Changes between Version 12 and Version 13 of Commentary/Libraries

Timestamp:

08/28/09 04:38:05 (4 years ago)

Author:

simonpj

Comment:

--

Commentary/Libraries

@@ -1 +1 @@
 = GHC Commentary: Libraries =
 
-All GHC build trees contain a set of libraries:
+All GHC build trees contain a set of libraries, called the '''Boot Packages'''.  These are the libraries that GHC's source code imports.  Obviously you need the boot packages to build GHC at all (whether the stage-1 or stage-2 compiler).
 
- * The '''Boot Packages''' are the libraries that GHC's source code imports.  Obviously you need the boot packages to build GHC at all (whether the stage-1 or stage-2 compiler).
+The Boot Packages, along with the other subcomponents of the GHC build system, are in the file `packages` in a GHC tree. To get a list of them, you can run `make show VALUE=PACKAGES` in a configured GHC build tree.  (This variable is set in `$(TOP)/ghc.mk`.)
 
- * The '''Zero-boot Packages''' are a small subset of the boot packages.  Since GHC's source code imports the boot packages, ''even the bootstrap compiler must have the boot packages available''.  But for certain fast-moving boot packages (eg Cabal), we don't want to rely on the user having installed a bang-up-to-date version of the package.  So we begin the entire build process by installing the zero-boot packages in the bootstrap compiler.  (This installation is purely local to the build tree.)  The bootstrap compiler is expected to have all other (non-zero-) boot packages already installed.
+Every installation of GHC includes the Boot Packages.
+
+== Zero-boot package ===
+
+The '''Zero-boot Packages''' are a small subset of the boot packages.  Since GHC's source code imports the boot packages, ''even the bootstrap compiler must have the boot packages available''.  But for certain fast-moving boot packages (eg Cabal), we don't want to rely on the user having installed a bang-up-to-date version of the package.  So we begin the entire build process by installing the zero-boot packages in the bootstrap compiler.  (This installation is purely local to the build tree.)  The bootstrap compiler is expected to have all other (non-zero-) boot packages already installed.
 
 As time goes on, a Zero-boot package may become an ordinary boot package, because the bootstrap compiler is expected to have (a sufficiently up to date) version of the package already.
 
-The Boot Packages, along with the other subcomponents of the GHC build system, are in the file `packages` in a GHC tree. To get a list of them, you can run `make show VALUE=PACKAGES` in a configured GHC build tree.  (This variable is set in `$(TOP)/ghc.mk`.)
+The current Zero-boot packages are:
+ * `Cabal`: we frequently update Cabal and GHC in sync
+ * `filepath`
 
 == Classifying the boot packages ==
@@ -20 +26 @@
 
 Most boot libraries are INDEPENDENT.  INDEPENDENT libraries have a
-master repository somewhere separate from the GHC repositories.
+master repository somewhere separate from the GHC repositories.  Whenever we release GHC, we ensure that the INDEPENDENT boot libraries that come with GHC are precisely sync'd with a particular released version of that library.
+
+The current classification of packages is:
+  * SPECIFIC: `ghc-prim`, `template-haskell`, `DPH`
+  * COUPLED: `base`
+  * INDEPENDENT: all other packages
 
 == Structure of the boot packages ==
@@ -56 +67 @@
 The `haskell98`, `old-time` and `random` packages are mostly only needed for Haskell 98 support, although `dph` currently uses `random` too.
 
-The current classification of packages is:
-  * SPECIFIC: `ghc-prim`, `template-haskell`
-  * COUPLED: `base`
-  * INDEPENDENT and Zero-Boot: `Cabal`, `filepath`
-  * INDEPENDENT: all other packages
+