Get rid of registers with trash values. More...
#include <coreaction.hh>
Public Member Functions | |
| virtual Action * | clone (const ActionGroupList &grouplist) const |
| Clone the Action. More... | |
| virtual int4 | apply (Funcdata &data) |
| Make a single attempt to apply this Action. More... | |
 Public Member Functions inherited from Action | |
| Action (uint4 f, const string &nm, const string &g) | |
| Base constructor for an Action. More... | |
| virtual void | printStatistics (ostream &s) const |
| Dump statistics to stream. More... | |
| int4 | perform (Funcdata &data) |
| Perform this action (if necessary) More... | |
| bool | setBreakPoint (uint4 tp, const string &specify) |
| Set a breakpoint on this action. More... | |
| virtual void | clearBreakPoints (void) |
| Clear all breakpoints set on this Action. | |
| bool | setWarning (bool val, const string &specify) |
| Set a warning on this action. More... | |
| bool | disableRule (const string &specify) |
| Disable a specific Rule within this. More... | |
| bool | enableRule (const string &specify) |
| Enable a specific Rule within this. More... | |
| virtual void | reset (Funcdata &data) |
| Reset the Action for a new function. More... | |
| virtual void | resetStats (void) |
| Reset all the counts to zero. More... | |
| virtual int4 | print (ostream &s, int4 num, int4 depth) const |
| Print a description of this Action to stream. More... | |
| virtual void | printState (ostream &s) const |
| Print status to stream. More... | |
| virtual Action * | getSubAction (const string &specify) |
| Retrieve a specific sub-action by name. More... | |
| virtual Rule * | getSubRule (const string &specify) |
| Retrieve a specific sub-rule by name. More... | |
Additional Inherited Members | |
| Public Types inherited from Action | |
| enum | ruleflags { rule_repeatapply = 4, rule_onceperfunc = 8, rule_oneactperfunc = 16, rule_debug = 32, rule_warnings_on = 64, rule_warnings_given = 128 } |
| Boolean behavior properties governing this particular Action. More... | |
| enum | statusflags { status_start =1, status_breakstarthit =2, status_repeat =4, status_mid =8, status_end =16, status_actionbreak =32 } |
| Boolean properties describing the status of an action. More... | |
| enum | breakflags { break_start = 1, tmpbreak_start = 2, break_action = 4, tmpbreak_action = 8 } |
| Break points associated with an Action. More... | |
| Protected Member Functions inherited from Action | |
| void | issueWarning (Architecture *glb) |
| Warn that this Action has applied. More... | |
| bool | checkStartBreak (void) |
| Check start breakpoint. More... | |
| bool | checkActionBreak (void) |
| Check action breakpoint. More... | |
| Protected Attributes inherited from Action | |
| int4 | lcount |
| Changes not including last call to apply() | |
| int4 | count |
| Number of changes made by this action so far. | |
| uint4 | status |
| Current status. | |
| uint4 | breakpoint |
| Breakpoint properties. | |
| uint4 | flags |
| Behavior properties. | |
| uint4 | count_tests |
| Number of times apply() has been called. | |
| uint4 | count_apply |
| Number of times apply() made changes. | |
| string | name |
| Name of the action. | |
| string | basegroup |
| Base group this action belongs to. | |
Detailed Description
Get rid of registers with trash values.
Register locations called likely trash are read as a side-effect of some instruction the compiler was using. The canonical example in x86 code is the PUSH ECX which compilers use to create space on the stack without caring about what's in ECX. Even though the decompiler can see that the read ECX value is never getting used directly by the function, because the value is getting copied to the stack, the decompiler frequently can't tell if the value has been aliased across sub-function calls. By marking the ECX register as likely \ trash the decompiler will assume that, unless there is a direct read of the incoming ECX, none of subfunctions alias the stack location where ECX was stored. This allows the spurious references to the register to be removed.
Member Function Documentation
◆ apply()
|
virtual |
Make a single attempt to apply this Action.
This is the main entry point for applying changes to a function that are specific to this Action. The method can inspect whatever it wants to decide if the Action does or does not apply. Changes are indicated by incrementing the count field.
- Parameters
-
data is the function to inspect/modify
- Returns
- 0 for a complete application, -1 for a partial completion (due to breakpoint)
Implements Action.
◆ clone()
|
inlinevirtual |
The documentation for this class was generated from the following files:
- coreaction.hh
- coreaction.cc
