From 8f97068be830f3462ec8283bec814474a078ab58 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Tue, 14 Feb 2023 21:44:52 +0100
Subject: [PATCH] doc: suppress useless "this pointer is null" warnings on GCC
 11+.

Having code snippets in docs compiled and checked for syntax and
outdated API errors is great. In theory. In practice the people reading
docs have NO IDEA how much needless suffering goes into making the
compiler collaborate with me on such a seemingly simple task. UGH.
---
 doc/snippets/MagnumShaderTools.cpp | 18 +++++++++++---
 doc/snippets/MagnumText.cpp        | 38 +++++++++++++++++++++++++-----
 doc/snippets/MagnumTrade.cpp       | 24 +++++++++++++++----
 3 files changed, 67 insertions(+), 13 deletions(-)

diff --git a/doc/snippets/MagnumShaderTools.cpp b/doc/snippets/MagnumShaderTools.cpp
index 8897c2d96..da4bdca18 100644
--- a/doc/snippets/MagnumShaderTools.cpp
+++ b/doc/snippets/MagnumShaderTools.cpp
@@ -100,7 +100,11 @@ Containers::Optional<Containers::Array<char>> spirv =
 }
 
 {
-Containers::Pointer<ShaderTools::AbstractConverter> converter;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<ShaderTools::AbstractConverter> manager;
+Containers::Pointer<ShaderTools::AbstractConverter> converter = manager.loadAndInstantiate("SomethingWhatever");
 Containers::Array<char> extract(const std::string&, const std::string&);
 /* [AbstractConverter-usage-callbacks] */
 struct Data {
@@ -136,7 +140,11 @@ auto result = converter->validateFile(ShaderTools::Stage::Fragment, "ssao.frag")
 }
 
 {
-Containers::Pointer<ShaderTools::AbstractConverter> converter;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<ShaderTools::AbstractConverter> manager;
+Containers::Pointer<ShaderTools::AbstractConverter> converter = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractConverter-setInputFileCallback] */
 converter->setInputFileCallback([](const std::string& filename,
     InputFileCallbackPolicy, void*) {
@@ -147,7 +155,11 @@ converter->setInputFileCallback([](const std::string& filename,
 }
 
 {
-Containers::Pointer<ShaderTools::AbstractConverter> converter;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<ShaderTools::AbstractConverter> manager;
+Containers::Pointer<ShaderTools::AbstractConverter> converter = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractConverter-setInputFileCallback-template] */
 const Utility::Resource rs{"data"};
 converter->setInputFileCallback([](const std::string& filename,
diff --git a/doc/snippets/MagnumText.cpp b/doc/snippets/MagnumText.cpp
index 4e21fb97a..5901d9a4c 100644
--- a/doc/snippets/MagnumText.cpp
+++ b/doc/snippets/MagnumText.cpp
@@ -39,6 +39,8 @@
 #include "Magnum/Text/DistanceFieldGlyphCache.h"
 #include "Magnum/Text/Renderer.h"
 
+#define DOXYGEN_ELLIPSIS(...) __VA_ARGS__
+
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
@@ -61,7 +63,11 @@ font->fillGlyphCache(cache, "abcdefghijklmnopqrstuvwxyz"
 
 #if defined(CORRADE_TARGET_UNIX) || (defined(CORRADE_TARGET_WINDOWS) && !defined(CORRADE_TARGET_WINDOWS_RT))
 {
-Containers::Pointer<Text::AbstractFont> font;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the font pointer. I don't care, I just want you to check compilation errors,
+   not more! */
+PluginManager::Manager<Text::AbstractFont> manager;
+Containers::Pointer<Text::AbstractFont> font = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractFont-usage-callbacks] */
 struct Data {
     std::unordered_map<std::string, Containers::Optional<
@@ -95,7 +101,11 @@ font->openFile("magnum-font.conf", 13.0f);
 #endif
 
 {
-Containers::Pointer<Text::AbstractFont> font;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the font pointer. I don't care, I just want you to check compilation errors,
+   not more! */
+PluginManager::Manager<Text::AbstractFont> manager;
+Containers::Pointer<Text::AbstractFont> font = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractFont-setFileCallback] */
 font->setFileCallback([](const std::string& filename,
     InputFileCallbackPolicy, void*) {
@@ -106,7 +116,11 @@ font->setFileCallback([](const std::string& filename,
 }
 
 {
-Containers::Pointer<Text::AbstractFont> font;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the font pointer. I don't care, I just want you to check compilation errors,
+   not more! */
+PluginManager::Manager<Text::AbstractFont> manager;
+Containers::Pointer<Text::AbstractFont> font = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractFont-setFileCallback-template] */
 const Utility::Resource rs{"data"};
 font->setFileCallback([](const std::string& filename,
@@ -117,8 +131,12 @@ font->setFileCallback([](const std::string& filename,
 }
 
 {
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the font pointer. I don't care, I just want you to check compilation errors,
+   not more! */
+PluginManager::Manager<Text::AbstractFont> manager;
 /* [DistanceFieldGlyphCache-usage] */
-Containers::Pointer<Text::AbstractFont> font;
+Containers::Pointer<Text::AbstractFont> font = DOXYGEN_ELLIPSIS(manager.loadAndInstantiate("SomethingWhatever"));
 Text::DistanceFieldGlyphCache cache{Vector2i{2048}, Vector2i{384}, 16};
 font->fillGlyphCache(cache, "abcdefghijklmnopqrstuvwxyz"
                             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -127,8 +145,12 @@ font->fillGlyphCache(cache, "abcdefghijklmnopqrstuvwxyz"
 }
 
 {
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the font pointer. I don't care, I just want you to check compilation errors,
+   not more! */
+PluginManager::Manager<Text::AbstractFont> manager;
 /* [GlyphCache-usage] */
-Containers::Pointer<Text::AbstractFont> font;
+Containers::Pointer<Text::AbstractFont> font = DOXYGEN_ELLIPSIS(manager.loadAndInstantiate("SomethingWhatever"));
 Text::GlyphCache cache{Vector2i{512}};
 font->fillGlyphCache(cache, "abcdefghijklmnopqrstuvwxyz"
                             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -138,9 +160,13 @@ font->fillGlyphCache(cache, "abcdefghijklmnopqrstuvwxyz"
 
 {
 Matrix3 projectionMatrix;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the font pointer. I don't care, I just want you to check compilation errors,
+   not more! */
+PluginManager::Manager<Text::AbstractFont> manager;
 /* [Renderer-usage1] */
 /* Font instance, received from a plugin manager */
-Containers::Pointer<Text::AbstractFont> font;
+Containers::Pointer<Text::AbstractFont> font = DOXYGEN_ELLIPSIS(manager.loadAndInstantiate("SomethingWhatever"));
 
 /* Configured glyph cache */
 Text::GlyphCache cache{Vector2i{512}};
diff --git a/doc/snippets/MagnumTrade.cpp b/doc/snippets/MagnumTrade.cpp
index 43eaad7d6..4c0359003 100644
--- a/doc/snippets/MagnumTrade.cpp
+++ b/doc/snippets/MagnumTrade.cpp
@@ -149,7 +149,11 @@ if(!image) Fatal{} << "Importing the image failed";
 }
 
 {
-Containers::Pointer<Trade::AbstractImporter> importer;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<Trade::AbstractImporter> manager;
+Containers::Pointer<Trade::AbstractImporter> importer = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractImporter-usage-data] */
 Utility::Resource rs{"data"};
 Containers::ArrayView<const char> data = rs.getRaw("image.png");
@@ -162,7 +166,11 @@ if(!importer->openData(data)) /* or openMemory() */
 
 #if defined(CORRADE_TARGET_UNIX) || (defined(CORRADE_TARGET_WINDOWS) && !defined(CORRADE_TARGET_WINDOWS_RT))
 {
-Containers::Pointer<Trade::AbstractImporter> importer;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<Trade::AbstractImporter> manager;
+Containers::Pointer<Trade::AbstractImporter> importer = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractImporter-usage-callbacks] */
 struct Data {
     std::unordered_map<std::string, Containers::Optional<
@@ -196,7 +204,11 @@ importer->openFile("scene.gltf"); // memory-maps all files
 #endif
 
 {
-Containers::Pointer<Trade::AbstractImporter> importer;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<Trade::AbstractImporter> manager;
+Containers::Pointer<Trade::AbstractImporter> importer = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractImporter-setFileCallback] */
 importer->setFileCallback([](const std::string& filename,
     InputFileCallbackPolicy, void*) {
@@ -207,7 +219,11 @@ importer->setFileCallback([](const std::string& filename,
 }
 
 {
-Containers::Pointer<Trade::AbstractImporter> importer;
+/* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
+   the converter pointer. I don't care, I just want you to check compilation
+   errors, not more! */
+PluginManager::Manager<Trade::AbstractImporter> manager;
+Containers::Pointer<Trade::AbstractImporter> importer = manager.loadAndInstantiate("SomethingWhatever");
 /* [AbstractImporter-setFileCallback-template] */
 const Utility::Resource rs{"data"};
 importer->setFileCallback([](const std::string& filename,