[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outdated for a long while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, 56 insertions, 0 deletions

diff --git a/clang/docs/analyzer/checkers/mismatched_deallocator_example.cpp b/clang/docs/analyzer/checkers/mismatched_deallocator_example.cpp
new file mode 100644
index 00000000000..2a4103240fe
--- /dev/null
+++ b/clang/docs/analyzer/checkers/mismatched_deallocator_example.cpp
@@ -0,0 +1,56 @@
+// C, C++
+void test() {
+  int *p = (int *)malloc(sizeof(int));
+  delete p; // warn
+}
+
+// C, C++
+void __attribute((ownership_returns(malloc))) *user_malloc(size_t);
+
+void test() {
+  int *p = (int *)user_malloc(sizeof(int));
+  delete p; // warn
+}
+
+// C, C++
+void test() {
+  int *p = new int;
+  free(p); // warn
+}
+
+// C, C++
+void test() {
+  int *p = new int[1];
+  realloc(p, sizeof(long)); // warn
+}
+
+// C, C++
+template <typename T>
+struct SimpleSmartPointer {
+  T *ptr;
+
+  explicit SimpleSmartPointer(T *p = 0) : ptr(p) {}
+  ~SimpleSmartPointer() {
+    delete ptr; // warn
+  }
+};
+
+void test() {
+  SimpleSmartPointer<int> a((int *)malloc(4));
+}
+
+// C++
+void test() {
+  int *p = (int *)operator new(0);
+  delete[] p; // warn
+}
+
+// Objective-C, C++
+void test(NSUInteger dataLength) {
+  int *p = new int;
+  NSData *d = [NSData dataWithBytesNoCopy:p
+               length:sizeof(int) freeWhenDone:1];
+    // warn +dataWithBytesNoCopy:length:freeWhenDone: cannot take
+    // ownership of memory allocated by 'new'
+}
+