[Doc] Small improvements to the flame graph section in the Eva user manual.

doc/eva/main.tex

@@ -2071,21 +2071,22 @@ In these three cases, the function \lstinline|f| is reached by the analysis
 
 When running long analyses with \Eva{}, you can use option
 \texttt{-eva-flamegraph <file>} to obtain profiling information about which
-functions are taking time. This option outputs textual data to the specified
-\texttt{<file>}, which can then be read by the \texttt{flamegraph.pl} script
-developed by Brendan Egg\footnote{\url{https://www.brendangregg.com/flamegraphs.html}}.
-This script is available as a package in some Linux distributions, and it is
-also included in Frama-C's shared files. The version shipped with Frama-C can
-be run with the following command:
+C functions are taking time to analyze.
+This option outputs textual data to the specified \texttt{<file>},
+which can then be read by the \texttt{flamegraph.pl} script developed by
+Brendan Egg\footnote{\url{https://www.brendangregg.com/flamegraphs.html}}.
+This script is available as a package in some Linux distributions; it is
+also included in Frama-C and can be run with the following command:
 
 \begin{listing}{1}
 frama-c-script flamegraph <file> [<dir>]
 \end{listing}
 
-The \texttt{<file>} argument must be the same given to option
-\texttt{-eva-flamegraph}. The \texttt{<dir>} argument is optional, but when
-specified, it stores the produced flame graph (in SVG and HTML versions)
-in that directory.
+This command generates the flame graph from \texttt{<file>},
+which must be the same given to option \texttt{-eva-flamegraph},
+and opens it in the default web browser.
+The \texttt{<dir>} argument is optional, but when specified, it stores the
+produced flame graph (in SVG and HTML versions) in that directory.
 
 Figure~\ref{fig:flamegraph} presents an example of a flame graph.
 
@@ -2096,9 +2097,10 @@ Figure~\ref{fig:flamegraph} presents an example of a flame graph.
 \label{fig:flamegraph}
 \end{figure}
 
-These flame graphs are interactive SVGs, which can be wrapped in an HTML page.
-It is possible to zoom and filter by name. The length of a bar is proportional
-to the time spent in that function. Note that if a function \texttt{f}
+These flame graphs are interactive SVGs wrapped in an HTML page.
+It is possible to zoom and filter functions by name. The length of a bar is
+proportional to the time spent analyzing this function (and all other functions
+called from this function). Note that if a function \texttt{f}
 contains several callsites for \texttt{g}, only the total aggregated time is
 displayed as a single bar \texttt{g} below \texttt{f}.
 Finally, note that \texttt{-eva-flamegraph} has a negligible cost in terms of