On Fri, Feb 2, 2024 at 2:05 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote: > > As it collected basic block and variable information in each scope, it > now can build a state table to find matching variable at the location. > > The struct type_state is to keep the type info saved in each register > and stack slot. The update_var_state() updates the table when it finds > variables in the current address. It expects die_collect_vars() filled > a list of variables with type info and starting address. > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> > --- > tools/perf/util/annotate-data.c | 155 ++++++++++++++++++++++++++++++++ > tools/perf/util/annotate-data.h | 29 ++++++ > tools/perf/util/dwarf-aux.c | 4 + > 3 files changed, 188 insertions(+) > > diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c > index b8e60c42af8c..f8768c224bcc 100644 > --- a/tools/perf/util/annotate-data.c > +++ b/tools/perf/util/annotate-data.c > @@ -23,6 +23,57 @@ > #include "symbol.h" > #include "symbol_conf.h" > > +/* Type information in a register, valid when ok is true */ > +struct type_state_reg { > + Dwarf_Die type; > + bool ok; > + bool scratch; > +}; > + > +/* Type information in a stack location, dynamically allocated */ > +struct type_state_stack { > + struct list_head list; > + Dwarf_Die type; > + int offset; > + int size; > + bool compound; > +}; > + > +/* FIXME: This should be arch-dependent */ > +#define TYPE_STATE_MAX_REGS 16 Perhaps 32, presumably 16 won't work on Arm64. Thanks, Ian > + > +/* > + * State table to maintain type info in each register and stack location. > + * It'll be updated when new variable is allocated or type info is moved > + * to a new location (register or stack). As it'd be used with the > + * shortest path of basic blocks, it only maintains a single table. > + */ > +struct type_state { > + struct type_state_reg regs[TYPE_STATE_MAX_REGS]; > + struct list_head stack_vars; > +}; > + > +static bool has_reg_type(struct type_state *state, int reg) > +{ > + return (unsigned)reg < ARRAY_SIZE(state->regs); > +} > + > +void init_type_state(struct type_state *state, struct arch *arch __maybe_unused) > +{ > + memset(state, 0, sizeof(*state)); > + INIT_LIST_HEAD(&state->stack_vars); > +} > + > +void exit_type_state(struct type_state *state) > +{ > + struct type_state_stack *stack, *tmp; > + > + list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) { > + list_del(&stack->list); > + free(stack); > + } > +} > + > /* > * Compare type name and size to maintain them in a tree. > * I'm not sure if DWARF would have information of a single type in many > @@ -238,6 +289,110 @@ static int check_variable(Dwarf_Die *var_die, Dwarf_Die *type_die, int offset, > return 0; > } > > +static struct type_state_stack *find_stack_state(struct type_state *state, > + int offset) > +{ > + struct type_state_stack *stack; > + > + list_for_each_entry(stack, &state->stack_vars, list) { > + if (offset == stack->offset) > + return stack; > + > + if (stack->compound && stack->offset < offset && > + offset < stack->offset + stack->size) > + return stack; > + } > + return NULL; > +} > + > +static void set_stack_state(struct type_state_stack *stack, int offset, > + Dwarf_Die *type_die) > +{ > + int tag; > + Dwarf_Word size; > + > + if (dwarf_aggregate_size(type_die, &size) < 0) > + size = 0; > + > + tag = dwarf_tag(type_die); > + > + stack->type = *type_die; > + stack->size = size; > + stack->offset = offset; > + > + switch (tag) { > + case DW_TAG_structure_type: > + case DW_TAG_union_type: > + stack->compound = true; > + break; > + default: > + stack->compound = false; > + break; > + } > +} > + > +static struct type_state_stack *findnew_stack_state(struct type_state *state, > + int offset, Dwarf_Die *type_die) > +{ > + struct type_state_stack *stack = find_stack_state(state, offset); > + > + if (stack) { > + set_stack_state(stack, offset, type_die); > + return stack; > + } > + > + stack = malloc(sizeof(*stack)); > + if (stack) { > + set_stack_state(stack, offset, type_die); > + list_add(&stack->list, &state->stack_vars); > + } > + return stack; > +} > + > +/** > + * update_var_state - Update type state using given variables > + * @state: type state table > + * @dloc: data location info > + * @addr: instruction address to update > + * @var_types: list of variables with type info > + * > + * This function fills the @state table using @var_types info. Each variable > + * is used only at the given location and updates an entry in the table. > + */ > +void update_var_state(struct type_state *state, struct data_loc_info *dloc, > + u64 addr, struct die_var_type *var_types) > +{ > + Dwarf_Die mem_die; > + struct die_var_type *var; > + int fbreg = dloc->fbreg; > + int fb_offset = 0; > + > + if (dloc->fb_cfa) { > + if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0) > + fbreg = -1; > + } > + > + for (var = var_types; var != NULL; var = var->next) { > + if (var->addr != addr) > + continue; > + /* Get the type DIE using the offset */ > + if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die)) > + continue; > + > + if (var->reg == DWARF_REG_FB) { > + findnew_stack_state(state, var->offset, &mem_die); > + } else if (var->reg == fbreg) { > + findnew_stack_state(state, var->offset - fb_offset, &mem_die); > + } else if (has_reg_type(state, var->reg)) { > + struct type_state_reg *reg; > + > + reg = &state->regs[var->reg]; > + reg->type = mem_die; > + reg->ok = true; > + } > + } > +} > + > /* The result will be saved in @type_die */ > static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) > { > diff --git a/tools/perf/util/annotate-data.h b/tools/perf/util/annotate-data.h > index ad6493ea2c8e..7fbb9eb2e96f 100644 > --- a/tools/perf/util/annotate-data.h > +++ b/tools/perf/util/annotate-data.h > @@ -8,9 +8,12 @@ > #include <linux/types.h> > > struct annotated_op_loc; > +struct arch; > struct debuginfo; > +struct die_var_type; > struct evsel; > struct map_symbol; > +struct type_state; > > /** > * struct annotated_member - Type of member field > @@ -146,6 +149,16 @@ int annotated_data_type__update_samples(struct annotated_data_type *adt, > /* Release all data type information in the tree */ > void annotated_data_type__tree_delete(struct rb_root *root); > > +/* Initialize type state table */ > +void init_type_state(struct type_state *state, struct arch *arch); > + > +/* Destroy type state table */ > +void exit_type_state(struct type_state *state); > + > +/* Update type state table using variables */ > +void update_var_state(struct type_state *state, struct data_loc_info *dloc, > + u64 addr, struct die_var_type *var_types); > + > #else /* HAVE_DWARF_SUPPORT */ > > static inline struct annotated_data_type * > @@ -168,6 +181,22 @@ static inline void annotated_data_type__tree_delete(struct rb_root *root __maybe > { > } > > +static inline void init_type_state(struct type_state *state __maybe_unused, > + struct arch *arch __maybe_unused) > +{ > +} > + > +static inline void exit_type_state(struct type_state *state __maybe_unused) > +{ > +} > + > +static inline void update_var_state(struct type_state *state __maybe_unused, > + struct data_loc_info *dloc __maybe_unused, > + u64 addr __maybe_unused, > + struct die_var_type *var_types __maybe_unused) > +{ > +} > + > #endif /* HAVE_DWARF_SUPPORT */ > > #endif /* _PERF_ANNOTATE_DATA_H */ > diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c > index 39851ff1d5c4..f88a8fb4a350 100644 > --- a/tools/perf/util/dwarf-aux.c > +++ b/tools/perf/util/dwarf-aux.c > @@ -9,6 +9,7 @@ > #include <stdlib.h> > #include "debug.h" > #include "dwarf-aux.h" > +#include "dwarf-regs.h" > #include "strbuf.h" > #include "string2.h" > > @@ -1147,6 +1148,8 @@ static int reg_from_dwarf_op(Dwarf_Op *op) > case DW_OP_regx: > case DW_OP_bregx: > return op->number; > + case DW_OP_fbreg: > + return DWARF_REG_FB; > default: > break; > } > @@ -1160,6 +1163,7 @@ static int offset_from_dwarf_op(Dwarf_Op *op) > case DW_OP_regx: > return 0; > case DW_OP_breg0 ... DW_OP_breg31: > + case DW_OP_fbreg: > return op->number; > case DW_OP_bregx: > return op->number2; > -- > 2.43.0.594.gd9cf4e227d-goog >