1 / 39

Daniela da Cruz Pedro Rangel Henriques Universidade do Minho Braga - Portugal

Daniela da Cruz Pedro Rangel Henriques Universidade do Minho Braga - Portugal. Project Context. This project emerged in the context of another project: CoCo/RF Partners: Universidade da Beira Interior (UBI), University of Linz, and Universidade do Minho (UM)

aadi
Download Presentation

Daniela da Cruz Pedro Rangel Henriques Universidade do Minho Braga - Portugal

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Daniela da Cruz Pedro Rangel Henriques Universidade do Minho Braga - Portugal gEPL / DI-UM

  2. Project Context This project emerged in the context of another project: CoCo/RF • Partners: Universidade da Beira Interior (UBI), University of Linz, and Universidade do Minho (UM) • Aim: to port the Compiler Generator CoCo/R (developped at ULinz) to OCaml (more precisely, to F#) gEPL / DI-UM

  3. Project Aims • To explore as much as possible one of the present implementations of CoCo/R (we choose C# version), to understand the generator, the generated compiler, and the CoCoL specifications. • To develop a complete compiler for an imperative and structured programming language. gEPL / DI-UM

  4. Compiler Translates a Source Program, written in LISS, into Assembly code of the Target Machine • First Version (simple LISS spec) • MSP (very simple virtual stack machine) • Second Version (full LISS spec) • VM (powerful virtual stack machine) gEPL / DI-UM

  5. Compiler • Top-Down parser • Pure Recursive-Descent • Solving LL() Conflits with a lookahead(n) strategy • Syntax-Directed Translator (static / dynamic semantic rules executed during parsing), supporting Inherited and Synthesized Attributes • Implemented in C# gEPL / DI-UM

  6. Compiler • Generated by the Compilers Compiler • CoCo/R (C# implementation) • LISS syntax and semantics was specified by and AG written in CoCoL • Input files • Liss.ATG +SymbolTable.cs+VMcodegen.cs • Output file • Liss.exe gEPL / DI-UM

  7. The Programming Language LISS LISS stands for Language of Integer, Sequences and Sets Liss is a high-level toy language, appropriate to teach basic skills on imperative (procedural) structured programming. The language follows the verbose Pascal style, with long keywords (case-insensitive) gEPL / DI-UM

  8. The Programming Language LISS LISS was designed with the main goal of being a challenging case-study for Compiler courses. With a proper Syntax (simplyfying the syntatic analysis), LISS has an unsual Semantic definition! It requires a powerful Semantic Analysis, and a clever Machine-code Generation. gEPL / DI-UM

  9. The Programming Language LISS The design of LISS emphasizes: • The static (compile time) and dynamic (run time) type checking • The scope analysis • The code generation strategies (translation schemas) to support non-standard Data-types, I/O and Control Statements gEPL / DI-UM

  10. Errors Detection program Errors { Declarations a := 4, b -> Integer; d := true, flag -> boolean; array1 := [[1,2],[2,3]], vector -> Array size 4,3; seq1 :=<<1,2,3,4>> -> Sequence; Statements // here we can't make "8/d", because "d" is boolean type b = 6 + 8 * 5 - 8/d; // "array1" it's a vector bi-dimensional, so we can't only give one index a = array1[1]; // we can't give a boolean type to result of indexing array1 b = array1[0,0]; // must flag an error because final tail w'll be empty a = head(tail(tail(tail(tail(seq1))))); } gEPL / DI-UM

  11. Variable Declarations Variables of any type can be initial declared. All variables are initialized with default values (0,empty,false) Initial values can be assigned in declarations i, j, count=100 -> INT; vec=[[[1,2,3],[4,5],[6]]] -> ARRAY size 4,3,6 lst1, lst2=<<9,8,7,6>>, lst=<<11>> -> SEQ; Codes, C3, C2, C1={y|y>250} -> SET; flag=True, exists, found=True -> Bool gEPL / DI-UM

  12. Data Types: Integers • Algebraic (+ - * /) • Successor (suc) & Predecessor (pred) • Relational Operators ( = != < <= > >= ) • I/O: • Read read( i ) • Write write( i ); writeLn( a*b/2 ) gEPL / DI-UM

  13. Data Types: Integers program IntegerTest { Declarations intA := 4, intB, intC := 6 -> Integer; i, j, k -> Integer; Statements // arithmetic operations intA = -3 + intB * (7 + intc); writeLn(intA); // input read(i); read(j); writeLn( i/j ); /* Inc/Dec operations */ writeLn( pred(INTc) ); writeLn( suc(INTc) ); } gEPL / DI-UM

  14. Data Types : IntegersConstraints - Division by zero is not defined gEPL / DI-UM

  15. Data Types: Static Sequences (Multi-Dimensional Arrays) • Indexing vec[i] = vec[2] + vec[j-4] vec3[i,j,k] = i*j*k • Assignment vec2 = vec1 • Length length( vec2 ) • I/O: • Write write( vec ) gEPL / DI-UM

  16. Data Types : Static SequencesConstraints • Any index must be in the values range • The number of indexes must agree with dimension gEPL / DI-UM

  17. Data Types: Static Sequences program ArrayTest { Declarations vector1 := [1,2,3], vector2 -> Array size 5; array1 := [[1,2],[4]] -> Array size 4,2; array2 := [ [[1],[5]], [[2,2],[3]] ] -> Array size 4,3,2; Statements a = array2[1,2,3]; b = array2[1,0,a*2]; array2[2,b,a] = 15; writeLn(array2); vector2 = vector1; } gEPL / DI-UM

  18. Data Types: Dynamic Sequences • Linked Lists • Empty List • List with some elements gEPL / DI-UM

  19. Data Types: Dynamic Sequences Opers: • Insert & Delete cons( 2,lst ); del( 2,lst ) • Head & Tail i = head(lst); list = tail(lst); • Member & IsEmpty if ( isMember(2,lst) )…; while ( isEmpty(lst) )…; gEPL / DI-UM

  20. Data Types: Dynamic Sequences (cont.) • Indexing lst[3]; names[2*i-j] • Length length( lst ); • Assignment lst2 = lst1; copy( lstSrc , lstDest ); • I/O: • Write write( lst ) gEPL / DI-UM

  21. Data Types: Dynamic Sequences program Seq { Declarations seq1 :=<<10,20,30,40,50>>, seq3 := <<1,2>>, seq2 -> Sequence; Statements // Selection Operations a = head(tail(tail(seq1))); seq2 = TAIL(seq3); seq1 = tail(seq1); // add & delete an element of a sequence cons(3*4+a,seq2); cons(a*int1*int2,seq2); del(30,seq1); // tests (empty & void) b = isEmpty(seq2); writeLn(b); if ( member(1,seq3) ) then writeLn(“Is member list"'); // indexing a sequence int1 = seq1[2*head(tail(seq3))]; // write the sequence seq3 = seq1; write(seq3); } gEPL / DI-UM

  22. Data Types : Dynamic SequenceConstraints - gEPL / DI-UM

  23. Data Types: Sets • Sets are: • Defined in comprehension Codes = { x | x>=100 && x<500 } • Represented (in memory) in a binary tree gEPL / DI-UM

  24. Data Types: Sets • Union (++) & Intersection (**) C3 = C1++C2; C3 = C1**C2 • Member (in) while ( N in Codes ) • I/O: • Write write( C3 ) gEPL / DI-UM

  25. Data Types: Sets program Sets { Declarations bool := true, flag, flag2 -> BOOLEAN; e, f := { x | x > 7}, g := {x | x < 8 || x > 15 && x < 13 } -> Set; Statements -- sets e = f ++ g; f = g ** f; g = g ** { x | x > 6 }; flag = a << e; flag2 = a << g; bool = 8 << {x | x < 10 && x > 7 }; } gEPL / DI-UM

  26. Data Types: Booleans • Boolean Operators • && • || • not gEPL / DI-UM

  27. Data Types: Booleans program BoolTest { Declarations intA := 4, intB, intC := 6 -> Integer; bool, flag := false -> booLEaN; Statements bool = intA < 8; writeLn(bool); /* logic operations */ flag = (intB != intA) && (intA > 7) || bool; writeLn(flag); bool = !( (intA == intB)||(intA != intC)&&(intC < 6) ) || flag; writeLn(bool) } gEPL / DI-UM

  28. SubPrograms Subprograms, with zero ormore parameters, can be • Functions (return a value) • Procedures (don’t return a value) can be declared • at the same Level • Nested (any deeper) can be called any where they are visible. gEPL / DI-UM

  29. SubPrograms subProgram calculate() :: integer { Declarations res := 6 -> integer; index -> INTeger; subprogram factorial(n -> integer) :: integer { Declarations res := 1 -> integer; Statements while (n > 0) { res = res * n; n = n -1; } return res; } for ( index in 0…4 ) { res = factorial(a); writeLn(res); } } gEPL / DI-UM

  30. SubPrograms • On most top level, with previous example, we can: intA = calculate(); • But, we can’t: • intA = factorial(6); gEPL / DI-UM

  31. SubPrograms subprogram factorial(n -> integer) :: integer { Declarations res := 1 -> integer; Statements while (n > 0) { res = res * n; pred(n); } return res; } subProgram calculate(m -> array size 4) :: array size 4 { Declarations fac := 6 -> integer; res := -16 -> integer; Statements for (a in 0..3) stepUP 1 { m[a] = factorial(fac + a); } return m; } gEPL / DI-UM

  32. Control Statements • If () Then {} [ Else {} ] • if d == true then { if( flag ) tHen { a = 6;} else { b = 9; } } • if !(c[2]==0) then { a = 5; write(a); } else { b=7; c[5] = 5; write(b); } gEPL / DI-UM

  33. Control Statements • While () {} • while(isMember(10,seq2)) { delete(10,seq2); writeLn(seq2); } • while(length(array) != 10) { array[i] = i; suc(i); } gEPL / DI-UM

  34. Control Statements For For i in v1[..v2 [stepup/stepdown N]] [satisfying Exp] gEPL / DI-UM

  35. VM Architecture • Virtual Machine with: • Instructions Stack ( program) • Calling stack - save pointers pairs (i,f): • i – save pc • f – save fp • Execution stack ( global/local/working memory) • Two Heaps • Four registers (pc, sp, fp, gp) gEPL / DI-UM

  36. VM Architecture gEPL / DI-UM

  37. VM - Instruction Set • Data Transfer • Push / Load • Pop • Store • Alloc / Free • IO • Read • Write gEPL / DI-UM

  38. VM - Instruction Set • Control • Jump • Call • Return • Miscellaneous • Type Conversion • Check • Start • Stop • Err gEPL / DI-UM

  39. Project Documentation • Technical Report on LISS Compiler Development, written in NoWeb, includes • LISS Specification (AG in CoCol)+ • Sample LISS Programs (Tests) • Compiler’s Internal Data Structures • Target Machine Description (VM) • Translation Schemas gEPL / DI-UM

More Related