1.0.18.28: Add NEWS entry and manual entry for SB-EXT:*MUFFLED-WARNINGS*.

[sbcl.git] / doc / manual / compiler.texinfo

diff --git a/doc/manual/compiler.texinfo b/doc/manual/compiler.texinfo
index f592415..35284f3 100644 (file)
--- a/doc/manual/compiler.texinfo
+++ b/doc/manual/compiler.texinfo
@@ -11,11 +11,12 @@ naive translation. Efficiency issues are sufficiently varied and
 separate that they have their own chapter, @ref{Efficiency}.
 
 @menu
-* Diagnostic Messages::         
+* Diagnostic Messages::
 * Handling of Types::           
 * Compiler Policy::             
 * Compiler Errors::             
 * Open Coding and Inline Expansion::  
+* Interpreter::
 @end menu
 
 @node  Diagnostic Messages
@@ -83,6 +84,9 @@ controlled via the alist
 
 @include var-sb-ext-star-compiler-print-variable-alist-star.texinfo
 
+For information about muffling warnings signaled outside of the
+compiler, see @ref{Customization Hooks for Users}.
+
 @c <!-- FIXME: How much control over error messages is in SBCL?
 @c      _     How much should be? How much of this documentation should
 @c      _     we save or adapt? 
@@ -125,7 +129,7 @@ controlled via the alist
 @comment  node-name,  next,  previous,  up
 @subsection Diagnostic Severity
 @cindex Severity of compiler messages
-@cindex compiler diagnostic severity
+@cindex Compiler Diagnostic Severity
 @tindex error
 @tindex warning
 @tindex style-warning
@@ -389,7 +393,7 @@ This message is not saying ``there is a problem somewhere in this
 @node The Processing Path
 @comment  node-name,  next,  previous,  up
 @subsubsection The Processing Path
-@cindex Processing path
+@cindex Processing Path
 @cindex Macroexpansion
 @cindex Source-to-source transformation
 
@@ -514,14 +518,16 @@ selectable via @code{optimize} declarations.
 All declarations are considered assertions to be checked at runtime,
 and all type checks are precise.
 
-Used when @code{(>= safety (max speed space compilation-speed)}. The
+Used when @code{(and (< 0 safety) (or (>= safety 2) (>= safety speed)))}. The
 default compilation policy provides full type checks.
 
 @item Weak Type Checks
 Any or all type declarations may be believed without runtime
-assertions, and assertions that are done may be imprecise.
+assertions, and assertions that are done may be imprecise. It should
+be noted that it is relatively easy to corrupt the heap when weak type
+checks are used, and type-errors are introduced into the program.
 
-Used when @code{(< 0 safety (max speed space compilation-speed)}.
+Used when @code{(and (< safety 2) (< safety speed))}
 
 @item No Type Checks
 All declarations are believed without assertions. Also disables
@@ -858,6 +864,7 @@ is to slow the program by causing cache misses or even swapping.
 @c      _  In addition to suppressing type checks, \code{0} also suppresses
 @c      _  argument count checking, unbound-symbol checking and array bounds
 @c      _  checks.
+@c      _  ... and checking of tag existence in RETURN-FROM and GO.
 @c      _
 @c      _\item[\code{extensions:inhibit-warnings}] \cindex{inhibit-warnings
 @c      _    optimization quality}This is a CMU extension that determines how
@@ -1015,8 +1022,8 @@ character position and gives up on the entire source file.
 @comment  node-name,  next,  previous,  up
 @section Open Coding and Inline Expansion
 @cindex Open-coding
-@cindex inline expansion
-@cindex static functions
+@cindex Inline expansion
+@cindex Static functions
 
 Since Common Lisp forbids the redefinition of standard functions, the
 compiler can have special knowledge of these standard functions
@@ -1087,3 +1094,20 @@ open-coded. Even when not open-coded, a call to a standard function
 may be transformed into a different function call (as in the last
 example) or compiled as @emph{static call}. Static function call uses
 a more efficient calling convention that forbids redefinition.
+
+@node  Interpreter
+@comment  node-name,  next,  previous,  up
+@section Interpreter
+@cindex Interpreter
+@vindex sb-ext:*evaluator-mode*
+
+By default SBCL implements @code{eval} by calling the native code
+compiler. SBCL also includes an interpreter for use in special cases
+where using the compiler is undesirable, for example due to compilation
+overhead. Unlike in some other Lisp implementations, in SBCL interpreted
+code is not safer or more debuggable than compiled code.
+
+Switching between the compiler and the interpreter is done using the
+special variable @code{sb-ext:*evaluator-mode*}. As of 0.9.17, valid
+values for @code{sb-ext:*evaluator-mode*} are @code{:compile} and
+@code{:interpret}.