introduce std.heap.ArenaAllocator and std.heap.DirectAllocator

 * DirectAllocator does the underlying syscall for every allocation.
 * ArenaAllocator takes another allocator as an argument and
   allocates bytes up front, falling back to DirectAllocator with
   increasingly large allocation sizes, to avoid calling it too often.
   Then the entire arena can be freed at once.

The self hosted parser is updated to take advantage of ArenaAllocator
for the AST that it returns. This significantly reduces the complexity
of cleanup code.

docgen and build runner are updated to use the combination of
ArenaAllocator and DirectAllocator instead of IncrementingAllocator,
which is now deprecated in favor of FixedBufferAllocator combined
with DirectAllocator.

The C allocator calls aligned_alloc instead of malloc, in order to
respect the alignment parameter.

Added asserts in Allocator to ensure that implementors of the
interface return slices of the correct size.

Fixed a bug in Allocator when you call realloc to grow the allocation.

1 files changed, 17 insertions, 5 deletions

diff --git a/std/os/windows/index.zig b/std/os/windows/index.zig
index e7bf1916f4..2709cf2a78 100644
--- a/std/os/windows/index.zig
+++ b/std/os/windows/index.zig
@@ -22,7 +22,7 @@ pub extern "kernel32" stdcallcc fn CreatePipe(hReadPipe: &HANDLE, hWritePipe: &H
 
 pub extern "kernel32" stdcallcc fn CreateProcessA(lpApplicationName: ?LPCSTR, lpCommandLine: LPSTR,
     lpProcessAttributes: ?&SECURITY_ATTRIBUTES, lpThreadAttributes: ?&SECURITY_ATTRIBUTES, bInheritHandles: BOOL,
-    dwCreationFlags: DWORD, lpEnvironment: ?LPVOID, lpCurrentDirectory: ?LPCSTR, lpStartupInfo: &STARTUPINFOA,
+    dwCreationFlags: DWORD, lpEnvironment: ?&c_void, lpCurrentDirectory: ?LPCSTR, lpStartupInfo: &STARTUPINFOA,
     lpProcessInformation: &PROCESS_INFORMATION) BOOL;
 
 pub extern "kernel32" stdcallcc fn CreateSymbolicLinkA(lpSymlinkFileName: LPCSTR, lpTargetFileName: LPCSTR,
@@ -61,16 +61,24 @@ pub extern "kernel32" stdcallcc fn GetFinalPathNameByHandleA(hFile: HANDLE, lpsz
 
 pub extern "kernel32" stdcallcc fn GetProcessHeap() ?HANDLE;
 
+pub extern "kernel32" stdcallcc fn HeapCreate(flOptions: DWORD, dwInitialSize: SIZE_T, dwMaximumSize: SIZE_T) ?HANDLE;
+pub extern "kernel32" stdcallcc fn HeapDestroy(hHeap: HANDLE) BOOL;
+pub extern "kernel32" stdcallcc fn HeapReAlloc(hHeap: HANDLE, dwFlags: DWORD, lpMem: &c_void, dwBytes: SIZE_T) ?&c_void;
+pub extern "kernel32" stdcallcc fn HeapSize(hHeap: HANDLE, dwFlags: DWORD, lpMem: &const c_void) SIZE_T;
+pub extern "kernel32" stdcallcc fn HeapValidate(hHeap: HANDLE, dwFlags: DWORD, lpMem: &const c_void) BOOL;
+pub extern "kernel32" stdcallcc fn HeapCompact(hHeap: HANDLE, dwFlags: DWORD) SIZE_T;
+pub extern "kernel32" stdcallcc fn HeapSummary(hHeap: HANDLE, dwFlags: DWORD, lpSummary: LPHEAP_SUMMARY) BOOL;
+
 pub extern "kernel32" stdcallcc fn GetStdHandle(in_nStdHandle: DWORD) ?HANDLE;
 
-pub extern "kernel32" stdcallcc fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) ?LPVOID;
+pub extern "kernel32" stdcallcc fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) ?&c_void;
 
-pub extern "kernel32" stdcallcc fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) BOOL;
+pub extern "kernel32" stdcallcc fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: &c_void) BOOL;
 
 pub extern "kernel32" stdcallcc fn MoveFileExA(lpExistingFileName: LPCSTR, lpNewFileName: LPCSTR,
     dwFlags: DWORD) BOOL;
 
-pub extern "kernel32" stdcallcc fn ReadFile(in_hFile: HANDLE, out_lpBuffer: LPVOID,
+pub extern "kernel32" stdcallcc fn ReadFile(in_hFile: HANDLE, out_lpBuffer: &c_void,
     in_nNumberOfBytesToRead: DWORD, out_lpNumberOfBytesRead: &DWORD,
     in_out_lpOverlapped: ?&OVERLAPPED) BOOL;
 
@@ -201,7 +209,7 @@ pub const VOLUME_NAME_NT = 0x2;
 
 pub const SECURITY_ATTRIBUTES = extern struct {
     nLength: DWORD,
-    lpSecurityDescriptor: ?LPVOID,
+    lpSecurityDescriptor: ?&c_void,
     bInheritHandle: BOOL,
 };
 pub const PSECURITY_ATTRIBUTES = &SECURITY_ATTRIBUTES;
@@ -296,3 +304,7 @@ pub const MOVEFILE_WRITE_THROUGH = 8;
 pub const FILE_BEGIN = 0;
 pub const FILE_CURRENT = 1;
 pub const FILE_END = 2;
+
+pub const HEAP_CREATE_ENABLE_EXECUTE = 0x00040000;
+pub const HEAP_GENERATE_EXCEPTIONS = 0x00000004;
+pub const HEAP_NO_SERIALIZE = 0x00000001;