Gcc compiler warning flags setting

README.md

@@ -28,32 +28,35 @@ toolchain_gcc_dependencies()
 ## Configuring the toolchain to a project needs
 The `score_toolchains_gcc` module currently supports only GNU GCC version **12.2.0**. Support for multiple GCC versions is planned, with future versions expected to be selectable via an extended toolchain interface. As of now, version 12.2.0 is the sole supported target.
 
-The module exposes an API that allows consumers to enable or disable specific toolchain behaviors related to compilation diagnostics. The following features can be individually configured:
+The module exposes an API that allows consumers to enable or disable specific toolchain behaviors related to compilation diagnostics.
+By default, the toolchain activates the following features using predefined compiler flags:
 
-1. Minimal warning flags — enables a basic set of compiler warnings
-2. Strict warning flags — enables a more aggressive set of warnings (e.g., `-Wall, -Wextra`)
+1. Minimal warning flags — enables a basic set of compiler warnings (e.g., `-Wall, -Wextra`)
+2. Strict warning flags — enables a more aggressive set of warnings (e.g., `-Wpedantic`)
 3. A `treat warnings as errors` flags — promotes all warnings to errors (e.g., `-Werror`)
 
-These features provide fine-grained control over the compiler's warning policy. If no features are explicitly selected, the toolchain will apply no additional warning-related flags by default.
+Consumers can disable any of these features by prefixing the feature name with a dash (e.g., `-minimal_warnings`). When a feature is disabled this way, neither the default nor any user-defined flags associated with it will be applied.
+Additionally, consumers can adjust the compiler's warning behavior by adding custom flags or disabling specific warnings using the `-Wno-` prefix.
+These features provide fine-grained control over the compiler's warning policy.
 
 To set wanted flags, the following API needs to be used:
 ```python
 gcc = use_extension("@score_toolchains_gcc//extentions:gcc.bzl", "gcc")
 gcc.extra_features(
     features = [
         "minimal_warnings",
-        "treat_warnings_as_errors",
+        "-treat_warnings_as_errors",
     ],
 )
 gcc.warning_flags(
-    minimal_warnings = ["-Wall", "-Wno-error=deprecated-declarations"],
-    strict_warnings = ["-Wextra", "-Wpedantic"],
+    minimal_warnings = ["-Wno-error=deprecated-declarations"],
+    strict_warnings = ["-Wno-bool-compare"],
     treat_warnings_as_errors = ["-Werror"],
 )
 use_repo(gcc, "gcc_toolchain", "gcc_toolchain_gcc")
 ```
-* `extra_features` - This will enable all features which are set in the list.
-* `warning_flags` - This will set flags for selected features.
+* `extra_features` - Enables or disables features listed by the consumer.
+* `warning_flags` - Sets compiler flags for the features that are currently enabled.
 
 ### Using WORKSPACE file
 The same approuch needs to be done when configuring toolchain over WORKSPACE file:
@@ -64,11 +67,11 @@ gcc_toolchain(
     gcc_repo = "gcc_toolchain_gcc",
     extra_features = [
         "minimal_warnings",
-        "treat_warnings_as_errors",
+        "-treat_warnings_as_errors",
     ],
     warning_flags = {
-        "minimal_warnings": ["-Wall", "-Wno-error=deprecated-declarations"],
-        "strict_warnings": ["-Wextra", "-Wpedantic"],
+        "minimal_warnings": ["-Wno-error=deprecated-declarations"],
+        "strict_warnings": ["-Wno-bool-compare"],
         "treat_warnings_as_errors": ["-Werror"],
     },
 )

extentions/gcc.bzl

@@ -21,9 +21,76 @@ def _gcc_impl(mctx):
         if not mod.is_root:
             fail("Only the root module can use the 'gcc' extension")
 
+    DEFAULT_FEATURES = [
+        "minimal_warnings",
+        "strict_warnings",
+        "treat_warnings_as_errors",
+    ]
+
+
+    DEFAULT_WARNING_FLAGS = {
+        "minimal_warnings": [
+            "-Wall",
+            "-Wextra",
+            "-Wundef",
+            "-Wwrite-strings",
+            "-Wpointer-arith",
+            "-Wcast-align",
+            "-Wshadow",
+            "-Wswitch-bool",
+            "-Wredundant-decls",
+            "-Wswitch-enum",
+            "-Wtype-limits",
+            "-Wformat",
+            "-Wformat-security",
+            "-Wconversion",
+            "-Wlogical-op",
+            "-Wreturn-local-addr",
+            "-Wunused-but-set-variable",
+            "-Wunused-parameter",
+            "-Wunused-but-set-parameter",
+            "-Wunused-variable",
+            "-Wunused",
+            "-Wparentheses",
+            "-Wuninitialized",
+            "-Wsequence-point",
+            "-Wsign-compare",
+            "-Wignored-qualifiers",
+            "-Wcast-qual",
+            "-Wreturn-type",
+            "-Wcomment"
+        ],
+        "strict_warnings": [
+            "-Wpedantic",
+            "-Wbad-function-cast",
+            "-Wstrict-prototypes",
+            "-Wodr",
+            "-Wlogical-not-parentheses",
+            "-Wsizeof-array-argument",
+            "-Wbool-compare",
+            "-Winvalid-pch",
+            "-Wformat=2",
+            "-Wmissing-format-attribute",
+            "-Wformat-nonliteral",
+            "-Wformat-signedness",
+            "-Wvla",
+            "-Wuseless-cast",
+            "-Wdouble-promotion",
+            "-Wmissing-prototypes",
+            "-Wreorder",
+            "-Wnarrowing"
+        ],
+        "treat_warnings_as_errors": []
+    }
+
+
     toolchain_info = None
-    features = []
-    warning_flags = None
+    features = list(DEFAULT_FEATURES)
+    warning_flags = {
+        "minimal_warnings": list(DEFAULT_WARNING_FLAGS["minimal_warnings"]),
+        "strict_warnings": list(DEFAULT_WARNING_FLAGS["strict_warnings"]),
+        "treat_warnings_as_errors": list(DEFAULT_WARNING_FLAGS["treat_warnings_as_errors"]),
+    }
 
     for mod in mctx.modules:
         for tag in mod.tags.toolchain:
@@ -36,14 +103,29 @@ def _gcc_impl(mctx):
 
         for tag in mod.tags.extra_features:
             for feature in tag.features:
-                features.append(feature)
+                f = feature.strip()
+                if not f:
+                    continue
+                if f.startswith("-"):
+                    remove_feature = f[1:].strip()
+                    if remove_feature in features:
+                        features.remove(remove_feature)
+                else:
+                    if f not in features:
+                        features.append(f)
 
         for tag in mod.tags.warning_flags:
-            warning_flags = {
-                "minimal_warnings":tag.minimal_warnings,
-                "strict_warnings":tag.strict_warnings,
-                "treat_warnings_as_errors":tag.treat_warnings_as_errors
-            }
+            for flag in tag.minimal_warnings:
+                if flag not in warning_flags["minimal_warnings"]:
+                    warning_flags["minimal_warnings"].append(flag)
+
+            for flag in tag.strict_warnings:
+                if flag not in warning_flags["strict_warnings"]:
+                    warning_flags["strict_warnings"].append(flag)
+
+            for flag in tag.treat_warnings_as_errors:
+                if flag not in warning_flags["treat_warnings_as_errors"]:
+                    warning_flags["treat_warnings_as_errors"].append(flag)
 
     if toolchain_info:
         http_archive(

test/.bazelversion

@@ -1 +1 @@
-8.1.1
+8.3.0

test/MODULE.bazel

@@ -32,12 +32,12 @@ gcc.toolchain(
 gcc.extra_features(
     features = [
         "minimal_warnings",
-        "treat_warnings_as_errors",
+        "-treat_warnings_as_errors",
     ],
-)
+) 
 gcc.warning_flags(
-    minimal_warnings = ["-Wall", "-Wno-error=deprecated-declarations"],
-    strict_warnings = ["-Wextra", "-Wpedantic"],
+    minimal_warnings = ["-Wno-error=deprecated-declarations", "-Wno-unused-variable"],
+    strict_warnings = ["-Wno-bool-compare"],
     treat_warnings_as_errors = ["-Werror"],
 )
 use_repo(gcc, "gcc_toolchain", "gcc_toolchain_gcc")

test/WORKSPACE

@@ -31,8 +31,8 @@ gcc_toolchain(
         "treat_warnings_as_errors",
     ],
     warning_flags = {
-        "minimal_warnings": ["-Wall", "-Wno-error=deprecated-declarations"],
-        "strict_warnings": ["-Wextra", "-Wpedantic"],
+        "minimal_warnings": ["-Wno-error=deprecated-declarations"],
+        "strict_warnings": ["-Wno-bool-compare"],
         "treat_warnings_as_errors": ["-Werror"],
     },
 )