msg-filter: abstract out notes about builtin models

... so that semantically equal findings are matched with each other

Resolves: https://issues.redhat.com/browse/OSH-700
Closes: #189

src/lib/msg-filter.cc

@@ -83,10 +83,12 @@ MsgFilter::MsgFilter():
     d->addMsgFilter("", "^[0-9]+ (occurrences of warning\\[.*\\] exceeded the specified limit) [0-9]+$",
             "NNNN \\1 NNNN");
 
-    d->addMsgFilter("UNUSED_VALUE",
-            "\\(instance [0-9]+\\)");
-    d->addMsgFilter("STRING_OVERFLOW",
-            "You might overrun the [0-9][0-9]* byte");
+    // whether a builtin model was used or not is insignificant for matching the finding
+    d->addMsgFilter("", " \\[Note: The source code implementation of the function has been overridden by a builtin model.\\]$");
+
+    d->addMsgFilter("UNUSED_VALUE", "\\(instance [0-9]+\\)");
+    d->addMsgFilter("STRING_OVERFLOW", "You might overrun the [0-9][0-9]* byte");
+
     // ignore changes in parameters -> it is still the same UNUSED_VALUE
     d->addMsgFilter("UNUSED_VALUE",
             "returned by \"([^\\(]+)\\(.*\\)\"",

tests/csdiff/CMakeLists.txt

@@ -91,5 +91,6 @@ test_csdiff(diff-misc 23-cov-parser-key-event)
 test_csdiff(diff-misc 24-shellcheck-line-content)
 test_csdiff(diff-misc 25-llvm-17-path-filter)
 test_csdiff(diff-misc 26-too-many-events-filter)
+test_csdiff(diff-misc 27-cov-builtin-model)
 
 add_subdirectory(filter-file)

tests/csdiff/diff-misc/27-cov-builtin-model-new.err

@@ -0,0 +1,23 @@
+Error: FORWARD_NULL (CWE-476):
+kernel-999/arch/x86/boot/compressed/kaslr.c:266:2: path: Condition "!args", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:271:2: path: Condition "!tmp_cmdline", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:281:2: path: Condition "*args", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: path: Condition "!val", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:287:3: path: Condition "!strcmp(param, "memmap")", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:289:3: path: Falling through to end of if statement.
+kernel-999/arch/x86/boot/compressed/kaslr.c:305:2: path: Jumping back to the beginning of the loop.
+kernel-999/arch/x86/boot/compressed/kaslr.c:281:2: path: Condition "*args", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: path: Condition "!val", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: var_compare_op: Comparing "val" to null implies that "val" might be null.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: path: Condition "strcmp(param, "--") == 0", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:287:3: path: Condition "!strcmp(param, "memmap")", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:289:10: path: Condition "1", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:289:10: path: Condition "strstr(param, "hugepages")", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:291:10: path: Condition "!strcmp(param, "mem")", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:292:4: alias_transfer: Assigning: "p" = "val".
+kernel-999/arch/x86/boot/compressed/kaslr.c:294:4: var_deref_model: Passing null pointer "p" to "strcmp", which dereferences it. [Note: The source code implementation of the function has been overridden by a builtin model.]
+#  292|                         char *p = val;
+#  293|   
+#  294|->                       if (!strcmp(p, "nopentium"))
+#  295|                                 continue;
+#  296|                         mem_size = memparse(p, &p);

tests/csdiff/diff-misc/27-cov-builtin-model-old.err

@@ -0,0 +1,23 @@
+Error: FORWARD_NULL (CWE-476):
+kernel-999/arch/x86/boot/compressed/kaslr.c:266:2: path: Condition "!args", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:271:2: path: Condition "!tmp_cmdline", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:281:2: path: Condition "*args", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: path: Condition "!val", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:287:3: path: Condition "!strcmp(param, "memmap")", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:289:3: path: Falling through to end of if statement.
+kernel-999/arch/x86/boot/compressed/kaslr.c:305:2: path: Jumping back to the beginning of the loop.
+kernel-999/arch/x86/boot/compressed/kaslr.c:281:2: path: Condition "*args", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: path: Condition "!val", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: var_compare_op: Comparing "val" to null implies that "val" might be null.
+kernel-999/arch/x86/boot/compressed/kaslr.c:284:3: path: Condition "strcmp(param, "--") == 0", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:287:3: path: Condition "!strcmp(param, "memmap")", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:289:10: path: Condition "1", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:289:10: path: Condition "strstr(param, "hugepages")", taking false branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:291:10: path: Condition "!strcmp(param, "mem")", taking true branch.
+kernel-999/arch/x86/boot/compressed/kaslr.c:292:4: alias_transfer: Assigning: "p" = "val".
+kernel-999/arch/x86/boot/compressed/kaslr.c:294:4: var_deref_model: Passing null pointer "p" to "strcmp", which dereferences it.
+#  292|                         char *p = val;
+#  293|   
+#  294|->                       if (!strcmp(p, "nopentium"))
+#  295|                                 continue;
+#  296|                         mem_size = memparse(p, &p);