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Introduce #@ pragmas
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This is an experimental syntax extension to add arbitrary annotations
into statement sequences.

This, together with the syntaxtree module will enable users to process
GAP source without writing their own ad-hoc parsers.
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@markuspf
markuspf committed Oct 26, 2017
1 parent 15dafab commit e729a4a
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Showing 8 changed files with 119 additions and 30 deletions.
11 changes: 11 additions & 0 deletions src/code.c
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Original file line number Diff line number Diff line change
Expand Up @@ -886,6 +886,17 @@ void CodeFuncExprEnd (

}

void CodePragma(Obj content)
{
Stat pragma;

pragma = NewStat( T_PRAGMA, SIZEBAG_STRINGLEN(GET_LEN_STRING(content)) );
memcpy( (void *)ADDR_STAT(pragma), CONST_ADDR_OBJ(content),
SIZEBAG_STRINGLEN(GET_LEN_STRING(content)) );

PushStat( pragma );
}


/****************************************************************************
**
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4 changes: 4 additions & 0 deletions src/code.h
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Expand Up @@ -220,6 +220,8 @@ enum STAT_TNUMS {
T_ASSERT_2ARGS,
T_ASSERT_3ARGS,

T_PRAGMA,

END_ENUM_RANGE(LAST_STAT_TNUM),
};

Expand Down Expand Up @@ -1401,6 +1403,8 @@ extern void CodeAssertEnd3Args ( void );
/* CodeContinue() . . . . . . . . . . . . . code continue-statement */
extern void CodeContinue ( void );

extern void CodePragma(Obj pragma);

/****************************************************************************
**
*V FilenameCache . . . . . . . . . . . . . . . . . . list of filenames
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10 changes: 10 additions & 0 deletions src/intrprtr.c
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Expand Up @@ -300,6 +300,16 @@ ExecStatus IntrEnd (
}


/* Interpret a pragma, that is, if we're coding, code it, otherwise
ignore it */
void IntrPragma(Obj pragma)
{
/* ignore or code */
if ( STATE(IntrReturning) > 0 ) { return; }
if ( STATE(IntrIgnoring) > 0 ) { return; }
if ( STATE(IntrCoding) > 0 ) { CodePragma(pragma); return; }
}

/****************************************************************************
**
*F IntrFuncCallBegin() . . . . . . . . . . . interpret function call, begin
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2 changes: 2 additions & 0 deletions src/intrprtr.h
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Expand Up @@ -977,6 +977,8 @@ extern void IntrSaveWSEnd ( void );
*/
extern void IntrContinue ( void );

extern void IntrPragma(Obj pragma);

/****************************************************************************
*F PushVoidObj() . . . . . . . . . . . . . . push void value onto the stack
*/
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76 changes: 51 additions & 25 deletions src/read.c
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Expand Up @@ -2572,6 +2572,14 @@ void ReadReturn (
}
}

void ReadPragma(TypSymbolSet follow)
{
Obj pragma;

C_NEW_STRING( pragma, STATE(ValueLen), (void *)STATE(Value) );
Match(S_PRAGMA, "pragma", follow);
IntrPragma( pragma );
}

/****************************************************************************
**
Expand Down Expand Up @@ -2657,37 +2665,55 @@ void ReadQUIT (
** | 'atomic' <QualifiedExpression> { ',' <QualifiedExpression> } 'do' <Statements> 'od' ';'
** | ';'
*/
UInt ReadStats (
TypSymbolSet follow )
UInt ReadStats(TypSymbolSet follow)
{
UInt nr; /* number of statements */
UInt nr; /* number of statements */

/* read the statements */
nr = 0;
while ( IS_IN( STATE(Symbol), STATBEGIN|S_SEMICOLON ) ) {

/* read a statement */
if ( STATE(Symbol) == S_IDENT ) ReadCallVarAss(follow,'s');
else if ( STATE(Symbol) == S_UNBIND ) ReadUnbind( follow );
else if ( STATE(Symbol) == S_INFO ) ReadInfo( follow );
else if ( STATE(Symbol) == S_ASSERT ) ReadAssert( follow );
else if ( STATE(Symbol) == S_IF ) ReadIf( follow );
else if ( STATE(Symbol) == S_FOR ) ReadFor( follow );
else if ( STATE(Symbol) == S_WHILE ) ReadWhile( follow );
else if ( STATE(Symbol) == S_REPEAT ) ReadRepeat( follow );
else if ( STATE(Symbol) == S_BREAK ) ReadBreak( follow );
else if ( STATE(Symbol) == S_CONTINUE) ReadContinue( follow );
else if ( STATE(Symbol) == S_RETURN ) ReadReturn( follow );
else if ( STATE(Symbol) == S_TRYNEXT) ReadTryNext( follow );
else if ( STATE(Symbol) == S_QUIT ) ReadQuit( follow );
else if ( STATE(Symbol) == S_ATOMIC ) ReadAtomic( follow );
else ReadEmpty( follow );
nr++;
Match( S_SEMICOLON, ";", follow );
while (IS_IN(STATE(Symbol), STATBEGIN | S_SEMICOLON)) {

if (STATE(Symbol) == S_PRAGMA)
ReadPragma(follow);
else {
/* read a statement */
if (STATE(Symbol) == S_IDENT)
ReadCallVarAss(follow, 's');
else if (STATE(Symbol) == S_UNBIND)
ReadUnbind(follow);
else if (STATE(Symbol) == S_INFO)
ReadInfo(follow);
else if (STATE(Symbol) == S_ASSERT)
ReadAssert(follow);
else if (STATE(Symbol) == S_IF)
ReadIf(follow);
else if (STATE(Symbol) == S_FOR)
ReadFor(follow);
else if (STATE(Symbol) == S_WHILE)
ReadWhile(follow);
else if (STATE(Symbol) == S_REPEAT)
ReadRepeat(follow);
else if (STATE(Symbol) == S_BREAK)
ReadBreak(follow);
else if (STATE(Symbol) == S_CONTINUE)
ReadContinue(follow);
else if (STATE(Symbol) == S_RETURN)
ReadReturn(follow);
else if (STATE(Symbol) == S_TRYNEXT)
ReadTryNext(follow);
else if (STATE(Symbol) == S_QUIT)
ReadQuit(follow);
else if (STATE(Symbol) == S_ATOMIC)
ReadAtomic(follow);
else if (STATE(Symbol) == S_PRAGMA)
ReadPragma(follow);
else
ReadEmpty(follow);
Match(S_SEMICOLON, ";", follow);
}
nr++;
}

/* return the number of statements */
/* return the number of statements */
return nr;
}

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32 changes: 27 additions & 5 deletions src/scanner.c
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Expand Up @@ -2105,6 +2105,22 @@ void GetChar ( void )
}
}

void GetPragma(void)
{
Int i = 0;

/* Skip @ */
GET_CHAR();
while (*STATE(In) != '\n' && *STATE(In) != '\r' &&
*STATE(In) != '\377') {
STATE(Value)[i] = *STATE(In);
i++;
GET_CHAR();
}
STATE(Value)[i] = '\0';
STATE(ValueLen) = i;
}

/****************************************************************************
**
*F GetSymbol() . . . . . . . . . . . . . . . . . get the next symbol, local
Expand Down Expand Up @@ -2151,20 +2167,26 @@ void GetSymbol ( void )
GET_CHAR();
}

/* skip over <spaces>, <tabs>, <newlines> and comments */
/* skip over <spaces>, <tabs>, and <newlines> */
while (*STATE(In) == ' ' || *STATE(In) == '\t' || *STATE(In) == '\n' ||
*STATE(In) == '\r' || *STATE(In) == '\f' || *STATE(In) == '#') {
if (*STATE(In) == '#') {
while (*STATE(In) != '\n' && *STATE(In) != '\r' &&
*STATE(In) != '\377')
GET_CHAR();
GET_CHAR();
if (*STATE(In) == '@') {
STATE(Symbol) = S_PRAGMA;
GetPragma();
return;
} else {
while (*STATE(In) != '\n' && *STATE(In) != '\r' &&
*STATE(In) != '\377')
GET_CHAR();
}
}
GET_CHAR();
}

/* switch according to the character */
switch (*STATE(In)) {

case '.':
STATE(Symbol) = S_DOT;
GET_CHAR();
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1 change: 1 addition & 0 deletions src/scanner.h
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Original file line number Diff line number Diff line change
Expand Up @@ -144,6 +144,7 @@ enum {
S_CONTINUE = (1UL<<29)+4,

S_SEMICOLON = (1UL<<30),
S_PRAGMA = (1UL<<30)+1,

S_EOF = (1UL<<31),
};
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13 changes: 13 additions & 0 deletions src/stats.c
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Expand Up @@ -2009,6 +2009,17 @@ void PrintAtomic (
Pr( "%4<\nod;", 0L, 0L );
}

void PrintPragma(Stat stat)
{
Char *pragma;

/* TODO: super ugly */
pragma = (Char *)((UInt *)(&ADDR_STAT(stat)[1]));

Pr("#@", 0L, 0L);
Pr("%s", (Int)(pragma), 0L);
}


/****************************************************************************
**
Expand Down Expand Up @@ -2271,6 +2282,7 @@ static Int InitKernel (
InstallExecStatFunc( T_RETURN_VOID , ExecReturnVoid);
InstallExecStatFunc( T_EMPTY , ExecEmpty);
InstallExecStatFunc( T_ATOMIC , ExecAtomic);
InstallExecStatFunc( T_PRAGMA , ExecEmpty);

/* install printers for non-statements */
for ( i = 0; i < ARRAY_SIZE(PrintStatFuncs); i++ ) {
Expand Down Expand Up @@ -2309,6 +2321,7 @@ static Int InitKernel (
InstallPrintStatFunc( T_RETURN_VOID , PrintReturnVoid);
InstallPrintStatFunc( T_EMPTY , PrintEmpty);
InstallPrintStatFunc( T_ATOMIC , PrintAtomic);
InstallPrintStatFunc( T_PRAGMA , PrintPragma);

for ( i = 0; i < ARRAY_SIZE(ExecStatFuncs); i++ )
IntrExecStatFuncs[i] = ExecIntrStat;
Expand Down

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