From b7750c5325d8bb3260462b21ee46e2dc675c6a3c Mon Sep 17 00:00:00 2001
From: Daniel Dunbar
Date: Wed, 1 Jul 2009 23:38:44 +0000
Subject: Try to clarify a point about getting DominatorTree info from a module
pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74668 91177308-0d34-0410-b5e6-96231b3b80d8
---
docs/WritingAnLLVMPass.html | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
(limited to 'docs/WritingAnLLVMPass.html')
diff --git a/docs/WritingAnLLVMPass.html b/docs/WritingAnLLVMPass.html
index 8374bfa..b8ac9e9 100644
--- a/docs/WritingAnLLVMPass.html
+++ b/docs/WritingAnLLVMPass.html
@@ -491,10 +491,15 @@ class is the most general of all superclasses that you can use. Deriving from
ModulePass indicates that your pass uses the entire program as a unit,
refering to function bodies in no predictable order, or adding and removing
functions. Because nothing is known about the behavior of ModulePass
-subclasses, no optimization can be done for their execution. A module pass
-can use function level passes (e.g. dominators) using getAnalysis interface
- getAnalysis<DominatorTree>(Function), if the function pass
-does not require any module passes.
+subclasses, no optimization can be done for their execution.
+
+A module pass can use function level passes (e.g. dominators) using
+the getAnalysis interface
+getAnalysis<DominatorTree>(llvm::Function *) to provide the
+function to retrieve analysis result for, if the function pass does not require
+any module passes. Note that this can only be done for functions for which the
+analysis ran, e.g. in the case of dominators you should only ask for the
+DominatorTree for function definitions, not declarations.
To write a correct ModulePass subclass, derive from
ModulePass and overload the runOnModule method with the
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