[cfe-commits] r39130 - in /cfe/cfe/trunk: NOTES.txt README.txt
sabre at cs.uiuc.edu
sabre at cs.uiuc.edu
Wed Jul 11 09:27:50 PDT 2007
Author: sabre
Date: Wed Jul 11 11:27:50 2007
New Revision: 39130
URL: http://llvm.org/viewvc/llvm-project?rev=39130&view=rev
Log:
move some content around to make README more focused
Modified:
cfe/cfe/trunk/NOTES.txt
cfe/cfe/trunk/README.txt
Modified: cfe/cfe/trunk/NOTES.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/cfe/trunk/NOTES.txt?rev=39130&r1=39129&r2=39130&view=diff
==============================================================================
--- cfe/cfe/trunk/NOTES.txt (original)
+++ cfe/cfe/trunk/NOTES.txt Wed Jul 11 11:27:50 2007
@@ -31,13 +31,85 @@
//===---------------------------------------------------------------------===//
-Interesting fact:
- clang -Eonly INPUTS/carbon-header-C-E.c
+TODO: File Manager Speedup:
+
+ We currently do a lot of stat'ing for files that don't exist, particularly
+ when lots of -I paths exist (e.g. see the <iostream> example, check for
+ failures in stat in FileManager::getFile). It would be far better to make
+ the following changes:
+ 1. FileEntry contains a sys::Path instead of a std::string for Name.
+ 2. sys::Path contains timestamp and size, lazily computed. Eliminate from
+ FileEntry.
+ 3. File UIDs are created on request, not when files are opened.
+ These changes make it possible to efficiently have FileEntry objects for
+ files that exist on the file system, but have not been used yet.
+
+ Once this is done:
+ 1. DirectoryEntry gets a boolean value "has read entries". When false, not
+ all entries in the directory are in the file mgr, when true, they are.
+ 2. Instead of stat'ing the file in FileManager::getFile, check to see if
+ the dir has been read. If so, fail immediately, if not, read the dir,
+ then retry.
+ 3. Reading the dir uses the getdirentries syscall, creating an FileEntry
+ for all files found.
+
+//===---------------------------------------------------------------------===//
+
+TODO: Fast #Import:
+
+ * Get frameworks that don't use #import to do so, e.g.
+ DirectoryService, AudioToolbox, CoreFoundation, etc. Why not using #import?
+ Because they work in C mode? C has #import.
+ * Have the lexer return a token for #import instead of handling it itself.
+ - Create a new preprocessor object with no external state (no -D/U options
+ from the command line, etc). Alternatively, keep track of exactly which
+ external state is used by a #import: declare it somehow.
+ * When having reading a #import file, keep track of whether we have (and/or
+ which) seen any "configuration" macros. Various cases:
+ - Uses of target args (__POWERPC__, __i386): Header has to be parsed
+ multiple times, per-target. What about #ifndef checks? How do we know?
+ - "Configuration" preprocessor macros not defined: POWERPC, etc. What about
+ things like __STDC__ etc? What is and what isn't allowed.
+ * Special handling for "umbrella" headers, which just contain #import stmts:
+ - Cocoa.h/AppKit.h - Contain pointers to digests instead of entire digests
+ themselves? Foundation.h isn't pure umbrella!
+ * Frameworks digests:
+ - Can put "digest" of a framework-worth of headers into the framework
+ itself. To open AppKit, just mmap
+ /System/Library/Frameworks/AppKit.framework/"digest", which provides a
+ symbol table in a well defined format. Lazily unstream stuff that is
+ needed. Contains declarations, macros, and debug information.
+ - System frameworks ship with digests. How do we handle configuration
+ information? How do we handle stuff like:
+ #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_2
+ which guards a bunch of decls? Should there be a couple of default
+ configs, then have the UI fall back to building/caching its own?
+ - GUI automatically builds digests when UI is idle, both of system
+ frameworks if they aren't not available in the right config, and of app
+ frameworks.
+ - GUI builds dependence graph of frameworks/digests based on #imports. If a
+ digest is out date, dependent digests are automatically invalidated.
+
+ * New constraints on #import for objc-v3:
+ - #imported file must not define non-inline function bodies.
+ - Alternatively, they can, and these bodies get compiled/linked *once*
+ per app into a dylib. What about building user dylibs?
+ - Restrictions on ObjC grammar: can't #import the body of a for stmt or fn.
+ - Compiler must detect and reject these cases.
+ - #defines defined within a #import have two behaviors:
+ - By default, they escape the header. These macros *cannot* be #undef'd
+ by other code: this is enforced by the front-end.
+ - Optionally, user can specify what macros escape (whitelist) or can use
+ #undef.
+
+//===---------------------------------------------------------------------===//
+
+TODO: New language feature: Configuration queries:
+ - Instead of #ifdef __POWERPC__, use "if (strcmp(`cpu`, __POWERPC__))", or
+ some other, better, syntax.
+ - Use it to increase the number of "architecture-clean" #import'd files,
+ allowing a single index to be used for all fat slices.
-is much faster than:
- wc -w INPUTS/carbon-header-C-E.c
-!!
-
//===---------------------------------------------------------------------===//
The 'portability' model in clang is sufficient to catch translation units (or
Modified: cfe/cfe/trunk/README.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/cfe/trunk/README.txt?rev=39130&r1=39129&r2=39130&view=diff
==============================================================================
--- cfe/cfe/trunk/README.txt (original)
+++ cfe/cfe/trunk/README.txt Wed Jul 11 11:27:50 2007
@@ -115,25 +115,7 @@
* Include search paths are hard-coded into the driver.
File Manager:
- * We currently do a lot of stat'ing for files that don't exist, particularly
- when lots of -I paths exist (e.g. see the <iostream> example, check for
- failures in stat in FileManager::getFile). It would be far better to make
- the following changes:
- 1. FileEntry contains a sys::Path instead of a std::string for Name.
- 2. sys::Path contains timestamp and size, lazily computed. Eliminate from
- FileEntry.
- 3. File UIDs are created on request, not when files are opened.
- These changes make it possible to efficiently have FileEntry objects for
- files that exist on the file system, but have not been used yet.
-
- Once this is done:
- 1. DirectoryEntry gets a boolean value "has read entries". When false, not
- all entries in the directory are in the file mgr, when true, they are.
- 2. Instead of stat'ing the file in FileManager::getFile, check to see if
- the dir has been read. If so, fail immediately, if not, read the dir,
- then retry.
- 3. Reading the dir uses the getdirentries syscall, creating an FileEntry
- for all files found.
+ * Reduce syscalls, see NOTES.txt.
Lexer:
* Source character mapping. GCC supports ASCII and UTF-8.
@@ -149,6 +131,7 @@
* MSExtension: "L#param" stringizes to a wide string literal.
* Consider merging the parser's expression parser into the preprocessor to
eliminate duplicate code.
+ * Add support for -M*
Traditional Preprocessor:
* All.
@@ -161,6 +144,7 @@
Parser Actions:
* All that are missing.
+ * SemaActions vs MinimalActions.
* Would like to either lazily resolve types [refactoring] or aggressively
resolve them [c compiler]. Need to know whether something is a type or not
to compile, but don't need to know what it is.
@@ -169,70 +153,4 @@
AST Builder:
* Implement more nodes as actions are available.
* Types.
- * Allow the AST Builder to be subclassed. This will allow clients to extend it
- and create their own specialized nodes for specific scenarios. Maybe the
- "full loc info" use case is just one extension.
-
-Fast #Import:
- * All.
- * Get frameworks that don't use #import to do so, e.g.
- DirectoryService, AudioToolbox, CoreFoundation, etc. Why not using #import?
- Because they work in C mode? C has #import.
- * Have the lexer return a token for #import instead of handling it itself.
- - Create a new preprocessor object with no external state (no -D/U options
- from the command line, etc). Alternatively, keep track of exactly which
- external state is used by a #import: declare it somehow.
- * When having reading a #import file, keep track of whether we have (and/or
- which) seen any "configuration" macros. Various cases:
- - Uses of target args (__POWERPC__, __i386): Header has to be parsed
- multiple times, per-target. What about #ifndef checks? How do we know?
- - "Configuration" preprocessor macros not defined: POWERPC, etc. What about
- things like __STDC__ etc? What is and what isn't allowed.
- * Special handling for "umbrella" headers, which just contain #import stmts:
- - Cocoa.h/AppKit.h - Contain pointers to digests instead of entire digests
- themselves? Foundation.h isn't pure umbrella!
- * Frameworks digests:
- - Can put "digest" of a framework-worth of headers into the framework
- itself. To open AppKit, just mmap
- /System/Library/Frameworks/AppKit.framework/"digest", which provides a
- symbol table in a well defined format. Lazily unstream stuff that is
- needed. Contains declarations, macros, and debug information.
- - System frameworks ship with digests. How do we handle configuration
- information? How do we handle stuff like:
- #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_2
- which guards a bunch of decls? Should there be a couple of default
- configs, then have the UI fall back to building/caching its own?
- - GUI automatically builds digests when UI is idle, both of system
- frameworks if they aren't not available in the right config, and of app
- frameworks.
- - GUI builds dependence graph of frameworks/digests based on #imports. If a
- digest is out date, dependent digests are automatically invalidated.
-
- * New constraints on #import for objc-v3:
- - #imported file must not define non-inline function bodies.
- - Alternatively, they can, and these bodies get compiled/linked *once*
- per app into a dylib. What about building user dylibs?
- - Restrictions on ObjC grammar: can't #import the body of a for stmt or fn.
- - Compiler must detect and reject these cases.
- - #defines defined within a #import have two behaviors:
- - By default, they escape the header. These macros *cannot* be #undef'd
- by other code: this is enforced by the front-end.
- - Optionally, user can specify what macros escape (whitelist) or can use
- #undef.
-
-New language feature: Configuration queries:
- - Instead of #ifdef __POWERPC__, use "if (strcmp(`cpu`, __POWERPC__))", or
- some other, better, syntax.
- - Use it to increase the number of "architecture-clean" #import'd files,
- allowing a single index to be used for all fat slices.
-
-Cocoa GUI Front-end:
- * All.
- * Start with very simple "textedit" GUI.
- * Trivial project model: list of files, list of cmd line options.
- * Build simple developer examples.
- * Tight integration with compiler components.
- * Primary advantage: batch compiles, keeping digests in memory, dependency mgmt
- between app frameworks, building code/digests in the background, etc.
- * Interesting idea: http://nickgravgaard.com/elastictabstops/
-
+ * Decls.
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