Fix QuakeWorld compilation by treating assignment to constants as a warning when...

[xonotic/gmqcc.git] / doc / gmqcc.1

diff --git a/doc/gmqcc.1 b/doc/gmqcc.1
index 56728d17588c4f432180f7bd1769faa784d160ec..185092e4c8c910a0bc13b4f01fdfa75cc32217b2 100644 (file)
--- a/doc/gmqcc.1
+++ b/doc/gmqcc.1
@@ -320,6 +320,22 @@ marked as such.
 Warn about possible mistakes caused by missing or wrong parenthesis,
 like an assignment in an 'if' condition when there's no additional set
 of parens around the assignment.
+.It Fl W Ns Cm unsafe-types
+When passing variadic parameters via
+.Li ...(N)
+it can happen that incompatible types are passed to functions. This
+enables several warnings when static typechecking cannot guarantee
+consistent behavior.
+.It Fl W Ns Cm breakdef
+When compiling original id1 QC there is a definition for `break`
+which conflicts with the 'break' keyword in GMQCC. Enabling this
+will print a warning when the definition occurs. The definition is
+ignored for both cases.
+.It Fl W Ns Cm const-overwrite
+When compiling original QuakeWorld QC there are instances where
+code overwrites constants. This is considered an error, however
+for QuakeWorld to compile it needs to be treated as a warning
+instead, as such this warning only works when -std=qcc.
 .El
 .Sh COMPILE FLAGS
 .Bl -tag -width Ds
@@ -497,6 +513,42 @@ void vafunc(string...count) {
 Most Quake VMs, including the one from FTEQW or up till recently
 Darkplaces, do not cope well with vector instructions with overlapping
 input and output. This option will avoid producing such code.
+.It Fl f Ns Cm expressions-for-builtins
+Usually builtin-numbers are just immediate constants. With this flag
+expressions can be used, as long as they are compile-time constant.
+.Pp
+Example:
+.Bd -literal -offset indent
+void printA() = #1; // the usual way
+void printB() = #2-1; // with a constant expression
+.Ed
+.It Fl f Ns Cm return-assignments
+Enabiling this option will allow assigning values or expressions to the
+return keyword as if it were a local variable of the same type as the
+function's signature's return type.
+.Pp
+Example:
+.Bd -literal -offset indent
+float bar() { return 1024; }
+float fun() {
+    return = bar();
+    return; // returns value of bar
+}
+.Ed
+.It Fl f Ns Cm unsafe-varargs
+When passing on varargs to a different functions, this turns some
+static error cases into warnings. Like when the caller's varargs are
+restricted to a different type than the callee's parameter. Or a list
+of unrestricted varargs is passed into restricted varargs.
+.It Fl f Ns Cm typeless-stores
+Always use STORE_F, LOAD_F, STOREP_F when accessing scalar variables.
+This is somewhat incorrect assembly instruction use, but in all engines
+they do exactly the same. This makes disassembly output harder to read,
+breaks decompilers, but causes the output file to be better compressible.
+.It Fl f Ns Cm sort-operands
+In commutative instructions, always put the lower-numbered operand first.
+This shaves off 1 byte of entropy from all these instructions, reducing
+compressed size of the output file.
 .El
 .Sh OPTIMIZATIONS
 .Bl -tag -width Ds
@@ -541,7 +593,7 @@ string being added.
 .Pp
 For example the following code will only generate 1 string:
 .Bd -literal -offset indent
-print("Hell you!\\n");
+print("Hello you!\\n");
 print("you!\\n"); // trailing substring of "Hello you!\\n"
 .Ed
 .Pp
@@ -573,6 +625,10 @@ in this case, the y component of a vector. This optimization will turn
 such a multiplication into a direct component access. If the factor is
 anything other than 1, a float-multiplication will be added, which is
 still faster than a vector multiplication.
+.It Fl O Ns Cm const-fold-dce
+For constant expressions that result in dead code (such as a branch whos
+condition can be evaluated at compile-time), this will eliminate the branch
+and else body (if present) to produce more optimal code.
 .El
 .Sh CONFIG
 The configuration file is similar to regular .ini files. Comments