Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Add support for __builtin_os_log_format[_buffer_size]
These new builtins support a mechanism for logging OS events, using a printf-like format string to specify the layout of data in a buffer. The _buffer_size version of the builtin can be used to determine the size of the buffer to allocate to hold the data, and then __builtin_os_log_format can write data into that buffer. This implements format checking to report mismatches between the format string and the data arguments. Most of this code was written by Chris Willmore. Differential Revision: https://reviews.llvm.org/D25888 llvm-svn: 284990
- Loading branch information
Showing
15 changed files
with
994 additions
and
95 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,155 @@ | ||
| //= OSLog.h - Analysis of calls to os_log builtins --*- C++ -*-===============// | ||
| // | ||
| // The LLVM Compiler Infrastructure | ||
| // | ||
| // This file is distributed under the University of Illinois Open Source | ||
| // License. See LICENSE.TXT for details. | ||
| // | ||
| //===----------------------------------------------------------------------===// | ||
| // | ||
| // This file defines APIs for determining the layout of the data buffer for | ||
| // os_log() and os_trace(). | ||
| // | ||
| //===----------------------------------------------------------------------===// | ||
|
|
||
| #ifndef LLVM_CLANG_ANALYSIS_ANALYSES_OSLOG_H | ||
| #define LLVM_CLANG_ANALYSIS_ANALYSES_OSLOG_H | ||
|
|
||
| #include "clang/AST/ASTContext.h" | ||
| #include "clang/AST/Expr.h" | ||
|
|
||
| namespace clang { | ||
| namespace analyze_os_log { | ||
|
|
||
| /// An OSLogBufferItem represents a single item in the data written by a call | ||
| /// to os_log() or os_trace(). | ||
| class OSLogBufferItem { | ||
| public: | ||
| enum Kind { | ||
| // The item is a scalar (int, float, raw pointer, etc.). No further copying | ||
| // is required. This is the only kind allowed by os_trace(). | ||
| ScalarKind = 0, | ||
|
|
||
| // The item is a count, which describes the length of the following item to | ||
| // be copied. A count may only be followed by an item of kind StringKind, | ||
| // WideStringKind, or PointerKind. | ||
| CountKind, | ||
|
|
||
| // The item is a pointer to a C string. If preceded by a count 'n', | ||
| // os_log() will copy at most 'n' bytes from the pointer. | ||
| StringKind, | ||
|
|
||
| // The item is a pointer to a block of raw data. This item must be preceded | ||
| // by a count 'n'. os_log() will copy exactly 'n' bytes from the pointer. | ||
| PointerKind, | ||
|
|
||
| // The item is a pointer to an Objective-C object. os_log() may retain the | ||
| // object for later processing. | ||
| ObjCObjKind, | ||
|
|
||
| // The item is a pointer to wide-char string. | ||
| WideStringKind, | ||
|
|
||
| // The item is corresponding to the '%m' format specifier, no value is | ||
| // populated in the buffer and the runtime is loading the errno value. | ||
| ErrnoKind | ||
| }; | ||
|
|
||
| enum { | ||
| // The item is marked "private" in the format string. | ||
| IsPrivate = 0x1, | ||
|
|
||
| // The item is marked "public" in the format string. | ||
| IsPublic = 0x2 | ||
| }; | ||
|
|
||
| private: | ||
| Kind TheKind = ScalarKind; | ||
| const Expr *TheExpr = nullptr; | ||
| CharUnits ConstValue; | ||
| CharUnits Size; // size of the data, not including the header bytes | ||
| unsigned Flags = 0; | ||
|
|
||
| public: | ||
| OSLogBufferItem(Kind kind, const Expr *expr, CharUnits size, unsigned flags) | ||
| : TheKind(kind), TheExpr(expr), Size(size), Flags(flags) {} | ||
|
|
||
| OSLogBufferItem(ASTContext &Ctx, CharUnits value, unsigned flags) | ||
| : TheKind(CountKind), ConstValue(value), | ||
| Size(Ctx.getTypeSizeInChars(Ctx.IntTy)), Flags(flags) {} | ||
|
|
||
| unsigned char getDescriptorByte() const { | ||
| unsigned char result = 0; | ||
| if (getIsPrivate()) | ||
| result |= IsPrivate; | ||
| if (getIsPublic()) | ||
| result |= IsPublic; | ||
| result |= ((unsigned)getKind()) << 4; | ||
| return result; | ||
| } | ||
|
|
||
| unsigned char getSizeByte() const { return size().getQuantity(); } | ||
|
|
||
| Kind getKind() const { return TheKind; } | ||
| bool getIsPrivate() const { return (Flags & IsPrivate) != 0; } | ||
| bool getIsPublic() const { return (Flags & IsPublic) != 0; } | ||
|
|
||
| const Expr *getExpr() const { return TheExpr; } | ||
| CharUnits getConstValue() const { return ConstValue; } | ||
| CharUnits size() const { return Size; } | ||
| }; | ||
|
|
||
| class OSLogBufferLayout { | ||
| public: | ||
| SmallVector<OSLogBufferItem, 4> Items; | ||
|
|
||
| enum Flags { HasPrivateItems = 1, HasNonScalarItems = 1 << 1 }; | ||
|
|
||
| CharUnits size() const { | ||
| CharUnits result; | ||
| result += CharUnits::fromQuantity(2); // summary byte, num-args byte | ||
| for (auto &item : Items) { | ||
| // descriptor byte, size byte | ||
| result += item.size() + CharUnits::fromQuantity(2); | ||
| } | ||
| return result; | ||
| } | ||
|
|
||
| bool hasPrivateItems() const { | ||
| return llvm::any_of( | ||
| Items, [](const OSLogBufferItem &Item) { return Item.getIsPrivate(); }); | ||
| } | ||
|
|
||
| bool hasPublicItems() const { | ||
| return llvm::any_of( | ||
| Items, [](const OSLogBufferItem &Item) { return Item.getIsPublic(); }); | ||
| } | ||
|
|
||
| bool hasNonScalar() const { | ||
| return llvm::any_of(Items, [](const OSLogBufferItem &Item) { | ||
| return Item.getKind() != OSLogBufferItem::ScalarKind; | ||
| }); | ||
| } | ||
|
|
||
| unsigned char getSummaryByte() const { | ||
| unsigned char result = 0; | ||
| if (hasPrivateItems()) | ||
| result |= HasPrivateItems; | ||
| if (hasNonScalar()) | ||
| result |= HasNonScalarItems; | ||
| return result; | ||
| } | ||
|
|
||
| unsigned char getNumArgsByte() const { return Items.size(); } | ||
| }; | ||
|
|
||
| // Given a call 'E' to one of the builtins __builtin_os_log_format() or | ||
| // __builtin_os_log_format_buffer_size(), compute the layout of the buffer that | ||
| // the call will write into and store it in 'layout'. Returns 'false' if there | ||
| // was some error encountered while computing the layout, and 'true' otherwise. | ||
| bool computeOSLogBufferLayout(clang::ASTContext &Ctx, const clang::CallExpr *E, | ||
| OSLogBufferLayout &layout); | ||
|
|
||
| } // namespace analyze_os_log | ||
| } // namespace clang | ||
| #endif |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.