Switch to CodeQL to detect prohibited function use

The LLVM/Clang developers pointed out that using the CPP to detect use
of functions that our QA policies prohibit risks invoking undefined
behavior. To resolve this, we configure CodeQL to detect forbidden
function usage.

Note that cpp in the context of CodeQL refers to C/C++, rather than the
C PreProcessor, which C++ also uses. It really should have been written
cxx, but that ship sailed a long time ago. This misuse of the term cpp
is retained in the CodeQL configuration for consistency with upstream
CodeQL.

Signed-off-by: Richard Yao <[email protected]>

.github/codeql-cpp.yml

@@ -0,0 +1,4 @@
+name: "Custom CodeQL Analysis"
+
+queries:
+  - uses: ./.github/codeql/custom-queries/cpp/deprecatedFunctionUsage.ql

.github/codeql-python.yml

@@ -0,0 +1,4 @@
+name: "Custom CodeQL Analysis"
+
+paths-ignore:
+  - tests

.github/codeql/custom-queries/cpp/deprecatedFunctionUsage.ql

@@ -0,0 +1,59 @@
+/**
+ * @name Deprecated function usage detection
+ * @description Detects functions whose usage is banned from the OpenZFS
+ *              codebase due to QA concerns.
+ * @kind problem
+ * @severity error
+ * @id cpp/deprecated-function-usage
+*/
+
+import cpp
+
+predicate isDeprecatedFunction(Function f) {
+  f.getName() = "strtok" or
+  f.getName() = "__xpg_basename" or
+  f.getName() = "basename" or
+  f.getName() = "dirname" or
+  f.getName() = "bcopy" or
+  f.getName() = "bcmp" or
+  f.getName() = "bzero" or
+  f.getName() = "asctime" or
+  f.getName() = "asctime_r" or
+  f.getName() = "gmtime" or
+  f.getName() = "localtime" or
+  f.getName() = "strncpy"
+
+}
+
+string getReplacementMessage(Function f) {
+  if f.getName() = "strtok" then
+    result = "Use strtok_r(3) instead!"
+  else if f.getName() = "__xpg_basename" then
+    result = "basename(3) is underspecified. Use zfs_basename() instead!"
+  else if f.getName() = "basename" then
+    result = "basename(3) is underspecified. Use zfs_basename() instead!"
+  else if f.getName() = "dirname" then
+    result = "dirname(3) is underspecified. Use zfs_dirnamelen() instead!"
+  else if f.getName() = "bcopy" then
+    result = "bcopy(3) is deprecated. Use memcpy(3)/memmove(3) instead!"
+  else if f.getName() = "bcmp" then
+    result = "bcmp(3) is deprecated. Use memcmp(3) instead!"
+  else if f.getName() = "bzero" then
+    result = "bzero(3) is deprecated. Use memset(3) instead!"
+  else if f.getName() = "asctime" then
+    result = "Use strftime(3) instead!"
+  else if f.getName() = "asctime_r" then
+    result = "Use strftime(3) instead!"
+  else if f.getName() = "gmtime" then
+    result = "gmtime(3) isn't thread-safe. Use gmtime_r(3) instead!"
+  else if f.getName() = "localtime" then
+    result = "localtime(3) isn't thread-safe. Use localtime_r(3) instead!"
+  else
+    result = "strncpy(3) is deprecated. Use strlcpy(3) instead!"
+}
+
+from FunctionCall fc, Function f
+where
+  fc.getTarget() = f and
+  isDeprecatedFunction(f)
+select fc, getReplacementMessage(f)

.github/codeql/custom-queries/cpp/qlpack.yml

@@ -0,0 +1,4 @@
+name: openzfs-cpp-queries
+version: 0.0.0
+libraryPathDependencies: codeql-cpp
+suites: openzfs-cpp-suite

.github/workflows/codeql.yml

@@ -29,6 +29,7 @@ jobs:
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v2
       with:
+        config-file: .github/codeql-${{ matrix.language }}.yml
         languages: ${{ matrix.language }}
 
     - name: Autobuild

config/Rules.am

@@ -42,21 +42,6 @@ AM_CPPFLAGS += $(DEBUG_CPPFLAGS)
 AM_CPPFLAGS += $(CODE_COVERAGE_CPPFLAGS)
 AM_CPPFLAGS += -DTEXT_DOMAIN=\"zfs-@ac_system_l@-user\"
 
-AM_CPPFLAGS_NOCHECK  = -D"strtok(...)=strtok(__VA_ARGS__) __attribute__((deprecated(\"Use strtok_r(3) instead!\")))"
-AM_CPPFLAGS_NOCHECK += -D"__xpg_basename(...)=__xpg_basename(__VA_ARGS__) __attribute__((deprecated(\"basename(3) is underspecified. Use zfs_basename() instead!\")))"
-AM_CPPFLAGS_NOCHECK += -D"basename(...)=basename(__VA_ARGS__) __attribute__((deprecated(\"basename(3) is underspecified. Use zfs_basename() instead!\")))"
-AM_CPPFLAGS_NOCHECK += -D"dirname(...)=dirname(__VA_ARGS__) __attribute__((deprecated(\"dirname(3) is underspecified. Use zfs_dirnamelen() instead!\")))"
-AM_CPPFLAGS_NOCHECK += -D"bcopy(...)=__attribute__((deprecated(\"bcopy(3) is deprecated. Use memcpy(3)/memmove(3) instead!\"))) bcopy(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"bcmp(...)=__attribute__((deprecated(\"bcmp(3) is deprecated. Use memcmp(3) instead!\"))) bcmp(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"bzero(...)=__attribute__((deprecated(\"bzero(3) is deprecated. Use memset(3) instead!\"))) bzero(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"asctime(...)=__attribute__((deprecated(\"Use strftime(3) instead!\"))) asctime(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"asctime_r(...)=__attribute__((deprecated(\"Use strftime(3) instead!\"))) asctime_r(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"gmtime(...)=__attribute__((deprecated(\"gmtime(3) isn't thread-safe. Use gmtime_r(3) instead!\"))) gmtime(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"localtime(...)=__attribute__((deprecated(\"localtime(3) isn't thread-safe. Use localtime_r(3) instead!\"))) localtime(__VA_ARGS__)"
-AM_CPPFLAGS_NOCHECK += -D"strncpy(...)=__attribute__((deprecated(\"strncpy(3) is deprecated. Use strlcpy(3) instead!\"))) strncpy(__VA_ARGS__)"
-
-AM_CPPFLAGS += $(AM_CPPFLAGS_NOCHECK)
-
 if ASAN_ENABLED
 AM_CPPFLAGS += -DZFS_ASAN_ENABLED
 endif