util/DwarfReader, ElfImporter: import address ranges

This change implements the following:
-DwarfReader now exports the address range of linetable-entries instead of
	only the first address
-ElfImporter saves this range alongside the mapping

Change-Id: I7fe6361178f761a8f605a44bb0183c56a236cc95

src/core/util/DwarfReader.cc

@@ -1,4 +1,5 @@
 #include <fstream>
+#include <limits>
 #include <fcntl.h>
 #include <unistd.h>
 
@@ -178,7 +179,7 @@ bool DwarfReader::read_source_files(const std::string& fileName,std::list<std::s
 	return true;
 }
 
-bool DwarfReader::read_mapping(std::string fileName, std::list<addrToLine>& addrToLineList) {
+bool DwarfReader::read_mapping(std::string fileName, std::list<DwarfLineMapping>& lineMapping) {
 
 	// Open The file
 	int fd=open(fileName.c_str(),O_RDONLY);
@@ -200,9 +201,11 @@ bool DwarfReader::read_mapping(std::string fileName, std::list<addrToLine>& addr
 
 	// Iterator over the headers
 	Dwarf_Unsigned header;
+	// iterate compilation unit headers
 	while (dwarf_next_cu_header(dbg,0,0,0,0,&header,0)==DW_DLV_OK) {
 		// Access the die
 		Dwarf_Die die;
+		// XXX: "if there are no sibling headers, die" | semantics unclear!
 		if (dwarf_siblingof(dbg,0,&die,0)!=DW_DLV_OK) {
 			return false;
 		}
@@ -234,8 +237,21 @@ bool DwarfReader::read_mapping(std::string fileName, std::list<addrToLine>& addr
 			}
 
 			if (lineNo&&isCode) {
-				struct addrToLine newLine = { addr, lineNo, normalize(lineSource) };
-				addrToLineList.push_back(newLine);
+				/* default the linetable's address range (->size) to the maximum
+				 * possible range. this results in the last linetable entry having
+				 * maximum range. as this always (?) is a function epilogue, its
+				 * irrelevant for our use-case. */
+				// TODO: properly determine the last interval's range, e.g. via __TEXT_END
+
+				DwarfLineMapping mapping(addr, (std::numeric_limits<unsigned>::max() - addr), 
+					lineNo, lineSource);
+				// the address range for the previous line ends with the current line's address
+				if (!lineMapping.empty()) {
+					DwarfLineMapping& back = lineMapping.back();
+					// update the previous lineRangeSize appropriately
+					back.line_range_size = (addr - back.absolute_addr);
+				}
+				lineMapping.push_back(mapping);
 			}
 
 			dwarf_dealloc(dbg,lineSource,DW_DLA_STRING);

src/core/util/DwarfReader.hpp

@@ -7,6 +7,16 @@
 
 namespace fail {
 
+class DwarfLineMapping {
+public:
+	unsigned absolute_addr;
+	unsigned line_range_size;
+	unsigned line_number;
+	std::string line_source;
+
+	DwarfLineMapping(unsigned addr, unsigned size, unsigned number, std::string src)
+		: absolute_addr(addr), line_range_size(size), line_number(number), line_source(src){}
+};
 
 /**
 	* This source code is based on bcov 0.2.
@@ -15,23 +25,16 @@ namespace fail {
 	* GNU GENERAL PUBLIC LICENSE
 */
 
-	struct addrToLine {
-		unsigned absoluteAddr;
-		unsigned lineNumber;
-		std::string lineSource;
-	};
-
-	/**
-	* \class DwarfReader
-	* ToDO
-	*/
-
-	class DwarfReader {
+/**
+* \class DwarfReader
+* ToDO
+*/
+class DwarfReader {
 
 		public:
 
 		bool read_source_files(const std::string& fileName, std::list<std::string>& lines);
-		bool read_mapping(std::string fileName, std::list<addrToLine>& addrToLineList);
+		bool read_mapping(std::string fileName, std::list<DwarfLineMapping>& lineMapping);
 };
 
 } // end-of-namespace fail

tools/import-trace/ElfImporter.cc

@@ -78,6 +78,7 @@ bool ElfImporter::create_database()
 		create_statement << "CREATE TABLE IF NOT EXISTS dbg_mapping ("
 			"	variant_id int(11) NOT NULL,"
 			"	instr_absolute int(11) UNSIGNED NOT NULL,"
+			"	line_range_size int(11) UNSIGNED NOT NULL,"
 			"	linenumber int(11) UNSIGNED NOT NULL,"
 			"	file_id int(11) NOT NULL,"
 			"	PRIMARY KEY (variant_id, instr_absolute ,linenumber)"
@@ -356,19 +357,18 @@ bool ElfImporter::import_source_files(const std::string& elf_filename, std::list
 
 bool ElfImporter::import_mapping(std::string fileName)
 {
-	std::list<addrToLine> mapping;
+	std::list<DwarfLineMapping> mapping;
 	if (!dwReader.read_mapping(fileName, mapping)) {
 		return false;
 	}
 
 	while (!mapping.empty()) {
-		struct addrToLine temp_addrToLine;
-		temp_addrToLine = mapping.front();
+		DwarfLineMapping tmp_mapping = mapping.front();
 
 		// FIXME reuse file_id from previous iteration if file name stays constant
 		std::stringstream ss;
 		ss << "SELECT file_id FROM dbg_filename "
-			<< "WHERE path = '" << temp_addrToLine.lineSource << "' "
+			<< "WHERE path = '" << tmp_mapping.line_source << "' "
 			<< "AND variant_id = " << m_variant_id;
 
 		MYSQL_RES *res = db->query(ss.str().c_str(), true);
@@ -380,17 +380,18 @@ bool ElfImporter::import_mapping(std::string fileName)
 
 		// INSERT group entry
 		std::stringstream sql;
-		sql << "(" << m_variant_id << "," << temp_addrToLine.absoluteAddr << "," << temp_addrToLine.lineNumber << ",";
+		sql << "(" << m_variant_id << "," << tmp_mapping.absolute_addr << ","
+			<< tmp_mapping.line_range_size << "," << tmp_mapping.line_number << ",";
 		if (row != NULL) {
 			sql << row[0] << ")";
 		} else {
 			// this should not happen
-			LOG << "error: no entry for '" << temp_addrToLine.lineSource << "' in dbg_filename, aborting" << std::endl;
+			LOG << "error: no entry for '" << tmp_mapping.line_source << "' in dbg_filename, aborting" << std::endl;
 			return false;
 		}
 
 		// TODO: Skip duplicated entries with ON DUPLICATE KEY UPDATE (?)
-		if (!db->insert_multiple("INSERT IGNORE INTO dbg_mapping (variant_id, instr_absolute, linenumber, file_id) VALUES ",
+		if (!db->insert_multiple("INSERT IGNORE INTO dbg_mapping (variant_id, instr_absolute, line_range_size, linenumber, file_id) VALUES ",
 			sql.str().c_str())) {
 			return false;
 		}