Tidy up cp_acp work

CHECKLIST-GCC.md

@@ -0,0 +1,175 @@
+# GCC Build Checklist
+
+Build configuration: `x64-linux-gnuc-debug` (GCC 13.3.0, x64, Linux, C++20)
+
+---
+
+## Summary
+
+**11 compilation units across 5 library sub-projects fail to build.**
+All failures trace back to **two root causes** in shared headers:
+
+| Root Cause | File | Fixable |
+|---|---|---|
+| 1 | `src/include/m/utility/compiler.h` — no GCC branch | ✅ Yes |
+| 2 | `src/libraries/strings/include/m/strings/literal_string_view.h` — GCC rejects `friend` declarations for UDL operators with qualified namespace names | ✅ Yes |
+
+Fixing these two headers would resolve all five library failures.
+
+---
+
+## Root Cause 1 — `src/include/m/utility/compiler.h`
+
+**Problem:** The file explicitly `#error`s for any compiler that is neither MSVC nor
+Clang:
+
+```cpp
+#if defined(_MSC_VER) && !defined(__clang__)
+    #define M_HAS_MSVC 1
+#elif defined(__clang__)
+    #define M_HAS_CLANG 1
+#else
+    #error Unsupported compiler   // ← GCC hits this
+#endif
+```
+
+A second `#else #error unsupported compiler` repeats this for the `M_NOINLINE`
+and C++ standard detection blocks, and then `M_HAS_CXX20` is never defined so
+a third `#error The M library requires C++20` fires.
+
+**Fix:** Add a `#elif defined(__GNUC__)` branch in all three gated blocks:
+- Define `M_HAS_GCC 1`
+- Define `M_NOINLINE __attribute__((noinline))` (identical to the Clang path)
+- Detect C++20/C++23 via `__cplusplus >= 202002L` / `>= 202302L` (same as Clang)
+
+**Assessment: ✅ Straightforward — identical to the existing Clang branch.**
+
+---
+
+## Root Cause 2 — `src/libraries/strings/include/m/strings/literal_string_view.h`
+
+**Problem:** GCC rejects `friend` declarations for user-defined literal (UDL)
+operators when the operator is named with a fully-qualified nested-namespace name
+inside a class body:
+
+```cpp
+// GCC error: "has invalid argument list"
+friend constexpr basic_literal_string_view<char>
+    string_view_literals::operator""_sl(const char*, std::size_t);
+```
+
+Because GCC rejects the friend declaration, the UDL operators cannot access the
+`protected` constructor, producing a second error:
+`'basic_literal_string_view(const CharT*, std::size_t)' is protected within this context`.
+
+This is a known GCC strictness difference from Clang/MSVC. The standard is
+ambiguous here and GCC takes the stricter reading.
+
+**Fix options (any one suffices):**
+1. Replace the `protected` constructor + `friend` pattern with a private tag-type
+   trick: add a private `struct key {}`, make the constructor `public` but require
+   a `key` argument, and have the UDL operators pass `key{}`. No friend declarations
+   needed.
+2. Move the UDL operator definitions into the same namespace as the class (`m`) and
+   declare them `inline friend` inside the class body rather than using qualified names.
+
+**Assessment: ✅ Fixable with a small structural refactor. No external API change is
+required if option 1 is used (the constructor remains effectively uncallable from
+outside the class without the tag type).**
+
+---
+
+## Failing Library Sub-Projects
+
+### `src/libraries/byte_streams`
+
+| | |
+|---|---|
+| **Failing units** | `src/byte_streams.cpp`, `src/memory_stream.cpp` |
+| **Error** | `compiler.h:27: #error Unsupported compiler` |
+| **Root cause** | Root Cause 1 only |
+| **Fixable?** | ✅ Yes — fixed automatically once `compiler.h` gains a GCC branch |
+
+---
+
+### `src/libraries/debugging`
+
+| | |
+|---|---|
+| **Failing units** | `src/dbg_format.cpp` |
+| **Error** | `compiler.h:27: #error Unsupported compiler` |
+| **Root cause** | Root Cause 1 only |
+| **Fixable?** | ✅ Yes — fixed automatically once `compiler.h` gains a GCC branch |
+
+---
+
+### `src/libraries/io`
+
+| | |
+|---|---|
+| **Failing units** | `src/io.cpp` |
+| **Error** | `compiler.h:27: #error Unsupported compiler` |
+| **Root cause** | Root Cause 1 only |
+| **Fixable?** | ✅ Yes — fixed automatically once `compiler.h` gains a GCC branch |
+
+---
+
+### `src/libraries/tracing`
+
+| | |
+|---|---|
+| **Failing units** | `src/message_source.cpp`, `src/sink.cpp` |
+| **Errors** | (1) `compiler.h:27: #error Unsupported compiler` via `tracing.h` → `frame.h` → `compiler.h`; (2) `literal_string_view.h:50: UDL operator has invalid argument list` via `sink.h` → `envelope.h` → `literal_string_view.h` |
+| **Root cause** | Root Causes 1 **and** 2 |
+| **Fixable?** | ✅ Yes — requires both root-cause fixes |
+
+---
+
+### `src/libraries/utf`
+
+| | |
+|---|---|
+| **Failing units** | `src/decode_utf16.cpp`, `src/decode_utf32.cpp`, `src/decode_utf8.cpp`, `src/encoding_size.cpp`, `src/utf.cpp` |
+| **Error** | `compiler.h:27: #error Unsupported compiler` |
+| **Root cause** | Root Cause 1 only |
+| **Fixable?** | ✅ Yes — fixed automatically once `compiler.h` gains a GCC branch |
+
+---
+
+## Libraries and Tests That Build Successfully
+
+The following libraries built cleanly under GCC and are not affected:
+
+- `src/libraries/arefc_ptr`
+- `src/libraries/atomic`
+- `src/libraries/bitset`
+- `src/libraries/block_buffer`
+- `src/libraries/cast`
+- `src/libraries/chrono`
+- `src/libraries/command_options`
+- `src/libraries/const_string`
+- `src/libraries/csv`
+- `src/libraries/error_handling`
+- `src/libraries/filesystem`
+- `src/libraries/googletest` / `googletest_main`
+- `src/libraries/inplace_vector`
+- `src/libraries/math`
+- `src/libraries/memory`
+- `src/libraries/pe`
+- `src/libraries/pil`
+- `src/libraries/Platform-Adaptive`
+- `src/libraries/pool`
+- `src/libraries/print`
+- `src/libraries/puddle`
+- `src/libraries/random`
+- `src/libraries/rfc3339_clock`
+- `src/libraries/sstring`
+- `src/libraries/string_buffer`
+- `src/libraries/strings`
+- `src/libraries/test_data`
+- `src/libraries/thread_description`
+- `src/libraries/threadpool`
+- `src/libraries/wrappers`
+- `src/mc`
+- `src/tools`
+- `src/Linux/libraries`

CMakePresets.json

@@ -54,6 +54,36 @@
       },
       "hidden": true
     },
+    {
+      "name": "linux-gnuc-base",
+      "inherits": [
+        "base"
+      ],
+      "environment": {
+        "CC": "gcc",
+        "CXX": "g++"
+      },
+      "cacheVariables": {
+        "CMAKE_C_COMPILER": "/usr/bin/gcc",
+        "CMAKE_CXX_COMPILER": "/usr/bin/g++",
+        "CMAKE_BUILD_WITH_INSTALL_RPATH": true
+      },
+      "vendor": {
+        "microsoft.com/VisualStudioRemoteSettings/CMake/2.0": {
+          "remoteSourceRootDir": "$env{HOME}/.vs/$ms{projectDirName}",
+          "copySourcesOptions": {
+            "exclusionList": [
+              "buildtrees",
+              ".vs",
+              "out",
+              "vcpkg/buildtrees",
+              "vcpkg/downloads"
+            ]
+          }
+        }
+      },
+      "hidden": true
+    },
     {
       "name": "win-base",
       "description": "Customizations for Windows Build",
@@ -431,6 +461,46 @@
           ]
         }
       }
+    },
+    {
+      "name": "x64-linux-gnuc-debug",
+      "displayName": "x64-linux-gnuc-debug",
+      "description": "g++ linux x64 debug",
+      "inherits": [
+        "linux-gnuc-base",
+        "x64",
+        "debug"
+      ],
+      "cacheVariables": {
+        "VCPKG_TARGET_TRIPLET": "x64-linux"
+      },
+      "vendor": {
+        "microsoft.com/VisualStudioSettings/CMake/1.0": {
+          "hostOS": [
+            "Linux"
+          ]
+        }
+      }
+    },
+    {
+      "name": "x64-linux-gnuc-release",
+      "displayName": "x64-linux-gnuc-release",
+      "description": "g++ linux x64 release",
+      "inherits": [
+        "linux-gnuc-base",
+        "x64",
+        "release"
+      ],
+      "cacheVariables": {
+        "VCPKG_TARGET_TRIPLET": "x64-linux"
+      },
+      "vendor": {
+        "microsoft.com/VisualStudioSettings/CMake/1.0": {
+          "hostOS": [
+            "Linux"
+          ]
+        }
+      }
     }
   ]
 }

codeql-custom-queries-cpp/codeql-pack.lock.yml

@@ -0,0 +1,28 @@
+---
+lockVersion: 1.0.0
+dependencies:
+  codeql/controlflow:
+    version: 2.0.26
+  codeql/cpp-all:
+    version: 7.1.1
+  codeql/dataflow:
+    version: 2.0.26
+  codeql/mad:
+    version: 1.0.42
+  codeql/quantum:
+    version: 0.0.20
+  codeql/rangeanalysis:
+    version: 1.0.42
+  codeql/ssa:
+    version: 2.0.18
+  codeql/tutorial:
+    version: 1.0.42
+  codeql/typeflow:
+    version: 1.0.42
+  codeql/typetracking:
+    version: 2.0.26
+  codeql/util:
+    version: 2.0.29
+  codeql/xml:
+    version: 1.0.42
+compiled: false

codeql-custom-queries-cpp/codeql-pack.yml

@@ -0,0 +1,7 @@
+---
+library: false
+warnOnImplicitThis: false
+name: getting-started/codeql-extra-queries-cpp
+version: 1.0.0
+dependencies:
+  codeql/cpp-all: ^7.1.1

codeql-custom-queries-cpp/example.ql

@@ -0,0 +1,12 @@
+/**
+ * This is an automatically generated file
+ * @name Hello world
+ * @kind problem
+ * @problem.severity warning
+ * @id cpp/example/hello-world
+ */
+
+import cpp
+
+from File f
+select f, "Hello, world!"

codeql-custom-queries-cpp/example2.ql

@@ -0,0 +1,12 @@
+/**
+ * This is an automatically generated file
+ * @name Hello world
+ * @kind problem
+ * @problem.severity warning
+ * @id cpp/example/hello-world
+ */
+
+import cpp
+
+from File f
+select f, "Hello, world!"