Merge pull request #261 from plasma-umass/macos_2026-02-fix

Fix macOS build: add missing header files

Author: emeryberger

libcoz/CMakeLists.txt

@@ -23,6 +23,7 @@ if(APPLE)
         macho_support.h
         mac_interpose.cpp
         mac_interpose.h
+        elf_compat.h
     )
 endif()
 

libcoz/elf_compat.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2015, Charlie Curtsinger and Emery Berger,
+ *                     University of Massachusetts Amherst
+ * This file is part of the Coz project. See LICENSE.md file at the top-level
+ * directory of this distribution and at http://github.com/plasma-umass/coz.
+ */
+
+#ifndef COZ_ELF_COMPAT_H
+#define COZ_ELF_COMPAT_H
+
+/**
+ * ELF compatibility definitions for macOS.
+ *
+ * On Linux, <elf.h> provides ELF format definitions. On macOS, these
+ * types don't exist natively, so we provide minimal compatibility
+ * definitions for the types used by coz.
+ */
+
+#ifdef __APPLE__
+
+#include <cstdint>
+
+/**
+ * ELF Note header structure.
+ * Used to parse NOTE sections in ELF files.
+ */
+typedef struct {
+  uint32_t n_namesz;  // Length of the note's name
+  uint32_t n_descsz;  // Length of the note's descriptor
+  uint32_t n_type;    // Type of the note
+} Elf64_Nhdr;
+
+/**
+ * Note type for GNU build ID.
+ * The build ID is a unique identifier for a particular build of a binary.
+ */
+#ifndef NT_GNU_BUILD_ID
+#define NT_GNU_BUILD_ID 3
+#endif
+
+#endif // __APPLE__
+
+#endif // COZ_ELF_COMPAT_H

libcoz/mac_interpose.cpp

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2015, Charlie Curtsinger and Emery Berger,
+ *                     University of Massachusetts Amherst
+ * This file is part of the Coz project. See LICENSE.md file at the top-level
+ * directory of this distribution and at http://github.com/plasma-umass/coz.
+ */
+
+#ifdef __APPLE__
+
+#include "mac_interpose.h"
+
+/**
+ * macOS interposition support implementation.
+ *
+ * On macOS, coz uses DYLD_INSERT_LIBRARIES to inject the profiler library.
+ * Function interposition is achieved through:
+ *
+ * 1. Symbol interposition: Functions defined in libcoz.cpp with the same
+ *    names as system functions (e.g., pthread_create, pthread_mutex_lock)
+ *    will override the system versions when the library is loaded.
+ *
+ * 2. DYLD interposition tuples: For more reliable interposition, the
+ *    __DATA,__interpose section can be used to explicitly specify
+ *    which functions to replace.
+ *
+ * Currently, coz relies on symbol interposition (method 1) which works
+ * well with DYLD_INSERT_LIBRARIES. The interposition tuples (method 2)
+ * are available via the INTERPOSE macro in mac_interpose.h if needed
+ * for specific functions that don't interpose correctly.
+ *
+ * Note: On macOS, some functions may require explicit interposition
+ * tuples due to two-level namespace lookup. If interposition issues
+ * are encountered, add INTERPOSE entries here.
+ */
+
+// Currently no explicit interposition tuples are needed.
+// The symbol-based interposition in libcoz.cpp handles the required
+// pthread and signal functions.
+
+#endif // __APPLE__

libcoz/mac_interpose.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2015, Charlie Curtsinger and Emery Berger,
+ *                     University of Massachusetts Amherst
+ * This file is part of the Coz project. See LICENSE.md file at the top-level
+ * directory of this distribution and at http://github.com/plasma-umass/coz.
+ */
+
+#ifndef COZ_MAC_INTERPOSE_H
+#define COZ_MAC_INTERPOSE_H
+
+#ifdef __APPLE__
+
+/**
+ * macOS DYLD interposition support.
+ *
+ * On macOS, function interposition is done via DYLD_INSERT_LIBRARIES.
+ * This header provides macros for creating interposition tuples that
+ * tell the dynamic linker which functions to replace.
+ *
+ * The interposition mechanism uses the __DATA,__interpose section.
+ */
+
+/**
+ * Structure used by dyld for interposition.
+ * When placed in the __DATA,__interpose section, dyld will replace
+ * calls to 'original' with calls to 'replacement'.
+ */
+typedef struct {
+  const void* replacement;
+  const void* original;
+} interpose_tuple_t;
+
+/**
+ * Macro to create an interposition entry.
+ * Usage: INTERPOSE(my_function, original_function)
+ *
+ * This creates a static entry in the __DATA,__interpose section that
+ * tells dyld to replace calls to 'original_function' with 'my_function'.
+ */
+#define INTERPOSE(replacement, original) \
+  __attribute__((used, section("__DATA,__interpose"))) \
+  static const interpose_tuple_t interpose_##original = { \
+    (const void*)(unsigned long)&replacement, \
+    (const void*)(unsigned long)&original \
+  }
+
+/**
+ * Alternative macro using dyld_interposing_tuple from mach-o/dyld-interposing.h
+ * if available. This is the official Apple mechanism.
+ */
+#ifdef DYLD_INTERPOSE
+#undef INTERPOSE
+#define INTERPOSE(replacement, original) DYLD_INTERPOSE(replacement, original)
+#endif
+
+#endif // __APPLE__
+
+#endif // COZ_MAC_INTERPOSE_H

libcoz/macho_support.cpp

@@ -334,8 +334,8 @@ bool get_section_type(const char* sectname, dwarf::section_type* out) {
   else if(std::strcmp(suffix, "pubtypes") == 0) *out = dwarf::section_type::pubtypes;
   else if(std::strcmp(suffix, "ranges") == 0) *out = dwarf::section_type::ranges;
   else if(std::strcmp(suffix, "str") == 0) *out = dwarf::section_type::str;
-  // Handle both full name and Mach-O truncated name (16 char limit)
-  else if(std::strcmp(suffix, "str_offsets") == 0 || std::strcmp(suffix, "str_offs") == 0) *out = dwarf::section_type::str_offsets;
+  // Note: str_offsets section is used in DWARF 5 but not all libelfin versions support it
+  // Skip it for now - the essential sections for line info are present
   else if(std::strcmp(suffix, "types") == 0) *out = dwarf::section_type::types;
   else if(assign_line_str(out,
                           suffix,

libcoz/macho_support.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2015, Charlie Curtsinger and Emery Berger,
+ *                     University of Massachusetts Amherst
+ * This file is part of the Coz project. See LICENSE.md file at the top-level
+ * directory of this distribution and at http://github.com/plasma-umass/coz.
+ */
+
+#ifndef COZ_MACHO_SUPPORT_H
+#define COZ_MACHO_SUPPORT_H
+
+#ifdef __APPLE__
+
+#include <memory>
+#include <string>
+
+namespace dwarf {
+class loader;
+}
+
+namespace macho_support {
+
+/**
+ * Find an existing .dSYM bundle for the given binary path.
+ * Returns the path to the DWARF file inside the bundle, or empty string if not found.
+ */
+std::string find_dsym_bundle(const std::string& binary_path);
+
+/**
+ * Extract the basename from a path.
+ */
+std::string basename_for(const std::string& path);
+
+/**
+ * Create a temporary directory for generated dSYM bundles.
+ * Returns the path to the created directory, or empty string on failure.
+ */
+std::string make_temp_dir();
+
+/**
+ * Run dsymutil to generate debug symbols for a binary.
+ * Returns true on success, false on failure.
+ */
+bool run_dsymutil(const std::string& binary_path, const std::string& bundle_path);
+
+/**
+ * Generate a dSYM bundle for the given binary if one doesn't exist.
+ * Returns the path to the DWARF file inside the bundle, or empty string on failure.
+ */
+std::string generate_dsym_bundle(const std::string& binary_path);
+
+/**
+ * Load DWARF debug information from a Mach-O binary.
+ * This will check for an existing .dSYM bundle, generate one if needed,
+ * and return a dwarf::loader for the debug information.
+ */
+std::shared_ptr<dwarf::loader> load_debug_info(const std::string& binary_path);
+
+} // namespace macho_support
+
+#endif // __APPLE__
+
+#endif // COZ_MACHO_SUPPORT_H