1Dbx is a descendant of pdx, a debugger that I wrote to work with 2Berkeley Pascal as my master's project at Berkeley. Pdx was released 3in the fall of 1981. While pdx was being completed, a version with 4different machine, process, and runtime modules was developed to run 5on VAX compiled code. 6 7In the spring of '82, the use of the string table for storing type encodings 8was designed and the VAX C compiler was modified to generate the new 9symbol information. In the fall of '82, the modifications to the C compiler 10and a new version of the debugger, by now named dbx, were installed locally 11at Berkeley. In early '83, dbx was installed on the 4.1c release of 12Berkeley UNIX. 13 14In the spring of '83, Alistair Fyfe, a graduate student at Berkeley, 15modified dbx and the f77 compiler to enable dbx to debug FORTRAN programs. 16During this time, dbx was also ported to the Sun. 17 18In the fall of '83, dbx was released with 4.2. During that winter and 19the spring of '84, dbx was extended to work with Modula-2 in conjunction 20with the development of the Modula-2 compiler at DEC Western Research Lab. 21In June of '84, a collection of updates reflected the current status 22of dbx, including bug fixes and support for Modula-2, was sent to net.sources. 23 24Below are some short notes on versions that have been installed since then. 25 26 Mark Linton 27 28 296/1 2.0 release to net.sources 30 31internal releases 327/2 2.5 rewrote name resolution, particularly for procedure nesting 337/17 2.6 single stepping through certain kinds of loops, 34 tracing through code compiled for profiling 35 support for Pascal installed on the side but not tested 36 (nor is the associated support in pc) 377/19 2.7 open arrays 387/31 2.8 print <proc>, qualified names in backtrace, 39 curevent to avoid some "missing trids", 408/1 2.9 increased maximum number of arguments from 100 to 1000, 41 increased maximum line size to 1024 to 10240 428/23 2.10 support for Pascal and test cases for modified pc, 43 code for -k (kernel debugging) added but not debugged, 44 qualified names in traces 45 no longer fatal to not link with -g -- assumes first global 46 is equivalent to -lg 47 better resolution of externals 48 reports when a core image is being used 498/25 2.11 fixed some problems with Pascal, e.g., enumerations, 50 increased maximum number of functions from 1001 to 4001, 51 fixed a nasty bug for C (and elsewhere?) having to do 52 with processing types for "known" global variables, 53 changed the syntax/semantics of "print x" where x is 54 a function so that it no longer tries to call it -- 55 "print x()" must be used instead 56 added/fixed syntax for type renaming so that term's can 57 be renamed 588/26 2.12 fixed problem with multiple imports (EXTREF's), 59 added dynamic name lookup if static lookup fails before picking 60 at random 618/27 2.13 fixed problem in dynamic lookup that caused an infinite loop, 62 if it picks one at random it now prints a message specifying 63 the fully qualified name of the symbol that was picked 648/27 2.15 first attack at fixing problem with type renames (loopholes) 659/16 2.16 major attempt to fix loopholes by revising node representation 66 and command grammar -- basic need was to make more sense 67 out of when to do indirection 68 changed identifier resolution in object and stabstring so 69 that globals are no longer in top scope (since they could 70 conflict with a module name) 719/18 2.17 another problem related to expressions having to do with 72 handling pointers to arrays 73 ... 741/1 2.25 made more inroads into kernel debugging, 75 added macros (aliases with arguments), and settable variables 761/7 2.26 fixed bug where only mapped first address of block read, 77 have to map each page (still wrong though) 781/13 2.27 fixed some user reported problems -- down in runtime 79 didn't work correctly if "curframe" wasn't already set, 80 the process instruction cache had to be flushed when 81 a process is killed (this caused a problem when an 82 object file was remade) 831/14 2.28 fixed problem with mapping addresses under -k, 84 added -c option for command files other than .dbxinit 85 fixed occasional problem with testing for end of stack frames 86 (symptom was infinite loop calling nextframe) 871/15 2.29 fixed problem with printing dynamic arrays inside aggregates 88 fixed type compatibility for builtin true and false 89