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-rw-r--r--src/common/linux/dump_symbols.cc5
-rw-r--r--src/common/stabs_reader.cc49
-rw-r--r--src/common/stabs_reader.h30
-rw-r--r--src/common/stabs_reader_unittest.cc89
4 files changed, 152 insertions, 21 deletions
diff --git a/src/common/linux/dump_symbols.cc b/src/common/linux/dump_symbols.cc
index ec689ec6..900385e1 100644
--- a/src/common/linux/dump_symbols.cc
+++ b/src/common/linux/dump_symbols.cc
@@ -142,12 +142,13 @@ static bool LoadStabs(const ElfW(Ehdr) *elf_header,
StabsToModule handler(module);
// Find the addresses of the STABS data, and create a STABS reader object.
// On Linux, STABS entries always have 32-bit values, regardless of the
- // address size of the architecture whose code they're describing.
+ // address size of the architecture whose code they're describing, and
+ // the strings are always "unitized".
uint8_t *stabs = reinterpret_cast<uint8_t *>(stab_section->sh_offset);
uint8_t *stabstr = reinterpret_cast<uint8_t *>(stabstr_section->sh_offset);
google_breakpad::StabsReader reader(stabs, stab_section->sh_size,
stabstr, stabstr_section->sh_size,
- big_endian, 4, &handler);
+ big_endian, 4, true, &handler);
// Read the STABS data, and do post-processing.
if (!reader.Process())
return false;
diff --git a/src/common/stabs_reader.cc b/src/common/stabs_reader.cc
index cdad80e7..1ca97412 100644
--- a/src/common/stabs_reader.cc
+++ b/src/common/stabs_reader.cc
@@ -37,6 +37,8 @@
#include <stab.h>
#include <string.h>
+using std::vector;
+
namespace google_breakpad {
StabsReader::EntryIterator::EntryIterator(const ByteBuffer *buffer,
@@ -61,11 +63,12 @@ void StabsReader::EntryIterator::Fetch() {
StabsReader::StabsReader(const uint8_t *stab, size_t stab_size,
const uint8_t *stabstr, size_t stabstr_size,
- bool big_endian, size_t value_size,
+ bool big_endian, size_t value_size, bool unitized,
StabsHandler *handler)
: entries_(stab, stab_size),
strings_(stabstr, stabstr_size),
iterator_(&entries_, big_endian, value_size),
+ unitized_(unitized),
handler_(handler),
string_offset_(0),
next_cu_string_offset_(0),
@@ -88,13 +91,14 @@ bool StabsReader::Process() {
if (iterator_->type == N_SO) {
if (! ProcessCompilationUnit())
return false;
- } else if (iterator_->type == N_UNDF) {
- // At the head of each compilation unit's entries there is an
- // N_UNDF stab giving the number of symbols in the compilation
- // unit, and the number of bytes that compilation unit's strings
- // take up in the .stabstr section. Each CU's strings are
- // separate; the n_strx values are offsets within the current
- // CU's portion of the .stabstr section.
+ } else if (iterator_->type == N_UNDF && unitized_) {
+ // In unitized STABS (including Linux STABS, and pretty much anything
+ // else that puts STABS data in sections), at the head of each
+ // compilation unit's entries there is an N_UNDF stab giving the
+ // number of symbols in the compilation unit, and the number of bytes
+ // that compilation unit's strings take up in the .stabstr section.
+ // Each CU's strings are separate; the n_strx values are offsets
+ // within the current CU's portion of the .stabstr section.
//
// As an optimization, the GNU linker combines all the
// compilation units into one, with a single N_UNDF at the
@@ -157,9 +161,26 @@ bool StabsReader::ProcessCompilationUnit() {
if (iterator_->type == N_FUN) {
if (! ProcessFunction())
return false;
- } else
+ } else if (iterator_->type == N_SLINE) {
+ // Mac OS X STABS place SLINE records before functions.
+ Line line;
+ // The value of an N_SLINE entry that appears outside a function is
+ // the absolute address of the line.
+ line.address = iterator_->value;
+ line.filename = current_source_file_;
+ // The n_desc of a N_SLINE entry is the line number. It's a
+ // signed 16-bit field; line numbers from 32768 to 65535 are
+ // stored as n-65536.
+ line.number = (uint16_t) iterator_->descriptor;
+ queued_lines_.push_back(line);
+ ++iterator_;
+ } else if (iterator_->type == N_SOL) {
+ current_source_file_ = SymbolString();
+ ++iterator_;
+ } else {
// Ignore anything else.
++iterator_;
+ }
}
// An N_SO with an empty name indicates the end of the compilation
@@ -177,6 +198,8 @@ bool StabsReader::ProcessCompilationUnit() {
if (! handler_->EndCompilationUnit(ending_address))
return false;
+ queued_lines_.clear();
+
return true;
}
@@ -196,6 +219,14 @@ bool StabsReader::ProcessFunction() {
return false;
++iterator_;
+ // If there were any SLINE records given before the function, report them now.
+ for (vector<Line>::const_iterator it = queued_lines_.begin();
+ it != queued_lines_.end(); it++) {
+ if (!handler_->Line(it->address, it->filename, it->number))
+ return false;
+ }
+ queued_lines_.clear();
+
while (!iterator_->at_end) {
if (iterator_->type == N_SO || iterator_->type == N_FUN)
break;
diff --git a/src/common/stabs_reader.h b/src/common/stabs_reader.h
index 9f954650..3c28b9ba 100644
--- a/src/common/stabs_reader.h
+++ b/src/common/stabs_reader.h
@@ -52,8 +52,12 @@
#ifdef HAVE_A_OUT_H
#include <a.out.h>
#endif
+#ifdef HAVE_MACH_O_NLIST_H
+#include <mach-o/nlist.h>
+#endif
#include <string>
+#include <vector>
#include "common/byte_cursor.h"
@@ -71,14 +75,22 @@ class StabsReader {
//
// BIG_ENDIAN should be true if the entries in the .stab section are in
// big-endian form, or false if they are in little-endian form.
+ //
// VALUE_SIZE should be either 4 or 8, indicating the size of the 'value'
// field in each entry in bytes.
+ //
+ // UNITIZED should be true if the STABS data is stored in units with
+ // N_UNDF headers. This is usually the case for STABS stored in sections,
+ // like .stab/.stabstr, and usually not the case for STABS stored in the
+ // actual symbol table; UNITIZED should be true when parsing Linux stabs,
+ // false when parsing Mac OS X STABS. For details, see:
+ // http://sourceware.org/gdb/current/onlinedocs/stabs/Stab-Section-Basics.html
//
// Note that, in ELF, the .stabstr section should be found using the
// 'sh_link' field of the .stab section header, not by name.
StabsReader(const uint8_t *stab, size_t stab_size,
const uint8_t *stabstr, size_t stabstr_size,
- bool big_endian, size_t value_size,
+ bool big_endian, size_t value_size, bool unitized,
StabsHandler *handler);
// Process the STABS data, calling the handler's member functions to
@@ -159,6 +171,13 @@ class StabsReader {
Entry entry_;
};
+ // A source line, saved to be reported later.
+ struct Line {
+ uint64_t address;
+ const char *filename;
+ int number;
+ };
+
// Return the name of the current symbol.
const char *SymbolString();
@@ -179,6 +198,10 @@ class StabsReader {
// The iterator walking the STABS entries.
EntryIterator iterator_;
+ // True if the data is "unitized"; see the explanation in the comment for
+ // StabsReader::StabsReader.
+ bool unitized_;
+
StabsHandler *handler_;
// The offset of the current compilation unit's strings within stabstr_.
@@ -190,6 +213,11 @@ class StabsReader {
// The current source file name.
const char *current_source_file_;
+
+ // Mac OS X STABS place SLINE records before functions; we accumulate a
+ // vector of these until we see the FUN record, and then report them
+ // after the StartFunction call.
+ std::vector<Line> queued_lines_;
};
// Consumer-provided callback structure for the STABS reader. Clients
diff --git a/src/common/stabs_reader_unittest.cc b/src/common/stabs_reader_unittest.cc
index c739bade..9d2f88cc 100644
--- a/src/common/stabs_reader_unittest.cc
+++ b/src/common/stabs_reader_unittest.cc
@@ -31,17 +31,18 @@
// stabs_reader_unittest.cc: Unit tests for google_breakpad::StabsReader.
-#include <cassert>
-#include <cerrno>
-#include <cstdarg>
-#include <cstdlib>
-#include <cstring>
+#include <assert.h>
+#include <errno.h>
+#include <stab.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <sstream>
-#include <stab.h>
#include "breakpad_googletest_includes.h"
#include "common/stabs_reader.h"
@@ -225,7 +226,7 @@ class MockStabsReaderHandler: public StabsHandler {
};
struct StabsFixture {
- StabsFixture() : stabs(&strings) { }
+ StabsFixture() : stabs(&strings), unitized(true) { }
// Create a StabsReader to parse the mock stabs data in stabs and
// strings, and pass the parsed information to mock_handler. Use the
@@ -244,12 +245,14 @@ struct StabsFixture {
stabs_contents.size(),
reinterpret_cast<const uint8_t *>(stabstr_contents.data()),
stabstr_contents.size(),
- stabs.endianness() == kBigEndian, stabs.value_size(), &mock_handler);
+ stabs.endianness() == kBigEndian, stabs.value_size(), unitized,
+ &mock_handler);
return reader.Process();
}
StringAssembler strings;
StabsAssembler stabs;
+ bool unitized;
MockStabsReaderHandler mock_handler;
};
@@ -401,7 +404,10 @@ TEST_F(Stabs, NoCUEnd) {
ASSERT_TRUE(ApplyHandlerToMockStabsData());
}
-TEST_F(Stabs, MultipleCUs) {
+// On systems that store STABS in sections, string offsets are relative to
+// the beginning of that compilation unit's strings, marked with N_UNDF
+// symbols; see the comments for StabsReader::StabsReader.
+TEST_F(Stabs, Unitized) {
stabs.set_endianness(kBigEndian);
stabs.set_value_size(4);
stabs
@@ -441,6 +447,32 @@ TEST_F(Stabs, MultipleCUs) {
ASSERT_TRUE(ApplyHandlerToMockStabsData());
}
+// On systems that store STABS entries in the real symbol table, the N_UNDF
+// entries have no special meaning, and shouldn't mess up the string
+// indices.
+TEST_F(Stabs, NonUnitized) {
+ stabs.set_endianness(kLittleEndian);
+ stabs.set_value_size(4);
+ unitized = false;
+ stabs
+ .Stab(N_UNDF, 21, 11551, 0x9bad2b2e, "")
+ .Stab(N_UNDF, 21, 11551, 0x9bad2b2e, "")
+ .Stab(N_SO, 71, 45139, 0x11a97352, "Tanzania")
+ .Stab(N_SO, 221, 41976, 0x21a97352, "");
+
+ {
+ InSequence s;
+ EXPECT_CALL(mock_handler,
+ StartCompilationUnit(StrEq("Tanzania"),
+ 0x11a97352, NULL))
+ .WillOnce(Return(true));
+ EXPECT_CALL(mock_handler, EndCompilationUnit(0x21a97352))
+ .WillOnce(Return(true));
+ }
+
+ ASSERT_TRUE(ApplyHandlerToMockStabsData());
+}
+
TEST_F(Stabs, FunctionEnd) {
stabs.set_endianness(kLittleEndian);
stabs.set_value_size(8);
@@ -484,6 +516,45 @@ TEST_F(Stabs, FunctionEnd) {
ASSERT_TRUE(ApplyHandlerToMockStabsData());
}
+// On Mac OS X, SLINE records can appear before the FUN stab to which they
+// belong, and their values are absolute addresses, not offsets.
+TEST_F(Stabs, LeadingLine) {
+ stabs.set_endianness(kBigEndian);
+ stabs.set_value_size(4);
+ stabs
+ .Stab(N_SO, 179, 27357, 0x8adabc15, "build directory/")
+ .Stab(N_SO, 52, 53058, 0x4c7e3bf4, "compilation unit")
+ .Stab(N_SOL, 165, 12086, 0x6a797ca3, "source file name")
+ .Stab(N_SLINE, 229, 20015, 0x4cb3d7e0, "")
+ .Stab(N_SLINE, 89, 43802, 0x4cba8b88, "")
+ .Stab(N_FUN, 251, 51639, 0xce1b98fa, "rutabaga")
+ .Stab(N_FUN, 218, 16113, 0x5798, "")
+ .Stab(N_SO, 52, 53058, 0xd4af4415, "");
+
+ {
+ InSequence s;
+ EXPECT_CALL(mock_handler,
+ StartCompilationUnit(StrEq("compilation unit"),
+ 0x4c7e3bf4, StrEq("build directory/")))
+ .WillOnce(Return(true));
+ EXPECT_CALL(mock_handler,
+ StartFunction(Eq("rutabaga"), 0xce1b98fa))
+ .WillOnce(Return(true));
+ EXPECT_CALL(mock_handler,
+ Line(0x4cb3d7e0, StrEq("source file name"), 20015))
+ .WillOnce(Return(true));
+ EXPECT_CALL(mock_handler,
+ Line(0x4cba8b88, StrEq("source file name"), 43802))
+ .WillOnce(Return(true));
+ EXPECT_CALL(mock_handler, EndFunction(0xce1b98fa + 0x5798))
+ .WillOnce(Return(true));
+ EXPECT_CALL(mock_handler, EndCompilationUnit(0xd4af4415))
+ .WillOnce(Return(true));
+ }
+
+ ASSERT_TRUE(ApplyHandlerToMockStabsData());
+}
+
// name duplication
} // anonymous namespace