Keep history of macro definitions and #undefs
Summary:
Summary: Keep history of macro definitions and #undefs with corresponding source locations, so that we can later find out all macros active in a specified source location. We don't save the history in PCH (no need currently). Memory overhead is about sizeof(void*)*3*<number of macro definitions and #undefs>+<in-memory size of all #undef'd macros>
I've run a test on a file composed of 109 .h files from boost 1.49 on x86-64 linux.
Stats before this patch:
*** Preprocessor Stats:
73222 directives found:
19171 #define.
4345 #undef.
#include/#include_next/#import:
5233 source files entered.
27 max include stack depth
19210 #if/#ifndef/#ifdef.
2384 #else/#elif.
6891 #endif.
408 #pragma.
14466 #if/#ifndef#ifdef regions skipped
80023/451669/1270 obj/fn/builtin macros expanded, 85724 on the fast path.
127145 token paste (##) operations performed, 11008 on the fast path.
Preprocessor Memory: 5874615B total
BumpPtr: 4399104
Macro Expanded Tokens: 417768
Predefines Buffer: 8135
Macros: 1048576
#pragma push_macro Info: 0
Poison Reasons: 1024
Comment Handlers: 8
Stats with this patch:
...
Preprocessor Memory: 7541687B total
BumpPtr: 6066176
Macro Expanded Tokens: 417768
Predefines Buffer: 8135
Macros: 1048576
#pragma push_macro Info: 0
Poison Reasons: 1024
Comment Handlers: 8
In my test increase in memory usage is about 1.7Mb, which is ~28% of initial preprocessor's memory usage and about 0.8% of clang's total VMM allocation.
As for CPU overhead, it should only be noticeable when iterating over all macros, and should mostly consist of couple extra dereferences and one comparison per macro + skipping of #undef'd macros. It's less trivial to measure, though, as the preprocessor consumes a very small fraction of compilation time.
Reviewers: doug.gregor, klimek, rsmith, djasper
Reviewed By: doug.gregor
CC: cfe-commits, chandlerc
Differential Revision: http://llvm-reviews.chandlerc.com/D28
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162810 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/MacroInfo.cpp b/lib/Lex/MacroInfo.cpp
index 3d0c9a1..7a4964f 100644
--- a/lib/Lex/MacroInfo.cpp
+++ b/lib/Lex/MacroInfo.cpp
@@ -15,44 +15,46 @@
#include "clang/Lex/Preprocessor.h"
using namespace clang;
-MacroInfo::MacroInfo(SourceLocation DefLoc) : Location(DefLoc) {
- IsFunctionLike = false;
- IsC99Varargs = false;
- IsGNUVarargs = false;
- IsBuiltinMacro = false;
- IsFromAST = false;
- ChangedAfterLoad = false;
- IsDisabled = false;
- IsUsed = false;
- IsAllowRedefinitionsWithoutWarning = false;
- IsWarnIfUnused = false;
- IsDefinitionLengthCached = false;
- IsPublic = true;
-
- ArgumentList = 0;
- NumArguments = 0;
+MacroInfo::MacroInfo(SourceLocation DefLoc)
+ : Location(DefLoc),
+ PreviousDefinition(0),
+ ArgumentList(0),
+ NumArguments(0),
+ IsDefinitionLengthCached(false),
+ IsFunctionLike(false),
+ IsC99Varargs(false),
+ IsGNUVarargs(false),
+ IsBuiltinMacro(false),
+ IsFromAST(false),
+ ChangedAfterLoad(false),
+ IsDisabled(false),
+ IsUsed(false),
+ IsAllowRedefinitionsWithoutWarning(false),
+ IsWarnIfUnused(false),
+ IsPublic(true) {
}
-MacroInfo::MacroInfo(const MacroInfo &MI, llvm::BumpPtrAllocator &PPAllocator) {
- Location = MI.Location;
- EndLocation = MI.EndLocation;
- ReplacementTokens = MI.ReplacementTokens;
- IsFunctionLike = MI.IsFunctionLike;
- IsC99Varargs = MI.IsC99Varargs;
- IsGNUVarargs = MI.IsGNUVarargs;
- IsBuiltinMacro = MI.IsBuiltinMacro;
- IsFromAST = MI.IsFromAST;
- ChangedAfterLoad = MI.ChangedAfterLoad;
- IsDisabled = MI.IsDisabled;
- IsUsed = MI.IsUsed;
- IsAllowRedefinitionsWithoutWarning = MI.IsAllowRedefinitionsWithoutWarning;
- IsWarnIfUnused = MI.IsWarnIfUnused;
- IsDefinitionLengthCached = MI.IsDefinitionLengthCached;
- DefinitionLength = MI.DefinitionLength;
- IsPublic = MI.IsPublic;
-
- ArgumentList = 0;
- NumArguments = 0;
+MacroInfo::MacroInfo(const MacroInfo &MI, llvm::BumpPtrAllocator &PPAllocator)
+ : Location(MI.Location),
+ EndLocation(MI.EndLocation),
+ UndefLocation(MI.UndefLocation),
+ PreviousDefinition(0),
+ ArgumentList(0),
+ NumArguments(0),
+ ReplacementTokens(MI.ReplacementTokens),
+ DefinitionLength(MI.DefinitionLength),
+ IsDefinitionLengthCached(MI.IsDefinitionLengthCached),
+ IsFunctionLike(MI.IsFunctionLike),
+ IsC99Varargs(MI.IsC99Varargs),
+ IsGNUVarargs(MI.IsGNUVarargs),
+ IsBuiltinMacro(MI.IsBuiltinMacro),
+ IsFromAST(MI.IsFromAST),
+ ChangedAfterLoad(MI.ChangedAfterLoad),
+ IsDisabled(MI.IsDisabled),
+ IsUsed(MI.IsUsed),
+ IsAllowRedefinitionsWithoutWarning(MI.IsAllowRedefinitionsWithoutWarning),
+ IsWarnIfUnused(MI.IsWarnIfUnused),
+ IsPublic(MI.IsPublic) {
setArgumentList(MI.ArgumentList, MI.NumArguments, PPAllocator);
}