Introduce in_inclusive_range, fix -Wtautological-compare warnings

When compiling with clang or gcc 8, we see warnings like this:

/home/emaisin/src/binutils-gdb/gdb/arm-tdep.c:10013:13: error: comparison of 0 <= unsigned expression is always true [-Werror,-Wtautological-compare]
      if (0 <= insn_op1 && 3 >= insn_op1)
          ~ ^  ~~~~~~~~
/home/emaisin/src/binutils-gdb/gdb/arm-tdep.c:11722:20: error: comparison of unsigned expression >= 0 is always true [-Werror,-Wtautological-compare]
      else if (opB >= 0 && opB <= 2)
               ~~~ ^  ~

This is because an unsigned integer (opB in this case) will always be >=
0.  It is still useful to keep both bounds of the range in the
expression, even if one is at the edge of the data type range.  This
patch introduces a utility function in_inclusive_range that gets rid of
the warning while conveying that we are checking for a range.

Tested by rebuilding.

gdb/ChangeLog:

	* common/common-utils.h (in_inclusive_range): New function.
	* arm-tdep.c (arm_record_extension_space): Use
	in_inclusive_range.
	(thumb_record_ld_st_reg_offset): Use in_inclusive_range.
	* cris-tdep.c (cris_spec_reg_applicable): Use
	in_inclusive_range.
This commit is contained in:
Simon Marchi 2017-10-30 14:27:30 -04:00
parent 1b81856f5b
commit b020ff8074
4 changed files with 27 additions and 9 deletions

View File

@ -1,3 +1,12 @@
2017-10-30 Simon Marchi <simon.marchi@ericsson.com>
* common/common-utils.h (in_inclusive_range): New function.
* arm-tdep.c (arm_record_extension_space): Use
in_inclusive_range.
(thumb_record_ld_st_reg_offset): Use in_inclusive_range.
* cris-tdep.c (cris_spec_reg_applicable): Use
in_inclusive_range.
2017-10-30 Pedro Alves <palves@redhat.com>
Simon Marchi <simon.marchi@ericsson.com>

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@ -10010,13 +10010,13 @@ arm_record_extension_space (insn_decode_record *arm_insn_r)
&& !INSN_RECORDED(arm_insn_r))
{
/* Handle MLA(S) and MUL(S). */
if (0 <= insn_op1 && 3 >= insn_op1)
if (in_inclusive_range (insn_op1, 0U, 3U))
{
record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15);
record_buf[1] = ARM_PS_REGNUM;
arm_insn_r->reg_rec_count = 2;
}
else if (4 <= insn_op1 && 15 >= insn_op1)
else if (in_inclusive_range (insn_op1, 4U, 15U))
{
/* Handle SMLAL(S), SMULL(S), UMLAL(S), UMULL(S). */
record_buf[0] = bits (arm_insn_r->arm_insn, 16, 19);
@ -11712,14 +11712,14 @@ thumb_record_ld_st_reg_offset (insn_decode_record *thumb_insn_r)
/* Handle load/store register offset. */
uint32_t opB = bits (thumb_insn_r->arm_insn, 9, 11);
if (opB >= 4 && opB <= 7)
if (in_inclusive_range (opB, 4U, 7U))
{
/* LDR(2), LDRB(2) , LDRH(2), LDRSB, LDRSH. */
reg_src1 = bits (thumb_insn_r->arm_insn,0, 2);
record_buf[0] = reg_src1;
thumb_insn_r->reg_rec_count = 1;
}
else if (opB >= 0 && opB <= 2)
else if (in_inclusive_range (opB, 0U, 2U))
{
/* STR(2), STRB(2), STRH(2) . */
reg_src1 = bits (thumb_insn_r->arm_insn, 3, 5);

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@ -125,4 +125,13 @@ extern void free_vector_argv (std::vector<char *> &v);
joining all the arguments with a whitespace separating them. */
extern std::string stringify_argv (const std::vector<char *> &argv);
/* Return true if VALUE is in [LOW, HIGH]. */
template <typename T>
static bool
in_inclusive_range (T value, T low, T high)
{
return value >= low && value <= high;
}
#endif

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@ -1434,19 +1434,19 @@ cris_spec_reg_applicable (struct gdbarch *gdbarch,
/* Indeterminate/obsolete. */
return 0;
case cris_ver_v0_3:
return (version >= 0 && version <= 3);
return in_inclusive_range (version, 0U, 3U);
case cris_ver_v3p:
return (version >= 3);
case cris_ver_v8:
return (version == 8 || version == 9);
return in_inclusive_range (version, 8U, 9U);
case cris_ver_v8p:
return (version >= 8);
case cris_ver_v0_10:
return (version >= 0 && version <= 10);
return in_inclusive_range (version, 0U, 10U);
case cris_ver_v3_10:
return (version >= 3 && version <= 10);
return in_inclusive_range (version, 3U, 10U);
case cris_ver_v8_10:
return (version >= 8 && version <= 10);
return in_inclusive_range (version, 8U, 10U);
case cris_ver_v10:
return (version == 10);
case cris_ver_v10p: