On Mon, Dec 2, 2024 at 1:50 AM Lewis Hyatt <[email protected]> wrote:
>
> With the codebase having already been prepared to handle it, change
> location_t to be a 64-bit integer instead of a 32-bit integer.
OK if there's no comments from others within 48h.
Thanks,
Richard.
> libcpp/ChangeLog:
>
> * include/cpplib.h (struct cpp_token): Adjust comment about the
> struct size.
> * include/line-map.h (location_t): Change typedef from 32-bit to
> 64-bit
> integer.
> (LINE_MAP_MAX_COLUMN_NUMBER): Increase size to be appropriate for
> 64-bit location_t.
> (LINE_MAP_MAX_LOCATION_WITH_PACKED_RANGES): Likewise.
> (LINE_MAP_MAX_LOCATION_WITH_COLS): Likewise.
> (LINE_MAP_MAX_LOCATION): Likewise.
> (MAX_LOCATION_T): Likewise.
> (line_map_suggested_range_bits): Likewise.
> (struct line_map): Adjust comment about the struct size.
> (struct line_map_macro): Likewise.
> (struct line_map_ordinary): Likewise. Rearrange fields to optimize
> padding.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/diagnostic/pr77949.C: Adapt the test for 64-bit location_t,
> when the previously expected failure doesn't actually happen.
> * g++.dg/modules/loc-prune-4.C: Adjust the expected output for the
> 64-bit location_t case.
> * gcc.dg/plugin/expensive_selftests_plugin.c: Don't try to test
> the maximum supported column number in 64-bit location_t mode.
> * gcc.dg/plugin/location_overflow_plugin.c: Adjust the base_location
> so it can effectively test 64-bit location_t.
> ---
> libcpp/include/cpplib.h | 6 ++-
> libcpp/include/line-map.h | 48 +++++++++++--------
> gcc/testsuite/g++.dg/diagnostic/pr77949.C | 5 +-
> gcc/testsuite/g++.dg/modules/loc-prune-4.C | 6 +--
> .../plugin/expensive_selftests_plugin.cc | 10 ++--
> .../gcc.dg/plugin/location_overflow_plugin.cc | 5 ++
> 6 files changed, 48 insertions(+), 32 deletions(-)
>
> diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
> index e73f77e67d8..73dd97df747 100644
> --- a/libcpp/include/cpplib.h
> +++ b/libcpp/include/cpplib.h
> @@ -255,8 +255,10 @@ struct GTY(()) cpp_identifier {
> spelling;
> };
>
> -/* A preprocessing token. This has been carefully packed and should
> - occupy 16 bytes on 32-bit hosts and 24 bytes on 64-bit hosts. */
> +/* A preprocessing token. This occupies 32 bytes on a 64-bit host. On a
> + 32-bit host it occupies 20 or 24 bytes, depending whether a uint64_t
> + requires 4- or 8-byte alignment. */
> +
> struct GTY(()) cpp_token {
>
> /* Location of first char of token, together with range of full token. */
> diff --git a/libcpp/include/line-map.h b/libcpp/include/line-map.h
> index 96fdf60644f..19fd64b9363 100644
> --- a/libcpp/include/line-map.h
> +++ b/libcpp/include/line-map.h
> @@ -291,7 +291,10 @@ enum lc_reason
>
> To further see how location_t works in practice, see the
> worked example in libcpp/location-example.txt. */
> -typedef unsigned int location_t;
> +
> +/* A 64-bit type to represent a location. We only use 63 of the 64 bits, so
> + that two location_t can be safely subtracted and stored in an int64_t. */
> +typedef uint64_t location_t;
> typedef int64_t location_diff_t;
>
> /* Sometimes we need a type that has the same size as location_t but that
> does
> @@ -302,24 +305,31 @@ typedef location_t line_map_uint_t;
> /* Do not track column numbers higher than this one. As a result, the
> range of column_bits is [12, 18] (or 0 if column numbers are
> disabled). */
> -const unsigned int LINE_MAP_MAX_COLUMN_NUMBER = (1U << 12);
> +const unsigned int LINE_MAP_MAX_COLUMN_NUMBER = (1U << 31) - 1;
>
> /* Do not pack ranges if locations get higher than this.
> If you change this, update:
> gcc.dg/plugin/location-overflow-test-*.c. */
> -const location_t LINE_MAP_MAX_LOCATION_WITH_PACKED_RANGES = 0x50000000;
> +const location_t LINE_MAP_MAX_LOCATION_WITH_PACKED_RANGES
> + = location_t (0x50000000) << 31;
>
> /* Do not track column numbers if locations get higher than this.
> If you change this, update:
> gcc.dg/plugin/location-overflow-test-*.c. */
> -const location_t LINE_MAP_MAX_LOCATION_WITH_COLS = 0x60000000;
> +const location_t LINE_MAP_MAX_LOCATION_WITH_COLS
> + = location_t (0x60000000) << 31;
> +
> +/* Highest possible source location encoded within an ordinary map. Higher
> + values up to MAX_LOCATION_T represent macro virtual locations. */
> +const location_t LINE_MAP_MAX_LOCATION = location_t (0x70000000) << 31;
>
> -/* Highest possible source location encoded within an ordinary map. */
> -const location_t LINE_MAP_MAX_LOCATION = 0x70000000;
> +/* This is the highest possible source location encoded within an
> + ordinary or macro map. */
> +const location_t MAX_LOCATION_T = location_t (-1) >> 2;
>
> /* This is the number of range bits suggested to enable, if range tracking is
> desired. */
> -const int line_map_suggested_range_bits = 5;
> +const int line_map_suggested_range_bits = 7;
>
> /* A range of source locations.
>
> @@ -397,7 +407,7 @@ typedef size_t (*line_map_round_alloc_size_func) (size_t);
> struct GTY((tag ("0"), desc ("MAP_ORDINARY_P (&%h) ? 1 : 2"))) line_map {
> location_t start_location;
>
> - /* Size and alignment is (usually) 4 bytes. */
> + /* Size is 8 bytes; alignment 4 or 8 depending on the arch. */
> };
>
> /* An ordinary line map encodes physical source locations. Those
> @@ -413,7 +423,7 @@ struct GTY((tag ("0"), desc ("MAP_ORDINARY_P (&%h) ? 1 :
> 2"))) line_map {
>
> The highest possible source location is MAX_LOCATION_T. */
> struct GTY((tag ("1"))) line_map_ordinary : public line_map {
> - /* Base class is 4 bytes. */
> + /* Base class is 8 bytes. */
>
> /* 4 bytes of integers, each 1 byte for easy extraction/insertion. */
>
> @@ -445,9 +455,7 @@ struct GTY((tag ("1"))) line_map_ordinary : public
> line_map {
> +-------------------------+-----------------------+-------------------+
> */
> unsigned int m_range_bits : 8;
>
> - /* Pointer alignment boundary on both 32 and 64-bit systems. */
> -
> - const char *to_file;
> + /* 32-bit int even in 64-bit mode. */
> linenum_type to_line;
>
> /* Location from whence this line map was included. For regular
> @@ -456,12 +464,11 @@ struct GTY((tag ("1"))) line_map_ordinary : public
> line_map {
> within a map. */
> location_t included_from;
>
> - /* Size is 20 or 24 bytes, no padding */
> -};
> + /* Pointer alignment boundary, whether 32-bit or 64-bit mode. */
> + const char *to_file;
>
> -/* This is the highest possible source location encoded within an
> - ordinary or macro map. */
> -const location_t MAX_LOCATION_T = 0x7FFFFFFF;
> + /* Size is 28 (32) bytes for 32-bit (64-bit) arch. */
> +};
>
> struct cpp_hashnode;
>
> @@ -480,7 +487,7 @@ struct GTY((tag ("2"))) line_map_macro : public line_map {
> return m_expansion;
> }
>
> - /* Base is 4 bytes. */
> + /* Base is 8 bytes. */
>
> /* The number of tokens inside the replacement-list of MACRO. */
> unsigned int n_tokens;
> @@ -556,7 +563,10 @@ struct GTY((tag ("2"))) line_map_macro : public line_map
> {
> if we are in a nested expansion context not. */
> location_t m_expansion;
>
> - /* Size is 20 or 32 (4 bytes padding on 64-bit). */
> + /* Size is one of the following:
> + 32-bit system: 28 or 32 bytes, depending whether a uint64_t requires
> + 4- or 8-byte alignment.
> + 64-bit arch: 40 bytes. */
> };
>
> #if CHECKING_P && (GCC_VERSION >= 2007)
> diff --git a/gcc/testsuite/g++.dg/diagnostic/pr77949.C
> b/gcc/testsuite/g++.dg/diagnostic/pr77949.C
> index b81d6e2bb46..e1a201e52c0 100644
> --- a/gcc/testsuite/g++.dg/diagnostic/pr77949.C
> +++ b/gcc/testsuite/g++.dg/diagnostic/pr77949.C
> @@ -1,7 +1,10 @@
> -// Ensure that no fix-it hints are emitted
> +// Ensure that fix-it hints are emitted even at a large column number.
> // { dg-options "-fdiagnostics-parseable-fixits" }
>
> /* Very long line, where a missing semicolon would be suggested for
> insertion at column 4097. */
> class test {
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> // { dg-error "-: expected .;. after class definition" "" { target *-*-* }
> .-1 }
> +/* { dg-begin-multiline-output "" }
> +fix-it:
> +{ dg-end-multiline-output "" } */
> diff --git a/gcc/testsuite/g++.dg/modules/loc-prune-4.C
> b/gcc/testsuite/g++.dg/modules/loc-prune-4.C
> index aa8f248b52b..19e85d8d8a6 100644
> --- a/gcc/testsuite/g++.dg/modules/loc-prune-4.C
> +++ b/gcc/testsuite/g++.dg/modules/loc-prune-4.C
> @@ -16,7 +16,7 @@ int bar (int); // merge lines
> int baz (int);
>
>
> -// { dg-final { scan-lang-dump {Ordinary maps:2 locs:12288 range_bits:5}
> module } }
> +// { dg-final { scan-lang-dump {Ordinary maps:2 locs:49152 range_bits:7}
> module } }
> // { dg-final { scan-lang-dump { 1 source file names\n Source
> file...=[^\n]*loc-prune-4.C\n} module } }
> -// { dg-final { scan-lang-dump { Span:0 ordinary
> \[[0-9]+\+12288,\+4096\)->\[0,\+4096\)} module } }
> -// { dg-final { scan-lang-dump { Span:1 ordinary
> \[[0-9]+\+40960,\+8192\)->\[4096,\+8192\)} module } }
> +// { dg-final { scan-lang-dump { Span:0 ordinary
> \[[0-9]+\+49152,\+16384\)->\[0,\+16384\)} module } }
> +// { dg-final { scan-lang-dump { Span:1 ordinary
> \[[0-9]+\+163840,\+32768\)->\[16384,\+32768\)} module } }
> diff --git a/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.cc
> b/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.cc
> index e96efe0bed5..217e8f8c9cb 100644
> --- a/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.cc
> +++ b/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.cc
> @@ -63,17 +63,13 @@ test_richloc (rich_location *richloc)
> static void
> test_fixit_on_very_long_line (const line_table_case &case_)
> {
> - /* Various interesting column/line-width values, to try to tickle
> - out bugs. */
> + /* Various interesting column/line-width values, to try to tickle out
> bugs. In
> + 64-bit location mode, we can't test the max because the maximum
> supported
> + column is unreasonably large. */
> const int VERY_LONG_LINE = 8192;
> const int columns[] = {0,
> 1,
> 80,
> - LINE_MAP_MAX_COLUMN_NUMBER - 2,
> - LINE_MAP_MAX_COLUMN_NUMBER - 1,
> - LINE_MAP_MAX_COLUMN_NUMBER,
> - LINE_MAP_MAX_COLUMN_NUMBER + 1,
> - LINE_MAP_MAX_COLUMN_NUMBER + 2,
> VERY_LONG_LINE,
> VERY_LONG_LINE + 5};
> for (unsigned int width_idx = 0; width_idx < ARRAY_SIZE (columns);
> diff --git a/gcc/testsuite/gcc.dg/plugin/location_overflow_plugin.cc
> b/gcc/testsuite/gcc.dg/plugin/location_overflow_plugin.cc
> index 45a01b5f917..f731b1421b0 100644
> --- a/gcc/testsuite/gcc.dg/plugin/location_overflow_plugin.cc
> +++ b/gcc/testsuite/gcc.dg/plugin/location_overflow_plugin.cc
> @@ -84,6 +84,11 @@ plugin_init (struct plugin_name_args *plugin_info,
> if (!base_location)
> error_at (UNKNOWN_LOCATION, "missing plugin argument");
>
> + /* With 64-bit locations, the thresholds are larger, so shift the base
> + location argument accordingly. */
> + gcc_assert (sizeof (location_t) == sizeof (uint64_t));
> + base_location = 1 + ((base_location - 1) << 31);
> +
> register_callback (plugin_info->base_name,
> PLUGIN_PRAGMAS,
> on_pragma_registration,
