From 02c727013cc3ae08b86ad360429f9a0dbdc0ec92 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Fri, 11 Dec 2020 09:59:15 -0700 Subject: [PATCH] Avoid side effects in expression lexers I noticed that some of the lexers were calling write_dollar_variable from the lexer. This seems like a bad practice, so this patch moves the side effects into the parsers. I tested this by re-running gdb.fortran and gdb.modula2; the Pascal compiler on my machine seems not to work, so I couldn't test gdb.pascal. I note that the type-tracking in the Pascal is also incorrect, in that a convenience variable's type may change between parsing and evaluation (or even during the course of evaluation). gdb/ChangeLog 2020-12-11 Tom Tromey * p-exp.y (intvar): Remove global. (DOLLAR_VARIABLE): Change type. (start): Update. (exp): Call write_dollar_variable here... (yylex): ... not here. * m2-exp.y (DOLLAR_VARIABLE): Change type. (variable): Call write_dollar_variable here... (yylex): ... not here. * f-exp.y (DOLLAR_VARIABLE): Change type. (exp): Call write_dollar_variable here... (yylex): ... not here. --- gdb/ChangeLog | 14 ++++++++++++++ gdb/f-exp.y | 10 ++++------ gdb/m2-exp.y | 8 +++----- gdb/p-exp.y | 48 +++++++++++++++++++++++------------------------- 4 files changed, 44 insertions(+), 36 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a3d977dc604..992da3db302 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,17 @@ +2020-12-11 Tom Tromey + + * p-exp.y (intvar): Remove global. + (DOLLAR_VARIABLE): Change type. + (start): Update. + (exp): Call write_dollar_variable here... + (yylex): ... not here. + * m2-exp.y (DOLLAR_VARIABLE): Change type. + (variable): Call write_dollar_variable here... + (yylex): ... not here. + * f-exp.y (DOLLAR_VARIABLE): Change type. + (exp): Call write_dollar_variable here... + (yylex): ... not here. + 2020-12-11 Tom Tromey * varobj.c (varobj_create): Update. diff --git a/gdb/f-exp.y b/gdb/f-exp.y index edfbe0cd220..ea32056f6db 100644 --- a/gdb/f-exp.y +++ b/gdb/f-exp.y @@ -174,7 +174,7 @@ static int parse_number (struct parser_state *, const char *, int, %token SINGLE DOUBLE PRECISION %token CHARACTER -%token DOLLAR_VARIABLE +%token DOLLAR_VARIABLE %token ASSIGN_MODIFY %token UNOP_INTRINSIC BINOP_INTRINSIC @@ -509,6 +509,7 @@ exp : variable ; exp : DOLLAR_VARIABLE + { write_dollar_variable (pstate, $1); } ; exp : SIZEOF '(' type ')' %prec UNARY @@ -1357,11 +1358,8 @@ yylex (void) yylval.sval.length = namelen; if (*tokstart == '$') - { - write_dollar_variable (pstate, yylval.sval); - return DOLLAR_VARIABLE; - } - + return DOLLAR_VARIABLE; + /* Use token-type TYPENAME for symbols that happen to be defined currently as names of types; NAME for other symbols. The caller is not constrained to care about the distinction. */ diff --git a/gdb/m2-exp.y b/gdb/m2-exp.y index f6f11126c69..d4f3c2c1e45 100644 --- a/gdb/m2-exp.y +++ b/gdb/m2-exp.y @@ -125,7 +125,7 @@ static int number_sign = 1; /* The GDB scope operator */ %token COLONCOLON -%token DOLLAR_VARIABLE +%token DOLLAR_VARIABLE /* M2 tokens */ %left ',' @@ -535,6 +535,7 @@ variable: fblock /* GDB internal ($foo) variable */ variable: DOLLAR_VARIABLE + { write_dollar_variable (pstate, $1); } ; /* GDB scope operator */ @@ -952,10 +953,7 @@ yylex (void) yylval.sval.length = namelen; if (*tokstart == '$') - { - write_dollar_variable (pstate, yylval.sval); - return DOLLAR_VARIABLE; - } + return DOLLAR_VARIABLE; /* Use token-type BLOCKNAME for symbols that happen to be defined as functions. If this is not so, then ... diff --git a/gdb/p-exp.y b/gdb/p-exp.y index 9caf15f69f5..618557c472a 100644 --- a/gdb/p-exp.y +++ b/gdb/p-exp.y @@ -115,7 +115,6 @@ static int parse_number (struct parser_state *, const char *, int, int, YYSTYPE *); static struct type *current_type; -static struct internalvar *intvar; static int leftdiv_is_integer; static void push_current_type (void); static void pop_current_type (void); @@ -161,7 +160,7 @@ static int search_field; /* Special type cases, put in to allow the parser to distinguish different legal basetypes. */ -%token DOLLAR_VARIABLE +%token DOLLAR_VARIABLE /* Object pascal */ @@ -192,7 +191,6 @@ static int search_field; %% start : { current_type = NULL; - intvar = NULL; search_field = 0; leftdiv_is_integer = 0; } @@ -526,17 +524,28 @@ exp : variable ; exp : DOLLAR_VARIABLE - /* Already written by write_dollar_variable. - Handle current_type. */ - { if (intvar) { - struct value * val, * mark; - - mark = value_mark (); - val = value_of_internalvar (pstate->gdbarch (), - intvar); - current_type = value_type (val); - value_release_to_mark (mark); - } + { + write_dollar_variable (pstate, $1); + + /* $ is the normal prefix for pascal + hexadecimal values but this conflicts + with the GDB use for debugger variables + so in expression to enter hexadecimal + values we still need to use C syntax with + 0xff */ + std::string tmp ($1.ptr, $1.length); + /* Handle current_type. */ + struct internalvar *intvar + = lookup_only_internalvar (tmp.c_str () + 1); + if (intvar != nullptr) + { + scoped_value_mark mark; + + value *val + = value_of_internalvar (pstate->gdbarch (), + intvar); + current_type = value_type (val); + } } ; @@ -1494,17 +1503,6 @@ yylex (void) if (*tokstart == '$') { - char *tmp; - - /* $ is the normal prefix for pascal hexadecimal values - but this conflicts with the GDB use for debugger variables - so in expression to enter hexadecimal values - we still need to use C syntax with 0xff */ - write_dollar_variable (pstate, yylval.sval); - tmp = (char *) alloca (namelen + 1); - memcpy (tmp, tokstart, namelen); - tmp[namelen] = '\0'; - intvar = lookup_only_internalvar (tmp + 1); free (uptokstart); return DOLLAR_VARIABLE; } -- 2.30.2