From e37633713d93b21533d8699d0b5cf4703e3f4039 Mon Sep 17 00:00:00 2001 From: George Burgess IV Date: Thu, 22 Dec 2016 02:50:20 +0000 Subject: Add the alloc_size attribute to clang, attempt 2. This is a recommit of r290149, which was reverted in r290169 due to msan failures. msan was failing because we were calling `isMostDerivedAnUnsizedArray` on an invalid designator, which caused us to read uninitialized memory. To fix this, the logic of the caller of said function was simplified, and we now have a `!Invalid` assert in `isMostDerivedAnUnsizedArray`, so we can catch this particular bug more easily in the future. Fingers crossed that this patch sticks this time. :) Original commit message: This patch does three things: - Gives us the alloc_size attribute in clang, which lets us infer the number of bytes handed back to us by malloc/realloc/calloc/any user functions that act in a similar manner. - Teaches our constexpr evaluator that evaluating some `const` variables is OK sometimes. This is why we have a change in test/SemaCXX/constant-expression-cxx11.cpp and other seemingly unrelated tests. Richard Smith okay'ed this idea some time ago in person. - Uniques some Blocks in CodeGen, which was reviewed separately at D26410. Lack of uniquing only really shows up as a problem when combined with our new eagerness in the face of const. llvm-svn: 290297 --- clang/lib/CodeGen/CodeGenModule.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'clang/lib/CodeGen/CodeGenModule.h') diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h index f26c92d5670..5f06ba90cf1 100644 --- a/clang/lib/CodeGen/CodeGenModule.h +++ b/clang/lib/CodeGen/CodeGenModule.h @@ -455,6 +455,10 @@ private: bool isTriviallyRecursive(const FunctionDecl *F); bool shouldEmitFunction(GlobalDecl GD); + /// Map of the global blocks we've emitted, so that we don't have to re-emit + /// them if the constexpr evaluator gets aggressive. + llvm::DenseMap EmittedGlobalBlocks; + /// @name Cache for Blocks Runtime Globals /// @{ @@ -776,6 +780,16 @@ public: /// Gets the address of a block which requires no captures. llvm::Constant *GetAddrOfGlobalBlock(const BlockExpr *BE, StringRef Name); + + /// Returns the address of a block which requires no caputres, or null if + /// we've yet to emit the block for BE. + llvm::Constant *getAddrOfGlobalBlockIfEmitted(const BlockExpr *BE) { + return EmittedGlobalBlocks.lookup(BE); + } + + /// Notes that BE's global block is available via Addr. Asserts that BE + /// isn't already emitted. + void setAddrOfGlobalBlock(const BlockExpr *BE, llvm::Constant *Addr); /// Return a pointer to a constant CFString object for the given string. ConstantAddress GetAddrOfConstantCFString(const StringLiteral *Literal); -- cgit v1.2.3