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| author | Frank Ch. Eigler <fche@elastic.org> | 2010-03-08 09:06:41 -0500 |
|---|---|---|
| committer | Frank Ch. Eigler <fche@elastic.org> | 2010-03-08 09:06:41 -0500 |
| commit | ab5e90c22127ef3c354835571414f9165c07bebe (patch) | |
| tree | 12124ebff1b557bdedc64838d581be29e86ff1fa | |
| parent | 14f0bb1853f944681823fbc72460f6eac6b58f2d (diff) | |
| download | systemtap-steved-ab5e90c22127ef3c354835571414f9165c07bebe.tar.gz systemtap-steved-ab5e90c22127ef3c354835571414f9165c07bebe.tar.xz systemtap-steved-ab5e90c22127ef3c354835571414f9165c07bebe.zip | |
docs: clarify that only -> is used for $var dereferencing, not .
| -rw-r--r-- | stap.1.in | 14 | ||||
| -rw-r--r-- | stapprobes.3stap.in | 12 |
2 files changed, 22 insertions, 4 deletions
@@ -582,6 +582,10 @@ variables whose names are prefixed with "$". They may be accessed only if the kernel's compiler preserved them despite optimization. This is the same constraint that a debugger user faces when working with optimized code. Some other events have very little context. +See the +.IR stapprobes (3stap) +man pages to see the kinds of context variables available at each kind +of probe point. .PP New probe points may be defined using "aliases". Probe point aliases look similar to probe definitions, but instead of activating a probe @@ -819,7 +823,15 @@ as a pointer to a struct/union named .I type_name and dereference the .I member -value. The optional +value. Further +.IR \->subfield +expressions may be appended to dereference more levels. +.BR +NOTE: +the same dereferencing operator +.IR \-> +is used to refer to both direct containment or pointer indirection. +Systemtap automatically determines which. The optional .I module tells the translator where to look for information about that type. Multiple modules may be specified as a list with diff --git a/stapprobes.3stap.in b/stapprobes.3stap.in index dbd77ce4..0e1bd66f 100644 --- a/stapprobes.3stap.in +++ b/stapprobes.3stap.in @@ -341,9 +341,15 @@ pointers (char *) may be copied to systemtap string values using the .IR kernel_string " or " user_string functions. .TP -$var\->field -traversal to a structure's field. The indirection operator -may be repeated to follow more levels of pointers. +$var\->field traversal via a structure's or a pointer's field. This +generalized indirection operator may be repeated to follow more +levels. Note that the +.IR . +operator is not used for plain structure +members, only +.IR \-> +for both purposes. (This is because "." is reserved for string +concatenation.) .TP $return is available in return probes only for functions that are declared |