[analyzer] Creating standard Sphinx documentation

The lack of documentation has been a long standing issue in the Static Analyzer,
and one of the leading reasons behind this was a lack of good documentation
infrastucture.

This lead serious drawbacks, such as
* Not having proper release notes for years
* Not being able to have a sensible auto-generated checker documentations (which
lead to most of them not having any)
* The HTML website that has to updated manually is a chore, and has been
outdated for a long while
* Many design discussions are now hidden in phabricator revisions

This patch implements a new documentation infrastucture using Sphinx, like most
of the other subprojects in LLVM. It transformed some pages as a proof-of-
concept, with many others to follow in later patches. The eventual goal is to
preserve the original website's (https://clang-analyzer.llvm.org/) frontpage,
but move everything else to the new format.

Some other ideas, like creating a unipage for each checker (similar to how
clang-tidy works now), are also being discussed.

Patch by Dániel Krupp!

Differential Revision: https://reviews.llvm.org/D54429

llvm-svn: 353126

1 files changed, 66 insertions, 0 deletions

diff --git a/clang/docs/analyzer/checkers/callandmessage_example.c b/clang/docs/analyzer/checkers/callandmessage_example.c
new file mode 100644
index 00000000000..7e14fbe464f
--- /dev/null
+++ b/clang/docs/analyzer/checkers/callandmessage_example.c
@@ -0,0 +1,66 @@
+//C
+void test() {
+   void (*foo)(void);
+   foo = 0;
+   foo(); // warn: function pointer is null
+ }
+
+ // C++
+ class C {
+ public:
+   void f();
+ };
+
+ void test() {
+   C *pc;
+   pc->f(); // warn: object pointer is uninitialized
+ }
+
+ // C++
+ class C {
+ public:
+   void f();
+ };
+
+ void test() {
+   C *pc = 0;
+   pc->f(); // warn: object pointer is null
+ }
+
+ // Objective-C
+ @interface MyClass : NSObject
+ @property (readwrite,assign) id x;
+ - (long double)longDoubleM;
+ @end
+
+ void test() {
+   MyClass *obj1;
+   long double ld1 = [obj1 longDoubleM];
+     // warn: receiver is uninitialized
+ }
+
+ // Objective-C
+ @interface MyClass : NSObject
+ @property (readwrite,assign) id x;
+ - (long double)longDoubleM;
+ @end
+
+ void test() {
+   MyClass *obj1;
+   id i = obj1.x; // warn: uninitialized object pointer
+ }
+
+ // Objective-C
+ @interface Subscriptable : NSObject
+ - (id)objectAtIndexedSubscript:(unsigned int)index;
+ @end
+
+ @interface MyClass : Subscriptable
+ @property (readwrite,assign) id x;
+ - (long double)longDoubleM;
+ @end
+
+ void test() {
+   MyClass *obj1;
+   id i = obj1[0]; // warn: uninitialized object pointer
+ }