
-$(HARNESS_GOTO)6.goto: $(HARNESS_GOTO)5.goto
+$(HARNESS_GOTO)0600.goto: $(HARNESS_GOTO)0500.goto
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_INSTRUMENT) $(CBMC_USE_DYNAMIC_FRAMES) $(NONDET_STATIC) $(CBMC_VERBOSITY) $(CBMC_CHECK_FUNCTION_CONTRACTS) $(CBMC_USE_FUNCTION_CONTRACTS) $(CBMC_APPLY_LOOP_CONTRACTS) $^ $@' \
@@ -754,7 +781,7 @@ $(HARNESS_GOTO)6.goto: $(HARNESS_GOTO)5.goto
 	  --description "$(PROOF_UID): checking function contracts"
 
 # Omit initialization of unused global variables (reduces problem size)
-$(HARNESS_GOTO)7.goto: $(HARNESS_GOTO)6.goto
+$(HARNESS_GOTO)0700.goto: $(HARNESS_GOTO)0600.goto
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_INSTRUMENT) $(CBMC_VERBOSITY) --slice-global-inits $^ $@' \
@@ -766,7 +793,7 @@ $(HARNESS_GOTO)7.goto: $(HARNESS_GOTO)6.goto
 	  --description "$(PROOF_UID): slicing global initializations"
 
 # Omit unused functions (sharpens coverage calculations)
-$(HARNESS_GOTO)8.goto: $(HARNESS_GOTO)7.goto
+$(HARNESS_GOTO)0800.goto: $(HARNESS_GOTO)0700.goto
 	$(LITANI) add-job \
 	  --command \
 	    '$(GOTO_INSTRUMENT) $(CBMC_VERBOSITY) --drop-unused-functions $^ $@' \
@@ -778,7 +805,7 @@ $(HARNESS_GOTO)8.goto: $(HARNESS_GOTO)7.goto
 	  --description "$(PROOF_UID): dropping unused functions"
 
 # Final name for proof harness
-$(HARNESS_GOTO).goto: $(HARNESS_GOTO)8.goto
+$(HARNESS_GOTO).goto: $(HARNESS_GOTO)0800.goto
 	$(LITANI) add-job \
 	  --command 'cp $< $@' \
 	  --inputs $^ \
@@ -794,7 +821,7 @@ ifdef CBMCFLAGS
   ifeq ($(strip $(CODE_CONTRACTS)),)
     CBMCFLAGS += $(CBMC_UNWINDSET) $(CBMC_CPROVER_LIBRARY_UNWINDSET) $(CBMC_DEFAULT_UNWIND) $(CBMC_OPT_CONFIG_LIBRARY)
   else ifeq ($(strip $(USE_DYNAMIC_FRAMES)),)
-    CBMCFLAGS += $(CBMC_CPROVER_LIBRARY_UNWINDSET) $(CBMC_DEFAULT_UNWIND) $(CBMC_OPT_CONFIG_LIBRARY)
+    CBMCFLAGS += $(CBMC_CPROVER_LIBRARY_UNWINDSET) $(CBMC_OPT_CONFIG_LIBRARY)
   endif
 endif
 
@@ -815,6 +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 \
@@ -880,7 +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'
@@ -889,7 +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'
@@ -898,7 +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'
@@ -907,7 +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'
@@ -916,7 +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'