duskos

commit e705cf3935d68404241c324272bfa8866786a711
parent 85bac318cea174ff197ba4ad71333d79e9eb3046
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Tue, 21 Jun 2022 21:21:09 -0400

cc: add support for array assignment

int a[3] = {1, 2, 3};

Diffstat:
M
fs/cc/ast.fs
 | 
26
+++++++++++++++++++++++---
M
fs/cc/gen.fs
 | 
8
+++++++-
M
fs/cc/vm.fs
 | 
11
++++++++++-
M
fs/tests/cc/test.c
 | 
5
+----

4 files changed, 41 insertions(+), 9 deletions(-)
diff --git a/fs/cc/ast.fs b/fs/cc/ast.fs
@@ -46,14 +46,14 @@ create bopsprectbl 1 c, 1 c, 0 c, 0 c, 2 c, 2 c, 2 c, 2 c,
 8 const AST_UNARYOP    \ data1=uopid
 9 const AST_POSTFIXOP  \ data1=popid
 10 const AST_BINARYOP  \ data1=bopid
-\ 11 = unused
+11 const AST_LIST      \ list of lvalues or constants: {1, 2, 3}
 12 const AST_IF
 \ 13 = unused
 14 const AST_FUNCALL   \ data1=name data2=MAP_FUNCTION
 
 ASTIDCNT stringlist astidnames
 "declare" "unit" "function" "return" "constant" "stmts" "args" "lvalue"
-"unaryop" "postop" "binop" "_" "if" "_" "call"
+"unaryop" "postop" "binop" "list" "if" "_" "call"
 
 0 value curunit \ points to current Unit, the beginning of the AST
 
@@ -121,6 +121,23 @@ ASTIDCNT wordtbl astdatatbl ( node -- node )
 
 alias noop parseExpression ( tok -- node ) \ forward declaration
 
+\ The first '{' has already been read
+: parseList ( -- node )
+  AST_LIST createnode nextt dup S" }" s= if drop exit then
+  begin ( lnode tok ) case
+      of isIdent? ( lnode )
+        AST_LVALUE createnode swap , ( lnode lvnode ) over addnode endof
+      of parse ( lnode n )
+        AST_CONSTANT createnode swap , ( lnode cnode ) over addnode endof
+      _err
+    endcase
+    nextt case
+      S" }" of s= r~ exit endof
+      S" ," of s= endof
+      _err
+    endcase
+  nextt again ;
+
 : parsePostfixOp ( tok lvnode -- node )
   over S" [" s= if ( tok lvnode ) \ x[y] is the equivalent of *(x+y)
     nip AST_BINARYOP createnode 0 ( + ) , ( lvnode bnode )
@@ -210,7 +227,10 @@ current to parseExpression
   drop ( dnode ) dup data1 ( dnode name )
   swap parentnode AST_BINARYOP newnode ( name anode ) 12 ( = ) ,
   AST_LVALUE newnode ( name lvnode ) swap , parentnode ( anode )
-  nextt parseExpression read; ( anode expr ) swap addnode ;
+  nextt dup S" {" s= if
+    drop parseList else
+    parseExpression then
+  read; ( anode expr-or-list ) swap addnode ;
 
 : parseArgSpecs ( funcnode -- )
   nextt '(' expectChar AST_ARGSPECS newnode nextt ( argsnode tok )
diff --git a/fs/cc/gen.fs b/fs/cc/gen.fs
@@ -177,7 +177,13 @@ ASTIDCNT wordtbl gentbl ( node -- )
     selop1 gennode selop2 gennode then
   bopgentblpost r> data1 wexec
   r> ( selectedop ) if op1<>op2 else selop1 then ;
-'w _err ( unused )
+\ TODO: this doesn't work with lvalues yet
+:w ( List )
+  dup childcount dup 1+ 4 * scratchallot dup >r ( node len a )
+  over >r tuck ! 4 + swap firstchild begin ( a node )
+    dup data1 ( a node value ) rot tuck ! ( node a )
+    4 + swap nextsibling next ( a node ) 2drop
+  r> constarray>op ;
 :w ( If )
   firstchild ?dup not if _err then dup gennode ( exprnode )
   vmjz, swap ( jump_addr exprnode ) ops$
diff --git a/fs/cc/vm.fs b/fs/cc/vm.fs
@@ -77,6 +77,7 @@ $00 const VM_NONE
 $01 const VM_CONSTANT    \ 42
 $02 const VM_STACKFRAME  \ ebp+x
 $03 const VM_REGISTER    \ eax
+$11 const VM_CONSTARRAY  \ pointer to an array with the 1st elem being length
 $12 const VM_*STACKFRAME \ [ebp+x]
 $13 const VM_*REGISTER   \ [eax]
 
@@ -108,6 +109,7 @@ operands value 'curop
 : hasop# optype VM_NONE = not _assert ;
 : noop# optype VM_NONE = _assert ;
 : const>op ( n -- ) noop# VM_CONSTANT optype! oparg! ;
+: constarray>op ( a -- ) noop# VM_CONSTARRAY optype! oparg! ;
 : sf+>op ( off -- ) noop# VM_*STACKFRAME optype! oparg! ;
 
 \ get current operand SF offset, adjusted with callsz
@@ -223,7 +225,14 @@ operands value 'curop
 \ op2. In other words, perform a AST_ASSIGN with the right part as op2
 \ and the left part as op1.
 : vmmov,
-  maybederef selop1 opAsm selop2 opAsm mov, opdeinit ;
+  selop2 optype VM_CONSTARRAY = if \ special case, we have a {1, 2, 3} assign
+    selop1 optype VM_STACKFRAME = _assert
+    *op>op selop2 oparg selop1 dup @ ( a len ) >r begin ( a )
+      opAsm 4 + dup @ i32 mov, ( a+4 ) oparg 4 + oparg! next ( a )
+    drop selop2
+  else
+    maybederef selop1 opAsm selop2 opAsm mov, then
+  opdeinit ;
 
 
 \ Code generation - Unary ops
diff --git a/fs/tests/cc/test.c b/fs/tests/cc/test.c
@@ -63,9 +63,6 @@ int* ptrari(int *x) {
     return x + 1;
 }
 int array() {
-    int a[3];
-    *a = 42;
-    *(a+1) = 12;
-    a[2] = 2;
+    int a[3] = {42, 12, 2};
     return *a + a[1] - *(a+2);
 }