Reapply Logging: make os_log buffer size an integer constant expression.
The size of an os_log buffer is known at any stage of compilation, so making it
a constant expression means that the common idiom of declaring a buffer for it
won't result in a VLA. That allows the compiler to skip saving and restoring
the stack pointer around such buffers.
This also moves the OSLog and other FormatString helpers from
libclangAnalysis to libclangAST to avoid a circular dependency.
llvm-svn: 345971
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 15efe43..a85d5cf 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -39,6 +39,7 @@
#include "clang/AST/ASTLambda.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/Expr.h"
+#include "clang/AST/OSLog.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/AST/TypeLoc.h"
@@ -8126,6 +8127,12 @@
llvm_unreachable("unexpected EvalMode");
}
+ case Builtin::BI__builtin_os_log_format_buffer_size: {
+ analyze_os_log::OSLogBufferLayout Layout;
+ analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout);
+ return Success(Layout.size().getQuantity(), E);
+ }
+
case Builtin::BI__builtin_bswap16:
case Builtin::BI__builtin_bswap32:
case Builtin::BI__builtin_bswap64: {