компилятор C и C ++ проекта GNU (GNU project C and C++ compiler)
Параметры подробно (Options detail)
Control Diagnostic Messages Formatting
Traditionally, diagnostic messages have been formatted
irrespective of the output device's aspect (e.g. its width, ...).
You can use the options described below to control the formatting
algorithm for diagnostic messages, e.g. how many characters per
line, how often source location information should be reported.
Note that some language front ends may not honor these options.
-fmessage-length=n
Try to format error messages so that they fit on lines of
about n characters. If n is zero, then no line-wrapping is
done; each error message appears on a single line. This is
the default for all front ends.
Note - this option also affects the display of the #error and
#warning pre-processor directives, and the deprecated
function/type/variable attribute. It does not however affect
the pragma GCC warning and pragma GCC error pragmas.
-fdiagnostics-show-location=once
Only meaningful in line-wrapping mode. Instructs the
diagnostic messages reporter to emit source location
information once; that is, in case the message is too long to
fit on a single physical line and has to be wrapped, the
source location won't be emitted (as prefix) again, over and
over, in subsequent continuation lines. This is the default
behavior.
-fdiagnostics-show-location=every-line
Only meaningful in line-wrapping mode. Instructs the
diagnostic messages reporter to emit the same source location
information (as prefix) for physical lines that result from
the process of breaking a message which is too long to fit on
a single line.
-fdiagnostics-color[=WHEN]
-fno-diagnostics-color
Use color in diagnostics. WHEN is never, always, or auto.
The default depends on how the compiler has been configured,
it can be any of the above WHEN options or also never if
GCC_COLORS environment variable isn't present in the
environment, and auto otherwise. auto means to use color
only when the standard error is a terminal. The forms
-fdiagnostics-color and -fno-diagnostics-color are aliases
for -fdiagnostics-color=always and -fdiagnostics-color=never,
respectively.
The colors are defined by the environment variable
GCC_COLORS. Its value is a colon-separated list of
capabilities and Select Graphic Rendition (SGR) substrings.
SGR commands are interpreted by the terminal or terminal
emulator. (See the section in the documentation of your text
terminal for permitted values and their meanings as character
attributes.) These substring values are integers in decimal
representation and can be concatenated with semicolons.
Common values to concatenate include 1 for bold, 4 for
underline, 5 for blink, 7 for inverse, 39 for default
foreground color, 30 to 37 for foreground colors, 90 to 97
for 16-color mode foreground colors, 38;5;0 to 38;5;255 for
88-color and 256-color modes foreground colors, 49 for
default background color, 40 to 47 for background colors, 100
to 107 for 16-color mode background colors, and 48;5;0 to
48;5;255 for 88-color and 256-color modes background colors.
The default GCC_COLORS is
error=01;31:warning=01;35:note=01;36:range1=32:range2=34:locus=01:\
quote=01:fixit-insert=32:fixit-delete=31:\
diff-filename=01:diff-hunk=32:diff-delete=31:diff-insert=32:\
type-diff=01;32
where 01;31 is bold red, 01;35 is bold magenta, 01;36 is bold
cyan, 32 is green, 34 is blue, 01 is bold, and 31 is red.
Setting GCC_COLORS to the empty string disables colors.
Supported capabilities are as follows.
"error="
SGR substring for error: markers.
"warning="
SGR substring for warning: markers.
"note="
SGR substring for note: markers.
"range1="
SGR substring for first additional range.
"range2="
SGR substring for second additional range.
"locus="
SGR substring for location information, file:line or
file:line:column etc.
"quote="
SGR substring for information printed within quotes.
"fixit-insert="
SGR substring for fix-it hints suggesting text to be
inserted or replaced.
"fixit-delete="
SGR substring for fix-it hints suggesting text to be
deleted.
"diff-filename="
SGR substring for filename headers within generated
patches.
"diff-hunk="
SGR substring for the starts of hunks within generated
patches.
"diff-delete="
SGR substring for deleted lines within generated patches.
"diff-insert="
SGR substring for inserted lines within generated
patches.
"type-diff="
SGR substring for highlighting mismatching types within
template arguments in the C++ frontend.
-fno-diagnostics-show-option
By default, each diagnostic emitted includes text indicating
the command-line option that directly controls the diagnostic
(if such an option is known to the diagnostic machinery).
Specifying the -fno-diagnostics-show-option flag suppresses
that behavior.
-fno-diagnostics-show-caret
By default, each diagnostic emitted includes the original
source line and a caret ^ indicating the column. This option
suppresses this information. The source line is truncated to
n characters, if the -fmessage-length=n option is given.
When the output is done to the terminal, the width is limited
to the width given by the COLUMNS environment variable or, if
not set, to the terminal width.
-fno-diagnostics-show-labels
By default, when printing source code (via
-fdiagnostics-show-caret), diagnostics can label ranges of
source code with pertinent information, such as the types of
expressions:
printf ("foo %s bar", long_i + long_j);
~^ ~~~~~~~~~~~~~~~
| |
char * long int
This option suppresses the printing of these labels (in the
example above, the vertical bars and the "char *" and "long
int" text).
-fno-diagnostics-show-line-numbers
By default, when printing source code (via
-fdiagnostics-show-caret), a left margin is printed, showing
line numbers. This option suppresses this left margin.
-fdiagnostics-minimum-margin-width=width
This option controls the minimum width of the left margin
printed by -fdiagnostics-show-line-numbers. It defaults to
6.
-fdiagnostics-parseable-fixits
Emit fix-it hints in a machine-parseable format, suitable for
consumption by IDEs. For each fix-it, a line will be printed
after the relevant diagnostic, starting with the string "fix-
it:". For example:
fix-it:"test.c":{45:3-45:21}:"gtk_widget_show_all"
The location is expressed as a half-open range, expressed as
a count of bytes, starting at byte 1 for the initial column.
In the above example, bytes 3 through 20 of line 45 of
"test.c" are to be replaced with the given string:
00000000011111111112222222222
12345678901234567890123456789
gtk_widget_showall (dlg);
^^^^^^^^^^^^^^^^^^
gtk_widget_show_all
The filename and replacement string escape backslash as "\\",
tab as "\t", newline as "\n", double quotes as "\"", non-
printable characters as octal (e.g. vertical tab as "\013").
An empty replacement string indicates that the given range is
to be removed. An empty range (e.g. "45:3-45:3") indicates
that the string is to be inserted at the given position.
-fdiagnostics-generate-patch
Print fix-it hints to stderr in unified diff format, after
any diagnostics are printed. For example:
--- test.c
+++ test.c
@ -42,5 +42,5 @
void show_cb(GtkDialog *dlg)
{
- gtk_widget_showall(dlg);
+ gtk_widget_show_all(dlg);
}
The diff may or may not be colorized, following the same
rules as for diagnostics (see -fdiagnostics-color).
-fdiagnostics-show-template-tree
In the C++ frontend, when printing diagnostics showing
mismatching template types, such as:
could not convert 'std::map<int, std::vector<double> >()'
from 'map<[...],vector<double>>' to 'map<[...],vector<float>>
the -fdiagnostics-show-template-tree flag enables printing a
tree-like structure showing the common and differing parts of
the types, such as:
map<
[...],
vector<
[double != float]>>
The parts that differ are highlighted with color ("double"
and "float" in this case).
-fno-elide-type
By default when the C++ frontend prints diagnostics showing
mismatching template types, common parts of the types are
printed as "[...]" to simplify the error message. For
example:
could not convert 'std::map<int, std::vector<double> >()'
from 'map<[...],vector<double>>' to 'map<[...],vector<float>>
Specifying the -fno-elide-type flag suppresses that behavior.
This flag also affects the output of the
-fdiagnostics-show-template-tree flag.
-fno-show-column
Do not print column numbers in diagnostics. This may be
necessary if diagnostics are being scanned by a program that
does not understand the column numbers, such as dejagnu.
-fdiagnostics-format=FORMAT
Select a different format for printing diagnostics. FORMAT
is text or json. The default is text.
The json format consists of a top-level JSON array containing
JSON objects representing the diagnostics.
The JSON is emitted as one line, without formatting; the
examples below have been formatted for clarity.
Diagnostics can have child diagnostics. For example, this
error and note:
misleading-indentation.c:15:3: warning: this 'if' clause does not
guard... [-Wmisleading-indentation]
15 | if (flag)
| ^~
misleading-indentation.c:17:5: note: ...this statement, but the latter
is misleadingly indented as if it were guarded by the 'if'
17 | y = 2;
| ^
might be printed in JSON form (after formatting) like this:
[
{
"kind": "warning",
"locations": [
{
"caret": {
"column": 3,
"file": "misleading-indentation.c",
"line": 15
},
"finish": {
"column": 4,
"file": "misleading-indentation.c",
"line": 15
}
}
],
"message": "this \u2018if\u2019 clause does not guard...",
"option": "-Wmisleading-indentation",
"children": [
{
"kind": "note",
"locations": [
{
"caret": {
"column": 5,
"file": "misleading-indentation.c",
"line": 17
}
}
],
"message": "...this statement, but the latter is ..."
}
]
},
...
]
where the "note" is a child of the "warning".
A diagnostic has a "kind". If this is "warning", then there
is an "option" key describing the command-line option
controlling the warning.
A diagnostic can contain zero or more locations. Each
location has up to three positions within it: a "caret"
position and optional "start" and "finish" positions. A
location can also have an optional "label" string. For
example, this error:
bad-binary-ops.c:64:23: error: invalid operands to binary + (have 'S' {aka
'struct s'} and 'T' {aka 'struct t'})
64 | return callee_4a () + callee_4b ();
| ~~~~~~~~~~~~ ^ ~~~~~~~~~~~~
| | |
| | T {aka struct t}
| S {aka struct s}
has three locations. Its primary location is at the "+"
token at column 23. It has two secondary locations,
describing the left and right-hand sides of the expression,
which have labels. It might be printed in JSON form as:
{
"children": [],
"kind": "error",
"locations": [
{
"caret": {
"column": 23, "file": "bad-binary-ops.c", "line": 64
}
},
{
"caret": {
"column": 10, "file": "bad-binary-ops.c", "line": 64
},
"finish": {
"column": 21, "file": "bad-binary-ops.c", "line": 64
},
"label": "S {aka struct s}"
},
{
"caret": {
"column": 25, "file": "bad-binary-ops.c", "line": 64
},
"finish": {
"column": 36, "file": "bad-binary-ops.c", "line": 64
},
"label": "T {aka struct t}"
}
],
"message": "invalid operands to binary + ..."
}
If a diagnostic contains fix-it hints, it has a "fixits"
array, consisting of half-open intervals, similar to the
output of -fdiagnostics-parseable-fixits. For example, this
diagnostic with a replacement fix-it hint:
demo.c:8:15: error: 'struct s' has no member named 'colour'; did you
mean 'color'?
8 | return ptr->colour;
| ^~~~~~
| color
might be printed in JSON form as:
{
"children": [],
"fixits": [
{
"next": {
"column": 21,
"file": "demo.c",
"line": 8
},
"start": {
"column": 15,
"file": "demo.c",
"line": 8
},
"string": "color"
}
],
"kind": "error",
"locations": [
{
"caret": {
"column": 15,
"file": "demo.c",
"line": 8
},
"finish": {
"column": 20,
"file": "demo.c",
"line": 8
}
}
],
"message": "\u2018struct s\u2019 has no member named ..."
}
where the fix-it hint suggests replacing the text from
"start" up to but not including "next" with "string"'s value.
Deletions are expressed via an empty value for "string",
insertions by having "start" equal "next".
